Merge pull request #308 from mholt/letsencrypt

Let's Encrypt

app/app.go

@@ -1,76 +0,0 @@
-// Package app holds application-global state to make it accessible
-// by other packages in the application.
-//
-// This package differs from config in that the things in app aren't
-// really related to server configuration.
-package app
-
-import (
-	"errors"
-	"runtime"
-	"strconv"
-	"strings"
-	"sync"
-
-	"github.com/mholt/caddy/server"
-)
-
-const (
-	// Name is the program name
-	Name = "Caddy"
-
-	// Version is the program version
-	Version = "0.7.6"
-)
-
-var (
-	// Servers is a list of all the currently-listening servers
-	Servers []*server.Server
-
-	// ServersMutex protects the Servers slice during changes
-	ServersMutex sync.Mutex
-
-	// Wg is used to wait for all servers to shut down
-	Wg sync.WaitGroup
-
-	// HTTP2 indicates whether HTTP2 is enabled or not
-	HTTP2 bool // TODO: temporary flag until http2 is standard
-
-	// Quiet mode hides non-error initialization output
-	Quiet bool
-)
-
-// SetCPU parses string cpu and sets GOMAXPROCS
-// according to its value. It accepts either
-// a number (e.g. 3) or a percent (e.g. 50%).
-func SetCPU(cpu string) error {
-	var numCPU int
-
-	availCPU := runtime.NumCPU()
-
-	if strings.HasSuffix(cpu, "%") {
-		// Percent
-		var percent float32
-		pctStr := cpu[:len(cpu)-1]
-		pctInt, err := strconv.Atoi(pctStr)
-		if err != nil || pctInt < 1 || pctInt > 100 {
-			return errors.New("invalid CPU value: percentage must be between 1-100")
-		}
-		percent = float32(pctInt) / 100
-		numCPU = int(float32(availCPU) * percent)
-	} else {
-		// Number
-		num, err := strconv.Atoi(cpu)
-		if err != nil || num < 1 {
-			return errors.New("invalid CPU value: provide a number or percent greater than 0")
-		}
-		numCPU = num
-	}
-
-	if numCPU > availCPU {
-		numCPU = availCPU
-	}
-
-	runtime.GOMAXPROCS(numCPU)
-	return nil
-}

caddy/assets/path.go

@@ -0,0 +1,29 @@
+package assets
+
+import (
+	"os"
+	"path/filepath"
+	"runtime"
+)
+
+// Path returns the path to the folder
+// where the application may store data. This
+// currently resolves to ~/.caddy
+func Path() string {
+	return filepath.Join(userHomeDir(), ".caddy")
+}
+
+// userHomeDir returns the user's home directory according to
+// environment variables.
+//
+// Credit: http://stackoverflow.com/a/7922977/1048862
+func userHomeDir() string {
+	if runtime.GOOS == "windows" {
+		home := os.Getenv("HOMEDRIVE") + os.Getenv("HOMEPATH")
+		if home == "" {
+			home = os.Getenv("USERPROFILE")
+		}
+		return home
+	}
+	return os.Getenv("HOME")
+}

caddy/assets/path_test.go

@@ -0,0 +1,12 @@
+package assets
+
+import (
+	"strings"
+	"testing"
+)
+
+func TestPath(t *testing.T) {
+	if actual := Path(); !strings.HasSuffix(actual, ".caddy") {
+		t.Errorf("Expected path to be a .caddy folder, got: %v", actual)
+	}
+}

caddy/caddy.go

@@ -0,0 +1,358 @@
+// Package caddy implements the Caddy web server as a service.
+//
+// To use this package, follow a few simple steps:
+//
+//   1. Set the AppName and AppVersion variables.
+//   2. Call LoadCaddyfile() to get the Caddyfile (it
+//      might have been piped in as part of a restart).
+//      You should pass in your own Caddyfile loader.
+//   3. Call caddy.Start() to start Caddy, caddy.Stop()
+//      to stop it, or caddy.Restart() to restart it.
+//
+// You should use caddy.Wait() to wait for all Caddy servers
+// to quit before your process exits.
+//
+// Importing this package has the side-effect of trapping
+// SIGINT on all platforms and SIGUSR1 on not-Windows systems.
+// It has to do this in order to perform shutdowns or reloads.
+package caddy
+
+import (
+	"bytes"
+	"encoding/gob"
+	"errors"
+	"fmt"
+	"io/ioutil"
+	"log"
+	"net"
+	"os"
+	"path"
+	"strings"
+	"sync"
+
+	"github.com/mholt/caddy/caddy/letsencrypt"
+	"github.com/mholt/caddy/server"
+)
+
+// Configurable application parameters
+var (
+	// The name and version of the application.
+	AppName, AppVersion string
+
+	// If true, initialization will not show any informative output.
+	Quiet bool
+
+	// DefaultInput is the default configuration to use when config input is empty or missing.
+	DefaultInput = CaddyfileInput{
+		Contents: []byte(fmt.Sprintf("%s:%s\nroot %s", DefaultHost, DefaultPort, DefaultRoot)),
+	}
+
+	// HTTP2 indicates whether HTTP2 is enabled or not
+	HTTP2 bool // TODO: temporary flag until http2 is standard
+)
+
+var (
+	// caddyfile is the input configuration text used for this process
+	caddyfile Input
+
+	// caddyfileMu protects caddyfile during changes
+	caddyfileMu sync.Mutex
+
+	// incompleteRestartErr occurs if this process is a fork
+	// of the parent but no Caddyfile was piped in
+	incompleteRestartErr = errors.New("cannot finish restart successfully")
+
+	// servers is a list of all the currently-listening servers
+	servers []*server.Server
+
+	// serversMu protects the servers slice during changes
+	serversMu sync.Mutex
+
+	// wg is used to wait for all servers to shut down
+	wg sync.WaitGroup
+
+	// loadedGob is used if this is a child process as part of
+	// a graceful restart; it is used to map listeners to their
+	// index in the list of inherited file descriptors. This
+	// variable is not safe for concurrent access.
+	loadedGob caddyfileGob
+)
+
+const (
+	DefaultHost = "0.0.0.0"
+	DefaultPort = "2015"
+	DefaultRoot = "."
+)
+
+// Start starts Caddy with the given Caddyfile. If cdyfile
+// is nil or the process is forked from a parent as part of
+// a graceful restart, Caddy will check to see if Caddyfile
+// was piped from stdin and use that. It blocks until all the
+// servers are listening.
+//
+// If this process is a fork and no Caddyfile was piped in,
+// an error will be returned (the Restart() function does this
+// for you automatically). If this process is NOT a fork and
+// cdyfile is nil, a default configuration will be assumed.
+// In any case, an error is returned if Caddy could not be
+// started.
+func Start(cdyfile Input) error {
+	// TODO: What if already started -- is that an error?
+
+	var err error
+
+	// Input must never be nil; try to load something
+	if cdyfile == nil {
+		cdyfile, err = LoadCaddyfile(nil)
+		if err != nil {
+			return err
+		}
+	}
+
+	caddyfileMu.Lock()
+	caddyfile = cdyfile
+	caddyfileMu.Unlock()
+
+	// load the server configs (activates Let's Encrypt)
+	configs, err := loadConfigs(path.Base(cdyfile.Path()), bytes.NewReader(cdyfile.Body()))
+	if err != nil {
+		return err
+	}
+
+	// group virtualhosts by address
+	groupings, err := arrangeBindings(configs)
+	if err != nil {
+		return err
+	}
+
+	// Start each server with its one or more configurations
+	err = startServers(groupings)
+	if err != nil {
+		return err
+	}
+
+	// Close remaining file descriptors we may have inherited that we don't need
+	if isRestart() {
+		for _, fdIndex := range loadedGob.ListenerFds {
+			file := os.NewFile(fdIndex, "")
+			fln, err := net.FileListener(file)
+			if err == nil {
+				fln.Close()
+			}
+		}
+	}
+
+	// Show initialization output
+	if !Quiet && !isRestart() {
+		var checkedFdLimit bool
+		for _, group := range groupings {
+			for _, conf := range group.Configs {
+				// Print address of site
+				fmt.Println(conf.Address())
+
+				// Note if non-localhost site resolves to loopback interface
+				if group.BindAddr.IP.IsLoopback() && !isLocalhost(conf.Host) {
+					fmt.Printf("Notice: %s is only accessible on this machine (%s)\n",
+						conf.Host, group.BindAddr.IP.String())
+				}
+				if !checkedFdLimit && !group.BindAddr.IP.IsLoopback() && !isLocalhost(conf.Host) {
+					checkFdlimit()
+					checkedFdLimit = true
+				}
+			}
+		}
+	}
+
+	// Tell parent process that we got this
+	if isRestart() {
+		ppipe := os.NewFile(3, "") // parent is listening on pipe at index 3
+		ppipe.Write([]byte("success"))
+		ppipe.Close()
+	}
+
+	return nil
+}
+
+// startServers starts all the servers in groupings,
+// taking into account whether or not this process is
+// a child from a graceful restart or not. It blocks
+// until the servers are listening.
+func startServers(groupings Group) error {
+	var startupWg sync.WaitGroup
+
+	for _, group := range groupings {
+		s, err := server.New(group.BindAddr.String(), group.Configs)
+		if err != nil {
+			log.Fatal(err)
+		}
+		s.HTTP2 = HTTP2 // TODO: This setting is temporary
+
+		var ln server.ListenerFile
+		if isRestart() {
+			// Look up this server's listener in the map of inherited file descriptors;
+			// if we don't have one, we must make a new one.
+			if fdIndex, ok := loadedGob.ListenerFds[s.Addr]; ok {
+				file := os.NewFile(fdIndex, "")
+
+				fln, err := net.FileListener(file)
+				if err != nil {
+					log.Fatal(err)
+				}
+
+				ln, ok = fln.(server.ListenerFile)
+				if !ok {
+					log.Fatal("listener was not a ListenerFile")
+				}
+
+				delete(loadedGob.ListenerFds, s.Addr) // mark it as used
+			}
+		}
+
+		wg.Add(1)
+		go func(s *server.Server, ln server.ListenerFile) {
+			defer wg.Done()
+
+			if ln != nil {
+				err = s.Serve(ln)
+			} else {
+				err = s.ListenAndServe()
+			}
+
+			// "use of closed network connection" is normal if doing graceful shutdown...
+			if err != nil && !strings.Contains(err.Error(), "use of closed network connection") {
+				if isRestart() {
+					log.Fatal(err)
+				} else {
+					log.Println(err)
+				}
+			}
+		}(s, ln)
+
+		startupWg.Add(1)
+		go func(s *server.Server) {
+			defer startupWg.Done()
+			s.WaitUntilStarted()
+		}(s)
+
+		serversMu.Lock()
+		servers = append(servers, s)
+		serversMu.Unlock()
+	}
+
+	startupWg.Wait()
+
+	return nil
+}
+
+// Stop stops all servers. It blocks until they are all stopped.
+// It does NOT execute shutdown callbacks that may have been
+// configured by middleware (they are executed on SIGINT).
+func Stop() error {
+	letsencrypt.Deactivate()
+
+	serversMu.Lock()
+	for _, s := range servers {
+		s.Stop() // TODO: error checking/reporting?
+	}
+	servers = []*server.Server{} // don't reuse servers
+	serversMu.Unlock()
+
+	return nil
+}
+
+// Wait blocks until all servers are stopped.
+func Wait() {
+	wg.Wait()
+}
+
+// LoadCaddyfile loads a Caddyfile in a way that prioritizes
+// reading from stdin pipe; otherwise it calls loader to load
+// the Caddyfile. If loader does not return a Caddyfile, the
+// default one will be returned. Thus, if there are no other
+// errors, this function always returns at least the default
+// Caddyfile (not the previously-used Caddyfile).
+func LoadCaddyfile(loader func() (Input, error)) (cdyfile Input, err error) {
+	// If we are a fork, finishing the restart is highest priority;
+	// piped input is required in this case.
+	if isRestart() {
+		err := gob.NewDecoder(os.Stdin).Decode(&loadedGob)
+		if err != nil {
+			return nil, err
+		}
+		cdyfile = loadedGob.Caddyfile
+	}
+
+	// Otherwise, we first try to get from stdin pipe
+	if cdyfile == nil {
+		cdyfile, err = CaddyfileFromPipe(os.Stdin)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	// No piped input, so try the user's loader instead
+	if cdyfile == nil && loader != nil {
+		cdyfile, err = loader()
+	}
+
+	// Otherwise revert to default
+	if cdyfile == nil {
+		cdyfile = DefaultInput
+	}
+
+	return
+}
+
+// CaddyfileFromPipe loads the Caddyfile input from f if f is
+// not interactive input. f is assumed to be a pipe or stream,
+// such as os.Stdin. If f is not a pipe, no error is returned
+// but the Input value will be nil. An error is only returned
+// if there was an error reading the pipe, even if the length
+// of what was read is 0.
+func CaddyfileFromPipe(f *os.File) (Input, error) {
+	fi, err := f.Stat()
+	if err == nil && fi.Mode()&os.ModeCharDevice == 0 {
+		// Note that a non-nil error is not a problem. Windows
+		// will not create a stdin if there is no pipe, which
+		// produces an error when calling Stat(). But Unix will
+		// make one either way, which is why we also check that
+		// bitmask.
+		// BUG: Reading from stdin after this fails (e.g. for the let's encrypt email address) (OS X)
+		confBody, err := ioutil.ReadAll(f)
+		if err != nil {
+			return nil, err
+		}
+		return CaddyfileInput{
+			Contents: confBody,
+			Filepath: f.Name(),
+		}, nil
+	}
+
+	// not having input from the pipe is not itself an error,
+	// just means no input to return.
+	return nil, nil
+}
+
+// Caddyfile returns the current Caddyfile
+func Caddyfile() Input {
+	caddyfileMu.Lock()
+	defer caddyfileMu.Unlock()
+	return caddyfile
+}
+
+// Input represents a Caddyfile; its contents and file path
+// (which should include the file name at the end of the path).
+// If path does not apply (e.g. piped input) you may use
+// any understandable value. The path is mainly used for logging,
+// error messages, and debugging.
+type Input interface {
+	// Gets the Caddyfile contents
+	Body() []byte
+
+	// Gets the path to the origin file
+	Path() string
+
+	// IsFile returns true if the original input was a file on the file system
+	// that could be loaded again later if requested.
+	IsFile() bool
+}

caddy/caddy_test.go

@@ -0,0 +1,32 @@
+package caddy
+
+import (
+	"net/http"
+	"testing"
+	"time"
+)
+
+func TestCaddyStartStop(t *testing.T) {
+	caddyfile := "localhost:1984\ntls off"
+
+	for i := 0; i < 2; i++ {
+		err := Start(CaddyfileInput{Contents: []byte(caddyfile)})
+		if err != nil {
+			t.Fatalf("Error starting, iteration %d: %v", i, err)
+		}
+
+		client := http.Client{
+			Timeout: time.Duration(2 * time.Second),
+		}
+		resp, err := client.Get("http://localhost:1984")
+		if err != nil {
+			t.Fatalf("Expected GET request to succeed (iteration %d), but it failed: %v", i, err)
+		}
+		resp.Body.Close()
+
+		err = Stop()
+		if err != nil {
+			t.Fatalf("Error stopping, iteration %d: %v", i, err)
+		}
+	}
+}

caddy/caddyfile/json.go

@@ -0,0 +1,163 @@
+package caddyfile
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"net"
+	"strconv"
+	"strings"
+
+	"github.com/mholt/caddy/caddy/parse"
+)
+
+const filename = "Caddyfile"
+
+// ToJSON converts caddyfile to its JSON representation.
+func ToJSON(caddyfile []byte) ([]byte, error) {
+	var j Caddyfile
+
+	serverBlocks, err := parse.ServerBlocks(filename, bytes.NewReader(caddyfile), false)
+	if err != nil {
+		return nil, err
+	}
+
+	for _, sb := range serverBlocks {
+		block := ServerBlock{Body: make(map[string]interface{})}
+
+		for _, host := range sb.HostList() {
+			block.Hosts = append(block.Hosts, strings.TrimSuffix(host, ":"))
+		}
+
+		for dir, tokens := range sb.Tokens {
+			disp := parse.NewDispenserTokens(filename, tokens)
+			disp.Next() // the first token is the directive; skip it
+			block.Body[dir] = constructLine(disp)
+		}
+
+		j = append(j, block)
+	}
+
+	result, err := json.Marshal(j)
+	if err != nil {
+		return nil, err
+	}
+
+	return result, nil
+}
+
+// constructLine transforms tokens into a JSON-encodable structure;
+// but only one line at a time, to be used at the top-level of
+// a server block only (where the first token on each line is a
+// directive) - not to be used at any other nesting level.
+func constructLine(d parse.Dispenser) interface{} {
+	var args []interface{}
+
+	all := d.RemainingArgs()
+	for _, arg := range all {
+		args = append(args, arg)
+	}
+
+	d.Next()
+	if d.Val() == "{" {
+		args = append(args, constructBlock(d))
+	}
+
+	return args
+}
+
+// constructBlock recursively processes tokens into a
+// JSON-encodable structure.
+func constructBlock(d parse.Dispenser) interface{} {
+	block := make(map[string]interface{})
+
+	for d.Next() {
+		if d.Val() == "}" {
+			break
+		}
+
+		dir := d.Val()
+		all := d.RemainingArgs()
+
+		var args []interface{}
+		for _, arg := range all {
+			args = append(args, arg)
+		}
+		if d.Val() == "{" {
+			args = append(args, constructBlock(d))
+		}
+
+		block[dir] = args
+	}
+
+	return block
+}
+
+// FromJSON converts JSON-encoded jsonBytes to Caddyfile text
+func FromJSON(jsonBytes []byte) ([]byte, error) {
+	var j Caddyfile
+	var result string
+
+	err := json.Unmarshal(jsonBytes, &j)
+	if err != nil {
+		return nil, err
+	}
+
+	for _, sb := range j {
+		for i, host := range sb.Hosts {
+			if hostname, port, err := net.SplitHostPort(host); err == nil {
+				if port == "http" || port == "https" {
+					host = port + "://" + hostname
+				}
+			}
+			if i > 0 {
+				result += ", "
+			}
+			result += strings.TrimSuffix(host, ":")
+		}
+		result += jsonToText(sb.Body, 1)
+	}
+
+	return []byte(result), nil
+}
+
+// jsonToText recursively transforms a scope of JSON into plain
+// Caddyfile text.
+func jsonToText(scope interface{}, depth int) string {
+	var result string
+
+	switch val := scope.(type) {
+	case string:
+		if strings.ContainsAny(val, "\" \n\t\r") {
+			result += ` "` + strings.Replace(val, "\"", "\\\"", -1) + `"`
+		} else {
+			result += " " + val
+		}
+	case int:
+		result += " " + strconv.Itoa(val)
+	case float64:
+		result += " " + fmt.Sprintf("%v", val)
+	case bool:
+		result += " " + fmt.Sprintf("%t", val)
+	case map[string]interface{}:
+		result += " {\n"
+		for param, args := range val {
+			result += strings.Repeat("\t", depth) + param
+			result += jsonToText(args, depth+1) + "\n"
+		}
+		result += strings.Repeat("\t", depth-1) + "}"
+	case []interface{}:
+		for _, v := range val {
+			result += jsonToText(v, depth)
+		}
+	}
+
+	return result
+}
+
+type Caddyfile []ServerBlock
+
+type ServerBlock struct {
+	Hosts []string               `json:"hosts"`
+	Body  map[string]interface{} `json:"body"`
+}

caddy/caddyfile/json_test.go

@@ -0,0 +1,91 @@
+package caddyfile
+
+import "testing"
+
+var tests = []struct {
+	caddyfile, json string
+}{
+	{ // 0
+		caddyfile: `foo {
+	root /bar
+}`,
+		json: `[{"hosts":["foo"],"body":{"root":["/bar"]}}]`,
+	},
+	{ // 1
+		caddyfile: `host1, host2 {
+	dir {
+		def
+	}
+}`,
+		json: `[{"hosts":["host1","host2"],"body":{"dir":[{"def":null}]}}]`,
+	},
+	{ // 2
+		caddyfile: `host1, host2 {
+	dir abc {
+		def ghi
+	}
+}`,
+		json: `[{"hosts":["host1","host2"],"body":{"dir":["abc",{"def":["ghi"]}]}}]`,
+	},
+	{ // 3
+		caddyfile: `host1:1234, host2:5678 {
+	dir abc {
+	}
+}`,
+		json: `[{"hosts":["host1:1234","host2:5678"],"body":{"dir":["abc",{}]}}]`,
+	},
+	{ // 4
+		caddyfile: `host {
+	foo "bar baz"
+}`,
+		json: `[{"hosts":["host"],"body":{"foo":["bar baz"]}}]`,
+	},
+	{ // 5
+		caddyfile: `host, host:80 {
+	foo "bar \"baz\""
+}`,
+		json: `[{"hosts":["host","host:80"],"body":{"foo":["bar \"baz\""]}}]`,
+	},
+	{ // 6
+		caddyfile: `host {
+	foo "bar
+baz"
+}`,
+		json: `[{"hosts":["host"],"body":{"foo":["bar\nbaz"]}}]`,
+	},
+	{ // 7
+		caddyfile: `host {
+	dir 123 4.56 true
+}`,
+		json: `[{"hosts":["host"],"body":{"dir":["123","4.56","true"]}}]`, // NOTE: I guess we assume numbers and booleans should be encoded as strings...?
+	},
+	{ // 8
+		caddyfile: `http://host, https://host {
+}`,
+		json: `[{"hosts":["host:http","host:https"],"body":{}}]`, // hosts in JSON are always host:port format (if port is specified), for consistency
+	},
+}
+
+func TestToJSON(t *testing.T) {
+	for i, test := range tests {
+		output, err := ToJSON([]byte(test.caddyfile))
+		if err != nil {
+			t.Errorf("Test %d: %v", i, err)
+		}
+		if string(output) != test.json {
+			t.Errorf("Test %d\nExpected:\n'%s'\nActual:\n'%s'", i, test.json, string(output))
+		}
+	}
+}
+
+func TestFromJSON(t *testing.T) {
+	for i, test := range tests {
+		output, err := FromJSON([]byte(test.json))
+		if err != nil {
+			t.Errorf("Test %d: %v", i, err)
+		}
+		if string(output) != test.caddyfile {
+			t.Errorf("Test %d\nExpected:\n'%s'\nActual:\n'%s'", i, test.caddyfile, string(output))
+		}
+	}
+}

caddy/config.go

@@ -1,4 +1,4 @@
-package config
+package caddy
 
 import (
 	"fmt"
@@ -7,43 +7,46 @@ import (
 	"net"
 	"sync"
 
-	"github.com/mholt/caddy/app"
-	"github.com/mholt/caddy/config/parse"
-	"github.com/mholt/caddy/config/setup"
+	"github.com/mholt/caddy/caddy/letsencrypt"
+	"github.com/mholt/caddy/caddy/parse"
+	"github.com/mholt/caddy/caddy/setup"
 	"github.com/mholt/caddy/middleware"
 	"github.com/mholt/caddy/server"
 )
 
 const (
-	DefaultHost = "0.0.0.0"
-	DefaultPort = "2015"
-	DefaultRoot = "."
-
 	// DefaultConfigFile is the name of the configuration file that is loaded
 	// by default if no other file is specified.
 	DefaultConfigFile = "Caddyfile"
 )
 
-// Load reads input (named filename) and parses it, returning server
-// configurations grouped by listening address.
-func Load(filename string, input io.Reader) (Group, error) {
+// loadConfigs reads input (named filename) and parses it, returning the
+// server configurations in the order they appeared in the input. As part
+// of this, it activates Let's Encrypt for the configs that are produced.
+// Thus, the returned configs are already optimally configured optimally
+// for HTTPS.
+func loadConfigs(filename string, input io.Reader) ([]server.Config, error) {
 	var configs []server.Config
 
 	// turn off timestamp for parsing
 	flags := log.Flags()
 	log.SetFlags(0)
 
-	serverBlocks, err := parse.ServerBlocks(filename, input)
+	// Each server block represents similar hosts/addresses, since they
+	// were grouped together in the Caddyfile.
+	serverBlocks, err := parse.ServerBlocks(filename, input, true)
 	if err != nil {
 		return nil, err
 	}
 	if len(serverBlocks) == 0 {
-		return Default()
+		return []server.Config{NewDefault()}, nil
 	}
 
-	// Each server block represents similar hosts/addresses.
+	var lastDirectiveIndex int // we set up directives in two parts; this stores where we left off
+
 	// Iterate each server block and make a config for each one,
-	// executing the directives that were parsed.
+	// executing the directives that were parsed in order up to the tls
+	// directive; this is because we must activate Let's Encrypt.
 	for i, sb := range serverBlocks {
 		onces := makeOnces()
 		storages := makeStorages()
@@ -55,17 +58,17 @@ func Load(filename string, input io.Reader) (Group, error) {
 				Root:       Root,
 				Middleware: make(map[string][]middleware.Middleware),
 				ConfigFile: filename,
-				AppName:    app.Name,
-				AppVersion: app.Version,
+				AppName:    AppName,
+				AppVersion: AppVersion,
 			}
 
 			// It is crucial that directives are executed in the proper order.
-			for _, dir := range directiveOrder {
+			for k, dir := range directiveOrder {
 				// Execute directive if it is in the server block
 				if tokens, ok := sb.Tokens[dir.name]; ok {
-					// Each setup function gets a controller, which is the
-					// server config and the dispenser containing only
-					// this directive's tokens.
+					// Each setup function gets a controller, from which setup functions
+					// get access to the config, tokens, and other state information useful
+					// to set up its own host only.
 					controller := &setup.Controller{
 						Config:    &config,
 						Dispenser: parse.NewDispenserTokens(filename, tokens),
@@ -81,7 +84,7 @@ func Load(filename string, input io.Reader) (Group, error) {
 						ServerBlockHosts:     sb.HostList(),
 						ServerBlockStorage:   storages[dir.name],
 					}
-
+					// execute setup function and append middleware handler, if any
 					midware, err := dir.setup(controller)
 					if err != nil {
 						return nil, err
@@ -92,20 +95,78 @@ func Load(filename string, input io.Reader) (Group, error) {
 					}
 					storages[dir.name] = controller.ServerBlockStorage // persist for this server block
 				}
-			}
 
-			if config.Port == "" {
-				config.Port = Port
+				// Stop after TLS setup, since we need to activate Let's Encrypt before continuing;
+				// it makes some changes to the configs that middlewares might want to know about.
+				if dir.name == "tls" {
+					lastDirectiveIndex = k
+					break
+				}
 			}
 
 			configs = append(configs, config)
 		}
 	}
 
+	// Now we have all the configs, but they have only been set up to the
+	// point of tls. We need to activate Let's Encrypt before setting up
+	// the rest of the middlewares so they have correct information regarding
+	// TLS configuration, if necessary. (this call is append-only, so our
+	// iterations below shouldn't be affected)
+	configs, err = letsencrypt.Activate(configs)
+	if err != nil {
+		return nil, err
+	}
+
+	// Finish setting up the rest of the directives, now that TLS is
+	// optimally configured. These loops are similar to above except
+	// we don't iterate all the directives from the beginning and we
+	// don't create new configs.
+	configIndex := -1
+	for i, sb := range serverBlocks {
+		onces := makeOnces()
+		storages := makeStorages()
+
+		for j := range sb.Addresses {
+			configIndex++
+
+			for k := lastDirectiveIndex + 1; k < len(directiveOrder); k++ {
+				dir := directiveOrder[k]
+
+				if tokens, ok := sb.Tokens[dir.name]; ok {
+					controller := &setup.Controller{
+						Config:    &configs[configIndex],
+						Dispenser: parse.NewDispenserTokens(filename, tokens),
+						OncePerServerBlock: func(f func() error) error {
+							var err error
+							onces[dir.name].Do(func() {
+								err = f()
+							})
+							return err
+						},
+						ServerBlockIndex:     i,
+						ServerBlockHostIndex: j,
+						ServerBlockHosts:     sb.HostList(),
+						ServerBlockStorage:   storages[dir.name],
+					}
+					midware, err := dir.setup(controller)
+					if err != nil {
+						return nil, err
+					}
+					if midware != nil {
+						// TODO: For now, we only support the default path scope /
+						configs[configIndex].Middleware["/"] = append(configs[configIndex].Middleware["/"], midware)
+					}
+					storages[dir.name] = controller.ServerBlockStorage // persist for this server block
+				}
+			}
+		}
+	}
+
 	// restore logging settings
 	log.SetFlags(flags)
 
-	return arrangeBindings(configs)
+	return configs, nil
 }
 
 // makeOnces makes a map of directive name to sync.Once
@@ -145,14 +206,19 @@ func makeStorages() map[string]interface{} {
 // bind address to list of configs that would become VirtualHosts on that
 // server. Use the keys of the returned map to create listeners, and use
 // the associated values to set up the virtualhosts.
-func arrangeBindings(allConfigs []server.Config) (map[*net.TCPAddr][]server.Config, error) {
-	addresses := make(map[*net.TCPAddr][]server.Config)
+func arrangeBindings(allConfigs []server.Config) (Group, error) {
+	var groupings Group
 
 	// Group configs by bind address
 	for _, conf := range allConfigs {
-		newAddr, warnErr, fatalErr := resolveAddr(conf)
+		// use default port if none is specified
+		if conf.Port == "" {
+			conf.Port = Port
+		}
+
+		bindAddr, warnErr, fatalErr := resolveAddr(conf)
 		if fatalErr != nil {
-			return addresses, fatalErr
+			return groupings, fatalErr
 		}
 		if warnErr != nil {
 			log.Println("[Warning]", warnErr)
@@ -161,37 +227,40 @@ func arrangeBindings(allConfigs []server.Config) (map[*net.TCPAddr][]server.Conf
 		// Make sure to compare the string representation of the address,
 		// not the pointer, since a new *TCPAddr is created each time.
 		var existing bool
-		for addr := range addresses {
-			if addr.String() == newAddr.String() {
-				addresses[addr] = append(addresses[addr], conf)
+		for i := 0; i < len(groupings); i++ {
+			if groupings[i].BindAddr.String() == bindAddr.String() {
+				groupings[i].Configs = append(groupings[i].Configs, conf)
 				existing = true
 				break
 			}
 		}
 		if !existing {
-			addresses[newAddr] = append(addresses[newAddr], conf)
+			groupings = append(groupings, BindingMapping{
+				BindAddr: bindAddr,
+				Configs:  []server.Config{conf},
+			})
 		}
 	}
 
 	// Don't allow HTTP and HTTPS to be served on the same address
-	for _, configs := range addresses {
-		isTLS := configs[0].TLS.Enabled
-		for _, config := range configs {
+	for _, group := range groupings {
+		isTLS := group.Configs[0].TLS.Enabled
+		for _, config := range group.Configs {
 			if config.TLS.Enabled != isTLS {
 				thisConfigProto, otherConfigProto := "HTTP", "HTTP"
 				if config.TLS.Enabled {
 					thisConfigProto = "HTTPS"
 				}
-				if configs[0].TLS.Enabled {
+				if group.Configs[0].TLS.Enabled {
 					otherConfigProto = "HTTPS"
 				}
-				return addresses, fmt.Errorf("configuration error: Cannot multiplex %s (%s) and %s (%s) on same address",
-					configs[0].Address(), otherConfigProto, config.Address(), thisConfigProto)
+				return groupings, fmt.Errorf("configuration error: Cannot multiplex %s (%s) and %s (%s) on same address",
+					group.Configs[0].Address(), otherConfigProto, config.Address(), thisConfigProto)
 			}
 		}
 	}
 
-	return addresses, nil
+	return groupings, nil
 }
 
 // resolveAddr determines the address (host and port) that a config will
@@ -209,6 +278,7 @@ func arrangeBindings(allConfigs []server.Config) (map[*net.TCPAddr][]server.Conf
 func resolveAddr(conf server.Config) (resolvAddr *net.TCPAddr, warnErr error, fatalErr error) {
 	bindHost := conf.BindHost
 
+	// TODO: Do we even need the port? Maybe we just need to look up the host.
 	resolvAddr, warnErr = net.ResolveTCPAddr("tcp", net.JoinHostPort(bindHost, conf.Port))
 	if warnErr != nil {
 		// Most likely the host lookup failed or the port is unknown
@@ -265,18 +335,27 @@ func NewDefault() server.Config {
 	}
 }
 
-// Default obtains a default config and arranges
-// bindings so it's ready to use.
-func Default() (Group, error) {
-	return arrangeBindings([]server.Config{NewDefault()})
-}
-
-// These three defaults are configurable through the command line
+// These defaults are configurable through the command line
 var (
+	// Site root
 	Root = DefaultRoot
+
+	// Site host
 	Host = DefaultHost
+
+	// Site port
 	Port = DefaultPort
 )
 
+// BindingMapping maps a network address to configurations
+// that will bind to it. The order of the configs is important.
+type BindingMapping struct {
+	BindAddr *net.TCPAddr
+	Configs  []server.Config
+}
+
 // Group maps network addresses to their configurations.
-type Group map[*net.TCPAddr][]server.Config
+// Preserving the order of the groupings is important
+// (related to graceful shutdown and restart)
+// so this is a slice, not a literal map.
+type Group []BindingMapping

caddy/config_test.go

@@ -1,4 +1,4 @@
-package config
+package caddy
 
 import (
 	"reflect"

caddy/directives.go

@@ -1,8 +1,8 @@
-package config
+package caddy
 
 import (
-	"github.com/mholt/caddy/config/parse"
-	"github.com/mholt/caddy/config/setup"
+	"github.com/mholt/caddy/caddy/parse"
+	"github.com/mholt/caddy/caddy/setup"
 	"github.com/mholt/caddy/middleware"
 )
 
@@ -42,7 +42,7 @@ func init() {
 var directiveOrder = []directive{
 	// Essential directives that initialize vital configuration settings
 	{"root", setup.Root},
-	{"tls", setup.TLS},
+	{"tls", setup.TLS}, // letsencrypt is set up just after tls
 	{"bind", setup.BindHost},
 
 	// Other directives that don't create HTTP handlers

caddy/helpers.go

@@ -0,0 +1,71 @@
+package caddy
+
+import (
+	"bytes"
+	"fmt"
+	"os"
+	"os/exec"
+	"runtime"
+	"strconv"
+	"strings"
+
+	"github.com/mholt/caddy/caddy/letsencrypt"
+)
+
+func init() {
+	letsencrypt.OnChange = func() error { return Restart(nil) }
+}
+
+// isLocalhost returns true if host looks explicitly like a localhost address.
+func isLocalhost(host string) bool {
+	return host == "localhost" || host == "::1" || strings.HasPrefix(host, "127.")
+}
+
+// checkFdlimit issues a warning if the OS max file descriptors is below a recommended minimum.
+func checkFdlimit() {
+	const min = 4096
+
+	// Warn if ulimit is too low for production sites
+	if runtime.GOOS == "linux" || runtime.GOOS == "darwin" {
+		out, err := exec.Command("sh", "-c", "ulimit -n").Output() // use sh because ulimit isn't in Linux $PATH
+		if err == nil {
+			// Note that an error here need not be reported
+			lim, err := strconv.Atoi(string(bytes.TrimSpace(out)))
+			if err == nil && lim < min {
+				fmt.Printf("Warning: File descriptor limit %d is too low for production sites. At least %d is recommended. Set with \"ulimit -n %d\".\n", lim, min, min)
+			}
+		}
+	}
+}
+
+// caddyfileGob maps bind address to index of the file descriptor
+// in the Files array passed to the child process. It also contains
+// the caddyfile contents. Used only during graceful restarts.
+type caddyfileGob struct {
+	ListenerFds map[string]uintptr
+	Caddyfile   Input
+}
+
+// isRestart returns whether this process is, according
+// to env variables, a fork as part of a graceful restart.
+func isRestart() bool {
+	return os.Getenv("CADDY_RESTART") == "true"
+}
+
+// CaddyfileInput represents a Caddyfile as input
+// and is simply a convenient way to implement
+// the Input interface.
+type CaddyfileInput struct {
+	Filepath string
+	Contents []byte
+	RealFile bool
+}
+
+// Body returns c.Contents.
+func (c CaddyfileInput) Body() []byte { return c.Contents }
+
+// Path returns c.Filepath.
+func (c CaddyfileInput) Path() string { return c.Filepath }
+
+// Path returns true if the original input was a real file on the file system.
+func (c CaddyfileInput) IsFile() bool { return c.RealFile }

caddy/letsencrypt/crypto.go

@@ -0,0 +1,30 @@
+package letsencrypt
+
+import (
+	"crypto/rsa"
+	"crypto/x509"
+	"encoding/pem"
+	"io/ioutil"
+	"os"
+)
+
+// loadRSAPrivateKey loads a PEM-encoded RSA private key from file.
+func loadRSAPrivateKey(file string) (*rsa.PrivateKey, error) {
+	keyBytes, err := ioutil.ReadFile(file)
+	if err != nil {
+		return nil, err
+	}
+	keyBlock, _ := pem.Decode(keyBytes)
+	return x509.ParsePKCS1PrivateKey(keyBlock.Bytes)
+}
+
+// saveRSAPrivateKey saves a PEM-encoded RSA private key to file.
+func saveRSAPrivateKey(key *rsa.PrivateKey, file string) error {
+	pemKey := pem.Block{Type: "RSA PRIVATE KEY", Bytes: x509.MarshalPKCS1PrivateKey(key)}
+	keyOut, err := os.Create(file)
+	if err != nil {
+		return err
+	}
+	defer keyOut.Close()
+	return pem.Encode(keyOut, &pemKey)
+}

caddy/letsencrypt/crypto_test.go

@@ -0,0 +1,51 @@
+package letsencrypt
+
+import (
+	"bytes"
+	"crypto/rand"
+	"crypto/rsa"
+	"crypto/x509"
+	"os"
+	"testing"
+)
+
+func init() {
+	rsaKeySizeToUse = 128 // make tests faster; small key size OK for testing
+}
+
+func TestSaveAndLoadRSAPrivateKey(t *testing.T) {
+	keyFile := "test.key"
+	defer os.Remove(keyFile)
+
+	privateKey, err := rsa.GenerateKey(rand.Reader, rsaKeySizeToUse)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	// test save
+	err = saveRSAPrivateKey(privateKey, keyFile)
+	if err != nil {
+		t.Fatal("error saving private key:", err)
+	}
+
+	// test load
+	loadedKey, err := loadRSAPrivateKey(keyFile)
+	if err != nil {
+		t.Error("error loading private key:", err)
+	}
+
+	// very loaded key is correct
+	if !rsaPrivateKeysSame(privateKey, loadedKey) {
+		t.Error("Expected key bytes to be the same, but they weren't")
+	}
+}
+
+// rsaPrivateKeyBytes returns the bytes of DER-encoded key.
+func rsaPrivateKeyBytes(key *rsa.PrivateKey) []byte {
+	return x509.MarshalPKCS1PrivateKey(key)
+}
+
+// rsaPrivateKeysSame compares the bytes of a and b and returns true if they are the same.
+func rsaPrivateKeysSame(a, b *rsa.PrivateKey) bool {
+	return bytes.Equal(rsaPrivateKeyBytes(a), rsaPrivateKeyBytes(b))
+}

caddy/letsencrypt/handler.go

@@ -0,0 +1,67 @@
+package letsencrypt
+
+import (
+	"crypto/tls"
+	"net/http"
+	"net/http/httputil"
+	"net/url"
+	"sync"
+	"sync/atomic"
+
+	"github.com/mholt/caddy/middleware"
+)
+
+// Handler is a Caddy middleware that can proxy ACME requests
+// to the real ACME endpoint. This is necessary to renew certificates
+// while the server is running. Obviously, a site served on port
+// 443 (HTTPS) binds to that port, so another listener created by
+// our acme client can't bind successfully and solve the challenge.
+// Thus, we chain this handler in so that it can, when activated,
+// proxy ACME requests to an ACME client listening on an alternate
+// port.
+type Handler struct {
+	sync.Mutex      // protects the ChallengePath property
+	Next            middleware.Handler
+	ChallengeActive int32  // use sync/atomic for speed to set/get this flag
+	ChallengePath   string // the exact request path to match before proxying
+}
+
+// ServeHTTP is basically a no-op unless an ACME challenge is active on this host
+// and the request path matches the expected path exactly.
+func (h *Handler) ServeHTTP(w http.ResponseWriter, r *http.Request) (int, error) {
+	// Only if challenge is active
+	if atomic.LoadInt32(&h.ChallengeActive) == 1 {
+		h.Lock()
+		path := h.ChallengePath
+		h.Unlock()
+
+		// Request path must be correct; if so, proxy to ACME client
+		if r.URL.Path == path {
+			upstream, err := url.Parse("https://" + r.Host + ":" + alternatePort)
+			if err != nil {
+				return http.StatusInternalServerError, err
+			}
+			proxy := httputil.NewSingleHostReverseProxy(upstream)
+			proxy.Transport = &http.Transport{
+				TLSClientConfig: &tls.Config{InsecureSkipVerify: true}, // client uses self-signed cert
+			}
+			proxy.ServeHTTP(w, r)
+			return 0, nil
+		}
+	}
+
+	return h.Next.ServeHTTP(w, r)
+}
+
+// ChallengeOn enables h to proxy ACME requests.
+func (h *Handler) ChallengeOn(challengePath string) {
+	h.Lock()
+	h.ChallengePath = challengePath
+	h.Unlock()
+	atomic.StoreInt32(&h.ChallengeActive, 1)
+}
+
+// ChallengeOff disables ACME proxying from this h.
+func (h *Handler) ChallengeOff(success bool) {
+	atomic.StoreInt32(&h.ChallengeActive, 0)
+}

caddy/letsencrypt/letsencrypt.go

@@ -0,0 +1,497 @@
+// Package letsencrypt integrates Let's Encrypt functionality into Caddy
+// with first-class support for creating and renewing certificates
+// automatically. It is designed to configure sites for HTTPS by default.
+package letsencrypt
+
+import (
+	"encoding/json"
+	"errors"
+	"io/ioutil"
+	"net/http"
+	"os"
+	"strings"
+	"time"
+
+	"github.com/mholt/caddy/middleware"
+	"github.com/mholt/caddy/middleware/redirect"
+	"github.com/mholt/caddy/server"
+	"github.com/xenolf/lego/acme"
+)
+
+// Activate sets up TLS for each server config in configs
+// as needed. It only skips the config if the cert and key
+// are already provided, if plaintext http is explicitly
+// specified as the port, TLS is explicitly disabled, or
+// the host looks like a loopback or wildcard address.
+//
+// This function may prompt the user to provide an email
+// address if none is available through other means. It
+// prefers the email address specified in the config, but
+// if that is not available it will check the command line
+// argument. If absent, it will use the most recent email
+// address from last time. If there isn't one, the user
+// will be prompted and shown SA link.
+//
+// Also note that calling this function activates asset
+// management automatically, which keeps certificates
+// renewed and OCSP stapling updated. This has the effect
+// of causing restarts when assets are updated.
+//
+// Activate returns the updated list of configs, since
+// some may have been appended, for example, to redirect
+// plaintext HTTP requests to their HTTPS counterpart.
+// This function only appends; it does not prepend or splice.
+func Activate(configs []server.Config) ([]server.Config, error) {
+	// just in case previous caller forgot...
+	Deactivate()
+
+	// TODO: All the output the end user should see when running caddy is something
+	// simple like "Setting up HTTPS..." (and maybe 'done' at the end of the line when finished).
+	// In other words, hide all the other logging except for on errors. Or maybe
+	// have a place to put those logs.
+
+	// reset cached ocsp statuses from any previous activations
+	ocspStatus = make(map[*[]byte]int)
+
+	// Identify and configure any eligible hosts for which
+	// we already have certs and keys in storage from last time.
+	configLen := len(configs) // avoid infinite loop since this loop appends plaintext to the slice
+	for i := 0; i < configLen; i++ {
+		if existingCertAndKey(configs[i].Host) && configQualifies(configs[i], configs) {
+			configs = autoConfigure(&configs[i], configs)
+		}
+	}
+
+	// Group configs by email address; only configs that are eligible
+	// for TLS management are included. We group by email so that we
+	// can request certificates in batches with the same client.
+	// Note: The return value is a map, and iteration over a map is
+	// not ordered. I don't think it will be a problem, but if an
+	// ordering problem arises, look at this carefully.
+	groupedConfigs, err := groupConfigsByEmail(configs)
+	if err != nil {
+		return configs, err
+	}
+
+	// obtain certificates for configs that need one, and reconfigure each
+	// config to use the certificates
+	for leEmail, serverConfigs := range groupedConfigs {
+		// make client to service this email address with CA server
+		client, err := newClient(leEmail)
+		if err != nil {
+			return configs, errors.New("error creating client: " + err.Error())
+		}
+
+		// client is ready, so let's get free, trusted SSL certificates!
+	Obtain:
+		certificates, failures := obtainCertificates(client, serverConfigs)
+		if len(failures) > 0 {
+			// Build an error string to return, using all the failures in the list.
+			var errMsg string
+
+			// If an error is because of updated SA, only prompt user for agreement once
+			var promptedForAgreement bool
+
+			for domain, obtainErr := range failures {
+				// If the failure was simply because the terms have changed, re-prompt and re-try
+				if tosErr, ok := obtainErr.(acme.TOSError); ok {
+					if !Agreed && !promptedForAgreement {
+						Agreed = promptUserAgreement(tosErr.Detail, true) // TODO: Use latest URL
+						promptedForAgreement = true
+					}
+					if Agreed {
+						err := client.AgreeToTOS()
+						if err != nil {
+							return configs, errors.New("error agreeing to updated terms: " + err.Error())
+						}
+						goto Obtain
+					}
+				}
+
+				// If user did not agree or it was any other kind of error, just append to the list of errors
+				errMsg += "[" + domain + "] failed to get certificate: " + obtainErr.Error() + "\n"
+			}
+
+			return configs, errors.New(errMsg)
+		}
+
+		// ... that's it. save the certs, keys, and metadata files to disk
+		err = saveCertsAndKeys(certificates)
+		if err != nil {
+			return configs, errors.New("error saving assets: " + err.Error())
+		}
+
+		// it all comes down to this: turning on TLS with all the new certs
+		for i := 0; i < len(serverConfigs); i++ {
+			configs = autoConfigure(serverConfigs[i], configs)
+		}
+	}
+
+	// renew all certificates that need renewal
+	renewCertificates(configs, false)
+
+	// keep certificates renewed and OCSP stapling updated
+	go maintainAssets(configs, stopChan)
+
+	return configs, nil
+}
+
+// Deactivate cleans up long-term, in-memory resources
+// allocated by calling Activate(). Essentially, it stops
+// the asset maintainer from running, meaning that certificates
+// will not be renewed, OCSP staples will not be updated, etc.
+func Deactivate() (err error) {
+	defer func() {
+		if rec := recover(); rec != nil {
+			err = errors.New("already deactivated")
+		}
+	}()
+	close(stopChan)
+	stopChan = make(chan struct{})
+	return
+}
+
+// configQualifies returns true if cfg qualifes for automatic LE activation,
+// but it does require the list of all configs to be passed in as well.
+// It does NOT check to see if a cert and key already exist for cfg.
+func configQualifies(cfg server.Config, allConfigs []server.Config) bool {
+	return cfg.TLS.Certificate == "" && // user could provide their own cert and key
+		cfg.TLS.Key == "" &&
+
+		// user can force-disable automatic HTTPS for this host
+		cfg.Port != "http" &&
+		cfg.TLS.LetsEncryptEmail != "off" &&
+
+		// obviously we get can't certs for loopback or internal hosts
+		cfg.Host != "localhost" &&
+		cfg.Host != "" &&
+		cfg.Host != "0.0.0.0" &&
+		cfg.Host != "::1" &&
+		!strings.HasPrefix(cfg.Host, "127.") && // to use a boulder on your own machine, add fake domain to hosts file
+		// not excluding 10.* and 192.168.* hosts for possibility of running internal Boulder instance
+
+		// make sure an HTTPS version of this config doesn't exist in the list already
+		!hostHasOtherScheme(cfg.Host, "https", allConfigs)
+}
+
+// groupConfigsByEmail groups configs by user email address. The returned map is
+// a map of email address to the configs that are serviced under that account.
+// If an email address is not available for an eligible config, the user will be
+// prompted to provide one. The returned map contains pointers to the original
+// server config values.
+func groupConfigsByEmail(configs []server.Config) (map[string][]*server.Config, error) {
+	initMap := make(map[string][]*server.Config)
+	for i := 0; i < len(configs); i++ {
+		// filter out configs that we already have certs for and
+		// that we won't be obtaining certs for - this way we won't
+		// bother the user for an email address unnecessarily and
+		// we don't obtain new certs for a host we already have certs for.
+		if existingCertAndKey(configs[i].Host) || !configQualifies(configs[i], configs) {
+			continue
+		}
+		leEmail := getEmail(configs[i])
+		initMap[leEmail] = append(initMap[leEmail], &configs[i])
+	}
+	return initMap, nil
+}
+
+// existingCertAndKey returns true if the host has a certificate
+// and private key in storage already, false otherwise.
+func existingCertAndKey(host string) bool {
+	_, err := os.Stat(storage.SiteCertFile(host))
+	if err != nil {
+		return false
+	}
+	_, err = os.Stat(storage.SiteKeyFile(host))
+	if err != nil {
+		return false
+	}
+	return true
+}
+
+// newClient creates a new ACME client to facilitate communication
+// with the Let's Encrypt CA server on behalf of the user specified
+// by leEmail. As part of this process, a user will be loaded from
+// disk (if already exists) or created new and registered via ACME
+// and saved to the file system for next time.
+func newClient(leEmail string) (*acme.Client, error) {
+	return newClientPort(leEmail, exposePort)
+}
+
+// newClientPort does the same thing as newClient, except it creates a
+// new client with a custom port used for ACME transactions instead of
+// the default port. This is important if the default port is already in
+// use or is not exposed to the public, etc.
+func newClientPort(leEmail, port string) (*acme.Client, error) {
+	// Look up or create the LE user account
+	leUser, err := getUser(leEmail)
+	if err != nil {
+		return nil, err
+	}
+
+	// The client facilitates our communication with the CA server.
+	client, err := acme.NewClient(CAUrl, &leUser, rsaKeySizeToUse, port)
+	if err != nil {
+		return nil, err
+	}
+
+	// If not registered, the user must register an account with the CA
+	// and agree to terms
+	if leUser.Registration == nil {
+		reg, err := client.Register()
+		if err != nil {
+			return nil, errors.New("registration error: " + err.Error())
+		}
+		leUser.Registration = reg
+
+		if !Agreed && reg.TosURL == "" {
+			Agreed = promptUserAgreement(saURL, false) // TODO - latest URL
+		}
+		if !Agreed && reg.TosURL == "" {
+			return nil, errors.New("user must agree to terms")
+		}
+
+		err = client.AgreeToTOS()
+		if err != nil {
+			saveUser(leUser) // TODO: Might as well try, right? Error check?
+			return nil, errors.New("error agreeing to terms: " + err.Error())
+		}
+
+		// save user to the file system
+		err = saveUser(leUser)
+		if err != nil {
+			return nil, errors.New("could not save user: " + err.Error())
+		}
+	}
+
+	return client, nil
+}
+
+// obtainCertificates obtains certificates from the CA server for
+// the configurations in serverConfigs using client.
+func obtainCertificates(client *acme.Client, serverConfigs []*server.Config) ([]acme.CertificateResource, map[string]error) {
+	// collect all the hostnames into one slice
+	var hosts []string
+	for _, cfg := range serverConfigs {
+		hosts = append(hosts, cfg.Host)
+	}
+
+	return client.ObtainCertificates(hosts, true)
+}
+
+// saveCertificates saves each certificate resource to disk. This
+// includes the certificate file itself, the private key, and the
+// metadata file.
+func saveCertsAndKeys(certificates []acme.CertificateResource) error {
+	for _, cert := range certificates {
+		os.MkdirAll(storage.Site(cert.Domain), 0700)
+
+		// Save cert
+		err := ioutil.WriteFile(storage.SiteCertFile(cert.Domain), cert.Certificate, 0600)
+		if err != nil {
+			return err
+		}
+
+		// Save private key
+		err = ioutil.WriteFile(storage.SiteKeyFile(cert.Domain), cert.PrivateKey, 0600)
+		if err != nil {
+			return err
+		}
+
+		// Save cert metadata
+		jsonBytes, err := json.MarshalIndent(&cert, "", "\t")
+		if err != nil {
+			return err
+		}
+		err = ioutil.WriteFile(storage.SiteMetaFile(cert.Domain), jsonBytes, 0600)
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// autoConfigure enables TLS on cfg and appends, if necessary, a new config
+// to allConfigs that redirects plaintext HTTP to its new HTTPS counterpart.
+// It expects the certificate and key to already be in storage. It returns
+// the new list of allConfigs, since it may append a new config. This function
+// assumes that cfg was already set up for HTTPS.
+func autoConfigure(cfg *server.Config, allConfigs []server.Config) []server.Config {
+	bundleBytes, err := ioutil.ReadFile(storage.SiteCertFile(cfg.Host))
+	// TODO: Handle these errors better
+	if err == nil {
+		ocsp, status, err := acme.GetOCSPForCert(bundleBytes)
+		ocspStatus[&bundleBytes] = status
+		if err == nil && status == acme.OCSPGood {
+			cfg.TLS.OCSPStaple = ocsp
+		}
+	}
+	cfg.TLS.Certificate = storage.SiteCertFile(cfg.Host)
+	cfg.TLS.Key = storage.SiteKeyFile(cfg.Host)
+	cfg.TLS.Enabled = true
+	if cfg.Port == "" {
+		cfg.Port = "https"
+	}
+
+	// Chain in ACME middleware proxy if we use up the SSL port
+	if cfg.Port == "https" || cfg.Port == "443" {
+		handler := new(Handler)
+		mid := func(next middleware.Handler) middleware.Handler {
+			handler.Next = next
+			return handler
+		}
+		cfg.Middleware["/"] = append(cfg.Middleware["/"], mid)
+		acmeHandlers[cfg.Host] = handler
+	}
+
+	// Set up http->https redirect as long as there isn't already
+	// a http counterpart in the configs
+	if !hostHasOtherScheme(cfg.Host, "http", allConfigs) {
+		allConfigs = append(allConfigs, redirPlaintextHost(*cfg))
+	}
+
+	return allConfigs
+}
+
+// hostHasOtherScheme tells you whether there is another config in the list
+// for the same host but with the port equal to scheme. For example, to see
+// if example.com has a https variant already, pass in example.com and
+// "https" along with the list of configs. This function considers "443"
+// and "https" to be the same scheme, as well as "http" and "80".
+func hostHasOtherScheme(host, scheme string, allConfigs []server.Config) bool {
+	if scheme == "80" {
+		scheme = "http"
+	} else if scheme == "443" {
+		scheme = "https"
+	}
+	for _, otherCfg := range allConfigs {
+		if otherCfg.Host == host {
+			if (otherCfg.Port == scheme) ||
+				(scheme == "https" && otherCfg.Port == "443") ||
+				(scheme == "http" && otherCfg.Port == "80") {
+				return true
+			}
+		}
+	}
+	return false
+}
+
+// redirPlaintextHost returns a new plaintext HTTP configuration for
+// a virtualHost that simply redirects to cfg, which is assumed to
+// be the HTTPS configuration. The returned configuration is set
+// to listen on the "http" port (port 80).
+func redirPlaintextHost(cfg server.Config) server.Config {
+	toUrl := "https://" + cfg.Host
+	if cfg.Port != "https" && cfg.Port != "http" {
+		toUrl += ":" + cfg.Port
+	}
+
+	redirMidware := func(next middleware.Handler) middleware.Handler {
+		return redirect.Redirect{Next: next, Rules: []redirect.Rule{
+			{
+				FromScheme: "http",
+				FromPath:   "/",
+				To:         toUrl + "{uri}",
+				Code:       http.StatusMovedPermanently,
+			},
+		}}
+	}
+
+	return server.Config{
+		Host: cfg.Host,
+		Port: "http",
+		Middleware: map[string][]middleware.Middleware{
+			"/": []middleware.Middleware{redirMidware},
+		},
+	}
+}
+
+// Revoke revokes the certificate for host via ACME protocol.
+func Revoke(host string) error {
+	if !existingCertAndKey(host) {
+		return errors.New("no certificate and key for " + host)
+	}
+
+	email := getEmail(server.Config{Host: host})
+	if email == "" {
+		return errors.New("email is required to revoke")
+	}
+
+	client, err := newClient(email)
+	if err != nil {
+		return err
+	}
+
+	certFile := storage.SiteCertFile(host)
+	certBytes, err := ioutil.ReadFile(certFile)
+	if err != nil {
+		return err
+	}
+
+	err = client.RevokeCertificate(certBytes)
+	if err != nil {
+		return err
+	}
+
+	err = os.Remove(certFile)
+	if err != nil {
+		return errors.New("certificate revoked, but unable to delete certificate file: " + err.Error())
+	}
+
+	return nil
+}
+
+var (
+	// Let's Encrypt account email to use if none provided
+	DefaultEmail string
+
+	// Whether user has agreed to the Let's Encrypt SA
+	Agreed bool
+
+	// The base URL to the CA's ACME endpoint
+	CAUrl string
+)
+
+// Some essential values related to the Let's Encrypt process
+const (
+	// The port to expose to the CA server for Simple HTTP Challenge.
+	// NOTE: Let's Encrypt requires port 443. If exposePort is not 443,
+	// then port 443 must be forwarded to exposePort.
+	exposePort = "443"
+
+	// If port 443 is in use by a Caddy server instance, then this is
+	// port on which the acme client will solve challenges. (Whatever is
+	// listening on port 443 must proxy ACME requests to this port.)
+	alternatePort = "5033"
+
+	// How often to check certificates for renewal.
+	renewInterval = 24 * time.Hour
+
+	// How often to update OCSP stapling.
+	ocspInterval = 1 * time.Hour
+)
+
+// KeySize represents the length of a key in bits.
+type KeySize int
+
+// Key sizes are used to determine the strength of a key.
+const (
+	ECC_224  KeySize = 224
+	ECC_256          = 256
+	RSA_2048         = 2048
+	RSA_4096         = 4096
+)
+
+// rsaKeySizeToUse is the size to use for new RSA keys.
+// This shouldn't need to change except for in tests;
+// the size can be drastically reduced for speed.
+var rsaKeySizeToUse = RSA_2048
+
+// stopChan is used to signal the maintenance goroutine
+// to terminate.
+var stopChan chan struct{}
+
+// ocspStatus maps certificate bundle to OCSP status at start.
+// It is used during regular OCSP checks to see if the OCSP
+// status has changed.
+var ocspStatus = make(map[*[]byte]int)

caddy/letsencrypt/letsencrypt_test.go

@@ -0,0 +1,51 @@
+package letsencrypt
+
+import (
+	"net/http"
+	"testing"
+
+	"github.com/mholt/caddy/middleware/redirect"
+	"github.com/mholt/caddy/server"
+)
+
+func TestRedirPlaintextHost(t *testing.T) {
+	cfg := redirPlaintextHost(server.Config{
+		Host: "example.com",
+		Port: "http",
+	})
+
+	// Check host and port
+	if actual, expected := cfg.Host, "example.com"; actual != expected {
+		t.Errorf("Expected redir config to have host %s but got %s", expected, actual)
+	}
+	if actual, expected := cfg.Port, "http"; actual != expected {
+		t.Errorf("Expected redir config to have port '%s' but got '%s'", expected, actual)
+	}
+
+	// Make sure redirect handler is set up properly
+	if cfg.Middleware == nil || len(cfg.Middleware["/"]) != 1 {
+		t.Fatalf("Redir config middleware not set up properly; got: %#v", cfg.Middleware)
+	}
+
+	handler, ok := cfg.Middleware["/"][0](nil).(redirect.Redirect)
+	if !ok {
+		t.Fatalf("Expected a redirect.Redirect middleware, but got: %#v", handler)
+	}
+	if len(handler.Rules) != 1 {
+		t.Fatalf("Expected one redirect rule, got: %#v", handler.Rules)
+	}
+
+	// Check redirect rule for correctness
+	if actual, expected := handler.Rules[0].FromScheme, "http"; actual != expected {
+		t.Errorf("Expected redirect rule to be from scheme '%s' but is actually from '%s'", expected, actual)
+	}
+	if actual, expected := handler.Rules[0].FromPath, "/"; actual != expected {
+		t.Errorf("Expected redirect rule to be for path '%s' but is actually for '%s'", expected, actual)
+	}
+	if actual, expected := handler.Rules[0].To, "https://example.com{uri}"; actual != expected {
+		t.Errorf("Expected redirect rule to be to URL '%s' but is actually to '%s'", expected, actual)
+	}
+	if actual, expected := handler.Rules[0].Code, http.StatusMovedPermanently; actual != expected {
+		t.Errorf("Expected redirect rule to have code %d but was %d", expected, actual)
+	}
+}

caddy/letsencrypt/maintain.go

@@ -0,0 +1,183 @@
+package letsencrypt
+
+import (
+	"encoding/json"
+	"io/ioutil"
+	"log"
+	"time"
+
+	"github.com/mholt/caddy/server"
+	"github.com/xenolf/lego/acme"
+)
+
+// OnChange is a callback function that will be used to restart
+// the application or the part of the application that uses
+// the certificates maintained by this package. When at least
+// one certificate is renewed or an OCSP status changes, this
+// function will be called.
+var OnChange func() error
+
+// maintainAssets is a permanently-blocking function
+// that loops indefinitely and, on a regular schedule, checks
+// certificates for expiration and initiates a renewal of certs
+// that are expiring soon. It also updates OCSP stapling and
+// performs other maintenance of assets.
+//
+// You must pass in the server configs to maintain and the channel
+// which you'll close when maintenance should stop, to allow this
+// goroutine to clean up after itself and unblock.
+func maintainAssets(configs []server.Config, stopChan chan struct{}) {
+	renewalTicker := time.NewTicker(renewInterval)
+	ocspTicker := time.NewTicker(ocspInterval)
+
+	for {
+		select {
+		case <-renewalTicker.C:
+			n, errs := renewCertificates(configs, true)
+			if len(errs) > 0 {
+				for _, err := range errs {
+					log.Printf("[ERROR] cert renewal: %v\n", err)
+				}
+			}
+			// even if there was an error, some renewals may have succeeded
+			if n > 0 && OnChange != nil {
+				err := OnChange()
+				if err != nil {
+					log.Printf("[ERROR] onchange after cert renewal: %v\n", err)
+				}
+			}
+		case <-ocspTicker.C:
+			for bundle, oldStatus := range ocspStatus {
+				_, newStatus, err := acme.GetOCSPForCert(*bundle)
+				if err == nil && newStatus != oldStatus && OnChange != nil {
+					log.Printf("[INFO] ocsp status changed from %v to %v\n", oldStatus, newStatus)
+					err := OnChange()
+					if err != nil {
+						log.Printf("[ERROR] onchange after ocsp update: %v\n", err)
+					}
+					break
+				}
+			}
+		case <-stopChan:
+			renewalTicker.Stop()
+			ocspTicker.Stop()
+			return
+		}
+	}
+}
+
+// renewCertificates loops through all configured site and
+// looks for certificates to renew. Nothing is mutated
+// through this function; all changes happen directly on disk.
+// It returns the number of certificates renewed and any errors
+// that occurred. It only performs a renewal if necessary.
+// If useCustomPort is true, a custom port will be used, and
+// whatever is listening at 443 better proxy ACME requests to it.
+// Otherwise, the acme package will create its own listener on 443.
+func renewCertificates(configs []server.Config, useCustomPort bool) (int, []error) {
+	log.Print("[INFO] Processing certificate renewals...")
+	var errs []error
+	var n int
+
+	defer func() {
+		// reset these so as to not interfere with other challenges
+		acme.OnSimpleHTTPStart = nil
+		acme.OnSimpleHTTPEnd = nil
+	}()
+
+	for _, cfg := range configs {
+		// Host must be TLS-enabled and have existing assets managed by LE
+		if !cfg.TLS.Enabled || !existingCertAndKey(cfg.Host) {
+			continue
+		}
+
+		// Read the certificate and get the NotAfter time.
+		certBytes, err := ioutil.ReadFile(storage.SiteCertFile(cfg.Host))
+		if err != nil {
+			errs = append(errs, err)
+			continue // still have to check other certificates
+		}
+		expTime, err := acme.GetPEMCertExpiration(certBytes)
+		if err != nil {
+			errs = append(errs, err)
+			continue
+		}
+
+		// The time returned from the certificate is always in UTC.
+		// So calculate the time left with local time as UTC.
+		// Directly convert it to days for the following checks.
+		daysLeft := int(expTime.Sub(time.Now().UTC()).Hours() / 24)
+
+		// Renew with two weeks or less remaining.
+		if daysLeft <= 14 {
+			log.Printf("[INFO] There are %d days left on the certificate of %s. Trying to renew now.", daysLeft, cfg.Host)
+			var client *acme.Client
+			if useCustomPort {
+				client, err = newClientPort("", alternatePort) // email not used for renewal
+			} else {
+				client, err = newClient("")
+			}
+			if err != nil {
+				errs = append(errs, err)
+				continue
+			}
+
+			// Read metadata
+			metaBytes, err := ioutil.ReadFile(storage.SiteMetaFile(cfg.Host))
+			if err != nil {
+				errs = append(errs, err)
+				continue
+			}
+
+			privBytes, err := ioutil.ReadFile(storage.SiteKeyFile(cfg.Host))
+			if err != nil {
+				errs = append(errs, err)
+				continue
+			}
+
+			var certMeta acme.CertificateResource
+			err = json.Unmarshal(metaBytes, &certMeta)
+			certMeta.Certificate = certBytes
+			certMeta.PrivateKey = privBytes
+
+			// Tell the handler to accept and proxy acme request in order to solve challenge
+			acme.OnSimpleHTTPStart = acmeHandlers[cfg.Host].ChallengeOn
+			acme.OnSimpleHTTPEnd = acmeHandlers[cfg.Host].ChallengeOff
+
+			// Renew certificate.
+			// TODO: revokeOld should be an option in the caddyfile
+			// TODO: bundle should be an option in the caddyfile as well :)
+		Renew:
+			newCertMeta, err := client.RenewCertificate(certMeta, true, true)
+			if err != nil {
+				if _, ok := err.(acme.TOSError); ok {
+					err := client.AgreeToTOS()
+					if err != nil {
+						errs = append(errs, err)
+					}
+					goto Renew
+				}
+
+				time.Sleep(10 * time.Second)
+				newCertMeta, err = client.RenewCertificate(certMeta, true, true)
+				if err != nil {
+					errs = append(errs, err)
+					continue
+				}
+			}
+
+			saveCertsAndKeys([]acme.CertificateResource{newCertMeta})
+			n++
+		} else if daysLeft <= 30 {
+			// Warn on 30 days remaining. TODO: Just do this once...
+			log.Printf("[WARN] There are %d days left on the certificate for %s. Will renew when 14 days remain.\n", daysLeft, cfg.Host)
+		}
+	}
+
+	return n, errs
+}
+
+// acmeHandlers is a map of host to ACME handler. These
+// are used to proxy ACME requests to the ACME client
+// when port 443 is in use.
+var acmeHandlers = make(map[string]*Handler)

caddy/letsencrypt/storage.go

@@ -0,0 +1,94 @@
+package letsencrypt
+
+import (
+	"path/filepath"
+	"strings"
+
+	"github.com/mholt/caddy/caddy/assets"
+)
+
+// storage is used to get file paths in a consistent,
+// cross-platform way for persisting Let's Encrypt assets
+// on the file system.
+var storage = Storage(filepath.Join(assets.Path(), "letsencrypt"))
+
+// Storage is a root directory and facilitates
+// forming file paths derived from it.
+type Storage string
+
+// Sites gets the directory that stores site certificate and keys.
+func (s Storage) Sites() string {
+	return filepath.Join(string(s), "sites")
+}
+
+// Site returns the path to the folder containing assets for domain.
+func (s Storage) Site(domain string) string {
+	return filepath.Join(s.Sites(), domain)
+}
+
+// CertFile returns the path to the certificate file for domain.
+func (s Storage) SiteCertFile(domain string) string {
+	return filepath.Join(s.Site(domain), domain+".crt")
+}
+
+// SiteKeyFile returns the path to domain's private key file.
+func (s Storage) SiteKeyFile(domain string) string {
+	return filepath.Join(s.Site(domain), domain+".key")
+}
+
+// SiteMetaFile returns the path to the domain's asset metadata file.
+func (s Storage) SiteMetaFile(domain string) string {
+	return filepath.Join(s.Site(domain), domain+".json")
+}
+
+// Users gets the directory that stores account folders.
+func (s Storage) Users() string {
+	return filepath.Join(string(s), "users")
+}
+
+// User gets the account folder for the user with email.
+func (s Storage) User(email string) string {
+	if email == "" {
+		email = emptyEmail
+	}
+	return filepath.Join(s.Users(), email)
+}
+
+// UserRegFile gets the path to the registration file for
+// the user with the given email address.
+func (s Storage) UserRegFile(email string) string {
+	if email == "" {
+		email = emptyEmail
+	}
+	fileName := emailUsername(email)
+	if fileName == "" {
+		fileName = "registration"
+	}
+	return filepath.Join(s.User(email), fileName+".json")
+}
+
+// UserKeyFile gets the path to the private key file for
+// the user with the given email address.
+func (s Storage) UserKeyFile(email string) string {
+	if email == "" {
+		email = emptyEmail
+	}
+	fileName := emailUsername(email)
+	if fileName == "" {
+		fileName = "private"
+	}
+	return filepath.Join(s.User(email), fileName+".key")
+}
+
+// emailUsername returns the username portion of an
+// email address (part before '@') or the original
+// input if it can't find the "@" symbol.
+func emailUsername(email string) string {
+	at := strings.Index(email, "@")
+	if at == -1 {
+		return email
+	} else if at == 0 {
+		return email[1:]
+	}
+	return email[:at]
+}

caddy/letsencrypt/storage_test.go

@@ -0,0 +1,84 @@
+package letsencrypt
+
+import (
+	"path/filepath"
+	"testing"
+)
+
+func TestStorage(t *testing.T) {
+	storage = Storage("./letsencrypt")
+
+	if expected, actual := filepath.Join("letsencrypt", "sites"), storage.Sites(); actual != expected {
+		t.Errorf("Expected Sites() to return '%s' but got '%s'", expected, actual)
+	}
+	if expected, actual := filepath.Join("letsencrypt", "sites", "test.com"), storage.Site("test.com"); actual != expected {
+		t.Errorf("Expected Site() to return '%s' but got '%s'", expected, actual)
+	}
+	if expected, actual := filepath.Join("letsencrypt", "sites", "test.com", "test.com.crt"), storage.SiteCertFile("test.com"); actual != expected {
+		t.Errorf("Expected SiteCertFile() to return '%s' but got '%s'", expected, actual)
+	}
+	if expected, actual := filepath.Join("letsencrypt", "sites", "test.com", "test.com.key"), storage.SiteKeyFile("test.com"); actual != expected {
+		t.Errorf("Expected SiteKeyFile() to return '%s' but got '%s'", expected, actual)
+	}
+	if expected, actual := filepath.Join("letsencrypt", "sites", "test.com", "test.com.json"), storage.SiteMetaFile("test.com"); actual != expected {
+		t.Errorf("Expected SiteMetaFile() to return '%s' but got '%s'", expected, actual)
+	}
+	if expected, actual := filepath.Join("letsencrypt", "users"), storage.Users(); actual != expected {
+		t.Errorf("Expected Users() to return '%s' but got '%s'", expected, actual)
+	}
+	if expected, actual := filepath.Join("letsencrypt", "users", "me@example.com"), storage.User("me@example.com"); actual != expected {
+		t.Errorf("Expected User() to return '%s' but got '%s'", expected, actual)
+	}
+	if expected, actual := filepath.Join("letsencrypt", "users", "me@example.com", "me.json"), storage.UserRegFile("me@example.com"); actual != expected {
+		t.Errorf("Expected UserRegFile() to return '%s' but got '%s'", expected, actual)
+	}
+	if expected, actual := filepath.Join("letsencrypt", "users", "me@example.com", "me.key"), storage.UserKeyFile("me@example.com"); actual != expected {
+		t.Errorf("Expected UserKeyFile() to return '%s' but got '%s'", expected, actual)
+	}
+
+	// Test with empty emails
+	if expected, actual := filepath.Join("letsencrypt", "users", emptyEmail), storage.User(emptyEmail); actual != expected {
+		t.Errorf("Expected User(\"\") to return '%s' but got '%s'", expected, actual)
+	}
+	if expected, actual := filepath.Join("letsencrypt", "users", emptyEmail, emptyEmail+".json"), storage.UserRegFile(""); actual != expected {
+		t.Errorf("Expected UserRegFile(\"\") to return '%s' but got '%s'", expected, actual)
+	}
+	if expected, actual := filepath.Join("letsencrypt", "users", emptyEmail, emptyEmail+".key"), storage.UserKeyFile(""); actual != expected {
+		t.Errorf("Expected UserKeyFile(\"\") to return '%s' but got '%s'", expected, actual)
+	}
+}
+
+func TestEmailUsername(t *testing.T) {
+	for i, test := range []struct {
+		input, expect string
+	}{
+		{
+			input:  "username@example.com",
+			expect: "username",
+		},
+		{
+			input:  "plus+addressing@example.com",
+			expect: "plus+addressing",
+		},
+		{
+			input:  "me+plus-addressing@example.com",
+			expect: "me+plus-addressing",
+		},
+		{
+			input:  "not-an-email",
+			expect: "not-an-email",
+		},
+		{
+			input:  "@foobar.com",
+			expect: "foobar.com",
+		},
+		{
+			input:  emptyEmail,
+			expect: emptyEmail,
+		},
+	} {
+		if actual := emailUsername(test.input); actual != test.expect {
+			t.Errorf("Test %d: Expected username to be '%s' but was '%s'", i, test.expect, actual)
+		}
+	}
+}

caddy/letsencrypt/user.go

@@ -0,0 +1,196 @@
+package letsencrypt
+
+import (
+	"bufio"
+	"crypto/rand"
+	"crypto/rsa"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+	"strings"
+
+	"github.com/mholt/caddy/server"
+	"github.com/xenolf/lego/acme"
+)
+
+// User represents a Let's Encrypt user account.
+type User struct {
+	Email        string
+	Registration *acme.RegistrationResource
+	key          *rsa.PrivateKey
+}
+
+// GetEmail gets u's email.
+func (u User) GetEmail() string {
+	return u.Email
+}
+
+// GetRegistration gets u's registration resource.
+func (u User) GetRegistration() *acme.RegistrationResource {
+	return u.Registration
+}
+
+// GetPrivateKey gets u's private key.
+func (u User) GetPrivateKey() *rsa.PrivateKey {
+	return u.key
+}
+
+// getUser loads the user with the given email from disk.
+// If the user does not exist, it will create a new one,
+// but it does NOT save new users to the disk or register
+// them via ACME.
+func getUser(email string) (User, error) {
+	var user User
+
+	// open user file
+	regFile, err := os.Open(storage.UserRegFile(email))
+	if err != nil {
+		if os.IsNotExist(err) {
+			// create a new user
+			return newUser(email)
+		}
+		return user, err
+	}
+	defer regFile.Close()
+
+	// load user information
+	err = json.NewDecoder(regFile).Decode(&user)
+	if err != nil {
+		return user, err
+	}
+
+	// load their private key
+	user.key, err = loadRSAPrivateKey(storage.UserKeyFile(email))
+	if err != nil {
+		return user, err
+	}
+
+	return user, nil
+}
+
+// saveUser persists a user's key and account registration
+// to the file system. It does NOT register the user via ACME.
+func saveUser(user User) error {
+	// make user account folder
+	err := os.MkdirAll(storage.User(user.Email), 0700)
+	if err != nil {
+		return err
+	}
+
+	// save private key file
+	err = saveRSAPrivateKey(user.key, storage.UserKeyFile(user.Email))
+	if err != nil {
+		return err
+	}
+
+	// save registration file
+	jsonBytes, err := json.MarshalIndent(&user, "", "\t")
+	if err != nil {
+		return err
+	}
+
+	return ioutil.WriteFile(storage.UserRegFile(user.Email), jsonBytes, 0600)
+}
+
+// newUser creates a new User for the given email address
+// with a new private key. This function does NOT save the
+// user to disk or register it via ACME. If you want to use
+// a user account that might already exist, call getUser
+// instead.
+func newUser(email string) (User, error) {
+	user := User{Email: email}
+	privateKey, err := rsa.GenerateKey(rand.Reader, rsaKeySizeToUse)
+	if err != nil {
+		return user, errors.New("error generating private key: " + err.Error())
+	}
+	user.key = privateKey
+	return user, nil
+}
+
+// getEmail does everything it can to obtain an email
+// address from the user to use for TLS for cfg. If it
+// cannot get an email address, it returns empty string.
+// (It will warn the user of the consequences of an
+// empty email.)
+func getEmail(cfg server.Config) string {
+	// First try the tls directive from the Caddyfile
+	leEmail := cfg.TLS.LetsEncryptEmail
+	if leEmail == "" {
+		// Then try memory (command line flag or typed by user previously)
+		leEmail = DefaultEmail
+	}
+	if leEmail == "" {
+		// Then try to get most recent user email ~/.caddy/users file
+		userDirs, err := ioutil.ReadDir(storage.Users())
+		if err == nil {
+			var mostRecent os.FileInfo
+			for _, dir := range userDirs {
+				if !dir.IsDir() {
+					continue
+				}
+				if mostRecent == nil || dir.ModTime().After(mostRecent.ModTime()) {
+					mostRecent = dir
+				}
+			}
+			if mostRecent != nil {
+				leEmail = mostRecent.Name()
+			}
+		}
+	}
+	if leEmail == "" {
+		// Alas, we must bother the user and ask for an email address;
+		// if they proceed they also agree to the SA.
+		reader := bufio.NewReader(stdin)
+		fmt.Println("Your sites will be served over HTTPS automatically using Let's Encrypt.")
+		fmt.Println("By continuing, you agree to the Let's Encrypt Subscriber Agreement at:")
+		fmt.Println("  " + saURL) // TODO: Show current SA link
+		fmt.Println("Please enter your email address so you can recover your account if needed.")
+		fmt.Println("You can leave it blank, but you'll lose the ability to recover your account.")
+		fmt.Print("Email address: ")
+		var err error
+		leEmail, err = reader.ReadString('\n')
+		if err != nil {
+			return ""
+		}
+		DefaultEmail = leEmail
+		Agreed = true
+	}
+	return strings.TrimSpace(leEmail)
+}
+
+// promptUserAgreement prompts the user to agree to the agreement
+// at agreementURL via stdin. If the agreement has changed, then pass
+// true as the second argument. If this is the user's first time
+// agreeing, pass false. It returns whether the user agreed or not.
+func promptUserAgreement(agreementURL string, changed bool) bool {
+	if changed {
+		fmt.Printf("The Let's Encrypt Subscriber Agreement has changed:\n  %s\n", agreementURL)
+		fmt.Print("Do you agree to the new terms? (y/n): ")
+	} else {
+		fmt.Printf("To continue, you must agree to the Let's Encrypt Subscriber Agreement:\n  %s\n", agreementURL)
+		fmt.Print("Do you agree to the terms? (y/n): ")
+	}
+
+	reader := bufio.NewReader(stdin)
+	answer, err := reader.ReadString('\n')
+	if err != nil {
+		return false
+	}
+	answer = strings.ToLower(strings.TrimSpace(answer))
+
+	return answer == "y" || answer == "yes"
+}
+
+// stdin is used to read the user's input if prompted;
+// this is changed by tests during tests.
+var stdin = io.ReadWriter(os.Stdin)
+
+// The name of the folder for accounts where the email
+// address was not provided; default 'username' if you will.
+const emptyEmail = "default"
+
+// TODO: Use latest
+const saURL = "https://letsencrypt.org/documents/LE-SA-v1.0.1-July-27-2015.pdf"

caddy/letsencrypt/user_test.go

@@ -0,0 +1,192 @@
+package letsencrypt
+
+import (
+	"bytes"
+	"crypto/rand"
+	"crypto/rsa"
+	"io"
+	"os"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/mholt/caddy/server"
+	"github.com/xenolf/lego/acme"
+)
+
+func TestUser(t *testing.T) {
+	privateKey, err := rsa.GenerateKey(rand.Reader, 128)
+	if err != nil {
+		t.Fatalf("Could not generate test private key: %v", err)
+	}
+	u := User{
+		Email:        "me@mine.com",
+		Registration: new(acme.RegistrationResource),
+		key:          privateKey,
+	}
+
+	if expected, actual := "me@mine.com", u.GetEmail(); actual != expected {
+		t.Errorf("Expected email '%s' but got '%s'", expected, actual)
+	}
+	if u.GetRegistration() == nil {
+		t.Error("Expected a registration resource, but got nil")
+	}
+	if expected, actual := privateKey, u.GetPrivateKey(); actual != expected {
+		t.Errorf("Expected the private key at address %p but got one at %p instead ", expected, actual)
+	}
+}
+
+func TestNewUser(t *testing.T) {
+	email := "me@foobar.com"
+	user, err := newUser(email)
+	if err != nil {
+		t.Fatalf("Error creating user: %v", err)
+	}
+	if user.key == nil {
+		t.Error("Private key is nil")
+	}
+	if user.Email != email {
+		t.Errorf("Expected email to be %s, but was %s", email, user.Email)
+	}
+	if user.Registration != nil {
+		t.Error("New user already has a registration resource; it shouldn't")
+	}
+}
+
+func TestSaveUser(t *testing.T) {
+	storage = Storage("./testdata")
+	defer os.RemoveAll(string(storage))
+
+	email := "me@foobar.com"
+	user, err := newUser(email)
+	if err != nil {
+		t.Fatalf("Error creating user: %v", err)
+	}
+
+	err = saveUser(user)
+	if err != nil {
+		t.Fatalf("Error saving user: %v", err)
+	}
+	_, err = os.Stat(storage.UserRegFile(email))
+	if err != nil {
+		t.Errorf("Cannot access user registration file, error: %v", err)
+	}
+	_, err = os.Stat(storage.UserKeyFile(email))
+	if err != nil {
+		t.Errorf("Cannot access user private key file, error: %v", err)
+	}
+}
+
+func TestGetUserDoesNotAlreadyExist(t *testing.T) {
+	storage = Storage("./testdata")
+	defer os.RemoveAll(string(storage))
+
+	user, err := getUser("user_does_not_exist@foobar.com")
+	if err != nil {
+		t.Fatalf("Error getting user: %v", err)
+	}
+
+	if user.key == nil {
+		t.Error("Expected user to have a private key, but it was nil")
+	}
+}
+
+func TestGetUserAlreadyExists(t *testing.T) {
+	storage = Storage("./testdata")
+	defer os.RemoveAll(string(storage))
+
+	email := "me@foobar.com"
+
+	// Set up test
+	user, err := newUser(email)
+	if err != nil {
+		t.Fatalf("Error creating user: %v", err)
+	}
+	err = saveUser(user)
+	if err != nil {
+		t.Fatalf("Error saving user: %v", err)
+	}
+
+	// Expect to load user from disk
+	user2, err := getUser(email)
+	if err != nil {
+		t.Fatalf("Error getting user: %v", err)
+	}
+
+	// Assert keys are the same
+	if !rsaPrivateKeysSame(user.key, user2.key) {
+		t.Error("Expected private key to be the same after loading, but it wasn't")
+	}
+
+	// Assert emails are the same
+	if user.Email != user2.Email {
+		t.Errorf("Expected emails to be equal, but was '%s' before and '%s' after loading", user.Email, user2.Email)
+	}
+}
+
+func TestGetEmail(t *testing.T) {
+	storage = Storage("./testdata")
+	defer os.RemoveAll(string(storage))
+	DefaultEmail = "test2@foo.com"
+
+	// Test1: Use email in config
+	config := server.Config{
+		TLS: server.TLSConfig{
+			LetsEncryptEmail: "test1@foo.com",
+		},
+	}
+	actual := getEmail(config)
+	if actual != "test1@foo.com" {
+		t.Errorf("Did not get correct email from config; expected '%s' but got '%s'", "test1@foo.com", actual)
+	}
+
+	// Test2: Use default email from flag (or user previously typing it)
+	actual = getEmail(server.Config{})
+	if actual != DefaultEmail {
+		t.Errorf("Did not get correct email from config; expected '%s' but got '%s'", DefaultEmail, actual)
+	}
+
+	// Test3: Get input from user
+	DefaultEmail = ""
+	stdin = new(bytes.Buffer)
+	_, err := io.Copy(stdin, strings.NewReader("test3@foo.com\n"))
+	if err != nil {
+		t.Fatalf("Could not simulate user input, error: %v", err)
+	}
+	actual = getEmail(server.Config{})
+	if actual != "test3@foo.com" {
+		t.Errorf("Did not get correct email from user input prompt; expected '%s' but got '%s'", "test3@foo.com", actual)
+	}
+
+	// Test4: Get most recent email from before
+	DefaultEmail = ""
+	for i, eml := range []string{
+		"test4-3@foo.com",
+		"test4-2@foo.com",
+		"test4-1@foo.com",
+	} {
+		u, err := newUser(eml)
+		if err != nil {
+			t.Fatalf("Error creating user %d: %v", i, err)
+		}
+		err = saveUser(u)
+		if err != nil {
+			t.Fatalf("Error saving user %d: %v", i, err)
+		}
+
+		// Change modified time so they're all different, so the test becomes deterministic
+		f, err := os.Stat(storage.User(eml))
+		if err != nil {
+			t.Fatalf("Could not access user folder for '%s': %v", eml, err)
+		}
+		chTime := f.ModTime().Add(-(time.Duration(i) * time.Second))
+		if err := os.Chtimes(storage.User(eml), chTime, chTime); err != nil {
+			t.Fatalf("Could not change user folder mod time for '%s': %v", eml, err)
+		}
+	}
+
+	actual = getEmail(server.Config{})
+	if actual != "test4-3@foo.com" {
+		t.Errorf("Did not get correct email from storage; expected '%s' but got '%s'", "test4-3@foo.com", actual)
+	}
+}

caddy/parse/parse.go

@@ -5,9 +5,11 @@ import "io"
 
 // ServerBlocks parses the input just enough to organize tokens,
 // in order, by server block. No further parsing is performed.
-// Server blocks are returned in the order in which they appear.
-func ServerBlocks(filename string, input io.Reader) ([]serverBlock, error) {
-	p := parser{Dispenser: NewDispenser(filename, input)}
+// If checkDirectives is true, only valid directives will be allowed
+// otherwise we consider it a parse error. Server blocks are returned
+// in the order in which they appear.
+func ServerBlocks(filename string, input io.Reader, checkDirectives bool) ([]serverBlock, error) {
+	p := parser{Dispenser: NewDispenser(filename, input), checkDirectives: checkDirectives}
 	blocks, err := p.parseAll()
 	return blocks, err
 }

caddy/parse/parsing.go

@@ -9,8 +9,9 @@ import (
 
 type parser struct {
 	Dispenser
-	block serverBlock // current server block being parsed
-	eof   bool        // if we encounter a valid EOF in a hard place
+	block           serverBlock // current server block being parsed
+	eof             bool        // if we encounter a valid EOF in a hard place
+	checkDirectives bool        // if true, directives must be known
 }
 
 func (p *parser) parseAll() ([]serverBlock, error) {
@@ -220,8 +221,10 @@ func (p *parser) directive() error {
 	dir := p.Val()
 	nesting := 0
 
-	if _, ok := ValidDirectives[dir]; !ok {
-		return p.Errf("Unknown directive '%s'", dir)
+	if p.checkDirectives {
+		if _, ok := ValidDirectives[dir]; !ok {
+			return p.Errf("Unknown directive '%s'", dir)
+		}
 	}
 
 	// The directive itself is appended as a relevant token

caddy/parse/parsing_test.go

@@ -375,6 +375,6 @@ func setupParseTests() {
 
 func testParser(input string) parser {
 	buf := strings.NewReader(input)
-	p := parser{Dispenser: NewDispenser("Test", buf)}
+	p := parser{Dispenser: NewDispenser("Test", buf), checkDirectives: true}
 	return p
 }

caddy/restart.go

@@ -0,0 +1,102 @@
+// +build !windows
+
+package caddy
+
+import (
+	"encoding/gob"
+	"io/ioutil"
+	"log"
+	"os"
+	"syscall"
+)
+
+func init() {
+	gob.Register(CaddyfileInput{})
+}
+
+// Restart restarts the entire application; gracefully with zero
+// downtime if on a POSIX-compatible system, or forcefully if on
+// Windows but with imperceptibly-short downtime.
+//
+// The restarted application will use newCaddyfile as its input
+// configuration. If newCaddyfile is nil, the current (existing)
+// Caddyfile configuration will be used.
+//
+// Note: The process must exist in the same place on the disk in
+// order for this to work. Thus, multiple graceful restarts don't
+// work if executing with `go run`, since the binary is cleaned up
+// when `go run` sees the initial parent process exit.
+func Restart(newCaddyfile Input) error {
+	if newCaddyfile == nil {
+		caddyfileMu.Lock()
+		newCaddyfile = caddyfile
+		caddyfileMu.Unlock()
+	}
+
+	if len(os.Args) == 0 { // this should never happen...
+		os.Args = []string{""}
+	}
+
+	// Tell the child that it's a restart
+	os.Setenv("CADDY_RESTART", "true")
+
+	// Prepare our payload to the child process
+	cdyfileGob := caddyfileGob{
+		ListenerFds: make(map[string]uintptr),
+		Caddyfile:   newCaddyfile,
+	}
+
+	// Prepare a pipe to the fork's stdin so it can get the Caddyfile
+	rpipe, wpipe, err := os.Pipe()
+	if err != nil {
+		return err
+	}
+
+	// Prepare a pipe that the child process will use to communicate
+	// its success or failure with us, the parent
+	sigrpipe, sigwpipe, err := os.Pipe()
+	if err != nil {
+		return err
+	}
+
+	// Pass along current environment and file descriptors to child.
+	// Ordering here is very important: stdin, stdout, stderr, sigpipe,
+	// and then the listener file descriptors (in order).
+	fds := []uintptr{rpipe.Fd(), os.Stdout.Fd(), os.Stderr.Fd(), sigwpipe.Fd()}
+
+	// Now add file descriptors of the sockets
+	serversMu.Lock()
+	for i, s := range servers {
+		fds = append(fds, s.ListenerFd())
+		cdyfileGob.ListenerFds[s.Addr] = uintptr(4 + i) // 4 fds come before any of the listeners
+	}
+	serversMu.Unlock()
+
+	// Fork the process with the current environment and file descriptors
+	execSpec := &syscall.ProcAttr{
+		Env:   os.Environ(),
+		Files: fds,
+	}
+	_, err = syscall.ForkExec(os.Args[0], os.Args, execSpec)
+	if err != nil {
+		return err
+	}
+
+	// Feed it the Caddyfile
+	err = gob.NewEncoder(wpipe).Encode(cdyfileGob)
+	if err != nil {
+		return err
+	}
+	wpipe.Close()
+
+	// Wait for child process to signal success or fail
+	sigwpipe.Close() // close our copy of the write end of the pipe or we might be stuck
+	answer, err := ioutil.ReadAll(sigrpipe)
+	if err != nil || len(answer) == 0 {
+		log.Println("restart: child failed to initialize; changes not applied")
+		return incompleteRestartErr
+	}
+
+	// Child process is listening now; we can stop all our servers here.
+	return Stop()
+}

caddy/restart_windows.go

@@ -0,0 +1,25 @@
+package caddy
+
+func Restart(newCaddyfile Input) error {
+	if newCaddyfile == nil {
+		caddyfileMu.Lock()
+		newCaddyfile = caddyfile
+		caddyfileMu.Unlock()
+	}
+
+	wg.Add(1) // barrier so Wait() doesn't unblock
+
+	err := Stop()
+	if err != nil {
+		return err
+	}
+
+	err = Start(newCaddyfile)
+	if err != nil {
+		return err
+	}
+
+	wg.Done() // take down our barrier
+
+	return nil
+}

caddy/setup/controller.go

@@ -5,7 +5,7 @@ import (
 	"net/http"
 	"strings"
 
-	"github.com/mholt/caddy/config/parse"
+	"github.com/mholt/caddy/caddy/parse"
 	"github.com/mholt/caddy/middleware"
 	"github.com/mholt/caddy/server"
 )

caddy/setup/tls.go

@@ -9,24 +9,37 @@ import (
 )
 
 func TLS(c *Controller) (middleware.Middleware, error) {
-	c.TLS.Enabled = true
-
 	if c.Port == "http" {
 		c.TLS.Enabled = false
 		log.Printf("Warning: TLS disabled for %s://%s. To force TLS over the plaintext HTTP port, "+
 			"specify port 80 explicitly (https://%s:80).", c.Port, c.Host, c.Host)
+	} else {
+		c.TLS.Enabled = true // they had a tls directive, so assume it's on unless we confirm otherwise later
 	}
 
 	for c.Next() {
-		if !c.NextArg() {
-			return nil, c.ArgErr()
-		}
-		c.TLS.Certificate = c.Val()
+		args := c.RemainingArgs()
+		switch len(args) {
+		case 1:
+			c.TLS.LetsEncryptEmail = args[0]
 
-		if !c.NextArg() {
+			// user can force-disable LE activation this way
+			if c.TLS.LetsEncryptEmail == "off" {
+				c.TLS.Enabled = false
+			}
+		case 2:
+			c.TLS.Certificate = args[0]
+			c.TLS.Key = args[1]
+
+			// manual HTTPS configuration without port specified should be
+			// served on the HTTPS port; that is what user would expect, and
+			// makes it consistent with how the letsencrypt package works.
+			if c.Port == "" {
+				c.Port = "https"
+			}
+		default:
 			return nil, c.ArgErr()
 		}
-		c.TLS.Key = c.Val()
 
 		// Optional block
 		for c.NextBlock() {

caddy/setup/tls_test.go

@@ -70,14 +70,7 @@ func TestTLSParseIncompleteParams(t *testing.T) {
 
 	_, err := TLS(c)
 	if err == nil {
-		t.Errorf("Expected errors, but no error returned")
-	}
-
-	c = NewTestController(`tls cert.key`)
-
-	_, err = TLS(c)
-	if err == nil {
-		t.Errorf("Expected errors, but no error returned")
+		t.Errorf("Expected errors (first check), but no error returned")
 	}
 }
 

caddy/sigtrap.go

@@ -0,0 +1,33 @@
+package caddy
+
+import (
+	"log"
+	"os"
+	"os/signal"
+
+	"github.com/mholt/caddy/server"
+)
+
+func init() {
+	// Trap quit signals (cross-platform)
+	go func() {
+		shutdown := make(chan os.Signal, 1)
+		signal.Notify(shutdown, os.Interrupt, os.Kill)
+		<-shutdown
+
+		var exitCode int
+
+		serversMu.Lock()
+		errs := server.ShutdownCallbacks(servers)
+		serversMu.Unlock()
+
+		if len(errs) > 0 {
+			for _, err := range errs {
+				log.Println(err)
+			}
+			exitCode = 1
+		}
+
+		os.Exit(exitCode)
+	}()
+}

caddy/sigtrap_posix.go

@@ -0,0 +1,43 @@
+// +build !windows
+
+package caddy
+
+import (
+	"io/ioutil"
+	"log"
+	"os"
+	"os/signal"
+	"syscall"
+)
+
+func init() {
+	// Trap POSIX-only signals
+	go func() {
+		reload := make(chan os.Signal, 1)
+		signal.Notify(reload, syscall.SIGUSR1) // reload configuration
+
+		for {
+			<-reload
+
+			var updatedCaddyfile Input
+
+			caddyfileMu.Lock()
+			if caddyfile.IsFile() {
+				body, err := ioutil.ReadFile(caddyfile.Path())
+				if err == nil {
+					caddyfile = CaddyfileInput{
+						Filepath: caddyfile.Path(),
+						Contents: body,
+						RealFile: true,
+					}
+				}
+			}
+			caddyfileMu.Unlock()
+
+			err := Restart(updatedCaddyfile)
+			if err != nil {
+				log.Println("error at restart:", err)
+			}
+		}
+	}()
+}

dist/CHANGES.txt

@@ -1,7 +1,24 @@
 CHANGES
 
-<master>
+0.8 beta
+- Let's Encrypt (free, automatic, fully-managed HTTPS for your sites)
+- Graceful restarts (for POSIX-compatible systems)
+- Major internal refactoring to allow use of Caddy as library
 - New directive 'mime' to customize Content-Type based on file extension
+- New -accept flag to accept Let's Encrypt SA without prompt
+- New -email flag to customize default email used for ACME transactions
+- New -ca flag to customize ACME CA server URL
+- New -revoke flag to revoke a certificate
+- browse: Render filenames with multiple whitespace properly
+- markdown: Include Last-Modified header in response
+- startup, shutdown: Better Windows support
+- templates: Bug fix for .Host when port is absent
+- templates: Include Last-Modified header in response
+- templates: Support for custom delimiters
+- tls: For non-local hosts, default port is now 443 unless specified
+- tls: Force-disable HTTPS
+- tls: Specify Let's Encrypt email address
+- Many, many more tests and numerous bug fixes and improvements
 
 
 0.7.6 (September 28, 2015)

dist/README.txt

@@ -1,4 +1,4 @@
-CADDY 0.7.6
+CADDY 0.8 beta
 
 Website
 	https://caddyserver.com

main.go

@@ -1,174 +1,160 @@
 package main
 
 import (
-	"bytes"
+	"errors"
 	"flag"
 	"fmt"
 	"io/ioutil"
 	"log"
 	"os"
-	"os/exec"
-	"path"
 	"runtime"
 	"strconv"
 	"strings"
 
-	"github.com/mholt/caddy/app"
-	"github.com/mholt/caddy/config"
-	"github.com/mholt/caddy/server"
+	"github.com/mholt/caddy/caddy"
+	"github.com/mholt/caddy/caddy/letsencrypt"
 )
 
 var (
 	conf    string
 	cpu     string
 	version bool
+	revoke  string
+)
+
+const (
+	appName    = "Caddy"
+	appVersion = "0.8 beta"
 )
 
 func init() {
-	flag.StringVar(&conf, "conf", "", "Configuration file to use (default="+config.DefaultConfigFile+")")
-	flag.BoolVar(&app.HTTP2, "http2", true, "Enable HTTP/2 support") // TODO: temporary flag until http2 merged into std lib
-	flag.BoolVar(&app.Quiet, "quiet", false, "Quiet mode (no initialization output)")
+	flag.StringVar(&conf, "conf", "", "Configuration file to use (default="+caddy.DefaultConfigFile+")")
+	flag.BoolVar(&caddy.HTTP2, "http2", true, "HTTP/2 support") // TODO: temporary flag until http2 merged into std lib
+	flag.BoolVar(&caddy.Quiet, "quiet", false, "Quiet mode (no initialization output)")
 	flag.StringVar(&cpu, "cpu", "100%", "CPU cap")
-	flag.StringVar(&config.Root, "root", config.DefaultRoot, "Root path to default site")
-	flag.StringVar(&config.Host, "host", config.DefaultHost, "Default host")
-	flag.StringVar(&config.Port, "port", config.DefaultPort, "Default port")
+	flag.StringVar(&caddy.Root, "root", caddy.DefaultRoot, "Root path to default site")
+	flag.StringVar(&caddy.Host, "host", caddy.DefaultHost, "Default host")
+	flag.StringVar(&caddy.Port, "port", caddy.DefaultPort, "Default port")
 	flag.BoolVar(&version, "version", false, "Show version")
+	// TODO: Boulder dev URL is: http://192.168.99.100:4000
+	// TODO: Staging API URL is: https://acme-staging.api.letsencrypt.org
+	// TODO: Production endpoint is: https://acme-v01.api.letsencrypt.org
+	flag.StringVar(&letsencrypt.CAUrl, "ca", "https://acme-staging.api.letsencrypt.org", "Certificate authority ACME server")
+	flag.BoolVar(&letsencrypt.Agreed, "agree", false, "Agree to Let's Encrypt Subscriber Agreement")
+	flag.StringVar(&letsencrypt.DefaultEmail, "email", "", "Default Let's Encrypt account email address")
+	flag.StringVar(&revoke, "revoke", "", "Hostname for which to revoke the certificate")
 }
 
 func main() {
 	flag.Parse()
 
+	caddy.AppName = appName
+	caddy.AppVersion = appVersion
+
 	if version {
-		fmt.Printf("%s %s\n", app.Name, app.Version)
+		fmt.Printf("%s %s\n", caddy.AppName, caddy.AppVersion)
+		os.Exit(0)
+	}
+	if revoke != "" {
+		err := letsencrypt.Revoke(revoke)
+		if err != nil {
+			log.Fatal(err)
+		}
+		fmt.Printf("Revoked certificate for %s\n", revoke)
 		os.Exit(0)
 	}
 
 	// Set CPU cap
-	err := app.SetCPU(cpu)
+	err := setCPU(cpu)
 	if err != nil {
 		log.Fatal(err)
 	}
 
-	// Load config from file
-	addresses, err := loadConfigs()
+	// Get Caddyfile input
+	caddyfile, err := caddy.LoadCaddyfile(loadCaddyfile)
 	if err != nil {
 		log.Fatal(err)
 	}
 
-	// Start each server with its one or more configurations
-	for addr, configs := range addresses {
-		s, err := server.New(addr.String(), configs)
-		if err != nil {
-			log.Fatal(err)
-		}
-		s.HTTP2 = app.HTTP2 // TODO: This setting is temporary
-		app.Wg.Add(1)
-		go func(s *server.Server) {
-			defer app.Wg.Done()
-			err := s.Serve()
-			if err != nil {
-				log.Fatal(err) // kill whole process to avoid a half-alive zombie server
-			}
-		}(s)
-
-		app.Servers = append(app.Servers, s)
+	// Start your engines
+	err = caddy.Start(caddyfile)
+	if err != nil {
+		log.Fatal(err)
 	}
 
-	// Show initialization output
-	if !app.Quiet {
-		var checkedFdLimit bool
-		for addr, configs := range addresses {
-			for _, conf := range configs {
-				// Print address of site
-				fmt.Println(conf.Address())
-
-				// Note if non-localhost site resolves to loopback interface
-				if addr.IP.IsLoopback() && !isLocalhost(conf.Host) {
-					fmt.Printf("Notice: %s is only accessible on this machine (%s)\n",
-						conf.Host, addr.IP.String())
-				}
-				if !checkedFdLimit && !addr.IP.IsLoopback() && !isLocalhost(conf.Host) {
-					checkFdlimit()
-					checkedFdLimit = true
-				}
-			}
-		}
-	}
-
-	// Wait for all listeners to stop
-	app.Wg.Wait()
+	// Twiddle your thumbs
+	caddy.Wait()
 }
 
-// checkFdlimit issues a warning if the OS max file descriptors is below a recommended minimum.
-func checkFdlimit() {
-	const min = 4096
-
-	// Warn if ulimit is too low for production sites
-	if runtime.GOOS == "linux" || runtime.GOOS == "darwin" {
-		out, err := exec.Command("sh", "-c", "ulimit -n").Output() // use sh because ulimit isn't in Linux $PATH
-		if err == nil {
-			// Note that an error here need not be reported
-			lim, err := strconv.Atoi(string(bytes.TrimSpace(out)))
-			if err == nil && lim < min {
-				fmt.Printf("Warning: File descriptor limit %d is too low for production sites. At least %d is recommended. Set with \"ulimit -n %d\".\n", lim, min, min)
-			}
-		}
-	}
-}
-
-// isLocalhost returns true if the string looks explicitly like a localhost address.
-func isLocalhost(s string) bool {
-	return s == "localhost" || s == "::1" || strings.HasPrefix(s, "127.")
-}
-
-// loadConfigs loads configuration from a file or stdin (piped).
-// The configurations are grouped by bind address.
-// Configuration is obtained from one of four sources, tried
-// in this order: 1. -conf flag, 2. stdin, 3. command line argument 4. Caddyfile.
-// If none of those are available, a default configuration is loaded.
-func loadConfigs() (config.Group, error) {
+func loadCaddyfile() (caddy.Input, error) {
 	// -conf flag
 	if conf != "" {
-		file, err := os.Open(conf)
+		contents, err := ioutil.ReadFile(conf)
 		if err != nil {
 			return nil, err
 		}
-		defer file.Close()
-		return config.Load(path.Base(conf), file)
+		return caddy.CaddyfileInput{
+			Contents: contents,
+			Filepath: conf,
+			RealFile: true,
+		}, nil
 	}
 
-	// stdin
-	fi, err := os.Stdin.Stat()
-	if err == nil && fi.Mode()&os.ModeCharDevice == 0 {
-		// Note that a non-nil error is not a problem. Windows
-		// will not create a stdin if there is no pipe, which
-		// produces an error when calling Stat(). But Unix will
-		// make one either way, which is why we also check that
-		// bitmask.
-		confBody, err := ioutil.ReadAll(os.Stdin)
-		if err != nil {
-			log.Fatal(err)
-		}
-		if len(confBody) > 0 {
-			return config.Load("stdin", bytes.NewReader(confBody))
-		}
-	}
-
-	// Command line Arg
+	// command line args
 	if flag.NArg() > 0 {
-		confBody := ":" + config.DefaultPort + "\n" + strings.Join(flag.Args(), "\n")
-		return config.Load("args", bytes.NewBufferString(confBody))
+		confBody := ":" + caddy.DefaultPort + "\n" + strings.Join(flag.Args(), "\n")
+		return caddy.CaddyfileInput{
+			Contents: []byte(confBody),
+			Filepath: "args",
+		}, nil
 	}
 
-	// Caddyfile
-	file, err := os.Open(config.DefaultConfigFile)
+	// Caddyfile in cwd
+	contents, err := ioutil.ReadFile(caddy.DefaultConfigFile)
 	if err != nil {
 		if os.IsNotExist(err) {
-			return config.Default()
+			return caddy.DefaultInput, nil
 		}
 		return nil, err
 	}
-	defer file.Close()
-
-	return config.Load(config.DefaultConfigFile, file)
+	return caddy.CaddyfileInput{
+		Contents: contents,
+		Filepath: caddy.DefaultConfigFile,
+		RealFile: true,
+	}, nil
+}
+
+// setCPU parses string cpu and sets GOMAXPROCS
+// according to its value. It accepts either
+// a number (e.g. 3) or a percent (e.g. 50%).
+func setCPU(cpu string) error {
+	var numCPU int
+
+	availCPU := runtime.NumCPU()
+
+	if strings.HasSuffix(cpu, "%") {
+		// Percent
+		var percent float32
+		pctStr := cpu[:len(cpu)-1]
+		pctInt, err := strconv.Atoi(pctStr)
+		if err != nil || pctInt < 1 || pctInt > 100 {
+			return errors.New("invalid CPU value: percentage must be between 1-100")
+		}
+		percent = float32(pctInt) / 100
+		numCPU = int(float32(availCPU) * percent)
+	} else {
+		// Number
+		num, err := strconv.Atoi(cpu)
+		if err != nil || num < 1 {
+			return errors.New("invalid CPU value: provide a number or percent greater than 0")
+		}
+		numCPU = num
+	}
+
+	if numCPU > availCPU {
+		numCPU = availCPU
+	}
+
+	runtime.GOMAXPROCS(numCPU)
+	return nil
 }

main_test.go

@@ -1,10 +1,8 @@
-package app_test
+package main
 
 import (
 	"runtime"
 	"testing"
-
-	"github.com/mholt/caddy/app"
 )
 
 func TestSetCPU(t *testing.T) {
@@ -26,7 +24,7 @@ func TestSetCPU(t *testing.T) {
 		{"invalid input%", currentCPU, true},
 		{"9999", maxCPU, false}, // over available CPU
 	} {
-		err := app.SetCPU(test.input)
+		err := setCPU(test.input)
 		if test.shouldErr && err == nil {
 			t.Errorf("Test %d: Expected error, but there wasn't any", i)
 		}

middleware/proxy/upstream.go

@@ -9,7 +9,7 @@ import (
 	"strings"
 	"time"
 
-	"github.com/mholt/caddy/config/parse"
+	"github.com/mholt/caddy/caddy/parse"
 )
 
 var (

server/config.go

@@ -50,13 +50,13 @@ func (c Config) Address() string {
 	return net.JoinHostPort(c.Host, c.Port)
 }
 
-// TLSConfig describes how TLS should be configured and used,
-// if at all. A certificate and key are both required.
-// The rest is optional.
+// TLSConfig describes how TLS should be configured and used.
 type TLSConfig struct {
 	Enabled                  bool
 	Certificate              string
 	Key                      string
+	LetsEncryptEmail         string
+	OCSPStaple               []byte
 	Ciphers                  []uint16
 	ProtocolMinVersion       uint16
 	ProtocolMaxVersion       uint16

server/graceful.go

@@ -0,0 +1,76 @@
+package server
+
+import (
+	"net"
+	"os"
+	"sync"
+	"syscall"
+)
+
+// newGracefulListener returns a gracefulListener that wraps l and
+// uses wg (stored in the host server) to count connections.
+func newGracefulListener(l ListenerFile, wg *sync.WaitGroup) *gracefulListener {
+	gl := &gracefulListener{ListenerFile: l, stop: make(chan error), httpWg: wg}
+	go func() {
+		<-gl.stop
+		gl.stopped = true
+		gl.stop <- gl.ListenerFile.Close()
+	}()
+	return gl
+}
+
+// gracefuListener is a net.Listener which can
+// count the number of connections on it. Its
+// methods mainly wrap net.Listener to be graceful.
+type gracefulListener struct {
+	ListenerFile
+	stop    chan error
+	stopped bool
+	httpWg  *sync.WaitGroup // pointer to the host's wg used for counting connections
+}
+
+// Accept accepts a connection. This type wraps
+func (gl *gracefulListener) Accept() (c net.Conn, err error) {
+	c, err = gl.ListenerFile.Accept()
+	if err != nil {
+		return
+	}
+	c = gracefulConn{Conn: c, httpWg: gl.httpWg}
+	gl.httpWg.Add(1)
+	return
+}
+
+// Close immediately closes the listener.
+func (gl *gracefulListener) Close() error {
+	if gl.stopped {
+		return syscall.EINVAL
+	}
+	gl.stop <- nil
+	return <-gl.stop
+}
+
+// File implements ListenerFile; it gets the file of the listening socket.
+func (gl *gracefulListener) File() (*os.File, error) {
+	return gl.ListenerFile.File()
+}
+
+// gracefulConn represents a connection on a
+// gracefulListener so that we can keep track
+// of the number of connections, thus facilitating
+// a graceful shutdown.
+type gracefulConn struct {
+	net.Conn
+	httpWg *sync.WaitGroup // pointer to the host server's connection waitgroup
+}
+
+// Close closes c's underlying connection while updating the wg count.
+func (c gracefulConn) Close() error {
+	err := c.Conn.Close()
+	if err != nil {
+		return err
+	}
+	// close can fail on http2 connections (as of Oct. 2015, before http2 in std lib)
+	// so don't decrement count unless close succeeds
+	c.httpWg.Done()
+	return nil
+}

server/server.go

@@ -12,23 +12,42 @@ import (
 	"net"
 	"net/http"
 	"os"
-	"os/signal"
+	"runtime"
+	"sync"
+	"time"
 
 	"golang.org/x/net/http2"
 )
 
 // Server represents an instance of a server, which serves
-// static content at a particular address (host and port).
+// HTTP requests at a particular address (host and port). A
+// server is capable of serving numerous virtual hosts on
+// the same address and the listener may be stopped for
+// graceful termination (POSIX only).
 type Server struct {
-	HTTP2   bool                   // temporary while http2 is not in std lib (TODO: remove flag when part of std lib)
-	address string                 // the actual address for net.Listen to listen on
-	tls     bool                   // whether this server is serving all HTTPS hosts or not
-	vhosts  map[string]virtualHost // virtual hosts keyed by their address
+	*http.Server
+	HTTP2      bool                   // temporary while http2 is not in std lib (TODO: remove flag when part of std lib)
+	tls        bool                   // whether this server is serving all HTTPS hosts or not
+	vhosts     map[string]virtualHost // virtual hosts keyed by their address
+	listener   ListenerFile           // the listener which is bound to the socket
+	listenerMu sync.Mutex             // protects listener
+	httpWg     sync.WaitGroup         // used to wait on outstanding connections
+	startChan  chan struct{}          // used to block until server is finished starting
+}
+
+type ListenerFile interface {
+	net.Listener
+	File() (*os.File, error)
 }
 
 // New creates a new Server which will bind to addr and serve
 // the sites/hosts configured in configs. This function does
 // not start serving.
+//
+// Do not re-use a server (start, stop, then start again). We
+// could probably add more locking to make this possible, but
+// as it stands, you should dispose of a server after stopping it.
+// The behavior of serving with a spent server is undefined.
 func New(addr string, configs []Config) (*Server, error) {
 	var tls bool
 	if len(configs) > 0 {
@@ -36,14 +55,31 @@ func New(addr string, configs []Config) (*Server, error) {
 	}
 
 	s := &Server{
-		address: addr,
-		tls:     tls,
-		vhosts:  make(map[string]virtualHost),
+		Server: &http.Server{
+			Addr: addr,
+			// TODO: Make these values configurable?
+			// ReadTimeout:    2 * time.Minute,
+			// WriteTimeout:   2 * time.Minute,
+			// MaxHeaderBytes: 1 << 16,
+		},
+		tls:       tls,
+		vhosts:    make(map[string]virtualHost),
+		startChan: make(chan struct{}),
 	}
+	s.Handler = s // this is weird, but whatever
 
+	// We have to bound our wg with one increment
+	// to prevent a "race condition" that is hard-coded
+	// into sync.WaitGroup.Wait() - basically, an add
+	// with a positive delta must be guaranteed to
+	// occur before Wait() is called on the wg.
+	// In a way, this kind of acts as a safety barrier.
+	s.httpWg.Add(1)
+
+	// Set up each virtualhost
 	for _, conf := range configs {
 		if _, exists := s.vhosts[conf.Host]; exists {
-			return nil, fmt.Errorf("cannot serve %s - host already defined for address %s", conf.Address(), s.address)
+			return nil, fmt.Errorf("cannot serve %s - host already defined for address %s", conf.Address(), s.Addr)
 		}
 
 		vh := virtualHost{config: conf}
@@ -60,98 +96,104 @@ func New(addr string, configs []Config) (*Server, error) {
 	return s, nil
 }
 
-// Serve starts the server. It blocks until the server quits.
-func (s *Server) Serve() error {
-	server := &http.Server{
-		Addr:    s.address,
-		Handler: s,
+// Serve starts the server with an existing listener. It blocks until the
+// server stops.
+func (s *Server) Serve(ln ListenerFile) error {
+	err := s.setup()
+	if err != nil {
+		close(s.startChan)
+		return err
+	}
+	return s.serve(ln)
+}
+
+// ListenAndServe starts the server with a new listener. It blocks until the server stops.
+func (s *Server) ListenAndServe() error {
+	err := s.setup()
+	if err != nil {
+		close(s.startChan)
+		return err
 	}
 
-	if s.HTTP2 {
-		// TODO: This call may not be necessary after HTTP/2 is merged into std lib
-		http2.ConfigureServer(server, nil)
-	}
-
-	for _, vh := range s.vhosts {
-		// Execute startup functions now
-		for _, start := range vh.config.Startup {
-			err := start()
-			if err != nil {
-				return err
+	ln, err := net.Listen("tcp", s.Addr)
+	if err != nil {
+		var succeeded bool
+		if runtime.GOOS == "windows" { // TODO: Limit this to Windows only? (it keeps sockets open after closing listeners)
+			for i := 0; i < 20; i++ {
+				time.Sleep(100 * time.Millisecond)
+				ln, err = net.Listen("tcp", s.Addr)
+				if err == nil {
+					succeeded = true
+					break
+				}
 			}
 		}
-
-		// Execute shutdown commands on exit
-		if len(vh.config.Shutdown) > 0 {
-			go func(vh virtualHost) {
-				// Wait for signal
-				interrupt := make(chan os.Signal, 1)
-				signal.Notify(interrupt, os.Interrupt, os.Kill) // TODO: syscall.SIGQUIT? (Ctrl+\, Unix-only)
-				<-interrupt
-
-				// Run callbacks
-				exitCode := 0
-				for _, shutdownFunc := range vh.config.Shutdown {
-					err := shutdownFunc()
-					if err != nil {
-						exitCode = 1
-						log.Println(err)
-					}
-				}
-				os.Exit(exitCode) // BUG: Other shutdown goroutines might be running; use sync.WaitGroup
-			}(vh)
+		if !succeeded {
+			close(s.startChan)
+			return err
 		}
 	}
 
+	return s.serve(ln.(*net.TCPListener))
+}
+
+// serve prepares s to listen on ln by wrapping ln in a
+// tcpKeepAliveListener (if ln is a *net.TCPListener) and
+// then in a gracefulListener, so that keep-alive is supported
+// as well as graceful shutdown/restart. It also configures
+// TLS listener on top of that if applicable.
+func (s *Server) serve(ln ListenerFile) error {
+	if tcpLn, ok := ln.(*net.TCPListener); ok {
+		ln = tcpKeepAliveListener{TCPListener: tcpLn}
+	}
+
+	s.listenerMu.Lock()
+	s.listener = newGracefulListener(ln, &s.httpWg)
+	s.listenerMu.Unlock()
+
 	if s.tls {
 		var tlsConfigs []TLSConfig
 		for _, vh := range s.vhosts {
 			tlsConfigs = append(tlsConfigs, vh.config.TLS)
 		}
-		return ListenAndServeTLSWithSNI(server, tlsConfigs)
+		return serveTLSWithSNI(s, s.listener, tlsConfigs)
 	}
-	return server.ListenAndServe()
+
+	close(s.startChan) // unblock anyone waiting for this to start listening
+	return s.Server.Serve(s.listener)
 }
 
-// copy from net/http/transport.go
-func cloneTLSConfig(cfg *tls.Config) *tls.Config {
-	if cfg == nil {
-		return &tls.Config{}
+// setup prepares the server s to begin listening; it should be
+// called just before the listener announces itself on the network
+// and should only be called when the server is just starting up.
+func (s *Server) setup() error {
+	if s.HTTP2 {
+		// TODO: This call may not be necessary after HTTP/2 is merged into std lib
+		http2.ConfigureServer(s.Server, nil)
 	}
-	return &tls.Config{
-		Rand:                     cfg.Rand,
-		Time:                     cfg.Time,
-		Certificates:             cfg.Certificates,
-		NameToCertificate:        cfg.NameToCertificate,
-		GetCertificate:           cfg.GetCertificate,
-		RootCAs:                  cfg.RootCAs,
-		NextProtos:               cfg.NextProtos,
-		ServerName:               cfg.ServerName,
-		ClientAuth:               cfg.ClientAuth,
-		ClientCAs:                cfg.ClientCAs,
-		InsecureSkipVerify:       cfg.InsecureSkipVerify,
-		CipherSuites:             cfg.CipherSuites,
-		PreferServerCipherSuites: cfg.PreferServerCipherSuites,
-		SessionTicketsDisabled:   cfg.SessionTicketsDisabled,
-		SessionTicketKey:         cfg.SessionTicketKey,
-		ClientSessionCache:       cfg.ClientSessionCache,
-		MinVersion:               cfg.MinVersion,
-		MaxVersion:               cfg.MaxVersion,
-		CurvePreferences:         cfg.CurvePreferences,
+
+	// Execute startup functions now
+	for _, vh := range s.vhosts {
+		for _, startupFunc := range vh.config.Startup {
+			err := startupFunc()
+			if err != nil {
+				return err
+			}
+		}
 	}
+
+	return nil
 }
 
-// ListenAndServeTLSWithSNI serves TLS with Server Name Indication (SNI) support, which allows
-// multiple sites (different hostnames) to be served from the same address. This method is
-// adapted directly from the std lib's net/http ListenAndServeTLS function, which was
-// written by the Go Authors. It has been modified to support multiple certificate/key pairs.
-func ListenAndServeTLSWithSNI(srv *http.Server, tlsConfigs []TLSConfig) error {
-	addr := srv.Addr
-	if addr == "" {
-		addr = ":https"
-	}
-
-	config := cloneTLSConfig(srv.TLSConfig)
+// serveTLSWithSNI serves TLS with Server Name Indication (SNI) support, which allows
+// multiple sites (different hostnames) to be served from the same address. It also
+// supports client authentication if srv has it enabled. It blocks until s quits.
+//
+// This method is adapted from the std lib's net/http ServeTLS function, which was written
+// by the Go Authors. It has been modified to support multiple certificate/key pairs,
+// client authentication, and our custom Server type.
+func serveTLSWithSNI(s *Server, ln net.Listener, tlsConfigs []TLSConfig) error {
+	config := cloneTLSConfig(s.TLSConfig)
 	if config.NextProtos == nil {
 		config.NextProtos = []string{"http/1.1"}
 	}
@@ -162,7 +204,9 @@ func ListenAndServeTLSWithSNI(srv *http.Server, tlsConfigs []TLSConfig) error {
 	config.Certificates = make([]tls.Certificate, len(tlsConfigs))
 	for i, tlsConfig := range tlsConfigs {
 		config.Certificates[i], err = tls.LoadX509KeyPair(tlsConfig.Certificate, tlsConfig.Key)
+		config.Certificates[i].OCSPStaple = tlsConfig.OCSPStaple
 		if err != nil {
+			close(s.startChan)
 			return err
 		}
 	}
@@ -177,48 +221,73 @@ func ListenAndServeTLSWithSNI(srv *http.Server, tlsConfigs []TLSConfig) error {
 	// TLS client authentication, if user enabled it
 	err = setupClientAuth(tlsConfigs, config)
 	if err != nil {
+		close(s.startChan)
 		return err
 	}
 
-	// Create listener and we're on our way
-	conn, err := net.Listen("tcp", addr)
-	if err != nil {
-		return err
-	}
-	tlsListener := tls.NewListener(conn, config)
+	// Create TLS listener - note that we do not replace s.listener
+	// with this TLS listener; tls.listener is unexported and does
+	// not implement the File() method we need for graceful restarts
+	// on POSIX systems.
+	ln = tls.NewListener(ln, config)
 
-	return srv.Serve(tlsListener)
+	close(s.startChan) // unblock anyone waiting for this to start listening
+	return s.Server.Serve(ln)
 }
 
-// setupClientAuth sets up TLS client authentication only if
-// any of the TLS configs specified at least one cert file.
-func setupClientAuth(tlsConfigs []TLSConfig, config *tls.Config) error {
-	var clientAuth bool
-	for _, cfg := range tlsConfigs {
-		if len(cfg.ClientCerts) > 0 {
-			clientAuth = true
-			break
+// Stop stops the server. It blocks until the server is
+// totally stopped. On POSIX systems, it will wait for
+// connections to close (up to a max timeout of a few
+// seconds); on Windows it will close the listener
+// immediately.
+func (s *Server) Stop() error {
+	s.Server.SetKeepAlivesEnabled(false)
+
+	if runtime.GOOS != "windows" {
+		// force connections to close after timeout
+		done := make(chan struct{})
+		go func() {
+			s.httpWg.Done() // decrement our initial increment used as a barrier
+			s.httpWg.Wait()
+			close(done)
+		}()
+
+		// Wait for remaining connections to finish or
+		// force them all to close after timeout
+		select {
+		case <-time.After(5 * time.Second): // TODO: make configurable
+		case <-done:
 		}
 	}
 
-	if clientAuth {
-		pool := x509.NewCertPool()
-		for _, cfg := range tlsConfigs {
-			for _, caFile := range cfg.ClientCerts {
-				caCrt, err := ioutil.ReadFile(caFile) // Anyone that gets a cert from Matt Holt can connect
-				if err != nil {
-					return err
-				}
-				if !pool.AppendCertsFromPEM(caCrt) {
-					return fmt.Errorf("error loading client certificate '%s': no certificates were successfully parsed", caFile)
-				}
-			}
-		}
-		config.ClientCAs = pool
-		config.ClientAuth = tls.RequireAndVerifyClientCert
+	// Close the listener now; this stops the server without delay
+	s.listenerMu.Lock()
+	err := s.listener.Close()
+	s.listenerMu.Unlock()
+	if err != nil {
+		// TODO: Better logging
+		log.Println(err)
 	}
 
-	return nil
+	return err
+}
+
+// WaitUntilStarted blocks until the server s is started, meaning
+// that practically the next instruction is to start the server loop.
+// It also unblocks if the server encounters an error during startup.
+func (s *Server) WaitUntilStarted() {
+	<-s.startChan
+}
+
+// ListenerFd gets the file descriptor of the listener.
+func (s *Server) ListenerFd() uintptr {
+	s.listenerMu.Lock()
+	defer s.listenerMu.Unlock()
+	file, err := s.listener.File()
+	if err != nil {
+		return 0
+	}
+	return file.Fd()
 }
 
 // ServeHTTP is the entry point for every request to the address that s
@@ -260,7 +329,7 @@ func (s *Server) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 		}
 	} else {
 		w.WriteHeader(http.StatusNotFound)
-		fmt.Fprintf(w, "No such host at %s", s.address)
+		fmt.Fprintf(w, "No such host at %s", s.Server.Addr)
 	}
 }
 
@@ -270,3 +339,110 @@ func DefaultErrorFunc(w http.ResponseWriter, r *http.Request, status int) {
 	w.WriteHeader(status)
 	fmt.Fprintf(w, "%d %s", status, http.StatusText(status))
 }
+
+// setupClientAuth sets up TLS client authentication only if
+// any of the TLS configs specified at least one cert file.
+func setupClientAuth(tlsConfigs []TLSConfig, config *tls.Config) error {
+	var clientAuth bool
+	for _, cfg := range tlsConfigs {
+		if len(cfg.ClientCerts) > 0 {
+			clientAuth = true
+			break
+		}
+	}
+
+	if clientAuth {
+		pool := x509.NewCertPool()
+		for _, cfg := range tlsConfigs {
+			for _, caFile := range cfg.ClientCerts {
+				caCrt, err := ioutil.ReadFile(caFile) // Anyone that gets a cert from this CA can connect
+				if err != nil {
+					return err
+				}
+				if !pool.AppendCertsFromPEM(caCrt) {
+					return fmt.Errorf("error loading client certificate '%s': no certificates were successfully parsed", caFile)
+				}
+			}
+		}
+		config.ClientCAs = pool
+		config.ClientAuth = tls.RequireAndVerifyClientCert
+	}
+
+	return nil
+}
+
+// tcpKeepAliveListener sets TCP keep-alive timeouts on accepted
+// connections. It's used by ListenAndServe and ListenAndServeTLS so
+// dead TCP connections (e.g. closing laptop mid-download) eventually
+// go away.
+//
+// Borrowed from the Go standard library.
+type tcpKeepAliveListener struct {
+	*net.TCPListener
+}
+
+// Accept accepts the connection with a keep-alive enabled.
+func (ln tcpKeepAliveListener) Accept() (c net.Conn, err error) {
+	tc, err := ln.AcceptTCP()
+	if err != nil {
+		return
+	}
+	tc.SetKeepAlive(true)
+	tc.SetKeepAlivePeriod(3 * time.Minute)
+	return tc, nil
+}
+
+// File implements ListenerFile; returns the underlying file of the listener.
+func (ln tcpKeepAliveListener) File() (*os.File, error) {
+	return ln.TCPListener.File()
+}
+
+// copied from net/http/transport.go
+func cloneTLSConfig(cfg *tls.Config) *tls.Config {
+	if cfg == nil {
+		return &tls.Config{}
+	}
+	return &tls.Config{
+		Rand:                     cfg.Rand,
+		Time:                     cfg.Time,
+		Certificates:             cfg.Certificates,
+		NameToCertificate:        cfg.NameToCertificate,
+		GetCertificate:           cfg.GetCertificate,
+		RootCAs:                  cfg.RootCAs,
+		NextProtos:               cfg.NextProtos,
+		ServerName:               cfg.ServerName,
+		ClientAuth:               cfg.ClientAuth,
+		ClientCAs:                cfg.ClientCAs,
+		InsecureSkipVerify:       cfg.InsecureSkipVerify,
+		CipherSuites:             cfg.CipherSuites,
+		PreferServerCipherSuites: cfg.PreferServerCipherSuites,
+		SessionTicketsDisabled:   cfg.SessionTicketsDisabled,
+		SessionTicketKey:         cfg.SessionTicketKey,
+		ClientSessionCache:       cfg.ClientSessionCache,
+		MinVersion:               cfg.MinVersion,
+		MaxVersion:               cfg.MaxVersion,
+		CurvePreferences:         cfg.CurvePreferences,
+	}
+}
+
+// ShutdownCallbacks executes all the shutdown callbacks
+// for all the virtualhosts in servers, and returns all the
+// errors generated during their execution. In other words,
+// an error executing one shutdown callback does not stop
+// execution of others. Only one shutdown callback is executed
+// at a time. You must protect the servers that are passed in
+// if they are shared across threads.
+func ShutdownCallbacks(servers []*Server) []error {
+	var errs []error
+	for _, s := range servers {
+		for _, vhost := range s.vhosts {
+			for _, shutdownFunc := range vhost.config.Shutdown {
+				err := shutdownFunc()
+				if err != nil {
+					errs = append(errs, err)
+				}
+			}
+		}
+	}
+	return errs
+}