cmd: Clean up, simplify reverse proxy command; fix some edge cases

Now we take advantage of the address parsing capabilities of the HTTP
caddyfile.
This commit is contained in:
Matthew Holt 2020-04-27 15:53:38 -06:00
parent 9770ce7c9f
commit c11d0e47a3
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GPG key ID: 2A349DD577D586A5

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@ -20,11 +20,11 @@ import (
"fmt"
"net"
"net/http"
"net/url"
"strings"
"strconv"
"github.com/caddyserver/caddy/v2"
"github.com/caddyserver/caddy/v2/caddyconfig"
"github.com/caddyserver/caddy/v2/caddyconfig/httpcaddyfile"
caddycmd "github.com/caddyserver/caddy/v2/cmd"
"github.com/caddyserver/caddy/v2/modules/caddyhttp"
"github.com/caddyserver/caddy/v2/modules/caddyhttp/headers"
@ -40,10 +40,15 @@ func init() {
A simple but production-ready reverse proxy. Useful for quick deployments,
demos, and development.
Simply shuttles HTTP traffic from the --from address to the --to address.
Simply shuttles HTTP(S) traffic from the --from address to the --to address.
If the --from address has a domain name, Caddy will attempt to serve the
proxy over HTTPS with a certificate.
Unless otherwise specified in the addresses, the --from address will be
assumed to be HTTPS if a hostname is given, and the --to address will be
assumed to be HTTP.
If the --from address has a host or IP, Caddy will attempt to serve the
proxy over HTTPS with a certificate (unless overridden by the HTTP scheme
or port).
If --change-host-header is set, the Host header on the request will be modified
from its original incoming value to the address of the upstream. (Otherwise, by
@ -51,7 +56,7 @@ default, all incoming headers are passed through unmodified.)
`,
Flags: func() *flag.FlagSet {
fs := flag.NewFlagSet("file-server", flag.ExitOnError)
fs.String("from", "localhost:443", "Address on which to receive traffic")
fs.String("from", "localhost", "Address on which to receive traffic")
fs.String("to", "", "Upstream address to which to to proxy traffic")
fs.Bool("change-host-header", false, "Set upstream Host header to address of upstream")
return fs
@ -64,43 +69,69 @@ func cmdReverseProxy(fs caddycmd.Flags) (int, error) {
to := fs.String("to")
changeHost := fs.Bool("change-host-header")
if from == "" {
from = "localhost:443"
httpPort := strconv.Itoa(caddyhttp.DefaultHTTPPort)
httpsPort := strconv.Itoa(caddyhttp.DefaultHTTPSPort)
if to == "" {
return caddy.ExitCodeFailedStartup, fmt.Errorf("--to is required")
}
// URLs need a scheme in order to parse successfully
if !strings.Contains(from, "://") {
from = "http://" + from
}
if !strings.Contains(to, "://") {
to = "http://" + to
}
fromURL, err := url.Parse(from)
// set up the downstream address; assume missing information from given parts
fromAddr, err := httpcaddyfile.ParseAddress(from)
if err != nil {
return caddy.ExitCodeFailedStartup, fmt.Errorf("parsing 'from' URL: %v", err)
return caddy.ExitCodeFailedStartup, fmt.Errorf("invalid downstream address %s: %v", from, err)
}
if fromAddr.Path != "" {
return caddy.ExitCodeFailedStartup, fmt.Errorf("paths are not allowed: %s", from)
}
if fromAddr.Scheme == "" {
if fromAddr.Port == httpPort || fromAddr.Host == "" {
fromAddr.Scheme = "http"
} else {
fromAddr.Scheme = "https"
}
}
if fromAddr.Port == "" {
if fromAddr.Scheme == "http" {
fromAddr.Port = httpPort
} else if fromAddr.Scheme == "https" {
fromAddr.Port = httpsPort
}
toURL, err := url.Parse(to)
if err != nil {
return caddy.ExitCodeFailedStartup, fmt.Errorf("parsing 'to' URL: %v", err)
}
if toURL.Port() == "" {
toPort := "80"
if toURL.Scheme == "https" {
toPort = "443"
// set up the upstream address; assume missing information from given parts
toAddr, err := httpcaddyfile.ParseAddress(to)
if err != nil {
return caddy.ExitCodeFailedStartup, fmt.Errorf("invalid upstream address %s: %v", to, err)
}
toURL.Host = net.JoinHostPort(toURL.Host, toPort)
if toAddr.Path != "" {
return caddy.ExitCodeFailedStartup, fmt.Errorf("paths are not allowed: %s", to)
}
if toAddr.Scheme == "" {
if toAddr.Port == httpsPort {
toAddr.Scheme = "https"
} else {
toAddr.Scheme = "http"
}
}
if toAddr.Port == "" {
if toAddr.Scheme == "http" {
toAddr.Port = httpPort
} else if toAddr.Scheme == "https" {
toAddr.Port = httpsPort
}
}
// proceed to build the handler and server
ht := HTTPTransport{}
if toURL.Scheme == "https" {
if toAddr.Scheme == "https" {
ht.TLS = new(TLSConfig)
}
handler := Handler{
TransportRaw: caddyconfig.JSONModuleObject(ht, "protocol", "http", nil),
Upstreams: UpstreamPool{{Dial: toURL.Host}},
Upstreams: UpstreamPool{{Dial: net.JoinHostPort(toAddr.Host, toAddr.Port)}},
}
if changeHost {
@ -118,23 +149,17 @@ func cmdReverseProxy(fs caddycmd.Flags) (int, error) {
caddyconfig.JSONModuleObject(handler, "handler", "reverse_proxy", nil),
},
}
urlHost := fromURL.Hostname()
if urlHost != "" {
if fromAddr.Host != "" {
route.MatcherSetsRaw = []caddy.ModuleMap{
{
"host": caddyconfig.JSON(caddyhttp.MatchHost{urlHost}, nil),
"host": caddyconfig.JSON(caddyhttp.MatchHost{fromAddr.Host}, nil),
},
}
}
listen := ":443"
if urlPort := fromURL.Port(); urlPort != "" {
listen = ":" + urlPort
}
server := &caddyhttp.Server{
Routes: caddyhttp.RouteList{route},
Listen: []string{listen},
Listen: []string{":" + fromAddr.Port},
}
httpApp := caddyhttp.App{
@ -153,7 +178,7 @@ func cmdReverseProxy(fs caddycmd.Flags) (int, error) {
return caddy.ExitCodeFailedStartup, err
}
fmt.Printf("Caddy 2 proxying from %s to %s\n", fromURL, toURL)
fmt.Printf("Caddy proxying %s -> %s\n", fromAddr.String(), toAddr.String())
select {}
}