headers: Support default header values in Caddyfile with '?' (#3807)

* implement default values for header directive

closes #3804

* remove `set_default` header op and rely on "require" handler instead

This has the following advantages over the previous attempt:

- It does not introduce a new operation for headers, but rather nicely
  extends over an existing feature in the header handler.
- It removes the need to specify the header as "deferred" because it is
  already implicitely deferred by the use of the require handler. This
  should be less confusing to the user.

* add integration test for header directive in caddyfile

* bubble up errors when parsing caddyfile header directive

* don't export unnecessarily and don't canonicalize headers unnecessarily

* fix response headers not passed in blocks

* caddyfile: fix clash when using default header in block

Each header is now set in a separate handler so that it doesn't clash
with other headers set/added/deleted in the same block.

* caddyhttp: New idle_timeout default of 5m

* reverseproxy: fix random hangs on http/2 requests with server push (#3875)

see https://github.com/golang/go/issues/42534

* Refactor and cleanup with improvements

* More specific link

Co-authored-by: Matthew Holt <mholt@users.noreply.github.com>
Co-authored-by: Денис Телюх <telyukh.denis@gmail.com>
This commit is contained in:
Gilbert Gilb's 2020-11-20 20:38:16 +01:00 committed by GitHub
parent 12cc69ab7a
commit b0d5c2c8ae
No known key found for this signature in database
GPG key ID: 4AEE18F83AFDEB23
6 changed files with 466 additions and 71 deletions

View file

@ -103,20 +103,11 @@ func RegisterHandlerDirective(dir string, setupFunc UnmarshalHandlerFunc) {
return nil, h.ArgErr()
}
matcherSet, ok, err := h.MatcherToken()
matcherSet, err := h.ExtractMatcherSet()
if err != nil {
return nil, err
}
if ok {
// strip matcher token; we don't need to
// use the return value here because a
// new dispenser should have been made
// solely for this directive's tokens,
// with no other uses of same slice
h.Dispenser.Delete()
}
h.Dispenser.Reset() // pretend this lookahead never happened
val, err := setupFunc(h)
if err != nil {
return nil, err
@ -201,7 +192,12 @@ func (h Helper) ExtractMatcherSet() (caddy.ModuleMap, error) {
return nil, err
}
if hasMatcher {
h.Dispenser.Delete() // strip matcher token
// strip matcher token; we don't need to
// use the return value here because a
// new dispenser should have been made
// solely for this directive's tokens,
// with no other uses of same slice
h.Dispenser.Delete()
}
h.Dispenser.Reset() // pretend this lookahead never happened
return matcherSet, nil

View file

@ -0,0 +1,107 @@
:80 {
header Denis "Ritchie"
header +Edsger "Dijkstra"
header ?John "von Neumann"
header -Wolfram
header {
Grace: "Hopper" # some users habitually suffix field names with a colon
+Ray "Solomonoff"
?Tim "Berners-Lee"
defer
}
}
----------
{
"apps": {
"http": {
"servers": {
"srv0": {
"listen": [
":80"
],
"routes": [
{
"handle": [
{
"handler": "headers",
"response": {
"set": {
"Denis": [
"Ritchie"
]
}
}
},
{
"handler": "headers",
"response": {
"add": {
"Edsger": [
"Dijkstra"
]
}
}
},
{
"handler": "headers",
"response": {
"require": {
"headers": {
"John": null
}
},
"set": {
"John": [
"von Neumann"
]
}
}
},
{
"handler": "headers",
"response": {
"deferred": true,
"delete": [
"Wolfram"
]
}
},
{
"handler": "headers",
"response": {
"add": {
"Ray": [
"Solomonoff"
]
},
"deferred": true,
"set": {
"Grace": [
"Hopper"
]
}
}
},
{
"handler": "headers",
"response": {
"require": {
"headers": {
"Tim": null
}
},
"set": {
"Tim": [
"Berners-Lee"
]
}
}
}
]
}
]
}
}
}
}
}

View file

@ -15,7 +15,9 @@
package headers
import (
"fmt"
"net/http"
"reflect"
"strings"
"github.com/caddyserver/caddy/v2/caddyconfig/httpcaddyfile"
@ -23,15 +25,16 @@ import (
)
func init() {
httpcaddyfile.RegisterHandlerDirective("header", parseCaddyfile)
httpcaddyfile.RegisterHandlerDirective("request_header", parseReqHdrCaddyfile)
httpcaddyfile.RegisterDirective("header", parseCaddyfile)
httpcaddyfile.RegisterDirective("request_header", parseReqHdrCaddyfile)
}
// parseCaddyfile sets up the handler for response headers from
// Caddyfile tokens. Syntax:
//
// header [<matcher>] [[+|-]<field> [<value|regexp>] [<replacement>]] {
// header [<matcher>] [[+|-|?]<field> [<value|regexp>] [<replacement>]] {
// [+]<field> [<value|regexp> [<replacement>]]
// ?<field> <default_value>
// -<field>
// [defer]
// }
@ -39,17 +42,23 @@ func init() {
// Either a block can be opened or a single header field can be configured
// in the first line, but not both in the same directive. Header operations
// are deferred to write-time if any headers are being deleted or if the
// 'defer' subdirective is used.
func parseCaddyfile(h httpcaddyfile.Helper) (caddyhttp.MiddlewareHandler, error) {
hdr := new(Handler)
// 'defer' subdirective is used. + appends a header value, - deletes a field,
// and ? conditionally sets a value only if the header field is not already
// set.
func parseCaddyfile(h httpcaddyfile.Helper) ([]httpcaddyfile.ConfigValue, error) {
matcherSet, err := h.ExtractMatcherSet()
if err != nil {
return nil, err
}
makeResponseOps := func() {
if hdr.Response == nil {
hdr.Response = &RespHeaderOps{
HeaderOps: new(HeaderOps),
}
makeHandler := func() Handler {
return Handler{
Response: &RespHeaderOps{
HeaderOps: &HeaderOps{},
},
}
}
handler, handlerWithRequire := makeHandler(), makeHandler()
for h.Next() {
// first see if headers are in the initial line
@ -64,10 +73,18 @@ func parseCaddyfile(h httpcaddyfile.Helper) (caddyhttp.MiddlewareHandler, error)
if h.NextArg() {
replacement = h.Val()
}
makeResponseOps()
CaddyfileHeaderOp(hdr.Response.HeaderOps, field, value, replacement)
if len(hdr.Response.HeaderOps.Delete) > 0 {
hdr.Response.Deferred = true
err := applyHeaderOp(
handler.Response.HeaderOps,
handler.Response,
field,
value,
replacement,
)
if err != nil {
return nil, h.Err(err.Error())
}
if len(handler.Response.HeaderOps.Delete) > 0 {
handler.Response.Deferred = true
}
}
@ -75,12 +92,18 @@ func parseCaddyfile(h httpcaddyfile.Helper) (caddyhttp.MiddlewareHandler, error)
for h.NextBlock(0) {
field := h.Val()
if field == "defer" {
hdr.Response.Deferred = true
handler.Response.Deferred = true
continue
}
if hasArgs {
return nil, h.Err("cannot specify headers in both arguments and block")
return nil, h.Err("cannot specify headers in both arguments and block") // because it would be weird
}
// sometimes it is habitual for users to suffix a field name with a colon,
// as if they were writing a curl command or something; see
// https://caddy.community/t/v2-reverse-proxy-please-add-cors-example-to-the-docs/7349/19
field = strings.TrimSuffix(field, ":")
var value, replacement string
if h.NextArg() {
value = h.Val()
@ -88,15 +111,34 @@ func parseCaddyfile(h httpcaddyfile.Helper) (caddyhttp.MiddlewareHandler, error)
if h.NextArg() {
replacement = h.Val()
}
makeResponseOps()
CaddyfileHeaderOp(hdr.Response.HeaderOps, field, value, replacement)
if len(hdr.Response.HeaderOps.Delete) > 0 {
hdr.Response.Deferred = true
handlerToUse := handler
if strings.HasPrefix(field, "?") {
handlerToUse = handlerWithRequire
}
err := applyHeaderOp(
handlerToUse.Response.HeaderOps,
handlerToUse.Response,
field,
value,
replacement,
)
if err != nil {
return nil, h.Err(err.Error())
}
}
}
return hdr, nil
var configValues []httpcaddyfile.ConfigValue
if !reflect.DeepEqual(handler, makeHandler()) {
configValues = append(configValues, h.NewRoute(matcherSet, handler)...)
}
if !reflect.DeepEqual(handlerWithRequire, makeHandler()) {
configValues = append(configValues, h.NewRoute(matcherSet, handlerWithRequire)...)
}
return configValues, nil
}
// parseReqHdrCaddyfile sets up the handler for request headers
@ -104,17 +146,27 @@ func parseCaddyfile(h httpcaddyfile.Helper) (caddyhttp.MiddlewareHandler, error)
//
// request_header [<matcher>] [[+|-]<field> [<value|regexp>] [<replacement>]]
//
func parseReqHdrCaddyfile(h httpcaddyfile.Helper) (caddyhttp.MiddlewareHandler, error) {
hdr := new(Handler)
func parseReqHdrCaddyfile(h httpcaddyfile.Helper) ([]httpcaddyfile.ConfigValue, error) {
matcherSet, err := h.ExtractMatcherSet()
if err != nil {
return nil, err
}
configValues := []httpcaddyfile.ConfigValue{}
for h.Next() {
if !h.NextArg() {
return nil, h.ArgErr()
}
field := h.Val()
hdr := Handler{
Request: &HeaderOps{},
}
// sometimes it is habitual for users to suffix a field name with a colon,
// as if they were writing a curl command or something; see
// https://caddy.community/t/v2-reverse-proxy-please-add-cors-example-to-the-docs/7349
// https://caddy.community/t/v2-reverse-proxy-please-add-cors-example-to-the-docs/7349/19
field = strings.TrimSuffix(field, ":")
var value, replacement string
@ -131,13 +183,17 @@ func parseReqHdrCaddyfile(h httpcaddyfile.Helper) (caddyhttp.MiddlewareHandler,
if hdr.Request == nil {
hdr.Request = new(HeaderOps)
}
CaddyfileHeaderOp(hdr.Request, field, value, replacement)
if err := CaddyfileHeaderOp(hdr.Request, field, value, replacement); err != nil {
return nil, h.Err(err.Error())
}
configValues = append(configValues, h.NewRoute(matcherSet, hdr)...)
if h.NextArg() {
return nil, h.ArgErr()
}
}
return hdr, nil
return configValues, nil
}
// CaddyfileHeaderOp applies a new header operation according to
@ -148,32 +204,59 @@ func parseReqHdrCaddyfile(h httpcaddyfile.Helper) (caddyhttp.MiddlewareHandler,
// will be used to search and then replacement will be used to
// complete the substring replacement; in that case, any + or -
// prefix to field will be ignored.
func CaddyfileHeaderOp(ops *HeaderOps, field, value, replacement string) {
if strings.HasPrefix(field, "+") {
func CaddyfileHeaderOp(ops *HeaderOps, field, value, replacement string) error {
return applyHeaderOp(ops, nil, field, value, replacement)
}
func applyHeaderOp(ops *HeaderOps, respHeaderOps *RespHeaderOps, field, value, replacement string) error {
switch {
case strings.HasPrefix(field, "+"): // append
if ops.Add == nil {
ops.Add = make(http.Header)
}
ops.Add.Set(field[1:], value)
} else if strings.HasPrefix(field, "-") {
case strings.HasPrefix(field, "-"): // delete
ops.Delete = append(ops.Delete, field[1:])
} else {
if replacement == "" {
if ops.Set == nil {
ops.Set = make(http.Header)
}
ops.Set.Set(field, value)
} else {
if ops.Replace == nil {
ops.Replace = make(map[string][]Replacement)
}
field = strings.TrimLeft(field, "+-")
ops.Replace[field] = append(
ops.Replace[field],
Replacement{
SearchRegexp: value,
Replace: replacement,
},
)
if respHeaderOps != nil {
respHeaderOps.Deferred = true
}
case strings.HasPrefix(field, "?"): // default (conditional on not existing) - response headers only
if respHeaderOps == nil {
return fmt.Errorf("%v: the default header modifier ('?') can only be used on response headers; for conditional manipulation of request headers, use matchers", field)
}
if respHeaderOps.Require == nil {
respHeaderOps.Require = &caddyhttp.ResponseMatcher{
Headers: make(http.Header),
}
}
field = strings.TrimPrefix(field, "?")
respHeaderOps.Require.Headers[field] = nil
if respHeaderOps.Set == nil {
respHeaderOps.Set = make(http.Header)
}
respHeaderOps.Set.Set(field, value)
case replacement != "": // replace
if ops.Replace == nil {
ops.Replace = make(map[string][]Replacement)
}
field = strings.TrimLeft(field, "+-?")
ops.Replace[field] = append(
ops.Replace[field],
Replacement{
SearchRegexp: value,
Replace: replacement,
},
)
default: // set (overwrite)
if ops.Set == nil {
ops.Set = make(http.Header)
}
ops.Set.Set(field, value)
}
return nil
}

View file

@ -14,8 +14,197 @@
package headers
import "testing"
import (
"context"
"fmt"
"net/http"
"net/http/httptest"
"reflect"
"testing"
func TestReqHeaders(t *testing.T) {
// TODO: write tests
"github.com/caddyserver/caddy/v2"
"github.com/caddyserver/caddy/v2/modules/caddyhttp"
)
func TestHandler(t *testing.T) {
for i, tc := range []struct {
handler Handler
reqHeader http.Header
respHeader http.Header
respStatusCode int
expectedReqHeader http.Header
expectedRespHeader http.Header
}{
{
handler: Handler{
Request: &HeaderOps{
Add: http.Header{
"Expose-Secrets": []string{"always"},
},
},
},
reqHeader: http.Header{
"Expose-Secrets": []string{"i'm serious"},
},
expectedReqHeader: http.Header{
"Expose-Secrets": []string{"i'm serious", "always"},
},
},
{
handler: Handler{
Request: &HeaderOps{
Set: http.Header{
"Who-Wins": []string{"batman"},
},
},
},
reqHeader: http.Header{
"Who-Wins": []string{"joker"},
},
expectedReqHeader: http.Header{
"Who-Wins": []string{"batman"},
},
},
{
handler: Handler{
Request: &HeaderOps{
Delete: []string{"Kick-Me"},
},
},
reqHeader: http.Header{
"Kick-Me": []string{"if you can"},
"Keep-Me": []string{"i swear i'm innocent"},
},
expectedReqHeader: http.Header{
"Keep-Me": []string{"i swear i'm innocent"},
},
},
{
handler: Handler{
Request: &HeaderOps{
Replace: map[string][]Replacement{
"Best-Server": {
Replacement{
Search: "NGINX",
Replace: "the Caddy web server",
},
Replacement{
SearchRegexp: `Apache(\d+)`,
Replace: "Caddy",
},
},
},
},
},
reqHeader: http.Header{
"Best-Server": []string{"it's NGINX, undoubtedly", "I love Apache2"},
},
expectedReqHeader: http.Header{
"Best-Server": []string{"it's the Caddy web server, undoubtedly", "I love Caddy"},
},
},
{
handler: Handler{
Response: &RespHeaderOps{
Require: &caddyhttp.ResponseMatcher{
Headers: http.Header{
"Cache-Control": nil,
},
},
HeaderOps: &HeaderOps{
Add: http.Header{
"Cache-Control": []string{"no-cache"},
},
},
},
},
respHeader: http.Header{},
expectedRespHeader: http.Header{
"Cache-Control": []string{"no-cache"},
},
},
{
handler: Handler{
Response: &RespHeaderOps{
Require: &caddyhttp.ResponseMatcher{
Headers: http.Header{
"Cache-Control": []string{"no-cache"},
},
},
HeaderOps: &HeaderOps{
Delete: []string{"Cache-Control"},
},
},
},
respHeader: http.Header{
"Cache-Control": []string{"no-cache"},
},
expectedRespHeader: http.Header{},
},
{
handler: Handler{
Response: &RespHeaderOps{
Require: &caddyhttp.ResponseMatcher{
StatusCode: []int{5},
},
HeaderOps: &HeaderOps{
Add: http.Header{
"Fail-5xx": []string{"true"},
},
},
},
},
respStatusCode: 503,
respHeader: http.Header{},
expectedRespHeader: http.Header{
"Fail-5xx": []string{"true"},
},
},
} {
rr := httptest.NewRecorder()
req := &http.Request{Header: tc.reqHeader}
repl := caddy.NewReplacer()
ctx := context.WithValue(req.Context(), caddy.ReplacerCtxKey, repl)
req = req.WithContext(ctx)
tc.handler.Provision(caddy.Context{})
next := nextHandler(func(w http.ResponseWriter, r *http.Request) error {
for k, hdrs := range tc.respHeader {
for _, v := range hdrs {
w.Header().Add(k, v)
}
}
status := 200
if tc.respStatusCode != 0 {
status = tc.respStatusCode
}
w.WriteHeader(status)
if tc.expectedReqHeader != nil && !reflect.DeepEqual(r.Header, tc.expectedReqHeader) {
return fmt.Errorf("expected request header %v, got %v", tc.expectedReqHeader, r.Header)
}
return nil
})
if err := tc.handler.ServeHTTP(rr, req, next); err != nil {
t.Errorf("Test %d: %w", i, err)
continue
}
actual := rr.Header()
if tc.expectedRespHeader != nil && !reflect.DeepEqual(actual, tc.expectedRespHeader) {
t.Errorf("Test %d: expected response header %v, got %v", i, tc.expectedRespHeader, actual)
continue
}
}
}
type nextHandler func(http.ResponseWriter, *http.Request) error
func (f nextHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) error {
return f(w, r)
}

View file

@ -59,6 +59,8 @@ func parseCaddyfile(h httpcaddyfile.Helper) (caddyhttp.MiddlewareHandler, error)
return nil, h.ArgErr()
}
for innerNesting := h.Nesting(); h.NextBlock(innerNesting); {
var err error
// include current token, which we treat as an argument here
args := []string{h.Val()}
args = append(args, h.RemainingArgs()...)
@ -66,16 +68,21 @@ func parseCaddyfile(h httpcaddyfile.Helper) (caddyhttp.MiddlewareHandler, error)
if handler.Headers == nil {
handler.Headers = new(HeaderConfig)
}
switch len(args) {
case 1:
headers.CaddyfileHeaderOp(&handler.Headers.HeaderOps, args[0], "", "")
err = headers.CaddyfileHeaderOp(&handler.Headers.HeaderOps, args[0], "", "")
case 2:
headers.CaddyfileHeaderOp(&handler.Headers.HeaderOps, args[0], args[1], "")
err = headers.CaddyfileHeaderOp(&handler.Headers.HeaderOps, args[0], args[1], "")
case 3:
headers.CaddyfileHeaderOp(&handler.Headers.HeaderOps, args[0], args[1], args[2])
err = headers.CaddyfileHeaderOp(&handler.Headers.HeaderOps, args[0], args[1], args[2])
default:
return nil, h.ArgErr()
}
if err != nil {
return nil, h.Err(err.Error())
}
}
case "GET", "HEAD":

View file

@ -480,6 +480,8 @@ func (h *Handler) UnmarshalCaddyfile(d *caddyfile.Dispenser) error {
h.BufferRequests = true
case "header_up":
var err error
if h.Headers == nil {
h.Headers = new(headers.Handler)
}
@ -487,18 +489,25 @@ func (h *Handler) UnmarshalCaddyfile(d *caddyfile.Dispenser) error {
h.Headers.Request = new(headers.HeaderOps)
}
args := d.RemainingArgs()
switch len(args) {
case 1:
headers.CaddyfileHeaderOp(h.Headers.Request, args[0], "", "")
err = headers.CaddyfileHeaderOp(h.Headers.Request, args[0], "", "")
case 2:
headers.CaddyfileHeaderOp(h.Headers.Request, args[0], args[1], "")
err = headers.CaddyfileHeaderOp(h.Headers.Request, args[0], args[1], "")
case 3:
headers.CaddyfileHeaderOp(h.Headers.Request, args[0], args[1], args[2])
err = headers.CaddyfileHeaderOp(h.Headers.Request, args[0], args[1], args[2])
default:
return d.ArgErr()
}
if err != nil {
return d.Err(err.Error())
}
case "header_down":
var err error
if h.Headers == nil {
h.Headers = new(headers.Handler)
}
@ -510,15 +519,19 @@ func (h *Handler) UnmarshalCaddyfile(d *caddyfile.Dispenser) error {
args := d.RemainingArgs()
switch len(args) {
case 1:
headers.CaddyfileHeaderOp(h.Headers.Response.HeaderOps, args[0], "", "")
err = headers.CaddyfileHeaderOp(h.Headers.Response.HeaderOps, args[0], "", "")
case 2:
headers.CaddyfileHeaderOp(h.Headers.Response.HeaderOps, args[0], args[1], "")
err = headers.CaddyfileHeaderOp(h.Headers.Response.HeaderOps, args[0], args[1], "")
case 3:
headers.CaddyfileHeaderOp(h.Headers.Response.HeaderOps, args[0], args[1], args[2])
err = headers.CaddyfileHeaderOp(h.Headers.Response.HeaderOps, args[0], args[1], args[2])
default:
return d.ArgErr()
}
if err != nil {
return d.Err(err.Error())
}
case "transport":
if !d.NextArg() {
return d.ArgErr()