Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Add HTTP headers support to common HTTP client. #416

Merged
merged 1 commit into from
Apr 29, 2024
Merged
Show file tree
Hide file tree
Changes from all commits
Commits
File filter

Filter by extension

Filter by extension

Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
4 changes: 2 additions & 2 deletions config/config.go
Original file line number Diff line number Diff line change
Expand Up @@ -60,9 +60,9 @@ func (s Secret) MarshalJSON() ([]byte, error) {
return json.Marshal(secretToken)
}

type Header map[string][]Secret
type ProxyHeader map[string][]Secret

func (h *Header) HTTPHeader() http.Header {
func (h *ProxyHeader) HTTPHeader() http.Header {
if h == nil || *h == nil {
return nil
}
Expand Down
44 changes: 22 additions & 22 deletions config/config_test.go
Original file line number Diff line number Diff line change
Expand Up @@ -83,11 +83,11 @@ func TestJSONMarshalSecret(t *testing.T) {

func TestHeaderHTTPHeader(t *testing.T) {
testcases := map[string]struct {
header Header
header ProxyHeader
expected http.Header
}{
"basic": {
header: Header{
header: ProxyHeader{
"single": []Secret{"v1"},
"multi": []Secret{"v1", "v2"},
"empty": []Secret{},
Expand Down Expand Up @@ -119,32 +119,32 @@ func TestHeaderHTTPHeader(t *testing.T) {
func TestHeaderYamlUnmarshal(t *testing.T) {
testcases := map[string]struct {
input string
expected Header
expected ProxyHeader
}{
"void": {
input: ``,
},
"simple": {
input: "single:\n- a\n",
expected: Header{"single": []Secret{"a"}},
expected: ProxyHeader{"single": []Secret{"a"}},
},
"multi": {
input: "multi:\n- a\n- b\n",
expected: Header{"multi": []Secret{"a", "b"}},
expected: ProxyHeader{"multi": []Secret{"a", "b"}},
},
"empty": {
input: "{}",
expected: Header{},
expected: ProxyHeader{},
},
"empty value": {
input: "empty:\n",
expected: Header{"empty": nil},
expected: ProxyHeader{"empty": nil},
},
}

for name, tc := range testcases {
t.Run(name, func(t *testing.T) {
var actual Header
var actual ProxyHeader
err := yaml.Unmarshal([]byte(tc.input), &actual)
if err != nil {
t.Fatalf("error unmarshaling %s: %s", tc.input, err)
Expand All @@ -158,23 +158,23 @@ func TestHeaderYamlUnmarshal(t *testing.T) {

func TestHeaderYamlMarshal(t *testing.T) {
testcases := map[string]struct {
input Header
input ProxyHeader
expected []byte
}{
"void": {
input: nil,
expected: []byte("{}\n"),
},
"simple": {
input: Header{"single": []Secret{"a"}},
input: ProxyHeader{"single": []Secret{"a"}},
expected: []byte("single:\n- <secret>\n"),
},
"multi": {
input: Header{"multi": []Secret{"a", "b"}},
input: ProxyHeader{"multi": []Secret{"a", "b"}},
expected: []byte("multi:\n- <secret>\n- <secret>\n"),
},
"empty": {
input: Header{"empty": nil},
input: ProxyHeader{"empty": nil},
expected: []byte("empty: []\n"),
},
}
Expand All @@ -195,32 +195,32 @@ func TestHeaderYamlMarshal(t *testing.T) {
func TestHeaderJsonUnmarshal(t *testing.T) {
testcases := map[string]struct {
input string
expected Header
expected ProxyHeader
}{
"void": {
input: `null`,
},
"simple": {
input: `{"single": ["a"]}`,
expected: Header{"single": []Secret{"a"}},
expected: ProxyHeader{"single": []Secret{"a"}},
},
"multi": {
input: `{"multi": ["a", "b"]}`,
expected: Header{"multi": []Secret{"a", "b"}},
expected: ProxyHeader{"multi": []Secret{"a", "b"}},
},
"empty": {
input: `{}`,
expected: Header{},
expected: ProxyHeader{},
},
"empty value": {
input: `{"empty":null}`,
expected: Header{"empty": nil},
expected: ProxyHeader{"empty": nil},
},
}

for name, tc := range testcases {
t.Run(name, func(t *testing.T) {
var actual Header
var actual ProxyHeader
err := json.Unmarshal([]byte(tc.input), &actual)
if err != nil {
t.Fatalf("error unmarshaling %s: %s", tc.input, err)
Expand All @@ -234,23 +234,23 @@ func TestHeaderJsonUnmarshal(t *testing.T) {

func TestHeaderJsonMarshal(t *testing.T) {
testcases := map[string]struct {
input Header
input ProxyHeader
expected []byte
}{
"void": {
input: nil,
expected: []byte("null"),
},
"simple": {
input: Header{"single": []Secret{"a"}},
input: ProxyHeader{"single": []Secret{"a"}},
expected: []byte("{\"single\":[\"\\u003csecret\\u003e\"]}"),
},
"multi": {
input: Header{"multi": []Secret{"a", "b"}},
input: ProxyHeader{"multi": []Secret{"a", "b"}},
expected: []byte("{\"multi\":[\"\\u003csecret\\u003e\",\"\\u003csecret\\u003e\"]}"),
},
"empty": {
input: Header{"empty": nil},
input: ProxyHeader{"empty": nil},
expected: []byte(`{"empty":null}`),
},
}
Expand Down
134 changes: 134 additions & 0 deletions config/headers.go
Original file line number Diff line number Diff line change
@@ -0,0 +1,134 @@
// Copyright 2024 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

// This package no longer handles safe yaml parsing. In order to
// ensure correct yaml unmarshalling, use "yaml.UnmarshalStrict()".

package config

import (
"fmt"
"net/http"
"os"
"strings"
)

// reservedHeaders that change the connection, are set by Prometheus, or can
// be changed otherwise.
var reservedHeaders = map[string]struct{}{
"Authorization": {},
"Host": {},
"Content-Encoding": {},
"Content-Length": {},
"Content-Type": {},
"User-Agent": {},
"Connection": {},
"Keep-Alive": {},
"Proxy-Authenticate": {},
"Proxy-Authorization": {},
"Www-Authenticate": {},
"Accept-Encoding": {},
"X-Prometheus-Remote-Write-Version": {},
"X-Prometheus-Remote-Read-Version": {},
"X-Prometheus-Scrape-Timeout-Seconds": {},

// Added by SigV4.
"X-Amz-Date": {},
"X-Amz-Security-Token": {},
"X-Amz-Content-Sha256": {},
}

// Headers represents the configuration for HTTP headers.
type Headers struct {
Headers map[string]Header `yaml:",inline" json:",inline"`
dir string
}

// Headers represents the configuration for HTTP headers.
type Header struct {
Values []string `yaml:"values,omitempty" json:"values,omitempty"`
Secrets []Secret `yaml:"secrets,omitempty" json:"secrets,omitempty"`
Files []string `yaml:"files,omitempty" json:"files,omitempty"`
}

// SetDirectory records the directory to make headers file relative to the
// configuration file.
func (h *Headers) SetDirectory(dir string) {
if h == nil {
return
}
h.dir = dir
}

// Validate validates the Headers config.
func (h *Headers) Validate() error {
for n, header := range h.Headers {
if _, ok := reservedHeaders[http.CanonicalHeaderKey(n)]; ok {
return fmt.Errorf("setting header %q is not allowed", http.CanonicalHeaderKey(n))
}
for _, v := range header.Files {
f := JoinDir(h.dir, v)
_, err := os.ReadFile(f)
if err != nil {
return fmt.Errorf("unable to read header %q from file %s: %w", http.CanonicalHeaderKey(n), f, err)
}
}
}
return nil
}

// NewHeadersRoundTripper returns a RoundTripper that sets HTTP headers on
// requests as configured.
func NewHeadersRoundTripper(config *Headers, next http.RoundTripper) http.RoundTripper {
if len(config.Headers) == 0 {
return next
}
return &headersRoundTripper{
config: config,
next: next,
}
}

type headersRoundTripper struct {
next http.RoundTripper
config *Headers
}

// RoundTrip implements http.RoundTripper.
func (rt *headersRoundTripper) RoundTrip(req *http.Request) (*http.Response, error) {
req = cloneRequest(req)
for n, h := range rt.config.Headers {
for _, v := range h.Values {
req.Header.Add(n, v)
}
for _, v := range h.Secrets {
req.Header.Add(n, string(v))
}
for _, v := range h.Files {
f := JoinDir(rt.config.dir, v)
b, err := os.ReadFile(f)
if err != nil {
return nil, fmt.Errorf("unable to read headers file %s: %w", f, err)
}
req.Header.Add(n, strings.TrimSpace(string(b)))
}
}
return rt.next.RoundTrip(req)
}

// CloseIdleConnections implements closeIdler.
func (rt *headersRoundTripper) CloseIdleConnections() {
if ci, ok := rt.next.(closeIdler); ok {
ci.CloseIdleConnections()
}
}
31 changes: 31 additions & 0 deletions config/headers_test.go
Original file line number Diff line number Diff line change
@@ -0,0 +1,31 @@
// Copyright 2024 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

// This package no longer handles safe yaml parsing. In order to
// ensure correct yaml unmarshalling, use "yaml.UnmarshalStrict()".

package config

import (
"net/http"
"testing"
)

func TestReservedHeaders(t *testing.T) {
for k := range reservedHeaders {
l := http.CanonicalHeaderKey(k)
if k != l {
t.Errorf("reservedHeaders keys should be lowercase: got %q, expected %q", k, http.CanonicalHeaderKey(k))
}
}
}
15 changes: 14 additions & 1 deletion config/http_config.go
Original file line number Diff line number Diff line change
Expand Up @@ -311,6 +311,9 @@ type HTTPClientConfig struct {
EnableHTTP2 bool `yaml:"enable_http2" json:"enable_http2"`
// Proxy configuration.
ProxyConfig `yaml:",inline"`
// HTTPHeaders specify headers to inject in the requests. Those headers
// could be marshalled back to the users.
HTTPHeaders *Headers `yaml:"http_headers" json:"http_headers"`
Copy link
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Should we at least make it omit empty?

}

// SetDirectory joins any relative file paths with dir.
Expand All @@ -322,6 +325,7 @@ func (c *HTTPClientConfig) SetDirectory(dir string) {
c.BasicAuth.SetDirectory(dir)
c.Authorization.SetDirectory(dir)
c.OAuth2.SetDirectory(dir)
c.HTTPHeaders.SetDirectory(dir)
c.BearerTokenFile = JoinDir(dir, c.BearerTokenFile)
}

Expand Down Expand Up @@ -388,6 +392,11 @@ func (c *HTTPClientConfig) Validate() error {
if err := c.ProxyConfig.Validate(); err != nil {
return err
}
if c.HTTPHeaders != nil {
if err := c.HTTPHeaders.Validate(); err != nil {
return err
}
}
return nil
}

Expand Down Expand Up @@ -572,6 +581,10 @@ func NewRoundTripperFromConfig(cfg HTTPClientConfig, name string, optFuncs ...HT
rt = NewOAuth2RoundTripper(cfg.OAuth2, rt, &opts)
}

if cfg.HTTPHeaders != nil {
rt = NewHeadersRoundTripper(cfg.HTTPHeaders, rt)
}

if opts.userAgent != "" {
rt = NewUserAgentRoundTripper(opts.userAgent, rt)
}
Expand Down Expand Up @@ -1236,7 +1249,7 @@ type ProxyConfig struct {
// proxies during CONNECT requests. Assume that at least _some_ of
// these headers are going to contain secrets and use Secret as the
// value type instead of string.
ProxyConnectHeader Header `yaml:"proxy_connect_header,omitempty" json:"proxy_connect_header,omitempty"`
ProxyConnectHeader ProxyHeader `yaml:"proxy_connect_header,omitempty" json:"proxy_connect_header,omitempty"`

proxyFunc func(*http.Request) (*url.URL, error)
}
Expand Down
Loading
Loading