Update vendor for prometheus deps

vendor/github.com/prometheus/common/config/headers.go

@@ -0,0 +1,140 @@
+// 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 (
+	"encoding/json"
+	"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"`
+	dir     string
+}
+
+// Header represents the configuration for a single HTTP header.
+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"`
+}
+
+func (h Headers) MarshalJSON() ([]byte, error) {
+	// Inline the Headers map when serializing JSON because json encoder doesn't support "inline" directive.
+	return json.Marshal(h.Headers)
+}
+
+// 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()
+	}
+}