mirror of
https://github.com/prometheus/prometheus.git
synced 2024-12-28 15:09:39 -08:00
65 lines
1.9 KiB
Go
65 lines
1.9 KiB
Go
// Copyright 2014 Google Inc. All Rights Reserved.
|
|
//
|
|
// 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.
|
|
|
|
// Package internal provides support for the cloud packages.
|
|
//
|
|
// Users should not import this package directly.
|
|
package internal
|
|
|
|
import (
|
|
"fmt"
|
|
"net/http"
|
|
)
|
|
|
|
const userAgent = "gcloud-golang/0.1"
|
|
|
|
// Transport is an http.RoundTripper that appends Google Cloud client's
|
|
// user-agent to the original request's user-agent header.
|
|
type Transport struct {
|
|
// TODO(bradfitz): delete internal.Transport. It's too wrappy for what it does.
|
|
// Do User-Agent some other way.
|
|
|
|
// Base is the actual http.RoundTripper
|
|
// requests will use. It must not be nil.
|
|
Base http.RoundTripper
|
|
}
|
|
|
|
// RoundTrip appends a user-agent to the existing user-agent
|
|
// header and delegates the request to the base http.RoundTripper.
|
|
func (t *Transport) RoundTrip(req *http.Request) (*http.Response, error) {
|
|
req = cloneRequest(req)
|
|
ua := req.Header.Get("User-Agent")
|
|
if ua == "" {
|
|
ua = userAgent
|
|
} else {
|
|
ua = fmt.Sprintf("%s %s", ua, userAgent)
|
|
}
|
|
req.Header.Set("User-Agent", ua)
|
|
return t.Base.RoundTrip(req)
|
|
}
|
|
|
|
// cloneRequest returns a clone of the provided *http.Request.
|
|
// The clone is a shallow copy of the struct and its Header map.
|
|
func cloneRequest(r *http.Request) *http.Request {
|
|
// shallow copy of the struct
|
|
r2 := new(http.Request)
|
|
*r2 = *r
|
|
// deep copy of the Header
|
|
r2.Header = make(http.Header)
|
|
for k, s := range r.Header {
|
|
r2.Header[k] = s
|
|
}
|
|
return r2
|
|
}
|