Golang proactively prints this error `http: proxy error: context canceled` when a request arrived to the current deployment and redirected to another deployment in a federated setup. Since this error can confuse users, this commit will just hide it.
180 lines
4.8 KiB
Go
180 lines
4.8 KiB
Go
/*
|
|
* MinIO Cloud Storage, (C) 2018-2019 MinIO, Inc.
|
|
*
|
|
* 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 handlers
|
|
|
|
import (
|
|
"context"
|
|
"net"
|
|
"net/http"
|
|
"net/http/httputil"
|
|
"net/url"
|
|
"strings"
|
|
"time"
|
|
)
|
|
|
|
const defaultFlushInterval = time.Duration(100) * time.Millisecond
|
|
|
|
// Forwarder forwards all incoming HTTP requests to configured transport.
|
|
type Forwarder struct {
|
|
RoundTripper http.RoundTripper
|
|
PassHost bool
|
|
Logger func(error)
|
|
|
|
// internal variables
|
|
rewriter *headerRewriter
|
|
}
|
|
|
|
// NewForwarder creates an instance of Forwarder based on the provided list of configuration options
|
|
func NewForwarder(f *Forwarder) *Forwarder {
|
|
f.rewriter = &headerRewriter{}
|
|
if f.RoundTripper == nil {
|
|
f.RoundTripper = http.DefaultTransport
|
|
}
|
|
|
|
return f
|
|
}
|
|
|
|
// ServeHTTP forwards HTTP traffic using the configured transport
|
|
func (f *Forwarder) ServeHTTP(w http.ResponseWriter, inReq *http.Request) {
|
|
outReq := new(http.Request)
|
|
*outReq = *inReq // includes shallow copies of maps, but we handle this in Director
|
|
|
|
revproxy := httputil.ReverseProxy{
|
|
Director: func(req *http.Request) {
|
|
f.modifyRequest(req, inReq.URL)
|
|
},
|
|
Transport: f.RoundTripper,
|
|
FlushInterval: defaultFlushInterval,
|
|
ErrorHandler: f.customErrHandler,
|
|
}
|
|
revproxy.ServeHTTP(w, outReq)
|
|
}
|
|
|
|
// customErrHandler is originally implemented to avoid having the following error
|
|
// `http: proxy error: context canceled` printed by Golang
|
|
func (f *Forwarder) customErrHandler(w http.ResponseWriter, r *http.Request, err error) {
|
|
if f.Logger != nil && err != context.Canceled {
|
|
f.Logger(err)
|
|
}
|
|
w.WriteHeader(http.StatusBadGateway)
|
|
}
|
|
|
|
func (f *Forwarder) getURLFromRequest(req *http.Request) *url.URL {
|
|
// If the Request was created by Go via a real HTTP request, RequestURI will
|
|
// contain the original query string. If the Request was created in code, RequestURI
|
|
// will be empty, and we will use the URL object instead
|
|
u := req.URL
|
|
if req.RequestURI != "" {
|
|
parsedURL, err := url.ParseRequestURI(req.RequestURI)
|
|
if err == nil {
|
|
u = parsedURL
|
|
}
|
|
}
|
|
return u
|
|
}
|
|
|
|
// copyURL provides update safe copy by avoiding shallow copying User field
|
|
func copyURL(i *url.URL) *url.URL {
|
|
out := *i
|
|
if i.User != nil {
|
|
out.User = &(*i.User)
|
|
}
|
|
return &out
|
|
}
|
|
|
|
// Modify the request to handle the target URL
|
|
func (f *Forwarder) modifyRequest(outReq *http.Request, target *url.URL) {
|
|
outReq.URL = copyURL(outReq.URL)
|
|
outReq.URL.Scheme = target.Scheme
|
|
outReq.URL.Host = target.Host
|
|
|
|
u := f.getURLFromRequest(outReq)
|
|
|
|
outReq.URL.Path = u.Path
|
|
outReq.URL.RawPath = u.RawPath
|
|
outReq.URL.RawQuery = u.RawQuery
|
|
outReq.RequestURI = "" // Outgoing request should not have RequestURI
|
|
|
|
// Do not pass client Host header unless requested.
|
|
if !f.PassHost {
|
|
outReq.Host = target.Host
|
|
}
|
|
|
|
// TODO: only supports HTTP 1.1 for now.
|
|
outReq.Proto = "HTTP/1.1"
|
|
outReq.ProtoMajor = 1
|
|
outReq.ProtoMinor = 1
|
|
|
|
f.rewriter.Rewrite(outReq)
|
|
|
|
// Disable closeNotify when method GET for http pipelining
|
|
if outReq.Method == http.MethodGet {
|
|
quietReq := outReq.WithContext(context.Background())
|
|
*outReq = *quietReq
|
|
}
|
|
}
|
|
|
|
// headerRewriter is responsible for removing hop-by-hop headers and setting forwarding headers
|
|
type headerRewriter struct{}
|
|
|
|
// Clean up IP in case if it is ipv6 address and it has {zone} information in it, like
|
|
// "[fe80::d806:a55d:eb1b:49cc%vEthernet (vmxnet3 Ethernet Adapter - Virtual Switch)]:64692"
|
|
func ipv6fix(clientIP string) string {
|
|
return strings.Split(clientIP, "%")[0]
|
|
}
|
|
|
|
func (rw *headerRewriter) Rewrite(req *http.Request) {
|
|
if clientIP, _, err := net.SplitHostPort(req.RemoteAddr); err == nil {
|
|
clientIP = ipv6fix(clientIP)
|
|
if req.Header.Get(xRealIP) == "" {
|
|
req.Header.Set(xRealIP, clientIP)
|
|
}
|
|
}
|
|
|
|
xfProto := req.Header.Get(xForwardedProto)
|
|
if xfProto == "" {
|
|
if req.TLS != nil {
|
|
req.Header.Set(xForwardedProto, "https")
|
|
} else {
|
|
req.Header.Set(xForwardedProto, "http")
|
|
}
|
|
}
|
|
|
|
if xfPort := req.Header.Get(xForwardedPort); xfPort == "" {
|
|
req.Header.Set(xForwardedPort, forwardedPort(req))
|
|
}
|
|
|
|
if xfHost := req.Header.Get(xForwardedHost); xfHost == "" && req.Host != "" {
|
|
req.Header.Set(xForwardedHost, req.Host)
|
|
}
|
|
}
|
|
|
|
func forwardedPort(req *http.Request) string {
|
|
if req == nil {
|
|
return ""
|
|
}
|
|
|
|
if _, port, err := net.SplitHostPort(req.Host); err == nil && port != "" {
|
|
return port
|
|
}
|
|
|
|
if req.TLS != nil {
|
|
return "443"
|
|
}
|
|
|
|
return "80"
|
|
}
|