// Copyright 2011 The Go Authors. All rights reserved. // Use of this source code is governed by a BSD-style // license that can be found in the LICENSE file. // Reverse proxy tests. package httputil import ( "bufio" "bytes" "context" "errors" "fmt" "io" "log" "net/http" "net/http/httptest" "net/http/internal/ascii" "net/url" "os" "reflect" "sort" "strconv" "strings" "sync" "testing" "time" ) const fakeHopHeader = "X-Fake-Hop-Header-For-Test" func init() { inOurTests = true hopHeaders = append(hopHeaders, fakeHopHeader) } func TestReverseProxy(t *testing.T) { const backendResponse = "I am the backend" const backendStatus = 404 backend := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { if r.Method == "GET" && r.FormValue("mode") == "hangup" { c, _, _ := w.(http.Hijacker).Hijack() c.Close() return } if len(r.TransferEncoding) > 0 { t.Errorf("backend got unexpected TransferEncoding: %v", r.TransferEncoding) } if r.Header.Get("X-Forwarded-For") == "" { t.Errorf("didn't get X-Forwarded-For header") } if c := r.Header.Get("Connection"); c != "" { t.Errorf("handler got Connection header value %q", c) } if c := r.Header.Get("Te"); c != "trailers" { t.Errorf("handler got Te header value %q; want 'trailers'", c) } if c := r.Header.Get("Upgrade"); c != "" { t.Errorf("handler got Upgrade header value %q", c) } if c := r.Header.Get("Proxy-Connection"); c != "" { t.Errorf("handler got Proxy-Connection header value %q", c) } if g, e := r.Host, "some-name"; g != e { t.Errorf("backend got Host header %q, want %q", g, e) } w.Header().Set("Trailers", "not a special header field name") w.Header().Set("Trailer", "X-Trailer") w.Header().Set("X-Foo", "bar") w.Header().Set("Upgrade", "foo") w.Header().Set(fakeHopHeader, "foo") w.Header().Add("X-Multi-Value", "foo") w.Header().Add("X-Multi-Value", "bar") http.SetCookie(w, &http.Cookie{Name: "flavor", Value: "chocolateChip"}) w.WriteHeader(backendStatus) w.Write([]byte(backendResponse)) w.Header().Set("X-Trailer", "trailer_value") w.Header().Set(http.TrailerPrefix+"X-Unannounced-Trailer", "unannounced_trailer_value") })) defer backend.Close() backendURL, err := url.Parse(backend.URL) if err != nil { t.Fatal(err) } proxyHandler := NewSingleHostReverseProxy(backendURL) proxyHandler.ErrorLog = log.New(io.Discard, "", 0) // quiet for tests frontend := httptest.NewServer(proxyHandler) defer frontend.Close() frontendClient := frontend.Client() getReq, _ := http.NewRequest("GET", frontend.URL, nil) getReq.Host = "some-name" getReq.Header.Set("Connection", "close, TE") getReq.Header.Add("Te", "foo") getReq.Header.Add("Te", "bar, trailers") getReq.Header.Set("Proxy-Connection", "should be deleted") getReq.Header.Set("Upgrade", "foo") getReq.Close = true res, err := frontendClient.Do(getReq) if err != nil { t.Fatalf("Get: %v", err) } if g, e := res.StatusCode, backendStatus; g != e { t.Errorf("got res.StatusCode %d; expected %d", g, e) } if g, e := res.Header.Get("X-Foo"), "bar"; g != e { t.Errorf("got X-Foo %q; expected %q", g, e) } if c := res.Header.Get(fakeHopHeader); c != "" { t.Errorf("got %s header value %q", fakeHopHeader, c) } if g, e := res.Header.Get("Trailers"), "not a special header field name"; g != e { t.Errorf("header Trailers = %q; want %q", g, e) } if g, e := len(res.Header["X-Multi-Value"]), 2; g != e { t.Errorf("got %d X-Multi-Value header values; expected %d", g, e) } if g, e := len(res.Header["Set-Cookie"]), 1; g != e { t.Fatalf("got %d SetCookies, want %d", g, e) } if g, e := res.Trailer, (http.Header{"X-Trailer": nil}); !reflect.DeepEqual(g, e) { t.Errorf("before reading body, Trailer = %#v; want %#v", g, e) } if cookie := res.Cookies()[0]; cookie.Name != "flavor" { t.Errorf("unexpected cookie %q", cookie.Name) } bodyBytes, _ := io.ReadAll(res.Body) if g, e := string(bodyBytes), backendResponse; g != e { t.Errorf("got body %q; expected %q", g, e) } if g, e := res.Trailer.Get("X-Trailer"), "trailer_value"; g != e { t.Errorf("Trailer(X-Trailer) = %q ; want %q", g, e) } if g, e := res.Trailer.Get("X-Unannounced-Trailer"), "unannounced_trailer_value"; g != e { t.Errorf("Trailer(X-Unannounced-Trailer) = %q ; want %q", g, e) } // Test that a backend failing to be reached or one which doesn't return // a response results in a StatusBadGateway. getReq, _ = http.NewRequest("GET", frontend.URL+"/?mode=hangup", nil) getReq.Close = true res, err = frontendClient.Do(getReq) if err != nil { t.Fatal(err) } res.Body.Close() if res.StatusCode != http.StatusBadGateway { t.Errorf("request to bad proxy = %v; want 502 StatusBadGateway", res.Status) } } // Issue 16875: remove any proxied headers mentioned in the "Connection" // header value. func TestReverseProxyStripHeadersPresentInConnection(t *testing.T) { const fakeConnectionToken = "X-Fake-Connection-Token" const backendResponse = "I am the backend" // someConnHeader is some arbitrary header to be declared as a hop-by-hop header // in the Request's Connection header. const someConnHeader = "X-Some-Conn-Header" backend := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { if c := r.Header.Get("Connection"); c != "" { t.Errorf("handler got header %q = %q; want empty", "Connection", c) } if c := r.Header.Get(fakeConnectionToken); c != "" { t.Errorf("handler got header %q = %q; want empty", fakeConnectionToken, c) } if c := r.Header.Get(someConnHeader); c != "" { t.Errorf("handler got header %q = %q; want empty", someConnHeader, c) } w.Header().Add("Connection", "Upgrade, "+fakeConnectionToken) w.Header().Add("Connection", someConnHeader) w.Header().Set(someConnHeader, "should be deleted") w.Header().Set(fakeConnectionToken, "should be deleted") io.WriteString(w, backendResponse) })) defer backend.Close() backendURL, err := url.Parse(backend.URL) if err != nil { t.Fatal(err) } proxyHandler := NewSingleHostReverseProxy(backendURL) frontend := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { proxyHandler.ServeHTTP(w, r) if c := r.Header.Get(someConnHeader); c != "should be deleted" { t.Errorf("handler modified header %q = %q; want %q", someConnHeader, c, "should be deleted") } if c := r.Header.Get(fakeConnectionToken); c != "should be deleted" { t.Errorf("handler modified header %q = %q; want %q", fakeConnectionToken, c, "should be deleted") } c := r.Header["Connection"] var cf []string for _, f := range c { for _, sf := range strings.Split(f, ",") { if sf = strings.TrimSpace(sf); sf != "" { cf = append(cf, sf) } } } sort.Strings(cf) expectedValues := []string{"Upgrade", someConnHeader, fakeConnectionToken} sort.Strings(expectedValues) if !reflect.DeepEqual(cf, expectedValues) { t.Errorf("handler modified header %q = %q; want %q", "Connection", cf, expectedValues) } })) defer frontend.Close() getReq, _ := http.NewRequest("GET", frontend.URL, nil) getReq.Header.Add("Connection", "Upgrade, "+fakeConnectionToken) getReq.Header.Add("Connection", someConnHeader) getReq.Header.Set(someConnHeader, "should be deleted") getReq.Header.Set(fakeConnectionToken, "should be deleted") res, err := frontend.Client().Do(getReq) if err != nil { t.Fatalf("Get: %v", err) } defer res.Body.Close() bodyBytes, err := io.ReadAll(res.Body) if err != nil { t.Fatalf("reading body: %v", err) } if got, want := string(bodyBytes), backendResponse; got != want { t.Errorf("got body %q; want %q", got, want) } if c := res.Header.Get("Connection"); c != "" { t.Errorf("handler got header %q = %q; want empty", "Connection", c) } if c := res.Header.Get(someConnHeader); c != "" { t.Errorf("handler got header %q = %q; want empty", someConnHeader, c) } if c := res.Header.Get(fakeConnectionToken); c != "" { t.Errorf("handler got header %q = %q; want empty", fakeConnectionToken, c) } } func TestReverseProxyStripEmptyConnection(t *testing.T) { // See Issue 46313. const backendResponse = "I am the backend" // someConnHeader is some arbitrary header to be declared as a hop-by-hop header // in the Request's Connection header. const someConnHeader = "X-Some-Conn-Header" backend := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { if c := r.Header.Values("Connection"); len(c) != 0 { t.Errorf("handler got header %q = %v; want empty", "Connection", c) } if c := r.Header.Get(someConnHeader); c != "" { t.Errorf("handler got header %q = %q; want empty", someConnHeader, c) } w.Header().Add("Connection", "") w.Header().Add("Connection", someConnHeader) w.Header().Set(someConnHeader, "should be deleted") io.WriteString(w, backendResponse) })) defer backend.Close() backendURL, err := url.Parse(backend.URL) if err != nil { t.Fatal(err) } proxyHandler := NewSingleHostReverseProxy(backendURL) frontend := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { proxyHandler.ServeHTTP(w, r) if c := r.Header.Get(someConnHeader); c != "should be deleted" { t.Errorf("handler modified header %q = %q; want %q", someConnHeader, c, "should be deleted") } })) defer frontend.Close() getReq, _ := http.NewRequest("GET", frontend.URL, nil) getReq.Header.Add("Connection", "") getReq.Header.Add("Connection", someConnHeader) getReq.Header.Set(someConnHeader, "should be deleted") res, err := frontend.Client().Do(getReq) if err != nil { t.Fatalf("Get: %v", err) } defer res.Body.Close() bodyBytes, err := io.ReadAll(res.Body) if err != nil { t.Fatalf("reading body: %v", err) } if got, want := string(bodyBytes), backendResponse; got != want { t.Errorf("got body %q; want %q", got, want) } if c := res.Header.Get("Connection"); c != "" { t.Errorf("handler got header %q = %q; want empty", "Connection", c) } if c := res.Header.Get(someConnHeader); c != "" { t.Errorf("handler got header %q = %q; want empty", someConnHeader, c) } } func TestXForwardedFor(t *testing.T) { const prevForwardedFor = "client ip" const backendResponse = "I am the backend" const backendStatus = 404 backend := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { if r.Header.Get("X-Forwarded-For") == "" { t.Errorf("didn't get X-Forwarded-For header") } if !strings.Contains(r.Header.Get("X-Forwarded-For"), prevForwardedFor) { t.Errorf("X-Forwarded-For didn't contain prior data") } w.WriteHeader(backendStatus) w.Write([]byte(backendResponse)) })) defer backend.Close() backendURL, err := url.Parse(backend.URL) if err != nil { t.Fatal(err) } proxyHandler := NewSingleHostReverseProxy(backendURL) frontend := httptest.NewServer(proxyHandler) defer frontend.Close() getReq, _ := http.NewRequest("GET", frontend.URL, nil) getReq.Host = "some-name" getReq.Header.Set("Connection", "close") getReq.Header.Set("X-Forwarded-For", prevForwardedFor) getReq.Close = true res, err := frontend.Client().Do(getReq) if err != nil { t.Fatalf("Get: %v", err) } if g, e := res.StatusCode, backendStatus; g != e { t.Errorf("got res.StatusCode %d; expected %d", g, e) } bodyBytes, _ := io.ReadAll(res.Body) if g, e := string(bodyBytes), backendResponse; g != e { t.Errorf("got body %q; expected %q", g, e) } } // Issue 38079: don't append to X-Forwarded-For if it's present but nil func TestXForwardedFor_Omit(t *testing.T) { backend := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { if v := r.Header.Get("X-Forwarded-For"); v != "" { t.Errorf("got X-Forwarded-For header: %q", v) } w.Write([]byte("hi")) })) defer backend.Close() backendURL, err := url.Parse(backend.URL) if err != nil { t.Fatal(err) } proxyHandler := NewSingleHostReverseProxy(backendURL) frontend := httptest.NewServer(proxyHandler) defer frontend.Close() oldDirector := proxyHandler.Director proxyHandler.Director = func(r *http.Request) { r.Header["X-Forwarded-For"] = nil oldDirector(r) } getReq, _ := http.NewRequest("GET", frontend.URL, nil) getReq.Host = "some-name" getReq.Close = true res, err := frontend.Client().Do(getReq) if err != nil { t.Fatalf("Get: %v", err) } res.Body.Close() } var proxyQueryTests = []struct { baseSuffix string // suffix to add to backend URL reqSuffix string // suffix to add to frontend's request URL want string // what backend should see for final request URL (without ?) }{ {"", "", ""}, {"?sta=tic", "?us=er", "sta=tic&us=er"}, {"", "?us=er", "us=er"}, {"?sta=tic", "", "sta=tic"}, } func TestReverseProxyQuery(t *testing.T) { backend := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { w.Header().Set("X-Got-Query", r.URL.RawQuery) w.Write([]byte("hi")) })) defer backend.Close() for i, tt := range proxyQueryTests { backendURL, err := url.Parse(backend.URL + tt.baseSuffix) if err != nil { t.Fatal(err) } frontend := httptest.NewServer(NewSingleHostReverseProxy(backendURL)) req, _ := http.NewRequest("GET", frontend.URL+tt.reqSuffix, nil) req.Close = true res, err := frontend.Client().Do(req) if err != nil { t.Fatalf("%d. Get: %v", i, err) } if g, e := res.Header.Get("X-Got-Query"), tt.want; g != e { t.Errorf("%d. got query %q; expected %q", i, g, e) } res.Body.Close() frontend.Close() } } func TestReverseProxyFlushInterval(t *testing.T) { const expected = "hi" backend := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { w.Write([]byte(expected)) })) defer backend.Close() backendURL, err := url.Parse(backend.URL) if err != nil { t.Fatal(err) } proxyHandler := NewSingleHostReverseProxy(backendURL) proxyHandler.FlushInterval = time.Microsecond frontend := httptest.NewServer(proxyHandler) defer frontend.Close() req, _ := http.NewRequest("GET", frontend.URL, nil) req.Close = true res, err := frontend.Client().Do(req) if err != nil { t.Fatalf("Get: %v", err) } defer res.Body.Close() if bodyBytes, _ := io.ReadAll(res.Body); string(bodyBytes) != expected { t.Errorf("got body %q; expected %q", bodyBytes, expected) } } func TestReverseProxyFlushIntervalHeaders(t *testing.T) { const expected = "hi" stopCh := make(chan struct{}) backend := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { w.Header().Add("MyHeader", expected) w.WriteHeader(200) w.(http.Flusher).Flush() <-stopCh })) defer backend.Close() defer close(stopCh) backendURL, err := url.Parse(backend.URL) if err != nil { t.Fatal(err) } proxyHandler := NewSingleHostReverseProxy(backendURL) proxyHandler.FlushInterval = time.Microsecond frontend := httptest.NewServer(proxyHandler) defer frontend.Close() req, _ := http.NewRequest("GET", frontend.URL, nil) req.Close = true ctx, cancel := context.WithTimeout(req.Context(), 10*time.Second) defer cancel() req = req.WithContext(ctx) res, err := frontend.Client().Do(req) if err != nil { t.Fatalf("Get: %v", err) } defer res.Body.Close() if res.Header.Get("MyHeader") != expected { t.Errorf("got header %q; expected %q", res.Header.Get("MyHeader"), expected) } } func TestReverseProxyCancellation(t *testing.T) { const backendResponse = "I am the backend" reqInFlight := make(chan struct{}) backend := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { close(reqInFlight) // cause the client to cancel its request select { case <-time.After(10 * time.Second): // Note: this should only happen in broken implementations, and the // closenotify case should be instantaneous. t.Error("Handler never saw CloseNotify") return case <-w.(http.CloseNotifier).CloseNotify(): } w.WriteHeader(http.StatusOK) w.Write([]byte(backendResponse)) })) defer backend.Close() backend.Config.ErrorLog = log.New(io.Discard, "", 0) backendURL, err := url.Parse(backend.URL) if err != nil { t.Fatal(err) } proxyHandler := NewSingleHostReverseProxy(backendURL) // Discards errors of the form: // http: proxy error: read tcp 127.0.0.1:44643: use of closed network connection proxyHandler.ErrorLog = log.New(io.Discard, "", 0) frontend := httptest.NewServer(proxyHandler) defer frontend.Close() frontendClient := frontend.Client() getReq, _ := http.NewRequest("GET", frontend.URL, nil) go func() { <-reqInFlight frontendClient.Transport.(*http.Transport).CancelRequest(getReq) }() res, err := frontendClient.Do(getReq) if res != nil { t.Errorf("got response %v; want nil", res.Status) } if err == nil { // This should be an error like: // Get "http://127.0.0.1:58079": read tcp 127.0.0.1:58079: // use of closed network connection t.Error("Server.Client().Do() returned nil error; want non-nil error") } } func req(t *testing.T, v string) *http.Request { req, err := http.ReadRequest(bufio.NewReader(strings.NewReader(v))) if err != nil { t.Fatal(err) } return req } // Issue 12344 func TestNilBody(t *testing.T) { backend := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { w.Write([]byte("hi")) })) defer backend.Close() frontend := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) { backURL, _ := url.Parse(backend.URL) rp := NewSingleHostReverseProxy(backURL) r := req(t, "GET / HTTP/1.0\r\n\r\n") r.Body = nil // this accidentally worked in Go 1.4 and below, so keep it working rp.ServeHTTP(w, r) })) defer frontend.Close() res, err := http.Get(frontend.URL) if err != nil { t.Fatal(err) } defer res.Body.Close() slurp, err := io.ReadAll(res.Body) if err != nil { t.Fatal(err) } if string(slurp) != "hi" { t.Errorf("Got %q; want %q", slurp, "hi") } } // Issue 15524 func TestUserAgentHeader(t *testing.T) { const explicitUA = "explicit UA" backend := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { if r.URL.Path == "/noua" { if c := r.Header.Get("User-Agent"); c != "" { t.Errorf("handler got non-empty User-Agent header %q", c) } return } if c := r.Header.Get("User-Agent"); c != explicitUA { t.Errorf("handler got unexpected User-Agent header %q", c) } })) defer backend.Close() backendURL, err := url.Parse(backend.URL) if err != nil { t.Fatal(err) } proxyHandler := NewSingleHostReverseProxy(backendURL) proxyHandler.ErrorLog = log.New(io.Discard, "", 0) // quiet for tests frontend := httptest.NewServer(proxyHandler) defer frontend.Close() frontendClient := frontend.Client() getReq, _ := http.NewRequest("GET", frontend.URL, nil) getReq.Header.Set("User-Agent", explicitUA) getReq.Close = true res, err := frontendClient.Do(getReq) if err != nil { t.Fatalf("Get: %v", err) } res.Body.Close() getReq, _ = http.NewRequest("GET", frontend.URL+"/noua", nil) getReq.Header.Set("User-Agent", "") getReq.Close = true res, err = frontendClient.Do(getReq) if err != nil { t.Fatalf("Get: %v", err) } res.Body.Close() } type bufferPool struct { get func() []byte put func([]byte) } func (bp bufferPool) Get() []byte { return bp.get() } func (bp bufferPool) Put(v []byte) { bp.put(v) } func TestReverseProxyGetPutBuffer(t *testing.T) { const msg = "hi" backend := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { io.WriteString(w, msg) })) defer backend.Close() backendURL, err := url.Parse(backend.URL) if err != nil { t.Fatal(err) } var ( mu sync.Mutex log []string ) addLog := func(event string) { mu.Lock() defer mu.Unlock() log = append(log, event) } rp := NewSingleHostReverseProxy(backendURL) const size = 1234 rp.BufferPool = bufferPool{ get: func() []byte { addLog("getBuf") return make([]byte, size) }, put: func(p []byte) { addLog("putBuf-" + strconv.Itoa(len(p))) }, } frontend := httptest.NewServer(rp) defer frontend.Close() req, _ := http.NewRequest("GET", frontend.URL, nil) req.Close = true res, err := frontend.Client().Do(req) if err != nil { t.Fatalf("Get: %v", err) } slurp, err := io.ReadAll(res.Body) res.Body.Close() if err != nil { t.Fatalf("reading body: %v", err) } if string(slurp) != msg { t.Errorf("msg = %q; want %q", slurp, msg) } wantLog := []string{"getBuf", "putBuf-" + strconv.Itoa(size)} mu.Lock() defer mu.Unlock() if !reflect.DeepEqual(log, wantLog) { t.Errorf("Log events = %q; want %q", log, wantLog) } } func TestReverseProxy_Post(t *testing.T) { const backendResponse = "I am the backend" const backendStatus = 200 var requestBody = bytes.Repeat([]byte("a"), 1<<20) backend := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { slurp, err := io.ReadAll(r.Body) if err != nil { t.Errorf("Backend body read = %v", err) } if len(slurp) != len(requestBody) { t.Errorf("Backend read %d request body bytes; want %d", len(slurp), len(requestBody)) } if !bytes.Equal(slurp, requestBody) { t.Error("Backend read wrong request body.") // 1MB; omitting details } w.Write([]byte(backendResponse)) })) defer backend.Close() backendURL, err := url.Parse(backend.URL) if err != nil { t.Fatal(err) } proxyHandler := NewSingleHostReverseProxy(backendURL) frontend := httptest.NewServer(proxyHandler) defer frontend.Close() postReq, _ := http.NewRequest("POST", frontend.URL, bytes.NewReader(requestBody)) res, err := frontend.Client().Do(postReq) if err != nil { t.Fatalf("Do: %v", err) } if g, e := res.StatusCode, backendStatus; g != e { t.Errorf("got res.StatusCode %d; expected %d", g, e) } bodyBytes, _ := io.ReadAll(res.Body) if g, e := string(bodyBytes), backendResponse; g != e { t.Errorf("got body %q; expected %q", g, e) } } type RoundTripperFunc func(*http.Request) (*http.Response, error) func (fn RoundTripperFunc) RoundTrip(req *http.Request) (*http.Response, error) { return fn(req) } // Issue 16036: send a Request with a nil Body when possible func TestReverseProxy_NilBody(t *testing.T) { backendURL, _ := url.Parse("http://fake.tld/") proxyHandler := NewSingleHostReverseProxy(backendURL) proxyHandler.ErrorLog = log.New(io.Discard, "", 0) // quiet for tests proxyHandler.Transport = RoundTripperFunc(func(req *http.Request) (*http.Response, error) { if req.Body != nil { t.Error("Body != nil; want a nil Body") } return nil, errors.New("done testing the interesting part; so force a 502 Gateway error") }) frontend := httptest.NewServer(proxyHandler) defer frontend.Close() res, err := frontend.Client().Get(frontend.URL) if err != nil { t.Fatal(err) } defer res.Body.Close() if res.StatusCode != 502 { t.Errorf("status code = %v; want 502 (Gateway Error)", res.Status) } } // Issue 33142: always allocate the request headers func TestReverseProxy_AllocatedHeader(t *testing.T) { proxyHandler := new(ReverseProxy) proxyHandler.ErrorLog = log.New(io.Discard, "", 0) // quiet for tests proxyHandler.Director = func(*http.Request) {} // noop proxyHandler.Transport = RoundTripperFunc(func(req *http.Request) (*http.Response, error) { if req.Header == nil { t.Error("Header == nil; want a non-nil Header") } return nil, errors.New("done testing the interesting part; so force a 502 Gateway error") }) proxyHandler.ServeHTTP(httptest.NewRecorder(), &http.Request{ Method: "GET", URL: &url.URL{Scheme: "http", Host: "fake.tld", Path: "/"}, Proto: "HTTP/1.0", ProtoMajor: 1, }) } // Issue 14237. Test ModifyResponse and that an error from it // causes the proxy to return StatusBadGateway, or StatusOK otherwise. func TestReverseProxyModifyResponse(t *testing.T) { backendServer := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { w.Header().Add("X-Hit-Mod", fmt.Sprintf("%v", r.URL.Path == "/mod")) })) defer backendServer.Close() rpURL, _ := url.Parse(backendServer.URL) rproxy := NewSingleHostReverseProxy(rpURL) rproxy.ErrorLog = log.New(io.Discard, "", 0) // quiet for tests rproxy.ModifyResponse = func(resp *http.Response) error { if resp.Header.Get("X-Hit-Mod") != "true" { return fmt.Errorf("tried to by-pass proxy") } return nil } frontendProxy := httptest.NewServer(rproxy) defer frontendProxy.Close() tests := []struct { url string wantCode int }{ {frontendProxy.URL + "/mod", http.StatusOK}, {frontendProxy.URL + "/schedule", http.StatusBadGateway}, } for i, tt := range tests { resp, err := http.Get(tt.url) if err != nil { t.Fatalf("failed to reach proxy: %v", err) } if g, e := resp.StatusCode, tt.wantCode; g != e { t.Errorf("#%d: got res.StatusCode %d; expected %d", i, g, e) } resp.Body.Close() } } type failingRoundTripper struct{} func (failingRoundTripper) RoundTrip(*http.Request) (*http.Response, error) { return nil, errors.New("some error") } type staticResponseRoundTripper struct{ res *http.Response } func (rt staticResponseRoundTripper) RoundTrip(*http.Request) (*http.Response, error) { return rt.res, nil } func TestReverseProxyErrorHandler(t *testing.T) { tests := []struct { name string wantCode int errorHandler func(http.ResponseWriter, *http.Request, error) transport http.RoundTripper // defaults to failingRoundTripper modifyResponse func(*http.Response) error }{ { name: "default", wantCode: http.StatusBadGateway, }, { name: "errorhandler", wantCode: http.StatusTeapot, errorHandler: func(rw http.ResponseWriter, req *http.Request, err error) { rw.WriteHeader(http.StatusTeapot) }, }, { name: "modifyresponse_noerr", transport: staticResponseRoundTripper{ &http.Response{StatusCode: 345, Body: http.NoBody}, }, modifyResponse: func(res *http.Response) error { res.StatusCode++ return nil }, errorHandler: func(rw http.ResponseWriter, req *http.Request, err error) { rw.WriteHeader(http.StatusTeapot) }, wantCode: 346, }, { name: "modifyresponse_err", transport: staticResponseRoundTripper{ &http.Response{StatusCode: 345, Body: http.NoBody}, }, modifyResponse: func(res *http.Response) error { res.StatusCode++ return errors.New("some error to trigger errorHandler") }, errorHandler: func(rw http.ResponseWriter, req *http.Request, err error) { rw.WriteHeader(http.StatusTeapot) }, wantCode: http.StatusTeapot, }, } for _, tt := range tests { t.Run(tt.name, func(t *testing.T) { target := &url.URL{ Scheme: "http", Host: "dummy.tld", Path: "/", } rproxy := NewSingleHostReverseProxy(target) rproxy.Transport = tt.transport rproxy.ModifyResponse = tt.modifyResponse if rproxy.Transport == nil { rproxy.Transport = failingRoundTripper{} } rproxy.ErrorLog = log.New(io.Discard, "", 0) // quiet for tests if tt.errorHandler != nil { rproxy.ErrorHandler = tt.errorHandler } frontendProxy := httptest.NewServer(rproxy) defer frontendProxy.Close() resp, err := http.Get(frontendProxy.URL + "/test") if err != nil { t.Fatalf("failed to reach proxy: %v", err) } if g, e := resp.StatusCode, tt.wantCode; g != e { t.Errorf("got res.StatusCode %d; expected %d", g, e) } resp.Body.Close() }) } } // Issue 16659: log errors from short read func TestReverseProxy_CopyBuffer(t *testing.T) { backendServer := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { out := "this call was relayed by the reverse proxy" // Coerce a wrong content length to induce io.UnexpectedEOF w.Header().Set("Content-Length", fmt.Sprintf("%d", len(out)*2)) fmt.Fprintln(w, out) })) defer backendServer.Close() rpURL, err := url.Parse(backendServer.URL) if err != nil { t.Fatal(err) } var proxyLog bytes.Buffer rproxy := NewSingleHostReverseProxy(rpURL) rproxy.ErrorLog = log.New(&proxyLog, "", log.Lshortfile) donec := make(chan bool, 1) frontendProxy := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { defer func() { donec <- true }() rproxy.ServeHTTP(w, r) })) defer frontendProxy.Close() if _, err = frontendProxy.Client().Get(frontendProxy.URL); err == nil { t.Fatalf("want non-nil error") } // The race detector complains about the proxyLog usage in logf in copyBuffer // and our usage below with proxyLog.Bytes() so we're explicitly using a // channel to ensure that the ReverseProxy's ServeHTTP is done before we // continue after Get. <-donec expected := []string{ "EOF", "read", } for _, phrase := range expected { if !bytes.Contains(proxyLog.Bytes(), []byte(phrase)) { t.Errorf("expected log to contain phrase %q", phrase) } } } type staticTransport struct { res *http.Response } func (t *staticTransport) RoundTrip(r *http.Request) (*http.Response, error) { return t.res, nil } func BenchmarkServeHTTP(b *testing.B) { res := &http.Response{ StatusCode: 200, Body: io.NopCloser(strings.NewReader("")), } proxy := &ReverseProxy{ Director: func(*http.Request) {}, Transport: &staticTransport{res}, } w := httptest.NewRecorder() r := httptest.NewRequest("GET", "/", nil) b.ReportAllocs() for i := 0; i < b.N; i++ { proxy.ServeHTTP(w, r) } } func TestServeHTTPDeepCopy(t *testing.T) { backend := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { w.Write([]byte("Hello Gopher!")) })) defer backend.Close() backendURL, err := url.Parse(backend.URL) if err != nil { t.Fatal(err) } type result struct { before, after string } resultChan := make(chan result, 1) proxyHandler := NewSingleHostReverseProxy(backendURL) frontend := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { before := r.URL.String() proxyHandler.ServeHTTP(w, r) after := r.URL.String() resultChan <- result{before: before, after: after} })) defer frontend.Close() want := result{before: "/", after: "/"} res, err := frontend.Client().Get(frontend.URL) if err != nil { t.Fatalf("Do: %v", err) } res.Body.Close() got := <-resultChan if got != want { t.Errorf("got = %+v; want = %+v", got, want) } } // Issue 18327: verify we always do a deep copy of the Request.Header map // before any mutations. func TestClonesRequestHeaders(t *testing.T) { log.SetOutput(io.Discard) defer log.SetOutput(os.Stderr) req, _ := http.NewRequest("GET", "http://foo.tld/", nil) req.RemoteAddr = "1.2.3.4:56789" rp := &ReverseProxy{ Director: func(req *http.Request) { req.Header.Set("From-Director", "1") }, Transport: roundTripperFunc(func(req *http.Request) (*http.Response, error) { if v := req.Header.Get("From-Director"); v != "1" { t.Errorf("From-Directory value = %q; want 1", v) } return nil, io.EOF }), } rp.ServeHTTP(httptest.NewRecorder(), req) if req.Header.Get("From-Director") == "1" { t.Error("Director header mutation modified caller's request") } if req.Header.Get("X-Forwarded-For") != "" { t.Error("X-Forward-For header mutation modified caller's request") } } type roundTripperFunc func(req *http.Request) (*http.Response, error) func (fn roundTripperFunc) RoundTrip(req *http.Request) (*http.Response, error) { return fn(req) } func TestModifyResponseClosesBody(t *testing.T) { req, _ := http.NewRequest("GET", "http://foo.tld/", nil) req.RemoteAddr = "1.2.3.4:56789" closeCheck := new(checkCloser) logBuf := new(bytes.Buffer) outErr := errors.New("ModifyResponse error") rp := &ReverseProxy{ Director: func(req *http.Request) {}, Transport: &staticTransport{&http.Response{ StatusCode: 200, Body: closeCheck, }}, ErrorLog: log.New(logBuf, "", 0), ModifyResponse: func(*http.Response) error { return outErr }, } rec := httptest.NewRecorder() rp.ServeHTTP(rec, req) res := rec.Result() if g, e := res.StatusCode, http.StatusBadGateway; g != e { t.Errorf("got res.StatusCode %d; expected %d", g, e) } if !closeCheck.closed { t.Errorf("body should have been closed") } if g, e := logBuf.String(), outErr.Error(); !strings.Contains(g, e) { t.Errorf("ErrorLog %q does not contain %q", g, e) } } type checkCloser struct { closed bool } func (cc *checkCloser) Close() error { cc.closed = true return nil } func (cc *checkCloser) Read(b []byte) (int, error) { return len(b), nil } // Issue 23643: panic on body copy error func TestReverseProxy_PanicBodyError(t *testing.T) { log.SetOutput(io.Discard) defer log.SetOutput(os.Stderr) backendServer := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { out := "this call was relayed by the reverse proxy" // Coerce a wrong content length to induce io.ErrUnexpectedEOF w.Header().Set("Content-Length", fmt.Sprintf("%d", len(out)*2)) fmt.Fprintln(w, out) })) defer backendServer.Close() rpURL, err := url.Parse(backendServer.URL) if err != nil { t.Fatal(err) } rproxy := NewSingleHostReverseProxy(rpURL) // Ensure that the handler panics when the body read encounters an // io.ErrUnexpectedEOF defer func() { err := recover() if err == nil { t.Fatal("handler should have panicked") } if err != http.ErrAbortHandler { t.Fatal("expected ErrAbortHandler, got", err) } }() req, _ := http.NewRequest("GET", "http://foo.tld/", nil) rproxy.ServeHTTP(httptest.NewRecorder(), req) } // Issue #46866: panic without closing incoming request body causes a panic func TestReverseProxy_PanicClosesIncomingBody(t *testing.T) { backend := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { out := "this call was relayed by the reverse proxy" // Coerce a wrong content length to induce io.ErrUnexpectedEOF w.Header().Set("Content-Length", fmt.Sprintf("%d", len(out)*2)) fmt.Fprintln(w, out) })) defer backend.Close() backendURL, err := url.Parse(backend.URL) if err != nil { t.Fatal(err) } proxyHandler := NewSingleHostReverseProxy(backendURL) proxyHandler.ErrorLog = log.New(io.Discard, "", 0) // quiet for tests frontend := httptest.NewServer(proxyHandler) defer frontend.Close() frontendClient := frontend.Client() var wg sync.WaitGroup for i := 0; i < 2; i++ { wg.Add(1) go func() { defer wg.Done() for j := 0; j < 10; j++ { const reqLen = 6 * 1024 * 1024 req, _ := http.NewRequest("POST", frontend.URL, &io.LimitedReader{R: neverEnding('x'), N: reqLen}) req.ContentLength = reqLen resp, _ := frontendClient.Transport.RoundTrip(req) if resp != nil { io.Copy(io.Discard, resp.Body) resp.Body.Close() } } }() } wg.Wait() } func TestSelectFlushInterval(t *testing.T) { tests := []struct { name string p *ReverseProxy res *http.Response want time.Duration }{ { name: "default", res: &http.Response{}, p: &ReverseProxy{FlushInterval: 123}, want: 123, }, { name: "server-sent events overrides non-zero", res: &http.Response{ Header: http.Header{ "Content-Type": {"text/event-stream"}, }, }, p: &ReverseProxy{FlushInterval: 123}, want: -1, }, { name: "server-sent events overrides zero", res: &http.Response{ Header: http.Header{ "Content-Type": {"text/event-stream"}, }, }, p: &ReverseProxy{FlushInterval: 0}, want: -1, }, { name: "server-sent events with media-type parameters overrides non-zero", res: &http.Response{ Header: http.Header{ "Content-Type": {"text/event-stream;charset=utf-8"}, }, }, p: &ReverseProxy{FlushInterval: 123}, want: -1, }, { name: "server-sent events with media-type parameters overrides zero", res: &http.Response{ Header: http.Header{ "Content-Type": {"text/event-stream;charset=utf-8"}, }, }, p: &ReverseProxy{FlushInterval: 0}, want: -1, }, { name: "Content-Length: -1, overrides non-zero", res: &http.Response{ ContentLength: -1, }, p: &ReverseProxy{FlushInterval: 123}, want: -1, }, { name: "Content-Length: -1, overrides zero", res: &http.Response{ ContentLength: -1, }, p: &ReverseProxy{FlushInterval: 0}, want: -1, }, } for _, tt := range tests { t.Run(tt.name, func(t *testing.T) { got := tt.p.flushInterval(tt.res) if got != tt.want { t.Errorf("flushLatency = %v; want %v", got, tt.want) } }) } } func TestReverseProxyWebSocket(t *testing.T) { backendServer := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { if upgradeType(r.Header) != "websocket" { t.Error("unexpected backend request") http.Error(w, "unexpected request", 400) return } c, _, err := w.(http.Hijacker).Hijack() if err != nil { t.Error(err) return } defer c.Close() io.WriteString(c, "HTTP/1.1 101 Switching Protocols\r\nConnection: upgrade\r\nUpgrade: WebSocket\r\n\r\n") bs := bufio.NewScanner(c) if !bs.Scan() { t.Errorf("backend failed to read line from client: %v", bs.Err()) return } fmt.Fprintf(c, "backend got %q\n", bs.Text()) })) defer backendServer.Close() backURL, _ := url.Parse(backendServer.URL) rproxy := NewSingleHostReverseProxy(backURL) rproxy.ErrorLog = log.New(io.Discard, "", 0) // quiet for tests rproxy.ModifyResponse = func(res *http.Response) error { res.Header.Add("X-Modified", "true") return nil } handler := http.HandlerFunc(func(rw http.ResponseWriter, req *http.Request) { rw.Header().Set("X-Header", "X-Value") rproxy.ServeHTTP(rw, req) if got, want := rw.Header().Get("X-Modified"), "true"; got != want { t.Errorf("response writer X-Modified header = %q; want %q", got, want) } }) frontendProxy := httptest.NewServer(handler) defer frontendProxy.Close() req, _ := http.NewRequest("GET", frontendProxy.URL, nil) req.Header.Set("Connection", "Upgrade") req.Header.Set("Upgrade", "websocket") c := frontendProxy.Client() res, err := c.Do(req) if err != nil { t.Fatal(err) } if res.StatusCode != 101 { t.Fatalf("status = %v; want 101", res.Status) } got := res.Header.Get("X-Header") want := "X-Value" if got != want { t.Errorf("Header(XHeader) = %q; want %q", got, want) } if !ascii.EqualFold(upgradeType(res.Header), "websocket") { t.Fatalf("not websocket upgrade; got %#v", res.Header) } rwc, ok := res.Body.(io.ReadWriteCloser) if !ok { t.Fatalf("response body is of type %T; does not implement ReadWriteCloser", res.Body) } defer rwc.Close() if got, want := res.Header.Get("X-Modified"), "true"; got != want { t.Errorf("response X-Modified header = %q; want %q", got, want) } io.WriteString(rwc, "Hello\n") bs := bufio.NewScanner(rwc) if !bs.Scan() { t.Fatalf("Scan: %v", bs.Err()) } got = bs.Text() want = `backend got "Hello"` if got != want { t.Errorf("got %#q, want %#q", got, want) } } func TestReverseProxyWebSocketCancellation(t *testing.T) { n := 5 triggerCancelCh := make(chan bool, n) nthResponse := func(i int) string { return fmt.Sprintf("backend response #%d\n", i) } terminalMsg := "final message" cst := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { if g, ws := upgradeType(r.Header), "websocket"; g != ws { t.Errorf("Unexpected upgrade type %q, want %q", g, ws) http.Error(w, "Unexpected request", 400) return } conn, bufrw, err := w.(http.Hijacker).Hijack() if err != nil { t.Error(err) return } defer conn.Close() upgradeMsg := "HTTP/1.1 101 Switching Protocols\r\nConnection: upgrade\r\nUpgrade: WebSocket\r\n\r\n" if _, err := io.WriteString(conn, upgradeMsg); err != nil { t.Error(err) return } if _, _, err := bufrw.ReadLine(); err != nil { t.Errorf("Failed to read line from client: %v", err) return } for i := 0; i < n; i++ { if _, err := bufrw.WriteString(nthResponse(i)); err != nil { select { case <-triggerCancelCh: default: t.Errorf("Writing response #%d failed: %v", i, err) } return } bufrw.Flush() time.Sleep(time.Second) } if _, err := bufrw.WriteString(terminalMsg); err != nil { select { case <-triggerCancelCh: default: t.Errorf("Failed to write terminal message: %v", err) } } bufrw.Flush() })) defer cst.Close() backendURL, _ := url.Parse(cst.URL) rproxy := NewSingleHostReverseProxy(backendURL) rproxy.ErrorLog = log.New(io.Discard, "", 0) // quiet for tests rproxy.ModifyResponse = func(res *http.Response) error { res.Header.Add("X-Modified", "true") return nil } handler := http.HandlerFunc(func(rw http.ResponseWriter, req *http.Request) { rw.Header().Set("X-Header", "X-Value") ctx, cancel := context.WithCancel(req.Context()) go func() { <-triggerCancelCh cancel() }() rproxy.ServeHTTP(rw, req.WithContext(ctx)) }) frontendProxy := httptest.NewServer(handler) defer frontendProxy.Close() req, _ := http.NewRequest("GET", frontendProxy.URL, nil) req.Header.Set("Connection", "Upgrade") req.Header.Set("Upgrade", "websocket") res, err := frontendProxy.Client().Do(req) if err != nil { t.Fatalf("Dialing to frontend proxy: %v", err) } defer res.Body.Close() if g, w := res.StatusCode, 101; g != w { t.Fatalf("Switching protocols failed, got: %d, want: %d", g, w) } if g, w := res.Header.Get("X-Header"), "X-Value"; g != w { t.Errorf("X-Header mismatch\n\tgot: %q\n\twant: %q", g, w) } if g, w := upgradeType(res.Header), "websocket"; !ascii.EqualFold(g, w) { t.Fatalf("Upgrade header mismatch\n\tgot: %q\n\twant: %q", g, w) } rwc, ok := res.Body.(io.ReadWriteCloser) if !ok { t.Fatalf("Response body type mismatch, got %T, want io.ReadWriteCloser", res.Body) } if got, want := res.Header.Get("X-Modified"), "true"; got != want { t.Errorf("response X-Modified header = %q; want %q", got, want) } if _, err := io.WriteString(rwc, "Hello\n"); err != nil { t.Fatalf("Failed to write first message: %v", err) } // Read loop. br := bufio.NewReader(rwc) for { line, err := br.ReadString('\n') switch { case line == terminalMsg: // this case before "err == io.EOF" t.Fatalf("The websocket request was not canceled, unfortunately!") case err == io.EOF: return case err != nil: t.Fatalf("Unexpected error: %v", err) case line == nthResponse(0): // We've gotten the first response back // Let's trigger a cancel. close(triggerCancelCh) } } } func TestUnannouncedTrailer(t *testing.T) { backend := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { w.WriteHeader(http.StatusOK) w.(http.Flusher).Flush() w.Header().Set(http.TrailerPrefix+"X-Unannounced-Trailer", "unannounced_trailer_value") })) defer backend.Close() backendURL, err := url.Parse(backend.URL) if err != nil { t.Fatal(err) } proxyHandler := NewSingleHostReverseProxy(backendURL) proxyHandler.ErrorLog = log.New(io.Discard, "", 0) // quiet for tests frontend := httptest.NewServer(proxyHandler) defer frontend.Close() frontendClient := frontend.Client() res, err := frontendClient.Get(frontend.URL) if err != nil { t.Fatalf("Get: %v", err) } io.ReadAll(res.Body) if g, w := res.Trailer.Get("X-Unannounced-Trailer"), "unannounced_trailer_value"; g != w { t.Errorf("Trailer(X-Unannounced-Trailer) = %q; want %q", g, w) } } func TestSingleJoinSlash(t *testing.T) { tests := []struct { slasha string slashb string expected string }{ {"https://www.google.com/", "/favicon.ico", "https://www.google.com/favicon.ico"}, {"https://www.google.com", "/favicon.ico", "https://www.google.com/favicon.ico"}, {"https://www.google.com", "favicon.ico", "https://www.google.com/favicon.ico"}, {"https://www.google.com", "", "https://www.google.com/"}, {"", "favicon.ico", "/favicon.ico"}, } for _, tt := range tests { if got := singleJoiningSlash(tt.slasha, tt.slashb); got != tt.expected { t.Errorf("singleJoiningSlash(%q,%q) want %q got %q", tt.slasha, tt.slashb, tt.expected, got) } } } func TestJoinURLPath(t *testing.T) { tests := []struct { a *url.URL b *url.URL wantPath string wantRaw string }{ {&url.URL{Path: "/a/b"}, &url.URL{Path: "/c"}, "/a/b/c", ""}, {&url.URL{Path: "/a/b", RawPath: "badpath"}, &url.URL{Path: "c"}, "/a/b/c", "/a/b/c"}, {&url.URL{Path: "/a/b", RawPath: "/a%2Fb"}, &url.URL{Path: "/c"}, "/a/b/c", "/a%2Fb/c"}, {&url.URL{Path: "/a/b", RawPath: "/a%2Fb"}, &url.URL{Path: "/c"}, "/a/b/c", "/a%2Fb/c"}, {&url.URL{Path: "/a/b/", RawPath: "/a%2Fb%2F"}, &url.URL{Path: "c"}, "/a/b//c", "/a%2Fb%2F/c"}, {&url.URL{Path: "/a/b/", RawPath: "/a%2Fb/"}, &url.URL{Path: "/c/d", RawPath: "/c%2Fd"}, "/a/b/c/d", "/a%2Fb/c%2Fd"}, } for _, tt := range tests { p, rp := joinURLPath(tt.a, tt.b) if p != tt.wantPath || rp != tt.wantRaw { t.Errorf("joinURLPath(URL(%q,%q),URL(%q,%q)) want (%q,%q) got (%q,%q)", tt.a.Path, tt.a.RawPath, tt.b.Path, tt.b.RawPath, tt.wantPath, tt.wantRaw, p, rp) } } }