391 lines
12 KiB
Go
391 lines
12 KiB
Go
package retry
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import (
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"context"
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"fmt"
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"io"
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"net/http"
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"net/http/httptest"
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"net/http/httptrace"
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"net/textproto"
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"strings"
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"testing"
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"time"
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"github.com/gorilla/websocket"
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"github.com/stretchr/testify/assert"
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"github.com/stretchr/testify/require"
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ptypes "github.com/traefik/paerser/types"
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"github.com/traefik/traefik/v2/pkg/config/dynamic"
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"github.com/traefik/traefik/v2/pkg/testhelpers"
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)
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func TestRetry(t *testing.T) {
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testCases := []struct {
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desc string
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config dynamic.Retry
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wantRetryAttempts int
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wantResponseStatus int
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amountFaultyEndpoints int
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}{
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{
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desc: "no retry on success",
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config: dynamic.Retry{Attempts: 5},
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wantRetryAttempts: 0,
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wantResponseStatus: http.StatusOK,
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amountFaultyEndpoints: 0,
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},
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{
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desc: "no retry on success with backoff",
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config: dynamic.Retry{Attempts: 5, InitialInterval: ptypes.Duration(time.Microsecond * 50)},
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wantRetryAttempts: 0,
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wantResponseStatus: http.StatusOK,
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amountFaultyEndpoints: 0,
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},
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{
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desc: "no retry when max request attempts is one",
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config: dynamic.Retry{Attempts: 1},
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wantRetryAttempts: 0,
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wantResponseStatus: http.StatusBadGateway,
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amountFaultyEndpoints: 1,
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},
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{
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desc: "no retry when max request attempts is one with backoff",
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config: dynamic.Retry{Attempts: 1, InitialInterval: ptypes.Duration(time.Microsecond * 50)},
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wantRetryAttempts: 0,
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wantResponseStatus: http.StatusBadGateway,
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amountFaultyEndpoints: 1,
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},
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{
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desc: "one retry when one server is faulty",
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config: dynamic.Retry{Attempts: 2},
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wantRetryAttempts: 1,
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wantResponseStatus: http.StatusOK,
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amountFaultyEndpoints: 1,
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},
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{
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desc: "one retry when one server is faulty with backoff",
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config: dynamic.Retry{Attempts: 2, InitialInterval: ptypes.Duration(time.Microsecond * 50)},
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wantRetryAttempts: 1,
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wantResponseStatus: http.StatusOK,
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amountFaultyEndpoints: 1,
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},
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{
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desc: "two retries when two servers are faulty",
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config: dynamic.Retry{Attempts: 3},
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wantRetryAttempts: 2,
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wantResponseStatus: http.StatusOK,
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amountFaultyEndpoints: 2,
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},
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{
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desc: "two retries when two servers are faulty with backoff",
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config: dynamic.Retry{Attempts: 3, InitialInterval: ptypes.Duration(time.Microsecond * 50)},
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wantRetryAttempts: 2,
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wantResponseStatus: http.StatusOK,
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amountFaultyEndpoints: 2,
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},
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{
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desc: "max attempts exhausted delivers the 5xx response",
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config: dynamic.Retry{Attempts: 3},
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wantRetryAttempts: 2,
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wantResponseStatus: http.StatusBadGateway,
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amountFaultyEndpoints: 3,
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},
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{
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desc: "max attempts exhausted delivers the 5xx response with backoff",
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config: dynamic.Retry{Attempts: 3, InitialInterval: ptypes.Duration(time.Microsecond * 50)},
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wantRetryAttempts: 2,
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wantResponseStatus: http.StatusBadGateway,
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amountFaultyEndpoints: 3,
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},
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}
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for _, test := range testCases {
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test := test
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t.Run(test.desc, func(t *testing.T) {
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t.Parallel()
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retryAttempts := 0
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next := http.HandlerFunc(func(rw http.ResponseWriter, r *http.Request) {
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retryAttempts++
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if retryAttempts > test.amountFaultyEndpoints {
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// calls WroteHeaders on httptrace.
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_ = r.Write(io.Discard)
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rw.WriteHeader(http.StatusOK)
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return
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}
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rw.WriteHeader(http.StatusBadGateway)
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})
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retryListener := &countingRetryListener{}
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retry, err := New(context.Background(), next, test.config, retryListener, "traefikTest")
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require.NoError(t, err)
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recorder := httptest.NewRecorder()
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req := httptest.NewRequest(http.MethodGet, "http://localhost:3000/ok", nil)
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retry.ServeHTTP(recorder, req)
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assert.Equal(t, test.wantResponseStatus, recorder.Code)
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assert.Equal(t, test.wantRetryAttempts, retryListener.timesCalled)
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})
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}
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}
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func TestRetryEmptyServerList(t *testing.T) {
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next := http.HandlerFunc(func(rw http.ResponseWriter, r *http.Request) {
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rw.WriteHeader(http.StatusServiceUnavailable)
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})
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retryListener := &countingRetryListener{}
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retry, err := New(context.Background(), next, dynamic.Retry{Attempts: 3}, retryListener, "traefikTest")
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require.NoError(t, err)
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recorder := httptest.NewRecorder()
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req := httptest.NewRequest(http.MethodGet, "http://localhost:3000/ok", nil)
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retry.ServeHTTP(recorder, req)
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assert.Equal(t, http.StatusServiceUnavailable, recorder.Code)
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assert.Equal(t, 0, retryListener.timesCalled)
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}
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func TestRetryListeners(t *testing.T) {
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req := httptest.NewRequest(http.MethodGet, "/", nil)
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retryListeners := Listeners{&countingRetryListener{}, &countingRetryListener{}}
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retryListeners.Retried(req, 1)
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retryListeners.Retried(req, 1)
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for _, retryListener := range retryListeners {
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listener := retryListener.(*countingRetryListener)
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if listener.timesCalled != 2 {
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t.Errorf("retry listener was called %d time(s), want %d time(s)", listener.timesCalled, 2)
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}
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}
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}
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func TestMultipleRetriesShouldNotLooseHeaders(t *testing.T) {
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attempt := 0
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expectedHeaderName := "X-Foo-Test-2"
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expectedHeaderValue := "bar"
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next := http.HandlerFunc(func(rw http.ResponseWriter, req *http.Request) {
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headerName := fmt.Sprintf("X-Foo-Test-%d", attempt)
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rw.Header().Add(headerName, expectedHeaderValue)
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if attempt < 2 {
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attempt++
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return
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}
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// Request has been successfully written to backend
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trace := httptrace.ContextClientTrace(req.Context())
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trace.WroteHeaders()
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// And we decide to answer to client
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rw.WriteHeader(http.StatusNoContent)
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})
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retry, err := New(context.Background(), next, dynamic.Retry{Attempts: 3}, &countingRetryListener{}, "traefikTest")
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require.NoError(t, err)
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responseRecorder := httptest.NewRecorder()
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retry.ServeHTTP(responseRecorder, testhelpers.MustNewRequest(http.MethodGet, "http://test", http.NoBody))
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headerValue := responseRecorder.Header().Get(expectedHeaderName)
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// Validate if we have the correct header
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if headerValue != expectedHeaderValue {
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t.Errorf("Expected to have %s for header %s, got %s", expectedHeaderValue, expectedHeaderName, headerValue)
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}
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// Validate that we don't have headers from previous attempts
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for i := 0; i < attempt; i++ {
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headerName := fmt.Sprintf("X-Foo-Test-%d", i)
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headerValue = responseRecorder.Header().Get("headerName")
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if headerValue != "" {
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t.Errorf("Expected no value for header %s, got %s", headerName, headerValue)
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}
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}
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}
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// countingRetryListener is a Listener implementation to count the times the Retried fn is called.
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type countingRetryListener struct {
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timesCalled int
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}
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func (l *countingRetryListener) Retried(req *http.Request, attempt int) {
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l.timesCalled++
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}
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func TestRetryWithFlush(t *testing.T) {
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next := http.HandlerFunc(func(rw http.ResponseWriter, req *http.Request) {
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rw.WriteHeader(http.StatusOK)
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_, err := rw.Write([]byte("FULL "))
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if err != nil {
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http.Error(rw, err.Error(), http.StatusInternalServerError)
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}
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rw.(http.Flusher).Flush()
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_, err = rw.Write([]byte("DATA"))
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if err != nil {
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http.Error(rw, err.Error(), http.StatusInternalServerError)
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}
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})
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retry, err := New(context.Background(), next, dynamic.Retry{Attempts: 1}, &countingRetryListener{}, "traefikTest")
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require.NoError(t, err)
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responseRecorder := httptest.NewRecorder()
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retry.ServeHTTP(responseRecorder, &http.Request{})
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assert.Equal(t, "FULL DATA", responseRecorder.Body.String())
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}
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func TestRetryWebsocket(t *testing.T) {
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testCases := []struct {
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desc string
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maxRequestAttempts int
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expectedRetryAttempts int
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expectedResponseStatus int
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expectedError bool
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amountFaultyEndpoints int
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}{
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{
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desc: "Switching ok after 2 retries",
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maxRequestAttempts: 3,
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expectedRetryAttempts: 2,
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amountFaultyEndpoints: 2,
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expectedResponseStatus: http.StatusSwitchingProtocols,
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},
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{
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desc: "Switching failed",
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maxRequestAttempts: 2,
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expectedRetryAttempts: 1,
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amountFaultyEndpoints: 2,
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expectedResponseStatus: http.StatusBadGateway,
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expectedError: true,
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},
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}
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for _, test := range testCases {
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test := test
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t.Run(test.desc, func(t *testing.T) {
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t.Parallel()
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retryAttempts := 0
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next := http.HandlerFunc(func(rw http.ResponseWriter, r *http.Request) {
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retryAttempts++
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if retryAttempts > test.amountFaultyEndpoints {
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upgrader := websocket.Upgrader{}
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_, err := upgrader.Upgrade(rw, r, nil)
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if err != nil {
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http.Error(rw, err.Error(), http.StatusInternalServerError)
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}
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return
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}
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rw.WriteHeader(http.StatusBadGateway)
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})
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retryListener := &countingRetryListener{}
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retryH, err := New(context.Background(), next, dynamic.Retry{Attempts: test.maxRequestAttempts}, retryListener, "traefikTest")
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require.NoError(t, err)
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retryServer := httptest.NewServer(retryH)
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url := strings.Replace(retryServer.URL, "http", "ws", 1)
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_, response, err := websocket.DefaultDialer.Dial(url, nil)
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if !test.expectedError {
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require.NoError(t, err)
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}
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assert.Equal(t, test.expectedResponseStatus, response.StatusCode)
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assert.Equal(t, test.expectedRetryAttempts, retryListener.timesCalled)
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})
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}
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}
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// This test is an adapted version of net/http/httputil.Test1xxResponses test.
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func Test1xxResponses(t *testing.T) {
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next := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
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h := w.Header()
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h.Add("Link", "</style.css>; rel=preload; as=style")
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h.Add("Link", "</script.js>; rel=preload; as=script")
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w.WriteHeader(http.StatusEarlyHints)
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h.Add("Link", "</foo.js>; rel=preload; as=script")
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w.WriteHeader(http.StatusProcessing)
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_, _ = w.Write([]byte("Hello"))
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})
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retryListener := &countingRetryListener{}
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retry, err := New(context.Background(), next, dynamic.Retry{Attempts: 1}, retryListener, "traefikTest")
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require.NoError(t, err)
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server := httptest.NewServer(retry)
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t.Cleanup(server.Close)
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frontendClient := server.Client()
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checkLinkHeaders := func(t *testing.T, expected, got []string) {
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t.Helper()
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if len(expected) != len(got) {
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t.Errorf("Expected %d link headers; got %d", len(expected), len(got))
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}
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for i := range expected {
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if i >= len(got) {
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t.Errorf("Expected %q link header; got nothing", expected[i])
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continue
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}
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if expected[i] != got[i] {
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t.Errorf("Expected %q link header; got %q", expected[i], got[i])
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}
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}
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}
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var respCounter uint8
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trace := &httptrace.ClientTrace{
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Got1xxResponse: func(code int, header textproto.MIMEHeader) error {
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switch code {
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case http.StatusEarlyHints:
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checkLinkHeaders(t, []string{"</style.css>; rel=preload; as=style", "</script.js>; rel=preload; as=script"}, header["Link"])
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case http.StatusProcessing:
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checkLinkHeaders(t, []string{"</style.css>; rel=preload; as=style", "</script.js>; rel=preload; as=script", "</foo.js>; rel=preload; as=script"}, header["Link"])
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default:
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t.Error("Unexpected 1xx response")
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}
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respCounter++
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return nil
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},
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}
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req, _ := http.NewRequestWithContext(httptrace.WithClientTrace(context.Background(), trace), http.MethodGet, server.URL, nil)
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res, err := frontendClient.Do(req)
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assert.Nil(t, err)
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defer res.Body.Close()
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if respCounter != 2 {
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t.Errorf("Expected 2 1xx responses; got %d", respCounter)
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}
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checkLinkHeaders(t, []string{"</style.css>; rel=preload; as=style", "</script.js>; rel=preload; as=script", "</foo.js>; rel=preload; as=script"}, res.Header["Link"])
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body, _ := io.ReadAll(res.Body)
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if string(body) != "Hello" {
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t.Errorf("Read body %q; want Hello", body)
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}
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assert.Equal(t, 0, retryListener.timesCalled)
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}
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