mirror of
https://github.com/traefik/traefik.git
synced 2025-11-04 02:11:15 +01:00
419 lines
12 KiB
Go
419 lines
12 KiB
Go
package retry
|
|
|
|
import (
|
|
"fmt"
|
|
"io"
|
|
"net/http"
|
|
"net/http/httptest"
|
|
"net/http/httptrace"
|
|
"net/textproto"
|
|
"strings"
|
|
"testing"
|
|
"time"
|
|
|
|
"github.com/gorilla/websocket"
|
|
"github.com/stretchr/testify/assert"
|
|
"github.com/stretchr/testify/require"
|
|
ptypes "github.com/traefik/paerser/types"
|
|
"github.com/traefik/traefik/v3/pkg/config/dynamic"
|
|
"github.com/traefik/traefik/v3/pkg/testhelpers"
|
|
)
|
|
|
|
func TestRetry(t *testing.T) {
|
|
testCases := []struct {
|
|
desc string
|
|
config dynamic.Retry
|
|
wantRetryAttempts int
|
|
wantResponseStatus int
|
|
amountFaultyEndpoints int
|
|
}{
|
|
{
|
|
desc: "no retry on success",
|
|
config: dynamic.Retry{Attempts: 5},
|
|
wantRetryAttempts: 0,
|
|
wantResponseStatus: http.StatusOK,
|
|
amountFaultyEndpoints: 0,
|
|
},
|
|
{
|
|
desc: "no retry on success with backoff",
|
|
config: dynamic.Retry{Attempts: 5, InitialInterval: ptypes.Duration(time.Microsecond * 50)},
|
|
wantRetryAttempts: 0,
|
|
wantResponseStatus: http.StatusOK,
|
|
amountFaultyEndpoints: 0,
|
|
},
|
|
{
|
|
desc: "no retry when max request attempts is one",
|
|
config: dynamic.Retry{Attempts: 1},
|
|
wantRetryAttempts: 0,
|
|
wantResponseStatus: http.StatusBadGateway,
|
|
amountFaultyEndpoints: 1,
|
|
},
|
|
{
|
|
desc: "no retry when max request attempts is one with backoff",
|
|
config: dynamic.Retry{Attempts: 1, InitialInterval: ptypes.Duration(time.Microsecond * 50)},
|
|
wantRetryAttempts: 0,
|
|
wantResponseStatus: http.StatusBadGateway,
|
|
amountFaultyEndpoints: 1,
|
|
},
|
|
{
|
|
desc: "one retry when one server is faulty",
|
|
config: dynamic.Retry{Attempts: 2},
|
|
wantRetryAttempts: 1,
|
|
wantResponseStatus: http.StatusOK,
|
|
amountFaultyEndpoints: 1,
|
|
},
|
|
{
|
|
desc: "one retry when one server is faulty with backoff",
|
|
config: dynamic.Retry{Attempts: 2, InitialInterval: ptypes.Duration(time.Microsecond * 50)},
|
|
wantRetryAttempts: 1,
|
|
wantResponseStatus: http.StatusOK,
|
|
amountFaultyEndpoints: 1,
|
|
},
|
|
{
|
|
desc: "two retries when two servers are faulty",
|
|
config: dynamic.Retry{Attempts: 3},
|
|
wantRetryAttempts: 2,
|
|
wantResponseStatus: http.StatusOK,
|
|
amountFaultyEndpoints: 2,
|
|
},
|
|
{
|
|
desc: "two retries when two servers are faulty with backoff",
|
|
config: dynamic.Retry{Attempts: 3, InitialInterval: ptypes.Duration(time.Microsecond * 50)},
|
|
wantRetryAttempts: 2,
|
|
wantResponseStatus: http.StatusOK,
|
|
amountFaultyEndpoints: 2,
|
|
},
|
|
{
|
|
desc: "max attempts exhausted delivers the 5xx response",
|
|
config: dynamic.Retry{Attempts: 3},
|
|
wantRetryAttempts: 2,
|
|
wantResponseStatus: http.StatusBadGateway,
|
|
amountFaultyEndpoints: 3,
|
|
},
|
|
{
|
|
desc: "max attempts exhausted delivers the 5xx response with backoff",
|
|
config: dynamic.Retry{Attempts: 3, InitialInterval: ptypes.Duration(time.Microsecond * 50)},
|
|
wantRetryAttempts: 2,
|
|
wantResponseStatus: http.StatusBadGateway,
|
|
amountFaultyEndpoints: 3,
|
|
},
|
|
}
|
|
|
|
for _, test := range testCases {
|
|
t.Run(test.desc, func(t *testing.T) {
|
|
t.Parallel()
|
|
|
|
retryAttempts := 0
|
|
next := http.HandlerFunc(func(rw http.ResponseWriter, req *http.Request) {
|
|
// This signals that a connection will be established with the backend
|
|
// to enable the Retry middleware mechanism.
|
|
shouldRetry := ContextShouldRetry(req.Context())
|
|
if shouldRetry != nil {
|
|
shouldRetry(true)
|
|
}
|
|
|
|
retryAttempts++
|
|
|
|
if retryAttempts > test.amountFaultyEndpoints {
|
|
// This signals that request headers have been sent to the backend.
|
|
if shouldRetry != nil {
|
|
shouldRetry(false)
|
|
}
|
|
|
|
rw.WriteHeader(http.StatusOK)
|
|
return
|
|
}
|
|
|
|
rw.WriteHeader(http.StatusBadGateway)
|
|
})
|
|
|
|
retryListener := &countingRetryListener{}
|
|
retry, err := New(t.Context(), next, test.config, retryListener, "traefikTest")
|
|
require.NoError(t, err)
|
|
|
|
recorder := httptest.NewRecorder()
|
|
req := httptest.NewRequest(http.MethodGet, "http://localhost:3000/ok", nil)
|
|
|
|
retry.ServeHTTP(recorder, req)
|
|
|
|
assert.Equal(t, test.wantResponseStatus, recorder.Code)
|
|
assert.Equal(t, test.wantRetryAttempts, retryListener.timesCalled)
|
|
})
|
|
}
|
|
}
|
|
|
|
func TestRetryEmptyServerList(t *testing.T) {
|
|
next := http.HandlerFunc(func(rw http.ResponseWriter, r *http.Request) {
|
|
rw.WriteHeader(http.StatusServiceUnavailable)
|
|
})
|
|
|
|
retryListener := &countingRetryListener{}
|
|
retry, err := New(t.Context(), next, dynamic.Retry{Attempts: 3}, retryListener, "traefikTest")
|
|
require.NoError(t, err)
|
|
|
|
recorder := httptest.NewRecorder()
|
|
req := httptest.NewRequest(http.MethodGet, "http://localhost:3000/ok", nil)
|
|
|
|
retry.ServeHTTP(recorder, req)
|
|
|
|
assert.Equal(t, http.StatusServiceUnavailable, recorder.Code)
|
|
assert.Equal(t, 0, retryListener.timesCalled)
|
|
}
|
|
|
|
func TestMultipleRetriesShouldNotLooseHeaders(t *testing.T) {
|
|
attempt := 0
|
|
expectedHeaderValue := "bar"
|
|
|
|
next := http.HandlerFunc(func(rw http.ResponseWriter, req *http.Request) {
|
|
shouldRetry := ContextShouldRetry(req.Context())
|
|
if shouldRetry != nil {
|
|
shouldRetry(true)
|
|
}
|
|
|
|
headerName := fmt.Sprintf("X-Foo-Test-%d", attempt)
|
|
rw.Header().Add(headerName, expectedHeaderValue)
|
|
if attempt < 2 {
|
|
attempt++
|
|
return
|
|
}
|
|
|
|
// Request has been successfully written to backend
|
|
shouldRetry(false)
|
|
|
|
// And we decide to answer to client.
|
|
rw.WriteHeader(http.StatusNoContent)
|
|
})
|
|
|
|
retry, err := New(t.Context(), next, dynamic.Retry{Attempts: 3}, &countingRetryListener{}, "traefikTest")
|
|
require.NoError(t, err)
|
|
|
|
res := httptest.NewRecorder()
|
|
retry.ServeHTTP(res, testhelpers.MustNewRequest(http.MethodGet, "http://test", http.NoBody))
|
|
|
|
// The third header attempt is kept.
|
|
headerValue := res.Header().Get("X-Foo-Test-2")
|
|
assert.Equal(t, expectedHeaderValue, headerValue)
|
|
|
|
// Validate that we don't have headers from previous attempts
|
|
for i := range attempt {
|
|
headerName := fmt.Sprintf("X-Foo-Test-%d", i)
|
|
headerValue = res.Header().Get(headerName)
|
|
if headerValue != "" {
|
|
t.Errorf("Expected no value for header %s, got %s", headerName, headerValue)
|
|
}
|
|
}
|
|
}
|
|
|
|
func TestRetryShouldNotLooseHeadersOnWrite(t *testing.T) {
|
|
next := http.HandlerFunc(func(rw http.ResponseWriter, req *http.Request) {
|
|
rw.Header().Add("X-Foo-Test", "bar")
|
|
|
|
// Request has been successfully written to backend.
|
|
shouldRetry := ContextShouldRetry(req.Context())
|
|
if shouldRetry != nil {
|
|
shouldRetry(false)
|
|
}
|
|
// And we decide to answer to client without calling WriteHeader.
|
|
_, err := rw.Write([]byte("bar"))
|
|
require.NoError(t, err)
|
|
})
|
|
|
|
retry, err := New(t.Context(), next, dynamic.Retry{Attempts: 3}, &countingRetryListener{}, "traefikTest")
|
|
require.NoError(t, err)
|
|
|
|
res := httptest.NewRecorder()
|
|
retry.ServeHTTP(res, testhelpers.MustNewRequest(http.MethodGet, "http://test", http.NoBody))
|
|
|
|
headerValue := res.Header().Get("X-Foo-Test")
|
|
assert.Equal(t, "bar", headerValue)
|
|
}
|
|
|
|
func TestRetryWithFlush(t *testing.T) {
|
|
next := http.HandlerFunc(func(rw http.ResponseWriter, req *http.Request) {
|
|
rw.WriteHeader(http.StatusOK)
|
|
_, err := rw.Write([]byte("FULL "))
|
|
if err != nil {
|
|
http.Error(rw, err.Error(), http.StatusInternalServerError)
|
|
}
|
|
rw.(http.Flusher).Flush()
|
|
_, err = rw.Write([]byte("DATA"))
|
|
if err != nil {
|
|
http.Error(rw, err.Error(), http.StatusInternalServerError)
|
|
}
|
|
})
|
|
|
|
retry, err := New(t.Context(), next, dynamic.Retry{Attempts: 1}, &countingRetryListener{}, "traefikTest")
|
|
require.NoError(t, err)
|
|
|
|
responseRecorder := httptest.NewRecorder()
|
|
|
|
retry.ServeHTTP(responseRecorder, &http.Request{})
|
|
|
|
assert.Equal(t, "FULL DATA", responseRecorder.Body.String())
|
|
}
|
|
|
|
func TestRetryWebsocket(t *testing.T) {
|
|
testCases := []struct {
|
|
desc string
|
|
maxRequestAttempts int
|
|
expectedRetryAttempts int
|
|
expectedResponseStatus int
|
|
expectedError bool
|
|
amountFaultyEndpoints int
|
|
}{
|
|
{
|
|
desc: "Switching ok after 2 retries",
|
|
maxRequestAttempts: 3,
|
|
expectedRetryAttempts: 2,
|
|
amountFaultyEndpoints: 2,
|
|
expectedResponseStatus: http.StatusSwitchingProtocols,
|
|
},
|
|
{
|
|
desc: "Switching failed",
|
|
maxRequestAttempts: 2,
|
|
expectedRetryAttempts: 1,
|
|
amountFaultyEndpoints: 2,
|
|
expectedResponseStatus: http.StatusBadGateway,
|
|
expectedError: true,
|
|
},
|
|
}
|
|
|
|
for _, test := range testCases {
|
|
t.Run(test.desc, func(t *testing.T) {
|
|
t.Parallel()
|
|
|
|
retryAttempts := 0
|
|
next := http.HandlerFunc(func(rw http.ResponseWriter, req *http.Request) {
|
|
// This signals that a connection will be established with the backend
|
|
// to enable the Retry middleware mechanism.
|
|
shouldRetry := ContextShouldRetry(req.Context())
|
|
if shouldRetry != nil {
|
|
shouldRetry(true)
|
|
}
|
|
|
|
retryAttempts++
|
|
|
|
if retryAttempts > test.amountFaultyEndpoints {
|
|
// This signals that request headers have been sent to the backend.
|
|
if shouldRetry != nil {
|
|
shouldRetry(false)
|
|
}
|
|
|
|
upgrader := websocket.Upgrader{}
|
|
_, err := upgrader.Upgrade(rw, req, nil)
|
|
if err != nil {
|
|
http.Error(rw, err.Error(), http.StatusInternalServerError)
|
|
}
|
|
return
|
|
}
|
|
|
|
rw.WriteHeader(http.StatusBadGateway)
|
|
})
|
|
|
|
retryListener := &countingRetryListener{}
|
|
retryH, err := New(t.Context(), next, dynamic.Retry{Attempts: test.maxRequestAttempts}, retryListener, "traefikTest")
|
|
require.NoError(t, err)
|
|
|
|
retryServer := httptest.NewServer(retryH)
|
|
|
|
url := strings.Replace(retryServer.URL, "http", "ws", 1)
|
|
_, response, err := websocket.DefaultDialer.Dial(url, nil)
|
|
|
|
if !test.expectedError {
|
|
require.NoError(t, err)
|
|
}
|
|
|
|
assert.Equal(t, test.expectedResponseStatus, response.StatusCode)
|
|
assert.Equal(t, test.expectedRetryAttempts, retryListener.timesCalled)
|
|
})
|
|
}
|
|
}
|
|
|
|
// This test is an adapted version of net/http/httputil.Test1xxResponses test.
|
|
func Test1xxResponses(t *testing.T) {
|
|
next := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
|
|
h := w.Header()
|
|
h.Add("Link", "</style.css>; rel=preload; as=style")
|
|
h.Add("Link", "</script.js>; rel=preload; as=script")
|
|
w.WriteHeader(http.StatusEarlyHints)
|
|
|
|
h.Add("Link", "</foo.js>; rel=preload; as=script")
|
|
w.WriteHeader(http.StatusProcessing)
|
|
|
|
_, _ = w.Write([]byte("Hello"))
|
|
})
|
|
|
|
retryListener := &countingRetryListener{}
|
|
retry, err := New(t.Context(), next, dynamic.Retry{Attempts: 1}, retryListener, "traefikTest")
|
|
require.NoError(t, err)
|
|
|
|
server := httptest.NewServer(retry)
|
|
t.Cleanup(server.Close)
|
|
frontendClient := server.Client()
|
|
|
|
checkLinkHeaders := func(t *testing.T, expected, got []string) {
|
|
t.Helper()
|
|
|
|
if len(expected) != len(got) {
|
|
t.Errorf("Expected %d link headers; got %d", len(expected), len(got))
|
|
}
|
|
|
|
for i := range expected {
|
|
if i >= len(got) {
|
|
t.Errorf("Expected %q link header; got nothing", expected[i])
|
|
|
|
continue
|
|
}
|
|
|
|
if expected[i] != got[i] {
|
|
t.Errorf("Expected %q link header; got %q", expected[i], got[i])
|
|
}
|
|
}
|
|
}
|
|
|
|
var respCounter uint8
|
|
trace := &httptrace.ClientTrace{
|
|
Got1xxResponse: func(code int, header textproto.MIMEHeader) error {
|
|
switch code {
|
|
case http.StatusEarlyHints:
|
|
checkLinkHeaders(t, []string{"</style.css>; rel=preload; as=style", "</script.js>; rel=preload; as=script"}, header["Link"])
|
|
case http.StatusProcessing:
|
|
checkLinkHeaders(t, []string{"</style.css>; rel=preload; as=style", "</script.js>; rel=preload; as=script", "</foo.js>; rel=preload; as=script"}, header["Link"])
|
|
default:
|
|
t.Error("Unexpected 1xx response")
|
|
}
|
|
|
|
respCounter++
|
|
|
|
return nil
|
|
},
|
|
}
|
|
req, _ := http.NewRequestWithContext(httptrace.WithClientTrace(t.Context(), trace), http.MethodGet, server.URL, nil)
|
|
|
|
res, err := frontendClient.Do(req)
|
|
assert.NoError(t, err)
|
|
|
|
defer res.Body.Close()
|
|
|
|
if respCounter != 2 {
|
|
t.Errorf("Expected 2 1xx responses; got %d", respCounter)
|
|
}
|
|
checkLinkHeaders(t, []string{"</style.css>; rel=preload; as=style", "</script.js>; rel=preload; as=script", "</foo.js>; rel=preload; as=script"}, res.Header["Link"])
|
|
|
|
body, _ := io.ReadAll(res.Body)
|
|
if string(body) != "Hello" {
|
|
t.Errorf("Read body %q; want Hello", body)
|
|
}
|
|
|
|
assert.Equal(t, 0, retryListener.timesCalled)
|
|
}
|
|
|
|
// countingRetryListener is a Listener implementation to count the times the Retried fn is called.
|
|
type countingRetryListener struct {
|
|
timesCalled int
|
|
}
|
|
|
|
func (l *countingRetryListener) Retried(req *http.Request, attempt int) {
|
|
l.timesCalled++
|
|
}
|