traefik/middlewares/retry_test.go

196 lines
5.8 KiB
Go

package middlewares
import (
"net/http"
"net/http/httptest"
"testing"
"github.com/containous/traefik/testhelpers"
"github.com/vulcand/oxy/forward"
"github.com/vulcand/oxy/roundrobin"
)
func TestRetry(t *testing.T) {
testCases := []struct {
desc string
maxRequestAttempts int
wantRetryAttempts int
wantResponseStatus int
amountFaultyEndpoints int
isWebsocketHandshakeRequest bool
}{
{
desc: "no retry on success",
maxRequestAttempts: 1,
wantRetryAttempts: 0,
wantResponseStatus: http.StatusOK,
amountFaultyEndpoints: 0,
},
{
desc: "no retry when max request attempts is one",
maxRequestAttempts: 1,
wantRetryAttempts: 0,
wantResponseStatus: http.StatusInternalServerError,
amountFaultyEndpoints: 1,
},
{
desc: "one retry when one server is faulty",
maxRequestAttempts: 2,
wantRetryAttempts: 1,
wantResponseStatus: http.StatusOK,
amountFaultyEndpoints: 1,
},
{
desc: "two retries when two servers are faulty",
maxRequestAttempts: 3,
wantRetryAttempts: 2,
wantResponseStatus: http.StatusOK,
amountFaultyEndpoints: 2,
},
{
desc: "max attempts exhausted delivers the 5xx response",
maxRequestAttempts: 3,
wantRetryAttempts: 2,
wantResponseStatus: http.StatusInternalServerError,
amountFaultyEndpoints: 3,
},
{
desc: "websocket request should not be retried",
maxRequestAttempts: 3,
wantRetryAttempts: 0,
wantResponseStatus: http.StatusBadGateway,
amountFaultyEndpoints: 1,
isWebsocketHandshakeRequest: true,
},
}
backendServer := httptest.NewServer(http.HandlerFunc(func(rw http.ResponseWriter, req *http.Request) {
rw.WriteHeader(http.StatusOK)
rw.Write([]byte("OK"))
}))
forwarder, err := forward.New()
if err != nil {
t.Fatalf("Error creating forwarder: %s", err)
}
for _, tc := range testCases {
tc := tc
t.Run(tc.desc, func(t *testing.T) {
t.Parallel()
loadBalancer, err := roundrobin.New(forwarder)
if err != nil {
t.Fatalf("Error creating load balancer: %s", err)
}
basePort := 33444
for i := 0; i < tc.amountFaultyEndpoints; i++ {
// 192.0.2.0 is a non-routable IP for testing purposes.
// See: https://stackoverflow.com/questions/528538/non-routable-ip-address/18436928#18436928
// We only use the port specification here because the URL is used as identifier
// in the load balancer and using the exact same URL would not add a new server.
loadBalancer.UpsertServer(testhelpers.MustParseURL("http://192.0.2.0:" + string(basePort+i)))
}
// add the functioning server to the end of the load balancer list
loadBalancer.UpsertServer(testhelpers.MustParseURL(backendServer.URL))
retryListener := &countingRetryListener{}
retry := NewRetry(tc.maxRequestAttempts, loadBalancer, retryListener)
recorder := httptest.NewRecorder()
req := httptest.NewRequest(http.MethodGet, "http://localhost:3000/ok", nil)
if tc.isWebsocketHandshakeRequest {
req.Header.Add("Connection", "Upgrade")
req.Header.Add("Upgrade", "websocket")
}
retry.ServeHTTP(recorder, req)
if tc.wantResponseStatus != recorder.Code {
t.Errorf("got status code %d, want %d", recorder.Code, tc.wantResponseStatus)
}
if tc.wantRetryAttempts != retryListener.timesCalled {
t.Errorf("retry listener called %d time(s), want %d time(s)", retryListener.timesCalled, tc.wantRetryAttempts)
}
})
}
}
func TestRetryEmptyServerList(t *testing.T) {
forwarder, err := forward.New()
if err != nil {
t.Fatalf("Error creating forwarder: %s", err)
}
loadBalancer, err := roundrobin.New(forwarder)
if err != nil {
t.Fatalf("Error creating load balancer: %s", err)
}
// The EmptyBackendHandler middleware ensures that there is a 503
// response status set when there is no backend server in the pool.
next := NewEmptyBackendHandler(loadBalancer)
retryListener := &countingRetryListener{}
retry := NewRetry(3, next, retryListener)
recorder := httptest.NewRecorder()
req := httptest.NewRequest(http.MethodGet, "http://localhost:3000/ok", nil)
retry.ServeHTTP(recorder, req)
const wantResponseStatus = http.StatusServiceUnavailable
if wantResponseStatus != recorder.Code {
t.Errorf("got status code %d, want %d", recorder.Code, wantResponseStatus)
}
const wantRetryAttempts = 0
if wantRetryAttempts != retryListener.timesCalled {
t.Errorf("retry listener called %d time(s), want %d time(s)", retryListener.timesCalled, wantRetryAttempts)
}
}
func TestRetryListeners(t *testing.T) {
req := httptest.NewRequest(http.MethodGet, "/", nil)
retryListeners := RetryListeners{&countingRetryListener{}, &countingRetryListener{}}
retryListeners.Retried(req, 1)
retryListeners.Retried(req, 1)
for _, retryListener := range retryListeners {
listener := retryListener.(*countingRetryListener)
if listener.timesCalled != 2 {
t.Errorf("retry listener was called %d time(s), want %d time(s)", listener.timesCalled, 2)
}
}
}
// countingRetryListener is a RetryListener 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++
}
func TestRetryWithFlush(t *testing.T) {
next := http.HandlerFunc(func(rw http.ResponseWriter, req *http.Request) {
rw.WriteHeader(200)
rw.Write([]byte("FULL "))
rw.(http.Flusher).Flush()
rw.Write([]byte("DATA"))
})
retry := NewRetry(1, next, &countingRetryListener{})
responseRecorder := httptest.NewRecorder()
retry.ServeHTTP(responseRecorder, &http.Request{})
if responseRecorder.Body.String() != "FULL DATA" {
t.Errorf("Wrong body %q want %q", responseRecorder.Body.String(), "FULL DATA")
}
}