traefik/middlewares/retry/retry_test.go
2019-02-05 17:10:03 +01:00

312 lines
9.6 KiB
Go

package retry
import (
"context"
"fmt"
"net/http"
"net/http/httptest"
"net/http/httptrace"
"strings"
"testing"
"github.com/containous/traefik/config"
"github.com/containous/traefik/middlewares/emptybackendhandler"
"github.com/containous/traefik/testhelpers"
"github.com/gorilla/websocket"
"github.com/stretchr/testify/assert"
"github.com/stretchr/testify/require"
"github.com/vulcand/oxy/forward"
"github.com/vulcand/oxy/roundrobin"
)
func TestRetry(t *testing.T) {
testCases := []struct {
desc string
config config.Retry
wantRetryAttempts int
wantResponseStatus int
amountFaultyEndpoints int
}{
{
desc: "no retry on success",
config: config.Retry{Attempts: 1},
wantRetryAttempts: 0,
wantResponseStatus: http.StatusOK,
amountFaultyEndpoints: 0,
},
{
desc: "no retry when max request attempts is one",
config: config.Retry{Attempts: 1},
wantRetryAttempts: 0,
wantResponseStatus: http.StatusInternalServerError,
amountFaultyEndpoints: 1,
},
{
desc: "one retry when one server is faulty",
config: config.Retry{Attempts: 2},
wantRetryAttempts: 1,
wantResponseStatus: http.StatusOK,
amountFaultyEndpoints: 1,
},
{
desc: "two retries when two servers are faulty",
config: config.Retry{Attempts: 3},
wantRetryAttempts: 2,
wantResponseStatus: http.StatusOK,
amountFaultyEndpoints: 2,
},
{
desc: "max attempts exhausted delivers the 5xx response",
config: config.Retry{Attempts: 3},
wantRetryAttempts: 2,
wantResponseStatus: http.StatusInternalServerError,
amountFaultyEndpoints: 3,
},
}
backendServer := httptest.NewServer(http.HandlerFunc(func(rw http.ResponseWriter, req *http.Request) {
rw.WriteHeader(http.StatusOK)
_, err := rw.Write([]byte("OK"))
if err != nil {
http.Error(rw, err.Error(), http.StatusInternalServerError)
}
}))
forwarder, err := forward.New()
require.NoError(t, err)
for _, test := range testCases {
test := test
t.Run(test.desc, func(t *testing.T) {
t.Parallel()
loadBalancer, err := roundrobin.New(forwarder)
require.NoError(t, err)
basePort := 33444
for i := 0; i < test.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.
err = loadBalancer.UpsertServer(testhelpers.MustParseURL("http://192.0.2.0:" + string(basePort+i)))
require.NoError(t, err)
}
// add the functioning server to the end of the load balancer list
err = loadBalancer.UpsertServer(testhelpers.MustParseURL(backendServer.URL))
require.NoError(t, err)
retryListener := &countingRetryListener{}
retry, err := New(context.Background(), loadBalancer, 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) {
forwarder, err := forward.New()
require.NoError(t, err)
loadBalancer, err := roundrobin.New(forwarder)
require.NoError(t, err)
// The EmptyBackend middleware ensures that there is a 503
// response status set when there is no backend server in the pool.
next := emptybackendhandler.New(loadBalancer)
retryListener := &countingRetryListener{}
retry, err := New(context.Background(), next, config.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 TestRetryListeners(t *testing.T) {
req := httptest.NewRequest(http.MethodGet, "/", nil)
retryListeners := Listeners{&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)
}
}
}
func TestMultipleRetriesShouldNotLooseHeaders(t *testing.T) {
attempt := 0
expectedHeaderName := "X-Foo-Test-2"
expectedHeaderValue := "bar"
next := http.HandlerFunc(func(rw http.ResponseWriter, req *http.Request) {
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
trace := httptrace.ContextClientTrace(req.Context())
trace.WroteHeaders()
// And we decide to answer to client
rw.WriteHeader(http.StatusNoContent)
})
retry, err := New(context.Background(), next, config.Retry{Attempts: 3}, &countingRetryListener{}, "traefikTest")
require.NoError(t, err)
responseRecorder := httptest.NewRecorder()
retry.ServeHTTP(responseRecorder, testhelpers.MustNewRequest(http.MethodGet, "http://test", http.NoBody))
headerValue := responseRecorder.Header().Get(expectedHeaderName)
// Validate if we have the correct header
if headerValue != expectedHeaderValue {
t.Errorf("Expected to have %s for header %s, got %s", expectedHeaderValue, expectedHeaderName, headerValue)
}
// Validate that we don't have headers from previous attempts
for i := 0; i < attempt; i++ {
headerName := fmt.Sprintf("X-Foo-Test-%d", i)
headerValue = responseRecorder.Header().Get("headerName")
if headerValue != "" {
t.Errorf("Expected no value for header %s, got %s", headerName, headerValue)
}
}
}
// 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++
}
func TestRetryWithFlush(t *testing.T) {
next := http.HandlerFunc(func(rw http.ResponseWriter, req *http.Request) {
rw.WriteHeader(200)
_, 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(context.Background(), next, config.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,
},
}
forwarder, err := forward.New()
if err != nil {
t.Fatalf("Error creating forwarder: %v", err)
}
backendServer := httptest.NewServer(http.HandlerFunc(func(rw http.ResponseWriter, req *http.Request) {
upgrader := websocket.Upgrader{}
_, err := upgrader.Upgrade(rw, req, nil)
if err != nil {
http.Error(rw, err.Error(), http.StatusInternalServerError)
}
}))
for _, test := range testCases {
test := test
t.Run(test.desc, func(t *testing.T) {
t.Parallel()
loadBalancer, err := roundrobin.New(forwarder)
if err != nil {
t.Fatalf("Error creating load balancer: %v", err)
}
basePort := 33444
for i := 0; i < test.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
err = loadBalancer.UpsertServer(testhelpers.MustParseURL(backendServer.URL))
if err != nil {
t.Fatalf("Fail to upsert server: %v", err)
}
retryListener := &countingRetryListener{}
retryH, err := New(context.Background(), loadBalancer, config.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)
})
}
}