test: get the retry times

examples/retry_test.go

@@ -0,0 +1,107 @@
+package examples
+
+import (
+	"context"
+	"fmt"
+	"io"
+	"net/http"
+	"net/http/httptest"
+	"os"
+	"testing"
+	"time"
+
+	"github.com/gojek/heimdall/v7"
+	"github.com/gojek/heimdall/v7/httpclient"
+)
+
+type ctxKey string
+
+const (
+	reqTime        ctxKey = "request_time_start"
+	RFC3339ZNoTNoZ        = "2006-01-02 15:04:05"
+)
+
+type retryRequestLogger struct {
+	out          io.Writer
+	errOut       io.Writer
+	backoff      heimdall.Backoff
+	currentRetry int
+}
+
+func NewRetryRequestLogger(out io.Writer, errOut io.Writer) *retryRequestLogger {
+	if out == nil {
+		out = os.Stdout
+	}
+
+	if errOut == nil {
+		errOut = os.Stderr
+	}
+
+	return &retryRequestLogger{
+		out:     out,
+		errOut:  errOut,
+		backoff: heimdall.NewConstantBackoff(100*time.Millisecond, 1000*time.Millisecond),
+	}
+}
+
+func (rl *retryRequestLogger) OnRequestStart(req *http.Request) {
+	ctx := context.WithValue(req.Context(), reqTime, time.Now())
+	*req = *(req.WithContext(ctx))
+}
+
+func (rl *retryRequestLogger) OnRequestEnd(req *http.Request, res *http.Response) {}
+
+func (rl *retryRequestLogger) Retrierfunc(retry int) time.Duration {
+	rl.currentRetry = retry
+	return rl.backoff.Next(retry)
+}
+
+func (rl *retryRequestLogger) OnError(req *http.Request, err error) {
+	reqDurationMs := getRequestDuration(req.Context()) / time.Millisecond
+	fmt.Fprintf(rl.errOut, "%s retry(%d) ERROR: %v [%dms]\n", time.Now().Format(RFC3339ZNoTNoZ), rl.currentRetry+1, err, reqDurationMs)
+}
+
+func getRequestDuration(ctx context.Context) time.Duration {
+	now := time.Now()
+	start := ctx.Value(reqTime)
+	if start == nil {
+		return 0
+	}
+	startTime, ok := start.(time.Time)
+	if !ok {
+		return 0
+	}
+	return now.Sub(startTime)
+}
+
+/*
+2022-04-02 13:28:03 retry(1) ERROR: Get "http://127.0.0.1:43817": context deadline exceeded (Client.Timeout exceeded while awaiting headers) [3002ms]
+2022-04-02 13:28:06 retry(1) ERROR: Get "http://127.0.0.1:43817": context deadline exceeded (Client.Timeout exceeded while awaiting headers) [3000ms]
+2022-04-02 13:28:10 retry(2) ERROR: Get "http://127.0.0.1:43817": context deadline exceeded (Client.Timeout exceeded while awaiting headers) [3002ms]
+2022-04-02 13:28:14 retry(3) ERROR: Get "http://127.0.0.1:43817": context deadline exceeded (Client.Timeout exceeded while awaiting headers) [3002ms]
+*/
+
+func TestHTTPTimeoutRetry(t *testing.T) {
+	plugin := NewRetryRequestLogger(nil, nil)
+	cli := httpclient.NewClient(
+		httpclient.WithHTTPTimeout(3*time.Second),
+		httpclient.WithRetrier(heimdall.NewRetrierFunc(plugin.Retrierfunc)),
+		httpclient.WithRetryCount(3),
+	)
+
+	cli.AddPlugin(plugin)
+
+	dummyHandler := func(w http.ResponseWriter, r *http.Request) {
+		time.Sleep(4 * time.Second)
+		w.WriteHeader(http.StatusGatewayTimeout)
+		w.Write([]byte(`{"response": "gateway timeout exceeded"}`))
+	}
+
+	server := httptest.NewServer(http.HandlerFunc(dummyHandler))
+	defer server.Close()
+
+	_, err := cli.Get(server.URL, http.Header{})
+	if err != nil {
+		fmt.Println(err)
+	}
+}