feat: Added option for configuring number of retries for http event sender, as well as additional logging (#465)

* feat: Added option for configuring number of retries for http event sender, as well as additional logging

Signed-off-by: Florian Bacher <florian.bacher@dynatrace.com>

* added option for injecting retry callback

Signed-off-by: Florian Bacher <florian.bacher@dynatrace.com>

* added option for injecting retry callback

Signed-off-by: Florian Bacher <florian.bacher@dynatrace.com>

* remove retry callback option

Signed-off-by: Florian Bacher <florian.bacher@dynatrace.com>

* remove retry callback option unit test

Signed-off-by: Florian Bacher <florian.bacher@dynatrace.com>

* added comment

Signed-off-by: Florian Bacher <florian.bacher@dynatrace.com>

Author: bacherfl

pkg/lib/v0_2_0/events.go

@@ -41,16 +41,27 @@ const keptnSpecVersionCEExtension = "shkeptnspecversion"
 const triggeredIDCEExtension = "triggeredid"
 const keptnGitCommitIDCEExtension = "gitcommitid"
 
+type HTTPSenderOption func(httpSender *HTTPEventSender)
+
+// WithSendRetries allows to specify the number of retries that are performed if the receiver of an event returns a HTTP error code
+func WithSendRetries(retries int) HTTPSenderOption {
+	return func(httpSender *HTTPEventSender) {
+		httpSender.nrRetries = retries
+	}
+}
+
 // HTTPEventSender sends CloudEvents via HTTP
 type HTTPEventSender struct {
 	// EventsEndpoint is the http endpoint the events are sent to
 	EventsEndpoint string
 	// Client is an implementation of the cloudevents.Client interface
 	Client cloudevents.Client
+	// nrRetries is the number of retries that are attempted if the endpoint an event is forwarded to returns an http code outside the 2xx range
+	nrRetries int
 }
 
 // NewHTTPEventSender creates a new HTTPSender
-func NewHTTPEventSender(endpoint string) (*HTTPEventSender, error) {
+func NewHTTPEventSender(endpoint string, opts ...HTTPSenderOption) (*HTTPEventSender, error) {
 	if endpoint == "" {
 		endpoint = DefaultHTTPEventEndpoint
 	}
@@ -75,6 +86,11 @@ func NewHTTPEventSender(endpoint string) (*HTTPEventSender, error) {
 	httpSender := &HTTPEventSender{
 		EventsEndpoint: endpoint,
 		Client:         c,
+		nrRetries:      MAX_SEND_RETRIES,
+	}
+
+	for _, o := range opts {
+		o(httpSender)
 	}
 	return httpSender, nil
 }
@@ -88,7 +104,7 @@ func (httpSender HTTPEventSender) Send(ctx context.Context, event cloudevents.Ev
 	ctx = cloudevents.ContextWithTarget(ctx, httpSender.EventsEndpoint)
 	ctx = cloudevents.WithEncodingStructured(ctx)
 	var result protocol.Result
-	for i := 0; i <= MAX_SEND_RETRIES; i++ {
+	for i := 0; i <= httpSender.nrRetries; i++ {
 		result = httpSender.Client.Send(ctx, event)
 		httpResult, ok := result.(*httpprotocol.Result)
 		switch {
@@ -103,7 +119,7 @@ func (httpSender HTTPEventSender) Send(ctx context.Context, event cloudevents.Ev
 			return nil
 		}
 	}
-	return errors.New("Failed to send cloudevent: " + result.Error())
+	return fmt.Errorf("could not send cloudevent after %d retries. Received result from the receiver: %w", httpSender.nrRetries, result)
 }
 
 // EventSender fakes the sending of CloudEvents

pkg/lib/v0_2_0/events_test.go

@@ -1,6 +1,7 @@
 package v0_2_0
 
 import (
+	"context"
 	"net/http"
 	"net/http/httptest"
 	"testing"
@@ -48,49 +49,53 @@ func TestKeptn_SendCloudEventWithRetry(t *testing.T) {
 				failOnFirstTry = false
 				w.WriteHeader(500)
 				w.Write([]byte(`{}`))
+				return
 			}
 			w.WriteHeader(200)
 			w.Write([]byte(`{}`))
 		}),
 	)
 	defer ts.Close()
 
-	type args struct {
-		event cloudevents.Event
-	}
-	tests := []struct {
-		name    string
-		fields  fields
-		args    args
-		wantErr bool
-	}{
-		{
-			name:   "",
-			fields: getKeptnFields(ts),
-			args: args{
-				event: getTestEvent(),
-			},
-			wantErr: false,
-		},
-	}
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			httpSender, _ := NewHTTPEventSender(ts.URL)
-			k := &Keptn{
-				KeptnBase: keptn.KeptnBase{
-					KeptnContext:       tt.fields.KeptnContext,
-					Event:              tt.fields.KeptnBase,
-					EventSender:        httpSender,
-					UseLocalFileSystem: tt.fields.useLocalFileSystem,
-					ResourceHandler:    tt.fields.resourceHandler,
-					EventHandler:       tt.fields.eventHandler,
-				},
-			}
-			if err := k.SendCloudEvent(tt.args.event); (err != nil) != tt.wantErr {
-				t.Errorf("SendCloudEvent() error = %v, wantErr %v", err, tt.wantErr)
+	httpSender, _ := NewHTTPEventSender(ts.URL)
+
+	err := httpSender.Send(context.TODO(), getTestEvent())
+
+	require.Nil(t, err)
+}
+
+func TestKeptn_SendCloudEventWithOneRetry(t *testing.T) {
+	nrRequests := 0
+	ts := httptest.NewServer(
+		http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			w.Header().Add("Content-Type", "application/json")
+			if nrRequests < 2 {
+				nrRequests++
+				w.WriteHeader(500)
+				w.Write([]byte(`{}`))
+				return
 			}
-		})
-	}
+			w.WriteHeader(200)
+			w.Write([]byte(`{}`))
+		}),
+	)
+	defer ts.Close()
+
+	httpSender, _ := NewHTTPEventSender(ts.URL, WithSendRetries(1))
+
+	err := httpSender.Send(context.TODO(), getTestEvent())
+
+	require.NotNil(t, err)
+
+	// reset nrRequests
+	nrRequests = 0
+
+	//initialize a new sender with 2 retries
+	httpSender, _ = NewHTTPEventSender(ts.URL, WithSendRetries(5))
+
+	err = httpSender.Send(context.TODO(), getTestEvent())
+
+	require.Nil(t, err)
 }
 
 func getTestEvent() cloudevents.Event {