fix: surface errors

runner/sidecar/sidecar.go

@@ -138,7 +138,7 @@ func patchStepStatus(ctx context.Context) {
 			"sinkStatuses":   sinkStatues,
 		},
 	})
-	logger.Info("patching step status (sinks/sources)", "patch", patch)
+	debug.Info("patching step status (sinks/sources)", "patch", patch)
 	if _, err := dynamicInterface.
 		Resource(dfv1.StepGroupVersionResource).
 		Namespace(namespace).
@@ -348,6 +348,7 @@ func connectSources(ctx context.Context, toMain func([]byte) error) error {
 				if err != nil {
 					logger.Error(err, "⚠ http →")
 					w.WriteHeader(500)
+					_, _ = w.Write([]byte(err.Error()))
 					withLock(func() { sourceStatues.IncErrors(sourceName, replica, err) })
 					return
 				}
@@ -356,6 +357,7 @@ func connectSources(ctx context.Context, toMain func([]byte) error) error {
 				if err := toMain(data); err != nil {
 					logger.Error(err, "⚠ http →")
 					w.WriteHeader(500)
+					_, _ = w.Write([]byte(err.Error()))
 					withLock(func() { sourceStatues.IncErrors(sourceName, replica, err) })
 				} else {
 					debug.Info("✔ http ")
@@ -435,7 +437,8 @@ func connectTo(ctx context.Context) (func([]byte) error, error) {
 				return fmt.Errorf("failed to send message to main via HTTP: %w", err)
 			}
 			if resp.StatusCode >= 300 {
-				return fmt.Errorf("failed to sent message to main via HTTP: %s", resp.Status)
+				body, _ := ioutil.ReadAll(resp.Body)
+				return fmt.Errorf("failed to sent message to main via HTTP: %q %q", resp.Status, body)
 			}
 			trace.Info("✔ source → http")
 			return nil
@@ -480,16 +483,18 @@ func connectOut(toSink func([]byte) error) {
 		if err != nil {
 			logger.Error(err, "failed to read message body from main via HTTP")
 			w.WriteHeader(500)
+			_, _ = w.Write([]byte(err.Error()))
 			return
 		}
 		trace.Info("◷ http → sink")
 		if err := toSink(data); err != nil {
 			logger.Error(err, "failed to send message from main to sink")
 			w.WriteHeader(500)
-			return
+			_, _ = w.Write([]byte(err.Error()))
+		} else {
+			trace.Info("✔ http → sink")
+			w.WriteHeader(200)
 		}
-		trace.Info("✔ http → sink")
-		w.WriteHeader(200)
 	})
 	go func() {
 		defer runtimeutil.HandleCrash(runtimeutil.PanicHandlers...)
@@ -561,8 +566,9 @@ func connectSink() (func([]byte) error, error) {
 				err := func() error {
 					if resp, err := http.Post(x.URL, "application/octet-stream", bytes.NewBuffer(m)); err != nil {
 						return err
-					} else if resp.StatusCode != 200 {
-						return fmt.Errorf("failed to send HTTP request: %q", resp.Status)
+					} else if resp.StatusCode >= 300 {
+						body, _ := ioutil.ReadAll(resp.Body)
+						return fmt.Errorf("failed to send HTTP request: %q %q", resp.Status, body)
 					} else {
 						return nil
 					}