Change antctl traceflow command to output results at timeout/failure

Output the Traceflow results, as long as there are any results returned,
so users can know the progress of the Traceflow session even the antctl
command is timeout, or the Traceflow operation fails.

pkg/antctl/raw/traceflow/command.go

@@ -18,6 +18,7 @@ import (
 	"bytes"
 	"context"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"net"
 	"strconv"
@@ -26,7 +27,7 @@ import (
 
 	"github.com/spf13/cobra"
 	"gopkg.in/yaml.v2"
-	"k8s.io/apimachinery/pkg/api/errors"
+	k8serrors "k8s.io/apimachinery/pkg/api/errors"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/util/rand"
 	"k8s.io/apimachinery/pkg/util/wait"
@@ -137,23 +138,31 @@ func runE(cmd *cobra.Command, _ []string) error {
 		return nil
 	}
 
-	if err := wait.Poll(1*time.Second, 15*time.Second, func() (bool, error) {
-		tf, err := client.OpsV1alpha1().Traceflows().Get(context.TODO(), tf.Name, metav1.GetOptions{})
+	var res *v1alpha1.Traceflow
+	err = wait.Poll(1*time.Second, 15*time.Second, func() (bool, error) {
+		res, err = client.OpsV1alpha1().Traceflows().Get(context.TODO(), tf.Name, metav1.GetOptions{})
 		if err != nil {
 			return false, err
 		}
-		if tf.Status.Phase != v1alpha1.Succeeded {
+		if res.Status.Phase != v1alpha1.Succeeded && res.Status.Phase != v1alpha1.Failed {
 			return false, nil
 		}
-		if err := output(tf); err != nil {
-			return false, fmt.Errorf("error when outputing result: %w", err)
-		}
 		return true, nil
-	}); err != nil {
+	})
+	if err == wait.ErrWaitTimeout {
+		err = errors.New("timeout waiting for Traceflow done")
+		// Still output the Traceflow results if any.
+		if res == nil {
+			return err
+		}
+	} else if err != nil {
 		return fmt.Errorf("error when retrieving Traceflow: %w", err)
 	}
 
-	return nil
+	if err := output(res); err != nil {
+		return fmt.Errorf("error when outputting result: %w", err)
+	}
+	return err
 }
 
 func newTraceflow(client kubernetes.Interface) (*v1alpha1.Traceflow, error) {
@@ -224,7 +233,7 @@ func dstIsPod(client kubernetes.Interface, ns string, name string) (bool, error)
 	defer cancel()
 	_, err := client.CoreV1().Pods(ns).Get(ctx, name, metav1.GetOptions{})
 	if err != nil {
-		if errors.IsNotFound(err) {
+		if k8serrors.IsNotFound(err) {
 			return false, nil
 		}
 		return false, fmt.Errorf("failed to get Pod from Kubernetes API: %w", err)