fix: print output from post render hook in console when withChange: false

integration/render_test.go

@@ -2050,6 +2050,7 @@ func TestRenderWithPostRenderHook(t *testing.T) {
 		description    string
 		projectDir     string
 		expectedOutput string
+		expectedStderr string
 		args           []string
 	}{
 		{
@@ -2160,12 +2161,38 @@ spec:
       name: module2
 `,
 		},
+		{
+			description: "single module project, one hook with changes, other without changes and with output",
+			projectDir:  "testdata/post-render-hooks",
+			args:        []string{"-m", "m1", "-p", "one-change-two-without-change-but-with-output", "-t", "customtag"},
+			expectedOutput: `apiVersion: v1
+kind: Pod
+metadata:
+  labels:
+    app1: before-change-1
+    app2: after-change-2
+  name: module1
+spec:
+  containers:
+    - image: us-central1-docker.pkg.dev/k8s-skaffold/testing/multi-config-module1:customtag
+      name: module1
+`,
+			expectedStderr: `Starting post-render hooks...
+running post-render hook 1
+running post-render hook 2
+Completed post-render hooks`,
+		},
 	}
 
 	for _, test := range tests {
 		testutil.Run(t, test.description, func(t *testutil.T) {
-			output := skaffold.Render(test.args...).InDir(test.projectDir).RunOrFailOutput(t.T)
-			t.CheckDeepEqual(test.expectedOutput, string(output), testutil.YamlObj(t.T))
+			stdout := new(bytes.Buffer)
+			stderr := new(bytes.Buffer)
+			skaffold.Render(test.args...).InDir(test.projectDir).RunWithStdoutAndStderrOrFail(t.T, stdout, stderr)
+			t.CheckDeepEqual(test.expectedOutput, stdout.String(), testutil.YamlObj(t.T))
+			if test.expectedStderr != "" {
+				t.CheckMatches(test.expectedStderr, stderr.String())
+			}
 		})
 	}
 }

integration/skaffold/helper.go

@@ -325,6 +325,28 @@ func (b *RunBuilder) RunOrFailOutput(t *testing.T) []byte {
 	return out
 }
 
+// RunWithStdoutAndStderrOrFail runs the Skaffold command copying the stdout and stderr to the given writers.
+// Fails if there is an error.
+func (b *RunBuilder) RunWithStdoutAndStderrOrFail(t *testing.T, stdout, stderr io.Writer) {
+	t.Helper()
+
+	cmd := b.cmd(context.Background())
+	cmd.Stdout = stdout
+	cmd.Stderr = stderr
+	t.Logf("Running %s in %s", cmd.Args, cmd.Dir)
+
+	start := time.Now()
+	err := cmd.Run()
+	if err != nil {
+		if ee, ok := err.(*exec.ExitError); ok {
+			defer t.Errorf(string(ee.Stderr))
+		}
+		t.Fatalf("skaffold %s: %v, %s", b.command, err, stderr)
+	}
+
+	t.Logf("Ran %s in %v", cmd.Args, timeutil.Humanize(time.Since(start)))
+}
+
 func (b *RunBuilder) cmd(ctx context.Context) *exec.Cmd {
 	args := []string{b.command}
 	command := b.getCobraCommand()

integration/testdata/post-render-hooks/module1/skaffold.yaml

@@ -47,4 +47,18 @@ profiles:
           - host:
               command:
                 - "sed"
-                - "s/before-change-1/after-change-1/g"
+                - "s/before-change-1/after-change-1/g"
+
+  - name: one-change-two-without-change-but-with-output
+    manifests:
+      hooks:
+        after:
+          - host:
+              command: ["sh", "-c", "echo running post-render hook 1"]
+          - host:
+              command:
+                - "sed"
+                - "s/before-change-2/after-change-2/g"
+              withChange: true
+          - host:
+              command: ["sh", "-c", "echo running post-render hook 2"]

pkg/skaffold/hooks/render.go

@@ -26,6 +26,7 @@ import (
 	"sync"
 
 	"github.com/GoogleContainerTools/skaffold/v2/pkg/skaffold/kubernetes/manifest"
+	"github.com/GoogleContainerTools/skaffold/v2/pkg/skaffold/output"
 	"github.com/GoogleContainerTools/skaffold/v2/pkg/skaffold/output/log"
 	"github.com/GoogleContainerTools/skaffold/v2/pkg/skaffold/schema/latest"
 )
@@ -69,8 +70,10 @@ func (r renderRunner) RunPreHooks(ctx context.Context, out io.Writer) error {
 }
 
 func (r renderRunner) RunPostHooks(ctx context.Context, list manifest.ManifestList, out io.Writer) (manifest.ManifestList, error) {
+	logWriter := log.GetWriter()
+
 	if len(r.PostHooks) > 0 {
-		log.Entry(context.TODO()).Errorf("Starting %s hooks...", phases.PostRender)
+		output.Default.Fprintln(logWriter, fmt.Sprintf("Starting %s hooks...", phases.PostRender))
 	}
 	updated, err := manifest.Load(list.Reader())
 	if err != nil {
@@ -100,14 +103,14 @@ func (r renderRunner) RunPostHooks(ctx context.Context, list manifest.ManifestLi
 					return manifest.ManifestList{}, fmt.Errorf("failed to load manifest")
 				}
 			} else {
-				if err := hook.run(ctx, updated.Reader(), &b); err != nil && !errors.Is(err, &Skip{}) {
+				if err := hook.run(ctx, updated.Reader(), logWriter); err != nil && !errors.Is(err, &Skip{}) {
 					return manifest.ManifestList{}, err
 				}
 			}
 		}
 	}
 	if len(r.PostHooks) > 0 {
-		log.Entry(context.TODO()).Errorf("Completed %s hooks", phases.PostRender)
+		output.Default.Fprintln(logWriter, fmt.Sprintf("Completed %s hooks", phases.PostRender))
 	}
 	return updated, nil
 }
@@ -119,8 +122,10 @@ func (r renderRunner) getEnv() []string {
 }
 
 func (r renderRunner) run(ctx context.Context, out io.Writer, hooks []latest.RenderHookItem, phase phase) error {
+	logWriter := log.GetWriter()
+
 	if len(hooks) > 0 {
-		log.Entry(context.TODO()).Errorf("Starting %s hooks...", phase)
+		output.Default.Fprintln(logWriter, fmt.Sprintf("Starting %s hooks...", phase))
 	}
 	env := r.getEnv()
 	for _, h := range hooks {
@@ -132,7 +137,7 @@ func (r renderRunner) run(ctx context.Context, out io.Writer, hooks []latest.Ren
 		}
 	}
 	if len(hooks) > 0 {
-		log.Entry(context.TODO()).Errorf("Completed %s hooks...", phase)
+		output.Default.Fprintln(logWriter, fmt.Sprintf("Completed %s hooks...", phase))
 	}
 	return nil
 }

pkg/skaffold/output/log/log.go

@@ -122,6 +122,11 @@ func Entry(ctx context.Context) *logrus.Entry {
 	})
 }
 
+// Returns the output used by the logger to write its content.
+func GetWriter() io.Writer {
+	return logger.Out
+}
+
 // IsDebugLevelEnabled returns true if debug level log is enabled.
 func IsDebugLevelEnabled() bool {
 	return logger.IsLevelEnabled(logrus.DebugLevel)