Merge 4a031e11b1 into 42f78ba60e

pkg/postrenderer/postrenderer.go

@@ -61,6 +61,8 @@ type postRendererPlugin struct {
 
 // Run implements PostRenderer by using the plugin's Runtime
 func (r *postRendererPlugin) Run(renderedManifests *bytes.Buffer) (*bytes.Buffer, error) {
+	renderedManifestsLen := renderedManifests.Len()
+
 	input := &plugin.Input{
 		Message: schema.InputMessagePostRendererV1{
 			ExtraArgs: r.args,
@@ -74,9 +76,9 @@ func (r *postRendererPlugin) Run(renderedManifests *bytes.Buffer) (*bytes.Buffer
 
 	outputMessage := output.Message.(schema.OutputMessagePostRendererV1)
 
-	// If the binary returned almost nothing, it's likely that it didn't
-	// successfully render anything
-	if len(bytes.TrimSpace(outputMessage.Manifests.Bytes())) == 0 {
+	// If the binary returned almost nothing and the input isn't empty, it's
+	// likely that it didn't successfully render anything
+	if len(bytes.TrimSpace(outputMessage.Manifests.Bytes())) == 0 && renderedManifestsLen != 0 {
 		return nil, fmt.Errorf("post-renderer %q produced empty output", r.plugin.Metadata().Name)
 	}
 

pkg/postrenderer/postrenderer_test.go

@@ -40,10 +40,27 @@ func TestNewPostRenderPluginRunWithNoOutput(t *testing.T) {
 	renderer, err := NewPostRendererPlugin(s, name, "")
 	require.NoError(t, err)
 
-	_, err = renderer.Run(bytes.NewBufferString(""))
+	_, err = renderer.Run(bytes.NewBufferString("FOOTEST"))
 	is.Error(err)
 }
 
+func TestNewPostRenderPluginRunWithNoInputAndOutput(t *testing.T) {
+	if runtime.GOOS == "windows" {
+		// the actual Run test uses a basic sed example, so skip this test on windows
+		t.Skip("skipping on windows")
+	}
+	is := assert.New(t)
+	s := cli.New()
+	s.PluginsDirectory = "testdata/plugins"
+	name := "postrenderer-v1"
+
+	renderer, err := NewPostRendererPlugin(s, name, "")
+	require.NoError(t, err)
+
+	_, err = renderer.Run(bytes.NewBufferString(""))
+	is.NoError(err)
+}
+
 func TestNewPostRenderPluginWithOneArgsRun(t *testing.T) {
 	if runtime.GOOS == "windows" {
 		// the actual Run test uses a basic sed example, so skip this test on windows