Add munge func to output writer (#173)

Some synthesizers may have their own internal structure (e.g. the helm shim) while some logically separate code performs final transformation(s) - adding annotations, etc. Co-authored-by: Jordan Olshevski <[email protected]>
Azure · Jul 23, 2024 · 2de1d5a · 2de1d5a
1 parent da0cbb9
commit 2de1d5a
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Showing 2 changed files with 27 additions and 4 deletions.
diff --git a/pkg/function/outputs.go b/pkg/function/outputs.go
@@ -16,17 +16,21 @@ type OutputWriter struct {
 	outputs   []*unstructured.Unstructured
 	io        io.Writer
 	committed bool
+	munge     MungeFunc
 }
 
+type MungeFunc func(*unstructured.Unstructured)
+
 func NewDefaultOutputWriter() *OutputWriter {
-	return NewOutputWriter(os.Stdout)
+	return NewOutputWriter(os.Stdout, nil)
 }
 
-func NewOutputWriter(w io.Writer) *OutputWriter {
+func NewOutputWriter(w io.Writer, munge MungeFunc) *OutputWriter {
 	return &OutputWriter{
 		outputs:   []*unstructured.Unstructured{},
 		io:        w,
 		committed: false,
+		munge:     munge,
 	}
 }
 
@@ -49,7 +53,11 @@ func (w *OutputWriter) Add(outs ...client.Object) error {
 				err,
 			)
 		}
-		w.outputs = append(w.outputs, &unstructured.Unstructured{Object: obj})
+		u := &unstructured.Unstructured{Object: obj}
+		if w.munge != nil {
+			w.munge(u)
+		}
+		w.outputs = append(w.outputs, u)
 	}
 	return nil
 }

diff --git a/pkg/function/outputs_test.go b/pkg/function/outputs_test.go
@@ -7,11 +7,12 @@ import (
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 	corev1 "k8s.io/api/core/v1"
+	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
 )
 
 func TestOutputWriter(t *testing.T) {
 	out := bytes.NewBuffer(nil)
-	w := NewOutputWriter(out)
+	w := NewOutputWriter(out, nil)
 
 	cm := &corev1.ConfigMap{}
 	cm.Name = "test-cm"
@@ -25,3 +26,17 @@ func TestOutputWriter(t *testing.T) {
 
 	require.Error(t, w.Add(nil))
 }
+
+func TestOutputWriterMunge(t *testing.T) {
+	out := bytes.NewBuffer(nil)
+	w := NewOutputWriter(out, func(u *unstructured.Unstructured) {
+		unstructured.SetNestedField(u.Object, "value from munge function", "data", "extra-val")
+	})
+
+	cm := &corev1.ConfigMap{}
+	cm.Name = "test-cm"
+
+	require.NoError(t, w.Add(cm))
+	require.NoError(t, w.Write())
+	assert.Equal(t, "{\"apiVersion\":\"config.kubernetes.io/v1\",\"kind\":\"ResourceList\",\"items\":[{\"data\":{\"extra-val\":\"value from munge function\"},\"metadata\":{\"creationTimestamp\":null,\"name\":\"test-cm\"}}]}\n", out.String())
+}