From 39094f2aebe152207cf0fd043734979deebca46e Mon Sep 17 00:00:00 2001
From: Jingfang Liu <jingfangliu@google.com>
Date: Thu, 27 Feb 2020 12:09:49 -0800
Subject: [PATCH 1/2] add SetLabel function in kyaml library

---
 kyaml/yaml/filters.go |  1 +
 kyaml/yaml/kfns.go    | 22 ++++++++++++++++++++++
 2 files changed, 23 insertions(+)

diff --git a/kyaml/yaml/filters.go b/kyaml/yaml/filters.go
index 46f22821a..7d6d00fad 100644
--- a/kyaml/yaml/filters.go
+++ b/kyaml/yaml/filters.go
@@ -15,6 +15,7 @@ var Filters = map[string]func() Filter{
 	"AnnotationClearer": func() Filter { return &AnnotationClearer{} },
 	"AnnotationGetter":  func() Filter { return &AnnotationGetter{} },
 	"AnnotationSetter":  func() Filter { return &AnnotationSetter{} },
+	"LabelSetter":       func() Filter { return &LabelSetter{} },
 	"ElementAppender":   func() Filter { return &ElementAppender{} },
 	"ElementMatcher":    func() Filter { return &ElementMatcher{} },
 	"FieldClearer":      func() Filter { return &FieldClearer{} },
diff --git a/kyaml/yaml/kfns.go b/kyaml/yaml/kfns.go
index 564682c64..84d3f2af7 100644
--- a/kyaml/yaml/kfns.go
+++ b/kyaml/yaml/kfns.go
@@ -68,3 +68,25 @@ func (g AnnotationGetter) Filter(rn *RNode) (*RNode, error) {
 func GetAnnotation(key string) AnnotationGetter {
 	return AnnotationGetter{Key: key}
 }
+
+// LabelSetter sets a label at metadata.labels.
+// Creates metadata.labels if does not exist.
+type LabelSetter struct {
+	Kind  string `yaml:"kind,omitempty"`
+	Key   string `yaml:"key,omitempty"`
+	Value string `yaml:"value,omitempty"`
+}
+
+func (s LabelSetter) Filter(rn *RNode) (*RNode, error) {
+	// some tools get confused about the type if labels are not quoted
+	v := NewScalarRNode(s.Value)
+	v.YNode().Tag = "!!str"
+	v.YNode().Style = yaml.SingleQuotedStyle
+	return rn.Pipe(
+		PathGetter{Path: []string{"metadata", "labels"}, Create: yaml.MappingNode},
+		FieldSetter{Name: s.Key, Value: v})
+}
+
+func SetLabel(key, value string) LabelSetter {
+	return LabelSetter{Key: key, Value: value}
+}

From ef76575ab61c70e4057ecd5378b329a149a43230 Mon Sep 17 00:00:00 2001
From: Jingfang Liu <jingfangliu@google.com>
Date: Thu, 27 Feb 2020 13:37:36 -0800
Subject: [PATCH 2/2] add test for SetLabel and SetAnnotation

---
 kyaml/yaml/kfns_test.go | 60 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 60 insertions(+)
 create mode 100644 kyaml/yaml/kfns_test.go

diff --git a/kyaml/yaml/kfns_test.go b/kyaml/yaml/kfns_test.go
new file mode 100644
index 000000000..7b0e0cb8f
--- /dev/null
+++ b/kyaml/yaml/kfns_test.go
@@ -0,0 +1,60 @@
+package yaml
+
+import (
+	"testing"
+)
+
+var input = `apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: the-map
+data:
+  altGreeting: "Good Morning!"
+  enableRisky: "false"
+`
+
+func TestSetLabel(t *testing.T) {
+	rn := MustParse(input)
+	_, err := rn.Pipe(SetLabel("foo", "bar"))
+	if err != nil {
+		t.Fatalf("unexpected error %v", err)
+	}
+	output := rn.MustString()
+
+	expected := `apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: the-map
+  labels:
+    foo: 'bar'
+data:
+  altGreeting: "Good Morning!"
+  enableRisky: "false"
+`
+	if output != expected {
+		t.Fatalf("expected \n%s\nbut got \n%s\n", expected, output)
+	}
+}
+
+func TestAnnotation(t *testing.T) {
+	rn := MustParse(input)
+	_, err := rn.Pipe(SetAnnotation("foo", "bar"))
+	if err != nil {
+		t.Fatalf("unexpected error %v", err)
+	}
+	output := rn.MustString()
+
+	expected := `apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: the-map
+  annotations:
+    foo: 'bar'
+data:
+  altGreeting: "Good Morning!"
+  enableRisky: "false"
+`
+	if output != expected {
+		t.Fatalf("expected \n%s\nbut got \n%s\n", expected, output)
+	}
+}