Access and set config and config history

Author: Priya Wadhwa

pkg/image/mutable_source.go

@@ -120,7 +120,7 @@ func gzipBytes(b []byte) ([]byte, error) {
 }
 
 // appendLayer appends an uncompressed blob to the image, preserving the invariants required across the config and manifest.
-func (m *MutableSource) AppendLayer(content []byte) error {
+func (m *MutableSource) AppendLayer(content []byte, author string) error {
 	compressedBlob, err := gzipBytes(content)
 	if err != nil {
 		return err
@@ -142,12 +142,7 @@ func (m *MutableSource) AppendLayer(content []byte) error {
 	// Also add it to the config.
 	diffID := digest.FromBytes(content)
 	m.cfg.RootFS.DiffIDs = append(m.cfg.RootFS.DiffIDs, diffID)
-	history := manifest.Schema2History{
-		Created: time.Now(),
-		Author:  "container-diff",
-	}
-	m.cfg.History = append(m.cfg.History, history)
-
+	m.appendConfigHistory(author, false)
 	return nil
 }
 
@@ -182,11 +177,30 @@ func (m *MutableSource) Env() map[string]string {
 
 // SetEnv takes a map of environment variables, and converts them to an array of strings
 // in the form KEY=VALUE, and then sets the image config
-func (m *MutableSource) SetEnv(envMap map[string]string) {
+func (m *MutableSource) SetEnv(envMap map[string]string, author string) {
 	envArray := []string{}
 	for key, value := range envMap {
 		entry := key + "=" + value
 		envArray = append(envArray, entry)
 	}
 	m.cfg.Schema2V1Image.Config.Env = envArray
+	m.appendConfigHistory(author, true)
+}
+
+func (m *MutableSource) Config() *manifest.Schema2Config {
+	return m.cfg.Schema2V1Image.Config
+}
+
+func (m *MutableSource) SetConfig(config *manifest.Schema2Config, author string, emptyLayer bool) {
+	m.cfg.Schema2V1Image.Config = config
+	m.appendConfigHistory(author, emptyLayer)
+}
+
+func (m *MutableSource) appendConfigHistory(author string, emptyLayer bool) {
+	history := manifest.Schema2History{
+		Created:    time.Now(),
+		Author:     author,
+		EmptyLayer: emptyLayer,
+	}
+	m.cfg.History = append(m.cfg.History, history)
 }

pkg/image/mutable_source_test.go

@@ -78,7 +78,7 @@ func TestMutableSource_AppendLayer(t *testing.T) {
 				extraBlobs: make(map[string][]byte),
 			}
 
-			if err := m.AppendLayer([]byte(tt.args.content)); (err != nil) != tt.wantErr {
+			if err := m.AppendLayer([]byte(tt.args.content), "container-diff"); (err != nil) != tt.wantErr {
 				t.Fatalf("MutableSource.AppendLayer() error = %v, wantErr %v", err, tt.wantErr)
 			}
 			if err := m.saveConfig(); err != nil {
@@ -144,7 +144,7 @@ func TestMutableSource_Env(t *testing.T) {
 
 	initialEnvMap["NEW"] = "new"
 
-	m.SetEnv(initialEnvMap)
+	m.SetEnv(initialEnvMap, "container-diff")
 
 	newEnvMap := m.Env()
 	expectedNewEnvMap := map[string]string{
@@ -154,4 +154,36 @@ func TestMutableSource_Env(t *testing.T) {
 	if !reflect.DeepEqual(newEnvMap, expectedNewEnvMap) {
 		t.Fatalf("Got incorrect environment map, got: %s, expected: %s", newEnvMap, expectedNewEnvMap)
 	}
+
+	// Ensure length of history is 1
+	if len(cfg.History) != 1 {
+		t.Fatalf("No layer added to image history: %v", cfg.History)
+	}
+}
+
+func TestMutableSource_Config(t *testing.T) {
+	cfg := &manifest.Schema2Image{
+		Schema2V1Image: manifest.Schema2V1Image{
+			Config: &manifest.Schema2Config{},
+		},
+	}
+
+	m := &MutableSource{
+		mfst:       &manifest.Schema2{},
+		cfg:        cfg,
+		extraBlobs: make(map[string][]byte),
+	}
+	config := m.Config()
+	user := "new-user"
+	config.User = user
+	m.SetConfig(config, "container-diff", true)
+	// Ensure length of history is 1
+	if len(cfg.History) != 1 {
+		t.Fatalf("No layer added to image history: %v", cfg.History)
+	}
+	// Ensure command was set
+	if !reflect.DeepEqual(m.Config().User, user) {
+		t.Fatalf("Config command incorrectly set, was: %s, expected: %s", m.Config().User, user)
+	}
+
 }