merge volumes/networks labels

Signed-off-by: Nicolas De Loof <nicolas.deloof@gmail.com>

override/merge.go

@@ -41,10 +41,13 @@ var mergeSpecials = map[tree.Path]merger{}
 
 func init() {
 	mergeSpecials["networks.*.ipam.config"] = mergeIPAMConfig
+	mergeSpecials["networks.*.labels"] = mergeToSequence
+	mergeSpecials["volumes.*.labels"] = mergeToSequence
 	mergeSpecials["services.*.annotations"] = mergeToSequence
 	mergeSpecials["services.*.build"] = mergeBuild
 	mergeSpecials["services.*.build.args"] = mergeToSequence
 	mergeSpecials["services.*.build.additional_contexts"] = mergeToSequence
+	mergeSpecials["services.*.build.extra_hosts"] = mergeToSequence
 	mergeSpecials["services.*.build.labels"] = mergeToSequence
 	mergeSpecials["services.*.command"] = override
 	mergeSpecials["services.*.depends_on"] = mergeDependsOn

override/merge_networks_test.go

@@ -187,9 +187,9 @@ networks:
         bar: foo
         baz: "0"
     labels:
-      com.example.description: "Financial transaction network"
-      com.example.department-new: "New"
-      com.example.label-with-empty-value: ""
+      - "com.example.department-new=New"
+      - "com.example.description=Financial transaction network"
+      - "com.example.label-with-empty-value="
   network2:
 `, `
 services:
@@ -219,10 +219,10 @@ networks:
         bar: foo
         baz: "0"
     labels:
-      com.example.description: "Financial transaction network"
-      com.example.department: "Finance"
-      com.example.label-with-empty-value: ""
-      com.example.department-new: "New"
+      - "com.example.department=Finance"
+      - "com.example.description=Financial transaction network"
+      - "com.example.label-with-empty-value="
+      - "com.example.department-new=New"
   network2:
 `)
 }

override/uncity.go

@@ -107,13 +107,17 @@ func enforceUnicity(value any, p tree.Path) (any, error) {
 	return value, nil
 }
 
-func keyValueIndexer(y any, _ tree.Path) (string, error) {
-	value := y.(string)
-	key, _, found := strings.Cut(value, "=")
-	if !found {
-		return value, nil
+func keyValueIndexer(y any, p tree.Path) (string, error) {
+	switch value := y.(type) {
+	case string:
+		key, _, found := strings.Cut(value, "=")
+		if !found {
+			return value, nil
+		}
+		return key, nil
+	default:
+		return "", fmt.Errorf("%s: unexpected type %T", p, y)
 	}
-	return key, nil
 }
 
 func volumeIndexer(y any, p tree.Path) (string, error) {