Parse x-kubernetes-list-type in CRD as the key of strategic merge patch (#1)

* Add testcases to reproduce #5878, testing CRD OpenApi extensions
* Add x-kubernetes-list-type CRD extension support

Author: tsekine354

examples/customOpenAPIschema.md

@@ -37,24 +37,24 @@ spec:
 EOF
 ```
 
-This resource has an image field. Let's change its value from server 
-to nginx with a patch. 
+This resource has an image field. Let's change its value from server
+to nginx with a patch.
 
 Kustomize gets its merge key information from the OpenAPI data
 provided by the kubernetes API server. It doesn't have information
-about custom resources, so we will have to provide our own 
-schema file. 
+about custom resources, so we will have to provide our own
+schema file.
 
 Note: CRDs support declarative validation using an OpenAPI v3 schema.
 See https://book.kubebuilder.io/reference/generating-crd.html#validation.
 
 You can get an OpenAPI document like this by fetching the OpenAPI
 document from your locally favored cluster with the command
 `kustomize openapi fetch`. Kustomize will use the OpenAPI extensions
-`x-kubernetes-patch-merge-key` and `x-kubernetes-patch-strategy` to
-perform a strategic merge. `x-kubernetes-patch-strategy` should be set
-to "merge", and you can set your merge key to whatever you like. Below,
-our custom resource inherits merge keys from `PodTemplateSpec`. 
+`x-kubernetes-list-map-keys` and `x-kubernetes-list-type` to
+perform a strategic merge. `x-kubernetes-list-type` should be set
+to "map", and you can set your merge keys to whatever you like. Below,
+our custom resource inherits merge keys from `PodTemplateSpec`.
 
 <!-- @addCustomSchema @testAgainstLatestRelease -->
 ```
@@ -124,6 +124,10 @@ cat <<EOF >>$DEMO_HOME/mycr_schema.json
             "\$ref": "#/definitions/io.k8s.api.core.v1.Container"
           },
           "type": "array",
+          "x-kubernetes-list-map-keys": [
+              "name"
+          ],
+          "x-kubernetes-list-type": "map",
           "x-kubernetes-patch-merge-key": "name",
           "x-kubernetes-patch-strategy": "merge"
         }

go.work.sum

@@ -23,8 +23,10 @@
           "properties": {
             "targets": {
               "type": "array",
-              "x-kubernetes-patch-merge-key": "app",
-              "x-kubernetes-patch-strategy": "merge",
+              "x-kubernetes-list-map-keys": [
+                "app"
+              ],
+              "x-kubernetes-list-type": "map",
               "items": {
                 "type": "object",
                 "required": [

kyaml/fn/framework/parser/testdata/schema1.json

@@ -23,8 +23,10 @@
           "properties": {
             "targets": {
               "type": "array",
-              "x-kubernetes-patch-merge-key": "app",
-              "x-kubernetes-patch-strategy": "merge",
+              "x-kubernetes-list-map-keys": [
+                "app"
+              ],
+              "x-kubernetes-list-type": "map",
               "items": {
                 "type": "object",
                 "required": [

kyaml/fn/framework/parser/testdata/schema2.json

@@ -23,8 +23,10 @@
           "properties": {
             "targets": {
               "type": "array",
-              "x-kubernetes-patch-merge-key": "app",
-              "x-kubernetes-patch-strategy": "merge",
+              "x-kubernetes-list-map-keys": [
+                "app"
+              ],
+              "x-kubernetes-list-type": "map",
               "items": {
                 "type": "object",
                 "required": [

kyaml/fn/framework/testdata/template-processor/schemas/foo.json

@@ -28,12 +28,12 @@ func Example_arrayMerge() {
 	f := s.Lookup("spec", "template", "spec", "containers")
 	fmt.Println(f.Schema.Description[:70] + "...")
 	fmt.Println(f.Schema.Type)
-	fmt.Println(f.PatchStrategyAndKey()) // merge patch strategy on name
+	fmt.Println(f.PatchStrategyAndKeyList()) // merge patch strategy on name
 
 	// Output:
 	// List of containers belonging to the pod. Containers cannot currently b...
 	// [array]
-	// merge name
+	// merge [name]
 }
 
 func Example_arrayReplace() {
@@ -42,11 +42,12 @@ func Example_arrayReplace() {
 	f := s.Lookup("spec", "template", "spec", "containers", openapi.Elements, "args")
 	fmt.Println(f.Schema.Description[:70] + "...")
 	fmt.Println(f.Schema.Type)
-	fmt.Println(f.PatchStrategyAndKey()) // no patch strategy or merge key
+	fmt.Println(f.PatchStrategyAndKeyList()) // no patch strategy or merge keys; empty string + empty list
 
 	// Output:
 	// Arguments to the entrypoint. The docker image's CMD is used if this is...
 	// [array]
+        //  []
 }
 
 func Example_arrayElement() {

kyaml/openapi/example_test.go

@@ -70,6 +70,10 @@
             "$ref": "#/definitions/io.k8s.api.apps.v1.ConfigMapArgs"
           },
           "type": "array",
+          "x-kubernetes-list-map-keys": [
+            "name"
+          ],
+          "x-kubernetes-list-type": "map",
           "x-kubernetes-patch-merge-key": "name",
           "x-kubernetes-patch-strategy": "merge"
         },
@@ -78,6 +82,10 @@
             "$ref": "#/definitions/io.k8s.api.apps.v1.SecretArgs"
           },
           "type": "array",
+          "x-kubernetes-list-map-keys": [
+            "name"
+          ],
+          "x-kubernetes-list-type": "map",
           "x-kubernetes-patch-merge-key": "name",
           "x-kubernetes-patch-strategy": "merge"
         }
@@ -98,7 +106,8 @@
           "items": {
             "type": "string"
           },
-          "type": "array"
+          "type": "array",
+          "x-kubernetes-list-type": "atomic"
         },
         "files": {
           "items": {
@@ -110,7 +119,8 @@
           "items": {
             "type": "string"
           },
-          "type": "array"
+          "type": "array",
+          "x-kubernetes-list-type": "atomic"
         },
         "env": {
           "type": "string"
@@ -127,4 +137,4 @@
       ]
     }
   }
-}
+}

kyaml/openapi/kustomizationapi/swagger.json

@@ -536,42 +536,35 @@ func (rs *ResourceSchema) Field(field string) *ResourceSchema {
 
 // PatchStrategyAndKeyList returns the patch strategy and complete merge key list
 func (rs *ResourceSchema) PatchStrategyAndKeyList() (string, []string) {
-	ps, found := rs.Schema.Extensions[kubernetesPatchStrategyExtensionKey]
-	if !found {
-		// empty patch strategy
-		return "", []string{}
-	}
-	mkList, found := rs.Schema.Extensions[kubernetesMergeKeyMapList]
+	// Try CRD extension first
+	lt, found := rs.Schema.Extensions[kubernetesListTypeExtensionKey]
 	if found {
+		mkList, foundKeys := rs.Schema.Extensions[kubernetesMergeKeyMapList]
+		if !foundKeys {
+			// no mergeKey -- may be "atomic" or "set" list
+			return lt.(string), []string{}
+		}
+
 		// mkList is []interface, convert to []string
 		mkListStr := make([]string, len(mkList.([]interface{})))
 		for i, v := range mkList.([]interface{}) {
 			mkListStr[i] = v.(string)
 		}
-		return ps.(string), mkListStr
+		return lt.(string), mkListStr
 	}
-	mk, found := rs.Schema.Extensions[kubernetesMergeKeyExtensionKey]
-	if !found {
-		// no mergeKey -- may be a primitive associative list (e.g. finalizers)
-		return ps.(string), []string{}
-	}
-	return ps.(string), []string{mk.(string)}
-}
 
-// PatchStrategyAndKey returns the patch strategy and merge key extensions
-func (rs *ResourceSchema) PatchStrategyAndKey() (string, string) {
+	// Fall back to k8s builtin extension
 	ps, found := rs.Schema.Extensions[kubernetesPatchStrategyExtensionKey]
 	if !found {
 		// empty patch strategy
-		return "", ""
+		return "", []string{}
 	}
-
 	mk, found := rs.Schema.Extensions[kubernetesMergeKeyExtensionKey]
 	if !found {
 		// no mergeKey -- may be a primitive associative list (e.g. finalizers)
-		mk = ""
+		return ps.(string), []string{}
 	}
-	return ps.(string), mk.(string)
+	return ps.(string), []string{mk.(string)}
 }
 
 const (
@@ -599,6 +592,10 @@ const (
 	// -- the extension is an array of strings
 	kubernetesMergeKeyMapList = "x-kubernetes-list-map-keys"
 
+	// kubernetesListTypeExtensionKey is the key to lookup the kubernetes list
+	// type in CRD -- the extension is a strings
+	kubernetesListTypeExtensionKey = "x-kubernetes-list-type"
+
 	// groupKey is the key to lookup the group from the GVK extension
 	groupKey = "group"
 	// versionKey is the key to lookup the version from the GVK extension

kyaml/openapi/openapi.go

@@ -560,7 +560,7 @@ spec:
 	//
 	// Test Case
 	//
-	{description: `no infer merge keys merge using explicit schema as line comment'`,
+	{description: `no infer merge keys merge using explicit schema with builtin extension as line comment'`,
 		source: `
 apiVersion: custom
 kind: Deployment
@@ -579,6 +579,37 @@ containers: # {"items":{"$ref": "#/definitions/io.k8s.api.core.v1.Container"},"t
 apiVersion: custom
 kind: Deployment
 containers: # {"items":{"$ref": "#/definitions/io.k8s.api.core.v1.Container"},"type":"array","x-kubernetes-patch-merge-key":"name","x-kubernetes-patch-strategy": "merge"}
+- name: foo
+  image: foo:bar
+  command: ['run2.sh']
+`,
+		infer: false,
+		mergeOptions: yaml.MergeOptions{
+			ListIncreaseDirection: yaml.MergeOptionsListAppend,
+		},
+	},
+	//
+	// Test Case
+	//
+	{description: `no infer merge keys merge using explicit schema with crd extension as line comment'`,
+		source: `
+apiVersion: custom
+kind: Deployment
+containers:
+- name: foo
+  command: ['run2.sh']
+`,
+		dest: `
+apiVersion: custom
+kind: Deployment
+containers: # {"items":{"$ref": "#/definitions/io.k8s.api.core.v1.Container"},"type":"array","x-kubernetes-list-map-keys":["name"],"x-kubernetes-list-type": "map"}
+- name: foo # hell ow
+  image: foo:bar
+`,
+		expected: `
+apiVersion: custom
+kind: Deployment
+containers: # {"items":{"$ref": "#/definitions/io.k8s.api.core.v1.Container"},"type":"array","x-kubernetes-list-map-keys":["name"],"x-kubernetes-list-type": "map"}
 - name: foo
   image: foo:bar
   command: ['run2.sh']
@@ -596,7 +627,7 @@ kind: Deployment
 metadata:
   finalizers:
   - a
-  - b 
+  - b
 `,
 		dest: `
 apiVersion: apps/v1

kyaml/yaml/merge2/element_test.go

@@ -742,7 +742,7 @@ spec:
 	// Test Case
 	//
 	{
-		description: `no infer merge keys merge using explicit schema as line comment'`,
+		description: `no infer merge keys merge using explicit schema with builtin extension as line comment'`,
 		origin: `
 apiVersion: custom
 kind: Deployment
@@ -786,6 +786,54 @@ spec:
 		infer: false,
 	},
 
+	//
+	// Test Case
+	//
+	{
+		description: `no infer merge keys merge using explicit schema with crd extension as line comment'`,
+		origin: `
+apiVersion: custom
+kind: Deployment
+spec:
+  template:
+    spec:
+      containers:
+      - name: foo
+`,
+		update: `
+apiVersion: custom
+kind: Deployment
+spec:
+  template:
+    spec:
+      containers:
+      - name: foo
+        command: ['run2.sh']
+`,
+		local: `
+apiVersion: custom
+kind: Deployment
+spec:
+  template:
+    spec:
+      containers: # {"items":{"$ref": "#/definitions/io.k8s.api.core.v1.Container"},"type":"array","x-kubernetes-list-map-keys":["name"],"x-kubernetes-list-type": "map"}
+      - name: foo # hell ow
+        image: foo:bar
+`,
+		expected: `
+apiVersion: custom
+kind: Deployment
+spec:
+  template:
+    spec:
+      containers: # {"items":{"$ref": "#/definitions/io.k8s.api.core.v1.Container"},"type":"array","x-kubernetes-list-map-keys":["name"],"x-kubernetes-list-type": "map"}
+      - name: foo # hell ow
+        image: foo:bar
+        command: ['run2.sh']
+`,
+		infer: false,
+	},
+
 	//
 	// Test Case
 	//