feat: add support for kustomize legacy plugin

Signed-off-by: Ardika Bagus <[email protected]>

README.md

@@ -12,9 +12,9 @@ With the likelihood of [glob support](https://github.com/kubernetes-sigs/kustomi
 
 ## Usage
 
-### Create directory
+### Exec KRM Function
 
-The Release specification:
+#### Create `HelmRelease` Manifest
 
 ```bash
 cat <<EOF > release-simple.yaml
@@ -75,7 +75,7 @@ spec:
 EOF
 ```
 
-Then, you put above Release yaml to the generators field in the `kustomization.yaml`:
+#### Generate Manifest
 
 ```bash
 cat <<EOF > kustomization.yaml
@@ -87,13 +87,85 @@ generators:
 - release-with-glob.yaml
 - release-with-oci-repo.yaml
 EOF
+
+kustomize build --enable-alpha-plugins --enable-exec .
+```
+
+### Legacy Plugin
+
+#### Download Helmize binary
+
+```bash
+curl -sSfL -O https://github.com/ardikabs/helmize/releases/download/v0.1.1/helmize_0.1.1_linux_amd64
+
+export HELMIZE_PLUGIN_DIR="${XDG_CONFIG_HOME:-$HOME/.config}/kustomize/plugin/toolkit.ardikabs.com/v1alpha1/helmrelease"
+mkdir -p $HELMIZE_PLUGIN_DIR
+mv helmize_0.1.1_linux_amd64 "${HELMIZE_PLUGIN_DIR}/HelmRelease"
+```
+
+#### Create `HelmRelease` Manifest
+
+```bash
+cat <<EOF > release-simple.yaml
+apiVersion: toolkit.ardikabs.com/v1alpha1
+kind: HelmRelease
+metadata:
+  name: simple-a
+  namespace: default
+spec:
+  chart: minecraft
+  repo:
+    name: minecraft
+    url: https://itzg.github.io/minecraft-server-charts
+EOF
+
+cat <<EOF > release-with-glob.yaml
+apiVersion: toolkit.ardikabs.com/v1alpha1
+kind: HelmRelease
+metadata:
+  name: service-a
+  namespace: default
+spec:
+  chart: common-app
+  repo:
+    name: ardikabs
+    url: https://charts.ardikabs.com
+  version: 0.4.1
+  values:
+    - values.yaml
+    - values/*.yaml
+    - values/**/*.yaml
+EOF
+
+cat <<EOF > release-with-oci-repo.yaml
+apiVersion: toolkit.ardikabs.com/v1alpha1
+kind: HelmRelease
+metadata:
+  name: envoy-gateway
+  namespace: envoy-gateway-system
+spec:
+  repo:
+    url: oci://docker.io/envoyproxy/gateway-helm
+  version: v0.5.0
+  includeCRDs: true
+  createNamespace: true
+EOF
 ```
 
-To generate the manifest you need to use the following command:
+#### Generate Manifest
+
 ```bash
+cat <<EOF > kustomization.yaml
+apiVersion: kustomize.config.k8s.io/v1beta1
+kind: Kustomization
 
-$ kustomize build --enable-alpha-plugins --enable-exec .
+generators:
+- release-simple.yaml
+- release-with-glob.yaml
+- release-with-oci-repo.yaml
+EOF
 
+kustomize build --enable-alpha-plugins .
 ```
 
 ## More

cmd/root.go

@@ -16,7 +16,16 @@ func MakeRoot() *cobra.Command {
 		Use:   "helmize",
 		Short: "helmize is a KRM Function to enable Helm on Kustomize with Glob support",
 		Example: dedent.Dedent(`
-			Initially Helmize used as KRM function only, but it also support for direct use through flag.
+			Initially Helmize used as KRM function only, but it also support for direct use through flag
+			as well as a Kustomize Legacy Plugin.
+
+			> Legacy usage:
+
+			export HELMIZE_PLUGIN_DIR="${XDG_CONFIG_HOME:-$HOME/.config}/kustomize/plugin/toolkit.ardikabs.com/v1alpha1/helmrelease"
+			mkdir -p $HELMIZE_PLUGIN_DIR
+			mv /path/to/helmize-binary "${HELMIZE_PLUGIN_DIR}/HelmRelease"
+
+			$ kustomize build --enable-alpha-plugins /path/to/kustomization_dir
 
 			> KRM usage:
 
@@ -35,53 +44,89 @@ func MakeRoot() *cobra.Command {
 		`),
 	}
 
-	cmd.Args = cobra.MaximumNArgs(0)
+	cmd.Args = cobra.MaximumNArgs(1)
 	cmd.RunE = run
 
 	cmd.Flags().StringArrayVarP(&files, "file", "f", []string{}, "specify HelmRelease in a YAML file (can specify multiple times)")
 	return cmd
 }
 
 func run(cmd *cobra.Command, args []string) error {
-	// Direct usage
-	if len(files) > 0 {
-		var generatedObjects fn.KubeObjects
-		for _, file := range files {
-
-			raw, err := os.ReadFile(file)
-			if err != nil {
-				return err
-			}
-
-			kubeObjects, err := fn.ParseKubeObjects(raw)
-			if err != nil {
-				return err
-			}
-
-			generated, err := processor.ProcessKubeObjects(kubeObjects)
-			if err != nil {
-				return err
-			}
-			generatedObjects = append(generatedObjects, generated...)
+	switch {
+	case len(files) > 0:
+		// Direct Use or Standalone
+		if err := runAsStandalone(); err != nil {
+			return err
+		}
+	case len(args) > 0:
+		// Kustomize Legacy Plugin
+		if err := runAsLegacyPlugin(args[0]); err != nil {
+			return err
+		}
+	default:
+		// Kustomize with KRM function
+		stdinStat, _ := os.Stdin.Stat()
+		// Check the StdIn content.
+		if (stdinStat.Mode() & os.ModeCharDevice) != 0 {
+			return cmd.Help()
 		}
 
-		if _, err := os.Stdout.Write([]byte(generatedObjects.String())); err != nil {
+		if err := fn.AsMain(fn.ResourceListProcessorFunc(processor.ProcessResourceList)); err != nil {
+			os.Exit(1)
+		}
+	}
+
+	return nil
+}
+
+func runAsStandalone() error {
+	var generatedObjects fn.KubeObjects
+	for _, file := range files {
+
+		rawObj, err := os.ReadFile(file)
+		if err != nil {
 			return err
 		}
 
-		return nil
+		kubeObjects, err := fn.ParseKubeObjects(rawObj)
+		if err != nil {
+			return err
+		}
+
+		generated, err := processor.ProcessKubeObjects(kubeObjects)
+		if err != nil {
+			return err
+		}
+		generatedObjects = append(generatedObjects, generated...)
 	}
 
-	// KRM usage
-	stdinStat, _ := os.Stdin.Stat()
-	// Check the StdIn content.
-	if (stdinStat.Mode() & os.ModeCharDevice) != 0 {
-		return cmd.Help()
+	if _, err := os.Stdout.Write([]byte(generatedObjects.String())); err != nil {
+		return err
 	}
 
-	if err := fn.AsMain(fn.ResourceListProcessorFunc(processor.ProcessResourceList)); err != nil {
-		os.Exit(1)
+	return nil
+
+}
+
+func runAsLegacyPlugin(resourceFile string) error {
+	rawObj, err := os.ReadFile(resourceFile)
+	if err != nil {
+		return err
+	}
+
+	kubeObjects, err := fn.ParseKubeObjects(rawObj)
+	if err != nil {
+		return err
 	}
 
+	var generatedObjects fn.KubeObjects
+	generated, err := processor.ProcessKubeObjects(kubeObjects)
+	if err != nil {
+		return err
+	}
+	generatedObjects = append(generatedObjects, generated...)
+	if _, err := os.Stdout.Write([]byte(generatedObjects.String())); err != nil {
+		return err
+	}
 	return nil
 }

examples/legacy/multi-releases/kustomization.yaml

@@ -0,0 +1,4 @@
+generators:
+  - release-1.yaml
+  - release-2.yaml
+  - release-3.yaml

examples/legacy/multi-releases/release-1.yaml

@@ -0,0 +1,13 @@
+apiVersion: toolkit.ardikabs.com/v1alpha1
+kind: HelmRelease
+metadata:
+  name: test-1
+  namespace: default
+spec:
+  chart: minecraft
+  repo:
+    name: minecraft
+    url: https://itzg.github.io/minecraft-server-charts
+  version: 3.1.3
+  values:
+    - release-1/values.yaml

examples/legacy/multi-releases/release-1/values.yaml

@@ -0,0 +1,3 @@
+minecraftServer:
+  rcon:
+    password: password

examples/legacy/multi-releases/release-2.yaml

@@ -0,0 +1,13 @@
+apiVersion: toolkit.ardikabs.com/v1alpha1
+kind: HelmRelease
+metadata:
+  name: test-2
+  namespace: default
+spec:
+  chart: minecraft
+  repo:
+    name: minecraft
+    url: https://itzg.github.io/minecraft-server-charts
+  version: 3.1.4
+  values:
+    - release-2/values.yaml

examples/legacy/multi-releases/release-2/values.yaml

@@ -0,0 +1,2 @@
+serviceAnnotations:
+  foo: bar

examples/legacy/multi-releases/release-3.yaml

@@ -0,0 +1,10 @@
+apiVersion: toolkit.ardikabs.com/v1alpha1
+kind: HelmRelease
+metadata:
+  name: test-3
+  namespace: default
+spec:
+  chart: minecraft
+  repo:
+    name: minecraft
+    url: https://itzg.github.io/minecraft-server-charts

examples/legacy/simple/kustomization.yaml

@@ -0,0 +1,2 @@
+generators:
+  - release.yaml

examples/legacy/simple/release.yaml

@@ -0,0 +1,10 @@
+apiVersion: toolkit.ardikabs.com/v1alpha1
+kind: HelmRelease
+metadata:
+  name: test-1
+  namespace: default
+spec:
+  chart: minecraft
+  repo:
+    name: minecraft
+    url: https://itzg.github.io/minecraft-server-charts