Add helm plugin to distribute projects

This PR introduces an optional Helm plugin, enabling users to scaffold Helm charts for Kubebuilder projects.

- **Helm Chart Scaffolding**: Allows generation of a Helm chart under the `dist/chart` directory, providing an alternative for distributing and managing projects via Helm.
- **Usage**:
  - **To add when init the project**: `kubebuilder init --plugins=helm/v1-alpha` for new projects.
  - **To Init/Update in a project previously scaffolded**: `kubebuilder edit --plugins=helm/v1-alpha` to add or update Helm charts for existing projects.
- **Sync Helm Chart**: Syncs the Helm chart with project manifests using the `edit` command, with `--force` required for updates after webhook or `DeployImage` plugin changes in order to overwritten the values.yaml and manager.yaml files.

.github/workflows/test-helm-samples.yml

@@ -0,0 +1,76 @@
+name: Helm Testdata Sample
+
+on:
+  push:
+    paths:
+      - 'testdata/project-v4-with-plugins/**'
+      - '.github/workflows/test-helm-samples.yml'
+  pull_request:
+    paths:
+      - 'testdata/project-v4-with-plugins/**'
+      - '.github/workflows/test-helm-samples.yml'
+
+jobs:
+  helm-test-project-v4-with-plugins:
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: true
+    if: github.event_name == 'push' || github.event.pull_request.head.repo.full_name != github.repository
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Setup Go
+        uses: actions/setup-go@v5
+        with:
+          go-version: '~1.22'
+
+      - name: Install the latest version of kind
+        run: |
+          curl -Lo ./kind https://kind.sigs.k8s.io/dl/latest/kind-linux-amd64
+          chmod +x ./kind
+          sudo mv ./kind /usr/local/bin/kind
+
+      - name: Verify kind installation
+        run: kind version
+
+      - name: Create kind cluster
+        run: kind create cluster
+
+      - name: Prepare project-v4-with-plugins
+        run: |
+          cd testdata/project-v4-with-plugins/
+          go mod tidy
+          make docker-build IMG=project-v4-with-plugins:v0.1.0
+          kind load docker-image project-v4-with-plugins:v0.1.0
+
+      - name: Install Helm
+        run: |
+          curl https://raw.githubusercontent.com/helm/helm/main/scripts/get-helm-3 | bash
+
+      - name: Verify Helm installation
+        run: helm version
+
+      - name: Lint Helm chart for project-v4-with-plugins
+        run: |
+          helm lint testdata/project-v4-with-plugins/dist/chart
+
+      - name: Install cert-manager via Helm
+        run: |
+          helm repo add jetstack https://charts.jetstack.io
+          helm repo update
+          helm install cert-manager jetstack/cert-manager --namespace cert-manager --create-namespace --set installCRDs=true
+
+      - name: Wait for cert-manager to be ready
+        run: |
+          kubectl wait --namespace cert-manager --for=condition=available --timeout=300s deployment/cert-manager
+          kubectl wait --namespace cert-manager --for=condition=available --timeout=300s deployment/cert-manager-cainjector
+          kubectl wait --namespace cert-manager --for=condition=available --timeout=300s deployment/cert-manager-webhook
+
+      - name: Install Helm chart for project-v4-with-plugins
+        run: |
+          helm install my-release testdata/project-v4-with-plugins/dist/chart --create-namespace --namespace project-v4-with-plugins-system
+
+      - name: Check Helm release status
+        run: |
+          helm status my-release --namespace project-v4-with-plugins-system

Makefile

@@ -97,7 +97,7 @@ lint-fix: golangci-lint ## Run golangci-lint linter and perform fixes
 
 .PHONY: yamllint
 yamllint:
-	@files=$$(find testdata -name '*.yaml' ! -path 'testdata/*/dist/install.yaml'); \
+	@files=$$(find testdata -name '*.yaml' ! -path 'testdata/*/dist/*'); \
     	docker run --rm $$(tty -s && echo "-it" || echo) -v $(PWD):/data cytopia/yamllint:latest $$files -d "{extends: relaxed, rules: {line-length: {max: 120}}}" --no-warnings
 
 GOLANGCI_LINT = $(shell pwd)/bin/golangci-lint
@@ -171,3 +171,11 @@ test-spaces:  ## Run the trailing spaces check
 test-legacy:  ## Run the tests to validate legacy path for webhooks
 	rm -rf  ./testdata/**legacy**/
 	./test/testdata/legacy-webhook-path.sh
+
+.PHONY: install-helm
+install-helm: ## Install the latest version of Helm locally
+	@curl https://raw.githubusercontent.com/helm/helm/main/scripts/get-helm-3 | bash
+
+.PHONY: helm-lint
+helm-lint: install-helm ## Lint the Helm chart in testdata
+	helm lint testdata/project-v4-with-plugins/dist/chart

cmd/main.go

@@ -30,6 +30,7 @@ import (
 	deployimagev1alpha1 "sigs.k8s.io/kubebuilder/v4/pkg/plugins/golang/deploy-image/v1alpha1"
 	golangv4 "sigs.k8s.io/kubebuilder/v4/pkg/plugins/golang/v4"
 	grafanav1alpha1 "sigs.k8s.io/kubebuilder/v4/pkg/plugins/optional/grafana/v1alpha"
+	helmv1alpha1 "sigs.k8s.io/kubebuilder/v4/pkg/plugins/optional/helm/v1alpha"
 )
 
 func init() {
@@ -61,6 +62,7 @@ func main() {
 			&kustomizecommonv2.Plugin{},
 			&deployimagev1alpha1.Plugin{},
 			&grafanav1alpha1.Plugin{},
+			&helmv1alpha1.Plugin{},
 		),
 		cli.WithPlugins(externalPlugins...),
 		cli.WithDefaultPlugins(cfgv3.Version, gov4Bundle),

docs/book/src/cronjob-tutorial/testdata/project/README.md

@@ -68,27 +68,48 @@ make undeploy
 
 ## Project Distribution
 
-Following are the steps to build the installer and distribute this project to users.
+Following the options to release and provide this solution to the users.
+
+### By providing a bundle with all YAML files
 
 1. Build the installer for the image built and published in the registry:
 
 ```sh
 make build-installer IMG=<some-registry>/project:tag
 ```
 
-NOTE: The makefile target mentioned above generates an 'install.yaml'
+**NOTE:** The makefile target mentioned above generates an 'install.yaml'
 file in the dist directory. This file contains all the resources built
-with Kustomize, which are necessary to install this project without
-its dependencies.
+with Kustomize, which are necessary to install this project without its
+dependencies.
 
 2. Using the installer
 
-Users can just run kubectl apply -f <URL for YAML BUNDLE> to install the project, i.e.:
+Users can just run 'kubectl apply -f <URL for YAML BUNDLE>' to install
+the project, i.e.:
 
 ```sh
 kubectl apply -f https://raw.githubusercontent.com/<org>/project/<tag or branch>/dist/install.yaml
 ```
 
+### By providing a Helm Chart
+
+1. Build the chart using the optional helm plugin
+
+```sh
+kubebuilder edit --plugins=helm/v1-alpha
+```
+
+2. See that a chart was generated under 'dist/chart', and users
+can obtain this solution from there.
+
+**NOTE:** If you change the project, you need to update the Helm Chart
+using the same command above to sync the latest changes. Furthermore,
+if you create webhooks, you need to use the above command with
+the '--force' flag and manually ensure that any custom configuration
+previously added to 'dist/chart/values.yaml' or 'dist/chart/manager/manager.yaml'
+is manually re-applied afterwards.
+
 ## Contributing
 // TODO(user): Add detailed information on how you would like others to contribute to this project
 

docs/book/src/cronjob-tutorial/testdata/project/config/network-policy/allow-metrics-traffic.yaml

@@ -1,6 +1,6 @@
 # This NetworkPolicy allows ingress traffic
 # with Pods running on namespaces labeled with 'metrics: enabled'. Only Pods on those
-# namespaces are able to gathering data from the metrics endpoint.
+# namespaces are able to gather data from the metrics endpoint.
 apiVersion: networking.k8s.io/v1
 kind: NetworkPolicy
 metadata:

docs/book/src/getting-started/testdata/project/README.md

@@ -68,27 +68,48 @@ make undeploy
 
 ## Project Distribution
 
-Following are the steps to build the installer and distribute this project to users.
+Following the options to release and provide this solution to the users.
+
+### By providing a bundle with all YAML files
 
 1. Build the installer for the image built and published in the registry:
 
 ```sh
 make build-installer IMG=<some-registry>/project:tag
 ```
 
-NOTE: The makefile target mentioned above generates an 'install.yaml'
+**NOTE:** The makefile target mentioned above generates an 'install.yaml'
 file in the dist directory. This file contains all the resources built
-with Kustomize, which are necessary to install this project without
-its dependencies.
+with Kustomize, which are necessary to install this project without its
+dependencies.
 
 2. Using the installer
 
-Users can just run kubectl apply -f <URL for YAML BUNDLE> to install the project, i.e.:
+Users can just run 'kubectl apply -f <URL for YAML BUNDLE>' to install
+the project, i.e.:
 
 ```sh
 kubectl apply -f https://raw.githubusercontent.com/<org>/project/<tag or branch>/dist/install.yaml
 ```
 
+### By providing a Helm Chart
+
+1. Build the chart using the optional helm plugin
+
+```sh
+kubebuilder edit --plugins=helm/v1-alpha
+```
+
+2. See that a chart was generated under 'dist/chart', and users
+can obtain this solution from there.
+
+**NOTE:** If you change the project, you need to update the Helm Chart
+using the same command above to sync the latest changes. Furthermore,
+if you create webhooks, you need to use the above command with
+the '--force' flag and manually ensure that any custom configuration
+previously added to 'dist/chart/values.yaml' or 'dist/chart/manager/manager.yaml'
+is manually re-applied afterwards.
+
 ## Contributing
 // TODO(user): Add detailed information on how you would like others to contribute to this project
 

docs/book/src/getting-started/testdata/project/config/network-policy/allow-metrics-traffic.yaml

@@ -1,6 +1,6 @@
 # This NetworkPolicy allows ingress traffic
 # with Pods running on namespaces labeled with 'metrics: enabled'. Only Pods on those
-# namespaces are able to gathering data from the metrics endpoint.
+# namespaces are able to gather data from the metrics endpoint.
 apiVersion: networking.k8s.io/v1
 kind: NetworkPolicy
 metadata:

docs/book/src/multiversion-tutorial/testdata/project/README.md

@@ -68,27 +68,48 @@ make undeploy
 
 ## Project Distribution
 
-Following are the steps to build the installer and distribute this project to users.
+Following the options to release and provide this solution to the users.
+
+### By providing a bundle with all YAML files
 
 1. Build the installer for the image built and published in the registry:
 
 ```sh
 make build-installer IMG=<some-registry>/project:tag
 ```
 
-NOTE: The makefile target mentioned above generates an 'install.yaml'
+**NOTE:** The makefile target mentioned above generates an 'install.yaml'
 file in the dist directory. This file contains all the resources built
-with Kustomize, which are necessary to install this project without
-its dependencies.
+with Kustomize, which are necessary to install this project without its
+dependencies.
 
 2. Using the installer
 
-Users can just run kubectl apply -f <URL for YAML BUNDLE> to install the project, i.e.:
+Users can just run 'kubectl apply -f <URL for YAML BUNDLE>' to install
+the project, i.e.:
 
 ```sh
 kubectl apply -f https://raw.githubusercontent.com/<org>/project/<tag or branch>/dist/install.yaml
 ```
 
+### By providing a Helm Chart
+
+1. Build the chart using the optional helm plugin
+
+```sh
+kubebuilder edit --plugins=helm/v1-alpha
+```
+
+2. See that a chart was generated under 'dist/chart', and users
+can obtain this solution from there.
+
+**NOTE:** If you change the project, you need to update the Helm Chart
+using the same command above to sync the latest changes. Furthermore,
+if you create webhooks, you need to use the above command with
+the '--force' flag and manually ensure that any custom configuration
+previously added to 'dist/chart/values.yaml' or 'dist/chart/manager/manager.yaml'
+is manually re-applied afterwards.
+
 ## Contributing
 // TODO(user): Add detailed information on how you would like others to contribute to this project
 

docs/book/src/multiversion-tutorial/testdata/project/config/network-policy/allow-metrics-traffic.yaml

@@ -1,6 +1,6 @@
 # This NetworkPolicy allows ingress traffic
 # with Pods running on namespaces labeled with 'metrics: enabled'. Only Pods on those
-# namespaces are able to gathering data from the metrics endpoint.
+# namespaces are able to gather data from the metrics endpoint.
 apiVersion: networking.k8s.io/v1
 kind: NetworkPolicy
 metadata:

docs/book/src/plugins/available/helm-v1-alpha.md

@@ -0,0 +1,92 @@
+# Helm Plugin (`helm/v1-alpha`)
+
+The Helm plugin is an optional plugin that can be used to scaffold a Helm chart, allowing you to distribute the project using Helm.
+
+By default, users can generate a bundle with all the manifests by running the following command:
+
+```bash
+make build-installer IMG=<some-registry>/<project-name:tag>
+```
+
+This allows the project consumer to install the solution by applying the bundle with:
+
+```bash
+kubectl apply -f https://raw.githubusercontent.com/<org>/project-v4/<tag or branch>/dist/install.yaml
+```
+
+However, in many scenarios, you might prefer to provide a Helm chart to package your solution.
+If so, you can use this plugin to generate the Helm chart under the `dist` directory.
+
+<aside class="note">
+<h1>Examples</h1>
+
+You can check the plugin usage by looking at `project-v4-with-plugins` samples
+under the [testdata][testdata] directory on the root directory of the Kubebuilder project.
+
+</aside>
+
+## When to use it
+
+- If you want to provide a Helm chart for users to install and manage your project.
+- If you need to update the Helm chart generated under `dist/chart/` with the latest project changes:
+  - After generating new manifests, use the `edit` option to sync the Helm chart.
+  - **IMPORTANT:** If you have created a webhook or an API using the [DeployImage][deployImage-plugin] plugin,
+  you must run the `edit` command with the `--force` flag to regenerate the Helm chart values based
+  on the latest manifests (_after running `make manifests`_) to ensure that the HelmChart values are
+  updated accordingly. In this case, if you have customized the files
+  under `dist/chart/values.yaml`, and the `templates/manager/manager.yaml`, you will need to manually reapply your customizations on top
+  of the latest changes after regenerating the Helm chart.
+
+## How to use it ?
+
+### Basic Usage
+
+The Helm plugin is attached to the `init` subcommand and the `edit` subcommand:
+
+```sh
+
+# Initialize a new project with helm chart
+kubebuilder init --plugins=helm/v1-alpha
+
+# Enable or Update the helm chart via the helm plugin to an existing project
+# Before run the edit command, run `make manifests` to generate the manifest under `config/`
+make manifests
+kubebuilder edit --plugins=helm/v1-alpha
+```
+<aside class="note">
+  <h1>Use the edit command to update the Helm Chart with the latest changes</h1>
+
+  After making changes to your project, ensure that you run `make manifests` and then
+  use the command `kubebuilder edit --plugins=helm/v1-alpha` to update the Helm Chart.
+
+  Note that the following files will **not** be updated unless you use the `--force` flag:
+
+  <pre>
+  dist/chart/
+  ├── values.yaml
+  └── templates/
+      └── manager/
+          └── manager.yaml
+  </pre>
+
+  The files `chart/Chart.yaml`, `chart/templates/_helpers.tpl`, and `chart/.helmignore` are never updated
+  after their initial creation unless you remove them.
+
+</aside>
+
+## Subcommands
+
+The Helm plugin implements the following subcommands:
+
+- edit (`$ kubebuilder edit [OPTIONS]`)
+
+- init (`$ kubebuilder init [OPTIONS]`)
+
+## Affected files
+
+The following scaffolds will be created or updated by this plugin:
+
+- `dist/chart/*`
+
+[testdata]: https://github.com/kubernetes-sigs/kubebuilder/tree/master/testdata/project-v4-with-plugins
+[deployImage-plugin]: ./deploy-image-plugin-v1-alpha.md