Developing Cluster API Provider GCP

Setting up

Base requirements

  1. Install go
    • Get the latest patch version for go v1.18.
  2. Install jq
    • brew install jq on macOS.
    • sudo apt install jq on Windows + WSL2.
    • sudo apt install jq on Ubuntu Linux.
  3. Install gettext package
    • brew install gettext && brew link --force gettext on macOS.
    • sudo apt install gettext on Windows + WSL2.
    • sudo apt install gettext on Ubuntu Linux.
  4. Install KIND
    • GO111MODULE="on" go get
  5. Install Kustomize
  6. Install Python 3.x, if neither is already installed.
  7. Install make.
    • brew install make on MacOS.
    • sudo apt install make on Windows + WSL2.
    • sudo apt install make on Linux.
  8. Install timeout
    • brew install coreutils on macOS.

When developing on Windows, it is suggested to set up the project on Windows + WSL2 and the file should be checked out on as wsl file system for better results.

Get the source

git clone
cd cluster-api-provider-gcp

Get familiar with basic concepts

This provider is modeled after the upstream Cluster API project. To get familiar with Cluster API resources, concepts and conventions (such as CAPI and CAPG), refer to the Cluster API Book.

Dev manifest files

Part of running cluster-api-provider-gcp is generating manifests to run. Generating dev manifests allows you to test dev images instead of the default releases.

Dev images

Container registry

Any public container registry can be leveraged for storing cluster-api-provider-gcp container images.

CAPG Node images

In order to deploy a workload cluster you will need to build the node images to use, for that you can reference the image-builder project, also you can read the image-builder book

Please refer to the image-builder documentation in order to get the latest requirements to build the node images.

To build the node images for GCP:


Change some code!

Modules and Dependencies

This repository uses Go Modules to track vendor dependencies.

To pin a new dependency:

  • Run go get <repository>@<version>
  • (Optional) Add a replace statement in go.mod

Makefile targets and scripts are offered to work with go modules:

  • make verify-modules checks whether go modules are out of date.
  • make modules runs go mod tidy to ensure proper vendoring.
  • hack/ checks that the Go version and environment variables are properly set.

Setting up the environment

Your environment must have the GCP credentials, check Authentication Getting Started

Tilt Requirements

Install Tilt:

  • brew install tilt-dev/tap/tilt on macOS or Linux
  • scoop bucket add tilt-dev & scoop install tilt on Windows

After the installation is done, verify that you have installed it correctly with: tilt version

Install Helm:

  • brew install helm on MacOS
  • choco install kubernetes-helm on Windows
  • Install instructions for Linux

As the project lacks a lot of feature for windows, it would be suggested to follow the above steps on Windows + WSL2 rather than Windows.

Using Tilt

Both of the Tilt setups below will get you started developing CAPG in a local kind cluster. The main difference is the number of components you will build from source and the scope of the changes you’d like to make. If you only want to make changes in CAPG, then follow CAPG instructions. This will save you from having to build all of the images for CAPI, which can take a while. If the scope of your development will span both CAPG and CAPI, then follow the CAPI and CAPG instructions.

Tilt for dev in CAPG

If you want to develop in CAPG and get a local development cluster working quickly, this is the path for you.

From the root of the CAPG repository, run the following to generate a tilt-settings.json file with your GCP service account credentials:

$ cat <<EOF > tilt-settings.json
  "kustomize_substitutions": {

Set the following environment variables with the appropriate values for your environment:

$ export GCP_REGION="<GCP_REGION>" \
# Make sure to use same kubernetes version here as building the GCE image
$ export KUBERNETES_VERSION=1.23.3 \
$ export GCP_CONTROL_PLANE_MACHINE_TYPE=n1-standard-2 \
$ export GCP_NODE_MACHINE_TYPE=n1-standard-2 \
$ export GCP_NETWORK_NAME=<GCP_NETWORK_NAME or default> \

To build a kind cluster and start Tilt, just run:

make tilt-up

Alternatively, you can also run:


It will setup the network, if you already setup the network you can skip this step for that just run:

./scripts/ --skip-init-network

By default, the Cluster API components deployed by Tilt have experimental features turned off. If you would like to enable these features, add extra_args as specified in The Cluster API Book.

Once your kind management cluster is up and running, you can deploy a workload cluster.

To tear down the kind cluster built by the command above, just run:

make kind-reset

And if you need to cleanup the network setup you can run:

./scripts/ --clean-network

Tilt for dev in both CAPG and CAPI

If you want to develop in both CAPI and CAPG at the same time, then this is the path for you.

To use Tilt for a simplified development workflow, follow the instructions in the cluster-api repo. The instructions will walk you through cloning the Cluster API (CAPI) repository and configuring Tilt to use kind to deploy the cluster api management components.

you may wish to checkout out the correct version of CAPI to match the version used in CAPG

Note that tilt up will be run from the cluster-api repository directory and the tilt-settings.json file will point back to the cluster-api-provider-gcp repository directory. Any changes you make to the source code in cluster-api or cluster-api-provider-gcp repositories will automatically redeployed to the kind cluster.

After you have cloned both repositories, your folder structure should look like:

|-- src/cluster-api-provider-gcp
|-- src/cluster-api (run `tilt up` here)

After configuring the environment variables, run the following to generate your tilt-settings.json file:

cat <<EOF > tilt-settings.json
  "default_registry": "${REGISTRY}",
  "provider_repos": ["../cluster-api-provider-gcp"],
  "enable_providers": ["gcp", "docker", "kubeadm-bootstrap", "kubeadm-control-plane"],
  "kustomize_substitutions": {

$REGISTRY should be in the format<dockerhub-username>

The cluster-api management components that are deployed are configured at the /config folder of each repository respectively. Making changes to those files will trigger a redeploy of the management cluster components.


If you would like to debug CAPG you can run the provider with delve, a Go debugger tool. This will then allow you to attach to delve and troubleshoot the processes.

To do this you need to use the debug configuration in tilt-settings.json. Full details of the options can be seen here.

An example tilt-settings.json:

  "default_registry": "",
  "provider_repos": ["../cluster-api-provider-gcp"],
  "enable_providers": ["gcp", "kubeadm-bootstrap", "kubeadm-control-plane"],
  "debug": {
    "gcp": {
      "continue": true,
      "port": 30000,
      "profiler_port": 40000,
      "metrics_port": 40001
  "kustomize_substitutions": {

Once you have run tilt (see section below) you will be able to connect to the running instance of delve.

For vscode, you can use the a launch configuration like this:

  "version": "0.2.0",
  "configurations": [
      "name": "Core CAPI Controller GCP",
      "type": "go",
      "request": "attach",
      "mode": "remote",
      "remotePath": "",
      "port": 30000,
      "host": "",
      "showLog": true,
      "trace": "log",
      "logOutput": "rpc"

Create a new configuration and add it to the “Debug” menu to configure debugging in GoLand/IntelliJ following these instructions.

Alternatively, you may use delve straight from the CLI by executing a command like this:

delve -a tcp://localhost:30000

Deploying a workload cluster

After your kind management cluster is up and running with Tilt, ensure you have all the environment variables set as described in Tilt for dev in CAPG, and deploy a workload cluster with the following:

make create-workload-cluster

To delete the cluster:

make delete-workload-cluster

Submitting PRs and testing

Pull requests and issues are highly encouraged! If you’re interested in submitting PRs to the project, please be sure to run some initial checks prior to submission:

Do make sure to set the GOOGLE_APPLICATION_CREDENTIALS environment variable with the path to your JSON file. Check out the this doc to generate the credential.

make lint # Runs a suite of quick scripts to check code structure
make test # Runs tests on the Go code

Executing unit tests

make test executes the project’s unit tests. These tests do not stand up a Kubernetes cluster, nor do they have external dependencies.