Using Garden in CI

In this guide we'll demonstrate how Garden can fit into your continuous integration (CI) pipeline. Simply by adding extra environments to the project configuration, you can use Garden for local development and for testing and deploying your project in CI. This approach has several benefits:

  • Use the same tool and the same set of commands for the entire development cycle, from source to finish.

  • No need to change your CI configuration when you change your stack since Garden holds the entire stack graph.

  • The only thing you need to install in CI is the Garden CLI and its dependencies.

To use Garden in a CI pipeline you need the following:

  1. Kubectl context on the CI agent that's configured against the remote cluster.

For the purposes of this example we'll be using CircleCI and deploying to a Google Kubernetes Engine (GKE) cluster. However, the instructions below can easily be applied to other CI platforms and cloud providers.

The guide is based on the Remote Kubernetes example. In what follows we assume that you've completed the steps in that guide and that you have a running Kubernetes cluster.

Prerequisites

Project overview

The project is based on our demo-project example, but configured for multiple environments. Additionally it contains a CircleCI config file. You'll find the entire source code here.

The CI pipeline in configured so that Garden tests the project and deploys it to a preview environment on every pull request. Additionally, it tests the project and deploys it to a separate staging environment on every merge to the master branch.

To see it in action, you can fork the repository and follow the set-up steps below. Once you've set everything up, you can submit a pull request to the fork to trigger a CircleCI job which in turns deploys the project to your remote Kubernetes cluster.

Configure remote environments

Configuring Garden to work against a remote Kubernetes cluster is explained step by step in our Remote Kubernetes guide.

For this project we're using three environments: local, preview and staging. The local environment is the default and is configured for a local Kubernetes cluster that runs on the user's machine. The other two run on remote clusters.

We deploy to the preview environment every time someone makes a pull request on Github. The configuration looks like this:

# garden.yml
kind: Project
name: ci-demo-project
environments:
...
- name: preview
providers:
- name: kubernetes
context: my-preview-cluster
defaultHostname: ci-demo-project-${local.env.CIRCLE_BRANCH || "default"}.preview.my-domain
namespace: ci-demo-project-${local.env.CIRCLE_BRANCH || "default"}
deploymentRegistry:
# The hostname of the registry, e.g. gcr.io for GCR (Google Container Registry)
hostname: my-registry-hostname
# Namespace to use in the registry for this project. For GCR, use the project ID where your cluster is.
namespace: my-registry-namespace

Notice that we're using the CIRCLE_BRANCH environment variable to label the project namespace. This ensures that each pull request gets deployed into its own namespace.

The staging environment is configured in a similar manner. The relevant CI job is triggered on merges to the master branch.

You'll find the rest of the config here.

Install Garden on your CI agent

As of CircleCI 2.1, you can define your own re-usable commands. That's what we've done for the install_garden command, which, as the name suggests, installs Garden and it's dependencies:

# .circleci/config
commands:
install_garden:
description: Installs the Garden CLI and it's dependencies
steps:
- run:
name: Install Garden dependencies
command: |
sudo apt-get update && sudo apt-get install rsync
mkdir $HOME/kubectl
curl -L -o $HOME/kubectl/kubectl "https://storage.googleapis.com/kubernetes-release/release/v1.11.3/bin/linux/amd64/kubectl"
chmod +x $HOME/kubectl/kubectl
- run:
name: Install the Garden CLI
command: |
mkdir $HOME/garden
curl -L https://github.com/garden-io/garden/releases/download/v0.9.6/garden-v0.9.6-linux-amd64.tar.gz | tar xvz -C $HOME/garden --strip-components=1
- run:
name: Add Garden and Kubectl to the CircleCI agent path
command: |
echo 'export PATH=$HOME/garden:$PATH' >> $BASH_ENV
echo 'export PATH=$HOME/kubectl:$PATH' >> $BASH_ENV

Although the YAML is specific to CircleCI, the commands can be adjusted to most Linux distributions. For Alpine, use our Alpine release. The first two steps install Garden and dependencies. The last one adds these to the CircleCI agent path (this might look differently on other CI platforms).

You can also find installation instructions in our documentation. Note that we do not install Docker since it's already enabled on the CircleCI agent when the setup_remote_docker flag is used:

# .circleci/config
jobs:
preview:
steps:
- setup_remote_docker

Garden Enterprise users can skip this step as the Enterprise version features in-cluster builds and layer caching out of the box. Please reach out to learn more.

Configure the kubectl context

With Garden installed, we need to make sure that it can access our remote cluster. We do this by setting up a kubectl context on the CI agent. How you set this up will vary by how and where you have deployed your cluster. What follows is specific to GKE users.

As before, we create a re-usable command for configuring the kubectl context:

# .circleci/config
commands:
configure_kubectl_context:
description: Configure the kubectl context so that we can access our remote cluster
steps:
- run:
name: Install GCloud
command: |
mkdir $HOME/gcloud
curl https://dl.google.com/dl/cloudsdk/release/google-cloud-sdk.tar.gz | tar xvz -C $HOME/gcloud
$HOME/gcloud/google-cloud-sdk/install.sh --quiet
- run:
name: Add GCloud to the CircleCI agent path
command: echo 'export PATH=$HOME/gcloud/google-cloud-sdk/bin:$PATH' >> $BASH_ENV
- run:
name: Configure kubectl context via gloud
command: |
gcloud --quiet components update
echo $GCLOUD_SERVICE_KEY | gcloud auth activate-service-account --key-file=-
gcloud --quiet config set project $GOOGLE_PROJECT_ID && gcloud --quiet config set compute/zone $GOOGLE_COMPUTE_ZONE
gcloud --quiet container clusters get-credentials $GOOGLE_CLUSTER_ID --zone $GOOGLE_COMPUTE_ZONE
gcloud --quiet auth configure-docker

The commands use the following environment variables that you can set on the Project Environment Variables page (see here) in the CircleCI dashboard:

  • GCLOUD_SERVICE_KEY: Follow these instructions to get a service account key.

  • GCLOUD_PROJECT_ID, GOOGLE_COMPUTE_ZONE, and GCLOUD_CLUSTER_ID: These you'll find under the relevant project in your Google Cloud Platform console.

Please refer to this doc for more information on using the Google Cloud SDK in CircleCI.

You'll find the entire CircleCI config for this project here.

Running Garden commands in CircleCI

Now that we have everything set up, we can add the project to CircleCI and start using Garden in our CI pipelines.

Here's what our preview job looks like:

# .circleci/config
jobs:
preview:
<<: *image-config
steps:
- checkout
- setup_remote_docker:
docker_layer_caching: true
- install_garden
- configure_kubectl_context
- run:
name: Test project
command: garden test --logger-type=basic --env=preview
- run:
name: Deploy project
command: garden deploy --logger-type=basic --env=preview

Notice that there are no configuration steps outside of just installing Garden and configuring the kubectl context. And no matter how you change your stack, these steps will remain the same, making for a highly portable workflow.