Setting up automated deployments

You can configure automated deployments for your workloads on Google Kubernetes Engine (GKE).

This page shows you how to set up a simple continuous integration/continuous delivery (CI/CD) pipeline for the workload. When you push a change to your repository, Cloud Build automatically builds and deploys the container to your GKE cluster.

How an automated deployment works

If you have a workload that references a single-container image in GKE, you can configure an automated deployment, so that your application is re-built and deployed each time a code change is checked into the repository.

With an automated deployment, you define your workload as a YAML file and store that YAML file in your repository (consistent with best practices). GKE generates YAML that you can use for this purpose.

You have the following two options for using YAML files:

If you don't yet have a YAML file that defines your workload, you can use the generated YAML file. Save the YAML file in your repository. Cloud Build uses it to deploy your workload each time.
If you already have a YAML file that defines your workload, you can point GKE to its location in your repository. You can compare the YAML file in your repository with the recommended YAML file to ensure you're deploying the correct workload in the correct way.

Before you begin

Before you start, make sure you have performed the following tasks:

Ensure that you have enabled the Google Kubernetes Engine API.

Enable Google Kubernetes Engine API

Ensure that you have installed the Cloud SDK.

Set up default gcloud settings using one of the following methods:

Using gcloud init, if you want to be walked through setting defaults.
Using gcloud config, to individually set your project ID, zone, and region.

Using gcloud init

If you receive the error One of [--zone, --region] must be supplied: Please specify location, complete this section.

Run gcloud init and follow the directions:
```
gcloud init
```
If you are using SSH on a remote server, use the --console-only flag to prevent the command from launching a browser:
```
gcloud init --console-only
```
Follow the instructions to authorize gcloud to use your Google Cloud account.
Create a new configuration or select an existing one.
Choose a Google Cloud project.
Choose a default Compute Engine zone.

Note: You can override these default settings in gcloud commands using the --project, --zone, and --region flags.

Using gcloud config

Set your default project ID:
```
gcloud config set project PROJECT_ID
```
If you are working with zonal clusters, set your default compute zone:
```
gcloud config set compute/zone COMPUTE_ZONE
```
If you are working with regional clusters, set your default compute region:
```
gcloud config set compute/region COMPUTE_REGION
```
Update gcloud to the latest version:
```
gcloud components update
```

Note: You can override these default settings in gcloud commands using the --project, --zone, and --region flags.

Enable the following additional APIs:
- Cloud Build
  
  Enable Cloud Build API
- Cloud Source Repositories
  
  Enable Cloud Source Repositories API

Requirements

Automated deployments have the following requirements:

You can only use an automated deployment with workloads of type Deployment that specify a single container image. Multi-container workloads and other workload types (for example, ReplicaSet) are not supported.
Your source-code repository must contain a Dockerfile to build the image.

You can host this repository on one of the following products:
- Cloud Source Repositories
- GitHub
- Bitbucket
If you use GitHub or Bitbucket, you need to grant Google Cloud access to your repository.
Store your container image in Container Registry, in the same Google Cloud project as your GKE cluster. You need to have the image in Container Registry, and you need to have deployed it at least once, so that you have a workload in GKE.

Creating the Deployment

To create a Deployment with an automated deployment, perform the following steps:

Visit the Workloads menu in Google Cloud Console.

Visit the Workloads menu
Click the name of the workload that you want to deploy.

This opens the Deployment details page for the workload.
Click the Actions menu, and select Automated deployment.

The Set up automated deployment screen appears.
Select the repository that contains your source code to build this workload.
1. From the Repository Provider drop-down, choose the provider for your repository.
  
  An automated deployment supports the following source control hosts:
  - Cloud Source Repositories
  - GitHub
  - Bitbucket
  If you are using GitHub or Bitbucket, authenticate with your username and password.
  
  Note: An automated deployment creates a mirror of your GitHub or Bitbucket repositories on Cloud Source Repositories. When you push changes to your original repository, the Cloud Source Repositories picks up the changes automatically.
2. From the Repository drop-down, select the name of the repository containing the source code for your workload.
Click Continue and specify the Build configuration information:
1. Enter the name of the branch from which you want to build, or a regular expression (RegExp2) to match the branch or branches. The default branch is master. When you push to this branch, Cloud Build builds your application.
2. Specify the directory of your Dockerfile, relative to the root of the repository.
3. Provide the file name of your Dockerfile containing your build information.
Note: The Image name field is automatically generated based on the repository name.
Click Continue.
Provide the location of the configuration YAML file.

The system automatically generates a YAML file, which you can use to populate the YAML file in your repository.
1. Click View Google-recommended YAML to see the generated YAML file.
2. Compare it to your own YAML file, if you have it, and update yours based on this one.
  
  Otherwise, create a new file and populate it with the generated YAML. This helps ensure the workload that gets deployed matches what's currently running. The file can have any name, but must have a .yaml or .yml extension.
3. Specify the directory where the YAML file is located, relative to the root of your repository.
  
  If there is more than one YAML file in the specified directory, GKE uses all of them.
Click Set up to finish configuring your automated deployment.

You might be prompted to grant permissions to the Cloud Build service account. This permission is required.

What happens next

After you set up an automated deployment for the selected workload, you have a Cloud Build trigger that builds a container image after a push to the selected branch of the repository. Cloud Build also deploys a new revision of your workload to the cluster where the original image was deployed.

For more information on your workload, see the Deployment Details page (Revision History tab).