Deploy to Google Compute Engine

Github action to simplify deploys to Google Compute Engine.

This action will...

1. Clone an existing instance template (using it as a base).
2. Update metadata config of the newly created instance template to run a startup script.
3. Tell the instance group manager to perform a rolling update with the new instance template.

Prerequisites

Set up the following resources manually in the Cloud Console or use a tool like Terraform.

• Create a base instance template to be cloned by this action.
• Create a managed instance group. Please note that currently only regional instance groups are supported.
• Create Service Account with Roles Compute Admin and Service Account User and export a new JSON key.

deploy.yml

By default this action expects a deploy.yml in the root directory of the repository. Here is an example:

common:
  labels:
    gitsha: ${{GITHUB_SHA}}

deploys:
  - name: my-app-deploy
    region: us-central1
    instance_group: my-app-instance-group
    instance_template_base: my-app-instance-template-base
    instance_template: my-app-${{GITHUB_RUN_NUMBER}}-${{GITHUB_SHA}}
    cloud_init: cloud-init.yml # see example dir
    labels: # will also have gitsha from common section
      version: ${{APP_VERSION}}
    tags:
      - my-tag123
    update_policy:
      min_ready_sec: 30

delete_instance_templates_after: false

Config Reference

Variable	Description
deploys.*.name	Required Name of the deploy
deploys.*.project	Name of the Google Cloud project. Defaults to Project from Credentials.
deploys.*.creds	Either a path or the contents of a Service Account JSON Key. Required, if not specified in Github action.
deploys.*.region	Required Region of the instance group.
deploys.*.instance_group	Required Name of the instance group.
deploys.*.instance_template_base	Required Instance template to be used as base.
deploys.*.instance_template	Required Name of the newly created instance template.
deploys.*.startup_script	Path or URL to script to run when VM boots. Read more
deploys.*.shutdown_script	Path or URL to script to run when VM shuts down. Read more
deploys.*.cloud_init	Path or URL to cloud-init file. Read more
deploys.*.labels	A set of key/value label pairs to assign to instances. Keys override common.*.labels.
deploys.*.metadata	A set of key/value metadata pairs to make available from within instances. Keys override common.*.metadata.
deploys.*.tags	A list of tags to assign to instances. Tags are merged with common.*.tags.
deploys.*.vars	A set of additional key/value variables which will be available in either startup_script, shutdown_script or cloud_init. Keys override existing ENV vars and common.*.vars.
deploys.*.update_policy.type=PROACTIVE	The type of update process, must be either PROACTIVE (default) or OPPORTUNISTIC. Read more
deploys.*.update_policy.replacement_method=SUBSTITUTE	What action should be used to replace instances, must be either SUBSTITUTE (default) or RECREATE. Read more
deploys.*.update_policy.minimal_action=REPLACE	Minimal action to be taken on an instance, possible values are NONE, REFRESH, REPLACE (default) or RESTART. Read more
deploys.*.update_policy.min_ready_sec=10	Time to wait between consecutive instance updates, default is 10 seconds. Read more
deploys.*.update_policy.max_surge=3	Maximum number (or percentage, i.e. 15%) of temporary instances to add while updating. Default is 3. Read more
deploys.*.update_policy.max_unavailable=0	Maximum number (or percentage, i.e. 100%) of instances that can be offline at the same time while updating. Default is 0. Read more
common.project	Set default for deploys.*.project
common.region	Set default for deploys.*.region
common.startup_script	Set default for deploys.*.startup_script
common.shutdown_script	Set default for deploys.*.shutdown_script
common.cloud_init	Set default for deploys.*.cloud_init
common.labels	Set default for deploys.*.labels
common.metadata	Set default for deploys.*.metadata
common.tags	Set default for deploys.*.tags
common.vars	Set default for deploys.*.vars
common.update_policy.type	Set default for deploys.*.update_policy.type
common.update_policy.replacement_method	Set default for deploys.*.update_policy.replacement_method
common.update_policy.minimal_action	Set default for deploys.*.update_policy.minimal_action
common.update_policy.min_ready_sec	Set default for deploys.*.update_policy.min_ready_sec
common.update_policy.max_surge	Set default for deploys.*.update_policy.max_surge
common.update_policy.max_unavailable	Set default for deploys.*.update_policy.max_unavailable
delete_instance_templates_after=336h	Delete old instance templates after duration, defaults to 336h (14 days). Set to false to disable.

Variables

Environment variables can be used in deploy.yml, startup_script, shutdown_script and cloud_init files. The syntax is ${{FOO}} and supports substring extraction, i.e. ${{GITHUB_SHA:0:7}}:

${{VAR:position}}        - Extracts substring from $VAR at "position"
${{VAR:position:length}} - Extracts "length" characters of substring from $VAR at "position"

Github sets a bunch of default environment variables.

Github Action Usage

uses: mattes/gce-deploy-action@v5
with:
  creds: ${{ secrets.GOOGLE_APPLICATION_CREDENTIALS }}

Variable	Description
creds	Required Either a path or the contents of a Service Account JSON Key.
config	Path to config file. Default deploy.yml or deploy.yaml.

More Documentation

• My own Heroku in 30 mins - Deploy Rails apps to Google Cloud Compute Engine
• Managed Instance Groups
• Container-Optimized OS
• cloud-init
• startup scripts
• Configuring an Instance