blue-green-beanstalk

GitHub Action to automate blue/green deployment with AWS Elastic Beanstalk.

The action will create the following resources:

• An Elastic Beanstalk application, if it doesn't already exist.
• An Elastic Beanstalk application version, if it doesn't already exist.
• An Elastic Beanstalk environment, if it doesn't already exist.

Getting Started

The easiest way to get started with this action is to use the example repo as a template.

Blue/Green Deployment

Based on the provided inputs, the action will determine which environment is the target environment, to which a new application version should be deployed.

The action uses the values of the production_cname and staging_cname inputs to determine which environment is the production or staging environment. Accordingly, the production CNAME should always point to the production environment, and the staging CNAME should always point to the staging environment.

If neither environment exists, the action will create a new environment with the production_cname input. If the production environment already exists, the action will target the staging environment, creating it if it doesn't exist.

After deploying, the action will swap the CNAMEs of the staging and production environments, if swap_cnames is set to true.

Example Blue/Green Deployment

See the example repo for an example of how to use this action. The example repo also contains a CloudFormation template to create the necessary IAM resources required to run the action using the GitHub OIDC provider.

name: Example Deploy Workflow
  on:
    workflow_dispatch:
    push:
      branches:
        - main
        - staging

jobs:
  deploy:
    runs-on: ubuntu-latest
    permissions:
      id-token: write
      contents: read
    steps:
      - name: Checkout
        uses: actions/checkout@v4
      - name: Configure AWS credentials
        uses: aws-actions/configure-aws-credentials@v4
        with:
          role-to-assume: ${{ vars.AWS_ROLE }}
          aws-region: ${{ vars.AWS_REGION }}
      - name: Generate source bundle
        run: zip -r bundle.zip . -x '*.git*'
      - name: Deploy
        uses: tmshkr/blue-green-beanstalk@v5
        with:
          app_name: "test-app"
          blue_env: "my-blue-env"
          deploy: true # Must be set to true to deploy
          green_env: "my-green-env"
          platform_branch_name: "Docker running on 64bit Amazon Linux 2023"
          production_cname: "blue-green-beanstalk-prod"
          source_bundle: "bundle.zip"
          staging_cname: "blue-green-beanstalk-staging"
          swap_cnames: ${{ github.ref_name == 'main' }}
          version_description: ${{ github.event.head_commit.message }}
          version_label: ${{ github.ref_name }}-${{ github.sha }}

Inputs

Required Inputs

Name	Description
app_name	Name of the Elastic Beanstalk application. If it doesn't exist, it will be created.

Dependent Inputs

Inputs that must be provided together.

Name	Description	Needs
blue_env	Name of the blue environment.	green_env, production_cname, staging_cname
green_env	Name of the green environment.	blue_env, production_cname, staging_cname
production_cname	CNAME prefix for the domain that serves production traffic when performing a blue/green deployment.	blue_env, green_env, staging_cname
single_env	Name of a single environment to deploy. If specified, the blue/green environments and production/staging CNAMEs must not be provided.	single_env_cname
single_env_cname	CNAME prefix to use for a single-environment deployment.	single_env
staging_cname	CNAME prefix of the staging environment for a blue/green deployment.	blue_env, green_env, production_cname

Optional Inputs

Name	Default	Description
aws_access_key_id		AWS Access Key ID. May instead be specified via the AWS_ACCESS_KEY_ID environment variable.
aws_region		AWS region. May instead be specified via the AWS_REGION environment variable.
aws_secret_access_key		AWS Secret Access Key. May instead be specified via the AWS_SECRET_ACCESS_KEY environment variable.
aws_session_token		AWS session token for using temporary credentials. May instead be specified via the AWS_SESSION_TOKEN environment variable.
create_environment	true	Whether to create a new environment during deployment if the target environment doesn't exist.
deploy	false	Whether to deploy to the target environment.
disable_termination_protection	false	Whether to disable termination protection for the target environment's CloudFormation stack before attempting to terminate it.
enable_termination_protection	false	Whether to enable termination protection for the target environment's CloudFormation stack after deployment.
minimum_health_color	Green	Minimum health color (Green, Yellow, Red, or Grey) required for the target environment to be considered healthy.
option_settings		Path to a JSON file consisting of an array of option settings to use when updating an existing evironment or creating a new environment.
platform_branch_name		Name of the platform branch to use. When creating a new environment, it will be launched with the latest version of the specified platform branch. To see the list of available platform branches, run the aws elasticbeanstalk list-platform-branches command.
send_command		Command to send to the target environment after (optional) deployment. Specify a shell script or series of commands to run. Useful for running tasks related to deployment, such as swapping environment variables before promoting an environment to production.
source_bundle		Path to the source bundle to deploy. If not specified, the sample application will be used.
swap_cnames	false	Whether to swap the CNAMEs of the blue and green environments.
template_name		Name of an Elastic Beanstalk configuration template to use when creating a new environment.
terminate_unhealthy_environment	false	Whether to terminate an unhealthy target environment. If set to false, the action will fail if the target environment is unhealthy.
update_environment	true	Whether to update an existing environment during deployment.
update_listener_rules	false	When set to true, the action will update any elbv2 listener rules on the environments' SharedLoadBalancer tagged with a bluegreenbeanstalk:target_cname key, whose value is equal to an environment's CNAME prefix, so that it forwards to the corresponding target group. For example, you can tag a listener rule that matches the host my-domain.com with a tag containing bluegreenbeanstalk:target_cname as its key and my-prod-cname as its value, and the action will update the listener rule to point to the same target group as the environment with the CNAME my-prod-cname. The listener rules are updated after the CNAMEs are swapped, so this keeps the listener rules in sync with the CNAMEs. The port of the process may be specified by another tag with the key bluegreenbeanstalk:target_port whose value is the port number. If no such tag is found, the default port of 80 will be used. If you'd only like to update the listener rules for a certain CNAME, you can set this input to the CNAME prefix you'd like to update.
use_default_option_settings	true	Whether to use default option settings when creating a new environment.
version_description		Description to use for the new application version.
version_label		Version label to use for the new application version.
wait_for_command	true	Whether to wait for the send_command execution to complete.
wait_for_deployment	true	Whether to wait for the deployment to complete.
wait_for_environment	true	Whether to wait for the target environment to be ready before deployment. If set to false, the action will fail if the target environment is not ready.
wait_for_termination	true	Whether to wait for an environment to be terminated. If set to false, the action will fail if the target environment is terminating.

Outputs

Name	Description
target_env_cname	CNAME of the target environment.
target_env_endpoint_url	URL of the environment's load balancer, or an Elastic IP address when using a single instance environment.
target_env_id	ID of the target environment.
target_env_json	JSON representation of the target environment.
target_env_name	Name of the target environment.
target_env_status	Status of the target environment.