ecr-deploy

Simple script to help with AWS ECR deploys.

Usage Overview

1. Set up services and JSON task definition configuration in S3
2. Install ecr-deploy: gem install ecr-deploy
3. Set up configuration file (see configuration.yml)

4. Run ecr-deploy:

   $ ecr-deploy path_to_configuration.yml $ENVIRONMENT_NAME $IMAGE_TAG
   

About

ecr-deploy makes a few assumptions about your ECR setup:

You have multiple environments of tasks and services. The name of a service is formatted ENVIRONMENT-NAME. So, for example, the "web" service in a production environment would have the service name of production-web.

Shared environment variables and ECS task definition files live in a S3 bucket. Shared environment variables are environment-specific, and are contained in a JSON file of the name ENVIRONMENT-env.json. Service and task configuration templates are contained in JSON files with the name ENVIRONMENT-NAME.json (where NAME is the service / task name specified in configuration.yml).

A quick overview of the steps ecr-deploy will take when you run it with $ ecr-deploy config.yml production 0abcdef, when config.yml has a single "web" service in the "production" environemnt:

1. Download the production-env.json
2. Download production-web.json
   1. Replace [ENVIRONMENT] with the environment loaded from production-env.json
   2. Replace [CURRENT_IMAGE_TAG] with 0abcdef
3. Register the task definition using the contents of the previous step
4. Update the production-web service to use the new task definition registered in the previous step
5. Wait for the production-web to reach a stable state (will throw an error after 10 minutes)

Task Definition templates

ecr-deploy uses the AWS SDK for Ruby which uses a slightly different format of the task definition JSON (under_scored instead of camelCased).

{
  "container_definitions": [
    {
      "volumes_from": [],
      "port_mappings": [
        {
          "host_port": 80,
          "container_port": 8000
        }
      ],
      "command": [
        "run_server"
      ],
      "environment": [
        [ENVIRONMENT]
      ],
      "essential": true,
      "entry_point": [],
      "links": [],
      "mount_points": [],
      "memory": 500,
      "name": "production-web",
      "cpu": 256,
      "image": "XXX.dkr.ecr.us-east-1.amazonaws.com/REPO_NAME:[CURRENT_IMAGE_TAG]"
    }
  ],
  "volumes": [],
  "family": "production-web"
}

Notice [ENVIRONMENT] and [CURRENT_IMAGE_TAG] -- these tokens will be replaced on deploy.

configuration.yml

---
base_config:
  # The S3 bucket that contains the task definition templates and environment
  # files.
  template_bucket: km-t01-config
  # The prefix for template object file names. Used for disambiguation if you
  # deploy multiple apps from the same bucket.
  template_bucket_prefix: ecr-deploy-

  # The name of the ECS cluster
  cluster: default

production:
  # Services that will be updated
  services:
    - web

  # Tasks that will be run as part of the deploy process (good for automatic
  # migrations, etc)
  run_tasks:
    - migrator

  # Tasks that will only be registered, not run. Good for on-demand workers.
  register_tasks:
    - worker