ecs-formation

ecs-formation is a tool for defining several Docker continers and clusters on Amazon EC2 Container Service(ECS).

Features

• Define services on ECS cluster, and Task Definitions.
• Supports YAML definition like docker-compose. Be able to run ecs-formation if copy docker-compose.yml(formerly fig.yml).
• Manage ECS Services and Task Definitions by AWS API.
• Support ELB(Classic Load Balancer) and ALB(Application Load Balancer)
• Service Auto Scaling
• Task Placement Policy

Usage

Setup

Installation

ecs-formation is written by Go. Please run go get.

$ go get github.com/openfresh/ecs-formation

Define environment variables

ecs-formation use cobra. It supports yaml configuration.

Prepare ~/.ecs-formation.yaml for project configuration.

project_dir: ~/your_project_dir/
aws_region: us-east-1

ecs-formation requires environment variables to run, as follows.

• AWS_ACCESS_KEY: AWS access key
• AWS_SECRET_ACCESS_KEY: AWS secret access key
• AWS_REGION: Target AWS region name

Make working directory

Make working directory for ecs-formation. This working directory should be managed by Git.

$ mkdir -p path-to-path/test-ecs-formation
$ mkdir -p path-to-path/test-ecs-formation/task
$ mkdir -p path-to-path/test-ecs-formation/service
$ mkdir -p path-to-path/test-ecs-formation/bluegreen

Manage Task Definition and Services

Make ECS Cluster

You need to create ECS cluster in advance. And also, ECS instance must be join in ECS cluster.

Define Task Definitions

Make Task Definitions file in task directory. This file name is used as ECS Task Definition name.

(path-to-path/test-ecs-formation/task) $ vim test-definition.yml
nginx:
  image: nginx:latest
  ports:
    - 80:80
  environment:
    PARAM1: value1
    PARAM2: value2
  links:
    - api
  memory_reservation: 256
  cpu_units: 512
  essential: true

api:
  image: your_namespace/your-api:latest
  ports:
    - 8080:8080
  memory: 1024
  cpu_units: 1024
  essential: true
  links:
    - redis

redis:
  image: redis:latest
  ports:
    - 6379:6379
  memory: 512
  cpu_units: 512
  essential: true

Define Services on Cluster

Make Service Definition file in cluster directory. This file name must be equal ECS cluster name.

For example, if target cluster name is test-cluster, you need to make test-cluster.yml.

(path-to-path/test-ecs-formation/service) $ vim test-cluster.yml
test-service:
  task_definition: test-definition
  desired_count: 1
  role: your-ecs-elb-role
  load_balancers:
    -
      name: test-elb
      container_name: nginx
      container_port: 80
  autoscaling:
    target:
      min_capacity: 0
      max_capacity: 1
      role: arn:aws:iam::your_account_id:role/ecsAutoscaleRole

In case of ALB, you should specify target_group_arn.

(path-to-path/test-ecs-formation/service) $ vim test-cluster.yml
test-service:
  task_definition: test-definition
  desired_count: 1
  role: your-ecs-elb-role
  load_balancers:
    -
      target_group_arn: test-target-group-arn
      container_name: nginx
      container_port: 80

Keep desired_count at updating service

If you modify value of desired_count by AWS Management Console or aws-cli, you'll fear override value of desired_count by ecs-formation. This value should be flexibly changed in the operation.

If keep_desired_count is true, keep current desired_count at updating service.

(path-to-path/test-ecs-formation/service) $ vim test-cluster.yml
test-service:
  task_definition: test-definition
  desired_count: 1
  keep_desired_count: true

Task Placement Policy

Supports placement_constraints and placement_strategy. If you update these options, it's necessary to rebuild service once.

(path-to-path/test-ecs-formation/service) $ vim test-cluster.yml
test-service:   
  task_definition: test-definition
  desired_count: 1
  keep_desired_count: true
  placement_constraints:
    - type: memberOf
      expression: "attribute:ecs.instance-type =~ t2.*"
  placement_strategy:
    - type: spread
      field: "attribute:ecs.availability-zone"

Manage Task Definitions

Show update plan.

(path-to-path/test-ecs-formation $ ecs-formation task plan --all
(path-to-path/test-ecs-formation $ ecs-formation task plan -t test_definition

Apply all definition.

(path-to-path/test-ecs-formation $ ecs-formation task apply --all
(path-to-path/test-ecs-formation $ ecs-formation task apply -t test_definition

Manage Services on Cluster

Show update plan. Required cluster.

(path-to-path/test-ecs-formation $ ecs-formation service plan -c test-cluster --all

Apply all services.

(path-to-path/test-ecs-formation $ ecs-formation service apply -c test-cluster --all

Specify cluster and service.

(path-to-path/test-ecs-formation $ ecs-formation service apply -c test-cluster -s test-service

Blue Green Deployment

ecs-formation supports blue-green deployment.

Requirements on ecs-formation

• Requires two ECS cluster. Blue and Green.
• Requires two ELB. Primary ELB and Standby ELB.
• ECS cluster should be built by EC2 Autoscaling group.

Define Blue Green Deployment

Make management file of Blue Green Deployment file in bluegreen directory.

(path-to-path/test-ecs-formation/bluegreen) $ vim test-bluegreen.yml
blue:
  cluster: test-blue
  service: test-service
  autoscaling_group: test-blue-asg
green:
  cluster: test-green
  service: test-service
  autoscaling_group: test-green-asg
primary_elb: test-elb-primary
standby_elb: test-elb-standby

Show blue green deployment plan.

(path-to-path/test-ecs-formation $ ecs-formation bluegreen plan

Apply blue green deployment.

(path-to-path/test-ecs-formation $ ecs-formation bluegreen apply -g test-bluegreen

if with --nodeploy option, not update services. Only swap ELB on blue and green groups.

(path-to-path/test-ecs-formation $ ecs-formation bluegreen apply --nodeploy -g test-bluegreen

If autoscaling group have several different classic ELB, you should specify array property of chain_elb. ecs-formation can swap chain_elb ELB group with main ELB group at the same time.

(path-to-path/test-ecs-formation/bluegreen) $ vim test-bluegreen.yml
blue:
  cluster: test-blue
  service: test-service
  autoscaling_group: test-blue-asg
green:
  cluster: test-green
  service: test-service
  autoscaling_group: test-green-asg
primary_elb: test-elb-primary
standby_elb: test-elb-standby
chain_elb:
  - primary_elb: test-internal-elb-primary
    standby_elb: test-internal-elb-standby

In case of ALB(Application Load Balancer), as follows.

(path-to-path/test-ecs-formation/bluegreen) $ vim test-bluegreen.yml
blue:
  cluster: test-blue
  service: test-service
  autoscaling_group: test-blue-asg
green:
  cluster: test-green
  service: test-service
  autoscaling_group: test-green-asg
elbv2:
  target_groups:
    - primary_group: test-internal-primary
      standby_group: test-internal-default

Others

Passing custom parameters

You can use custom parameters. Define parameters in yaml file(task, service, bluegreen) as follows.

nginx:
    image: openfresh/nginx:${NGINX_VERSION}
    ports:
        - 80:${NGINX_PORT}

You can set value for these parameters by using -p option.

ecs-formation task -p NGINX_VERSION=1.0 -p NGINX_PORT=80 plan -t your-web-task

Also, support default parameter value.

nginx:
    image: openfresh/nginx:${NGINX_VERSION|latest}
    ports:
        - 80:${NGINX_PORT|80}

env_file

You can use env_file like docker-compose. https://docs.docker.com/compose/compose-file/#env-file

nginx:
    image: openfresh/nginx:${NGINX_VERSION}
    ports:
        - 80:${NGINX_PORT}
    env_file:
        - ./test1.env
        - ../test2.env

License

See LICENSE.

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