AWS ECS Rollback - Hello World

Sample AWS Elastic Container Service (ECS) application with deploy and rollback deploy scripts, referenced in Rolling back AWS Elastic Container Service (ECS) Deployments.

Dependencies

Install required dependencies:

• bash (command-not-found)
• aws-cli v2
• terraform
• jq
• dialog (command-not-found)

Building Infrastructure

Create IAM user with relevant permissions for Terraform ECS setup (S3, DynamoDB, ECS, ECR, etc), or AdministratorAccess for quicker setup.

Add ecs-rollback-hello-world AWS profile to credentials list:

sudo vim ~/.aws/credentials

[ecs-rollback-hello-world]
aws_access_key_id = <iam user access key id>
aws_secret_access_key = <iam user secret key>

Create infrastructure

Fork or clone the project.

Create a .env file from the .env/example in the project root with required configuration variables.

Run build script:

./bin/build_infrastructure

Create ECS Infrastructure

IMPORTANT: The infrastructure required for ECS is not covered by the AWS Always free tier, therefore running this command may cost you money. Remember evaluate costs and to teardown project afterwards.

Run the ./bin/build_infrastructure to build sample ECS infrastructure.

Initial Deploy

Deploy the first revision of the application to ECR:

./bin/deploy

After a couple minutes the application should be available at the 'Application URL' output at the end of the script.

Rolling Back

Update Application

Make noticeable change to the application. For example:

// ./hello.go
// ...

func HelloServer(w http.ResponseWriter, r *http.Request) {
  // fmt.Fprintf(w, "Hello, World!")
  fmt.Fprintf(w, "Roll me back!")
  log.Printf("Received request for path: %s", r.URL.Path)
}

Commit with suitable message and deploy changes:

git add ./hello.go
git commit -m 'updated server welcome message'
./bin/deploy

Check the application url for the changes.

Rollback Application

Once changes have been applied, rollback using either:

• simple rollback script - ./bin/rollback
• dialog rollback script - ./bin/rollback_dialog

Rollbacks will take a couple minutes as new tasks are provisioned and started, check the application url for the changes.

Teardown Infrastructure

Run the ./bin/teardown_infrastructure to use Terraform to remove the sample ECS application infrastructure.

You may also need to deregister any additional ECS task definitions not managed by Terraform.