AWS ECS restart Service with the same task definition and image with no downtime

Question

I am trying to restart an AWS service (basically stop and start all tasks within the service) without making any changes to the task definition.

The reason for this is because the image has the latest tag attached with every build.

I have tried stopping all tasks and having the services recreate them but this means that there is some temporarily unavailable error when the services are restarting in my instances (2).

What is the best way to handle this? Say, A blue-green deployment strategy so that there is no downtime?

This is what I have currently. It'shortcomings is that my app will be down for a couple of seconds as the service's tasks are being rebuilt after deleting them.

configure_aws_cli(){
    aws --version
    aws configure set default.region us-east-1
    aws configure set default.output json
}

start_tasks() {
    start_task=$(aws ecs start-task --cluster $CLUSTER --task-definition $DEFINITION --container-instances $EC2_INSTANCE --group $SERVICE_GROUP --started-by $SERVICE_ID)
    echo "$start_task"
}

stop_running_tasks() {
    tasks=$(aws ecs list-tasks --cluster $CLUSTER --service $SERVICE | $JQ ".taskArns | . []");
    tasks=( $tasks )
    for task in "${tasks[@]}"
    do
        [[ ! -z "$task" ]] && stop_task=$(aws ecs stop-task --cluster $CLUSTER --task "$task")
    done
}

push_ecr_image(){
    echo "Push built image to ECR"
    eval $(aws ecr get-login --region us-east-1)
    docker push $AWS_ACCOUNT_ID.dkr.ecr.us-east-1.amazonaws.com/repository:$TAG
}

configure_aws_cli
push_ecr_image
stop_running_tasks
start_tasks

Answer 1

Use update-service and the --force-new-deployment flag:

aws ecs update-service --force-new-deployment --service my-service --cluster cluster-name