Deploy Docker container into AWS ECS Fargate using Gitlab CI

.gitlab-ci.yml

image: docker:19.03

variables:
  REPOSITORY_URL: <AWS_ACCOUNT_ID>.dkr.ecr.<REGION_NAME>.amazonaws.com/<ECR_REPOSITORY_NAME>
  REGION: <REGION_NAME>
  TASK_DEFINITION_NAME: <TASK_DEFINITION_NAME>
  CLUSTER_NAME: <CLUSTER_NAME>
  SERVICE_NAME: <SERVICE_NAME>
  CPU: <CPU>
  MEMORY: <MEMORY>
  TASKS_COUNT: <DESIRED_TASKS_COUNT>
  EXECUTION_ROLE_ARN: arn:aws:iam::<AWS_ACCOUNT_ID>:role/ecsTaskExecutionRole
  AWS_ACCESS_KEY_ID: <AWS_ACCESS_KEY_ID>
  AWS_SECRET_ACCESS_KEY: <AWS_SECRET_ACCESS_KEY>

services:
- docker:19.03.1-dind

before_script:
  - apk add --no-cache python py-pip
  - pip install awscli
  - IMAGE_TAG="$CI_COMMIT_SHORT_SHA"

stages:
  - build
  - deploy

build:
  stage: build
  script:
    - echo "Building image..."
    - docker build -t $REPOSITORY_URL:latest .
    - echo "Tagging image..."
    - IMAGE_TAG="$CI_COMMIT_SHORT_SHA"
    - docker tag $REPOSITORY_URL:latest $REPOSITORY_URL:$IMAGE_TAG
    - echo "Pushing image..."
    - docker push $REPOSITORY_URL:latest
    - docker push $REPOSITORY_URL:$IMAGE_TAG
  only:
    - master
  tags:
    - docker

deploy:
  stage: deploy
  script:
    - apk add --no-cache jq
    - TASK_DEFINITION=$(aws ecs describe-task-definition --task-definition "$TASK_DEFINITION_NAME" --region "${REGION}")
    - NEW_CONTAINER_DEFINTIION=$(echo $TASK_DEFINITION | jq --arg IMAGE "$REPOSITORY_URL:$IMAGE_TAG" '.taskDefinition.containerDefinitions[0].image = $IMAGE | .taskDefinition.containerDefinitions')
    - echo "Registering new container definition..."
    - aws ecs register-task-definition --region "${REGION}" --family "${TASK_DEFINITION_NAME}" --container-definitions "${NEW_CONTAINER_DEFINTIION}" --cpu ${CPU} --memory ${MEMORY} --execution-role-arn "${EXECUTION_ROLE_ARN}" --network-mode "awsvpc" --requires-compatibilities "FARGATE"
    - TASK_ARN=$(aws ecs list-tasks --region "${REGION}" --cluster "${CLUSTER_NAME}" --service-name "${SERVICE_NAME}")
    - TASK_ID=$(echo ${TASK_ARN:72:36})
    - echo "Updating the service..."
    - aws ecs update-service --region "${REGION}" --cluster "${CLUSTER_NAME}" --service "${SERVICE_NAME}"  --task-definition "${TASK_DEFINITION_NAME}" --desired-count "${TASKS_COUNT}"
    - echo "Waiting until the previous task ${TASK_ID} is stopped..."
    - aws ecs wait tasks-stopped --region "${REGION}" --cluster "${CLUSTER_NAME}" --tasks "${TASK_ID}"
    - echo "The previous task ${TASK_ID} has stopped."
    - TASK_ARN=$(aws ecs list-tasks --region "${REGION}" --cluster "${CLUSTER_NAME}" --service-name "${SERVICE_NAME}")
    - TASK_ID=$(echo ${TASK_ARN:72:36})
    - echo "New task ${TASK_ID} is running."
    - aws ecs describe-tasks --region "${REGION}" --cluster "${CLUSTER_NAME}" --tasks "${TASK_ID}"
  only:
    - master
  tags:
    - docker