Continuous deployment to Amazon Elastic Container Service (Amazon ECS) with Bitbucket Pipelines

Before getting started you have to create a user in AWS IAM. For this user you can create the access key and the secret key.

Next you have to define following environment variables in the Bitbucket Pipeline settings:

• AWS_DEFAULT_REGION
• AWS_ACCESS_KEY_ID
• AWS_SECRET_ACCESS_KEY [check Secured here]
• AWS_REGISTRY_URL

Here is how the general deployment workflow looks like

You can download the source code on bitbucket.

Commit code to bitbucket

Once your commit has been made on the master branch, bitbucket pipelines gets triggered automatically and all the steps illustrated under master branch in the bitbucket-pipelines.yml will get executed. In our case we are using master branch for deployment but it is customizable. The environment variables which we have defined earlier in the bitbucket pipeline settings will be used in this bitbucket-pipelines.yml file.

Test & Build

Run your test cases to make sure that the code is working as expected before it is being deployed. For this i’ve created a file named Dockerfile and included some sample commands for testing and building NodeJS application. You can update the commands accordingly w.r.t the technology that you’re using.

The following command mentioned in bitbucket-pipelines.yml will execute the instructions in the Dockerfile and create a docker image

docker build -t ${AWS_REGISTRY_URL}:$BUILD_ID .

Push your code to Amazon ECR

The following command mentioned in bitbucket-pipelines.yml will push the docker image to Amazon ECR

docker push ${AWS_REGISTRY_URL}:$BUILD_ID

Deploy

For deployment I wrote the deploy.sh script and task-definition.json.

A task definition is required to run Docker containers in Amazon ECS. In task definition you need to specify the following parameters based on your requirement:

• The Docker images to use with the containers in your task
• How much CPU and memory to use with each container
• Working directory of the application (In our case we have placed the files under app directory)
• The ports from the container to map to the host container instance

The deploy.sh script will create a new revision of your task definition for you and update your service. You only have to pass following parameters from the bitbucket-pipelines.yml file:

• name of cluster [-b]
• the service you want to deploy [-s]
• the deployment environment (staging in our case) [-e]
• the image name [-i]

bash ./deploy.sh -b CLUSTER_NAME -s SERVICE_NAME -e ${DEPLOYMENT_ENV} -i $BUILD_ID

Note: Place all the files in the root directory of your project.