metcalfc / docker-simple-flask Goto Github PK

This sample application was demoed as part of the AWS Cloud Containers Conference on 2020-07-09. It has been tested on Linux and macOS.

Note that $ is used to denote commands in blocks where the command and its output are included.

+--------------------+              +------------------+
|                    |              |                  |
|    Python Flask    |  timestamps  |      Redis       |
|    Application     |------------->|                  |
|                    |              |                  |
+--------------------+              +------------------+

There are a number of places you'll need to fill in information. You can find them with:

$ grep -r '<<<' ./*
./docker-compose.yml:    x-aws-pull_credentials: <<<your arn for your secret you can get with docker ecs secret list>>>
./docker-compose.yml:    image: <<<your docker hub user name>>>/timestamper
## Walk through

You should use a Personal Access Token (PAT) rather than your account password. If you have 2FA enabled on your Hub account you will need to create a PAT. You can read more about managing access tokens here: https://docs.docker.com/docker-hub/access-tokens/

You can then create DockerHubToken secret on AWS Secret Manager using following command

docker ecs secret create -d MyKey -u myhubusername -p myhubpat DockerHubToken

To initialize the Docker ECS integration, you will need to run the setup command. This will create a Docker context that works with AWS ECS.

$ docker ecs setup
Enter context name: aws
✔ sandbox.devtools.developer
Enter cluster name:
Enter region: us-west-2
✗ Enter credentials:

You can verify that the context was created by listing your Docker contexts:

$ docker context ls
NAME                DESCRIPTION                               DOCKER ENDPOINT               KUBERNETES ENDPOINT   ORCHESTRATOR
aws
default *           Current DOCKER_HOST based configuration   unix:///var/run/docker.sock                         swarm

The first step is to test your application works locally. To do this, you will need to switch to using the default local context so that you are targeting your local machine.

docker context use default

You can then run the application using docker-compose:

docker-compose up

Once the application has started, you can navigate to http://localhost:5000 using your Web browser using the following command:

open http://localhost:5000

In order to run your application in the cloud, you will need your container images to be in a registry. You can push them from your local machine using:

docker-compose push

You can verify that this command pushed to the Docker Hub by logging in and looking for the timestamper repository under your user name.

Now that you've tested the application works locally and that you've pushed the container images to the Docker Hub, you can switch to using the aws context you created earlier.

docker context use aws

Running the application on ECS is then as simple as doing a compose up:

docker ecs compose up

Once the application is running in ECS, you can list the running containers with the ps command. Note that you will need to run this from the directory where you Compose file is.

docker ecs compose ps

You can also read the application logs using compose logs:

docker ecs compose logs

You can see all the AWS components created for your running application in the AWS console. There you will find:

• CloudFormation being used to manage all the infrastructure
• CloudWatch for logs
• Security Groups for network policies
• Load balancers (ELB for this example / ALB if your app only uses 80/443)

The ECS Docker CLI integration has the ability to output the CloudFormation template used to create the application in the compose convert command. You can see this by running:

docker ecs compose convert

To shut down your application, you simply need to run:

docker ecs compose down

If you'd like to use AWS ECR instead of Docker Hub, the Makefile has an example setup for creating an ECR repository and pushing to it. You'll need to have the AWS CLI installed and your AWS credentials available.

make create-ecr
REGISTRY_ID=<from the create above> make build-image
REGISTRY_ID=<from the create above> make push-image-ecr

Note that you will need to change the name of the image in the Compose file.

If you want to use this often, you'll likely want to replace PUT_ECR_REGISTRY_ID_HERE with the value from above.