Manage Applications with Docker Compose

Manage Applications with Docker Compose#

We recommend adopting docker and docker compose for your managing your app in production. Docker has extensive documentation which you can refer to but here is a basic example.

While docker compose can be use to run containers on your own system, kube compose works the same way but manages containers running remotely on the cluster. Get everything running on your own system first, and things should work when they get deployed to the cluster.

Example#

Make the following additions in your app directory:

  • Dockerfile: Use this define a container capable of running your app

    # this base image has python setup and ready to go
FROM python

# install dependencies
COPY requirements.txt /app/requirements.txt
RUN pip install -r /app/requirements.txt

# add source to app
COPY . /app
WORKDIR /app

# the port your app uses -- this is essential for dokku deployment
EXPOSE 5000

# what to do when the container starts
CMD gunicorn --bind 0.0.0.0:5000 app:app

  • docker-compose.yaml: Manage potentially multiple containers for running your app

    services:
  # generally good practice to prefix service by your app name, change yourapp to your app's name
  yourapp-app:
    build: .
    # make sure it's built for the cpu architecture running on our cluster
    platform: linux/amd64
    image: your-docker-username/yourapp-app:0.1.0
    environment:
    # gets this from your .env
    - YOURAPP_WHAT
    ports:
    # 5000 (your system, i.e. http://localhost:5000) maps to the container's port 5000
    - 5000:5000
    x-kubernetes:
      annotations:
        # this is where it will be deployed when it is published
        maayanlab.cloud/ingress: https://yourapp.k8s.dev.maayanlab.cloud
x-kubernetes:
  name: yourapp

  • README.md

    ...

## Deploy
`docker compose build # build the container`
`docker compose up # verify that it works the way you expect at http://localhost:5000`

App management#

Build the container for a service#

docker compose build yourapp-app

Run your app’s services#

# -d flag runs them in the background
docker compose up -d

Logging#

# get logs of a service
docker compose logs yourapp-app

Process management#

# restart a service
docker compose restart yourapp-app

# stop a service
docker compose stop yourapp-app

# start a service that was stopped
docker compose start yourapp-app

Manual container inspection#

# open a shell in your running app for debugging
docker compose exec -it yourapp-app /bin/sh

Stopping your app#

docker compose down

# if you have persistent data, you can opt-in to remove them as well
docker compose down -v
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