docker compose up –watch

I used to volume mount to get “hot-reload” behaviour. Now I’ve switched to docker compose watch.

Its much simpler to understand. Here’s an example of syncing code and restart a celery worker container:

services:
  worker:
    build:
      context: .
      network: host
    network_mode: host
    command: celery
    env_file:
      - .env
    depends_on:
      db:
        condition: service_healthy
      rabbit:
        condition: service_healthy
    volumes:
      - worker_data:/usr/src/app
    develop:
      watch:
        - action: sync+restart
          path: ./
          target: /app
          ignore:
            - .venv
volumes:
  worker_data:

A simplified compose.yml file but the core part I want to showcase is the develop key.

Using develop.watch lets you define the path to “watch”, target to sync the changes to and the action to take.

For this container I have to restart it but its very robust and simple to follow. You can also just sync which would work well for some applications.

It’s possible to achieve similar things with other tools (watchfiles is a good one) and methods but I prefer to lean on a docker builtin these days.

Tags:

#docker