Backend Hot Reload Not Working in Docker Compose Development Environmen

[rgalvish]

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• I added a very descriptive title here.
• I used the GitHub search to find a similar question and didn't find it.
• I searched in the documentation/README.
• I already searched in Google "How to do X" and didn't find any information.
• I already read and followed all the tutorial in the docs/README and didn't find an answer.

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Example Code

#docker-compose.override.yml
#original
services:

  # Local services are available on their ports, but also available on:
  # http://api.localhost.tiangolo.com: backend
  # http://dashboard.localhost.tiangolo.com: frontend
  # etc. To enable it, update .env, set:
  # DOMAIN=localhost.tiangolo.com
  proxy:
    image: traefik:3.0
    volumes:
      - /var/run/docker.sock:/var/run/docker.sock
    ports:
      - "80:80"
      - "8090:8080"
    # Duplicate the command from docker-compose.yml to add --api.insecure=true
    command:
      # Enable Docker in Traefik, so that it reads labels from Docker services
      - --providers.docker
      # Add a constraint to only use services with the label for this stack
      - --providers.docker.constraints=Label(`traefik.constraint-label`, `traefik-public`)
      # Do not expose all Docker services, only the ones explicitly exposed
      - --providers.docker.exposedbydefault=false
      # Create an entrypoint "http" listening on port 80
      - --entrypoints.http.address=:80
      # Create an entrypoint "https" listening on port 443
      - --entrypoints.https.address=:443
      # Enable the access log, with HTTP requests
      - --accesslog
      # Enable the Traefik log, for configurations and errors
      - --log
      # Enable debug logging for local development
      - --log.level=DEBUG
      # Enable the Dashboard and API
      - --api
      # Enable the Dashboard and API in insecure mode for local development
      - --api.insecure=true
    labels:
      # Enable Traefik for this service, to make it available in the public network
      - traefik.enable=true
      - traefik.constraint-label=traefik-public
      # Dummy https-redirect middleware that doesn't really redirect, only to
      # allow running it locally
      - traefik.http.middlewares.https-redirect.contenttype.autodetect=false
    networks:
      - traefik-public
      - default

  db:
    restart: "no"
    ports:
      - "5432:5432"

  adminer:
    restart: "no"
    ports:
      - "8080:8080"

  backend:
    restart: "no"
    ports:
      - "8000:8000"
    build:
      context: ./backend
    # command: sleep infinity  # Infinite loop to keep container alive doing nothing
    command:
      - fastapi
      - run
      - --reload
      - "app/main.py"
    develop:
      watch:
        - path: ./backend
          action: sync
          target: /app
          ignore:
            - ./backend/.venv
            - .venv
        - path: ./backend/pyproject.toml
          action: rebuild
    # TODO: remove once coverage is done locally
    volumes:
      - ./backend/htmlcov:/app/htmlcov
    environment:
      SMTP_HOST: "mailcatcher"
      SMTP_PORT: "1025"
      SMTP_TLS: "false"
      EMAILS_FROM_EMAIL: "[email protected]"

  mailcatcher:
    image: schickling/mailcatcher
    ports:
      - "1080:1080"
      - "1025:1025"

  frontend:
    restart: "no"
    ports:
      - "5173:80"
    build:
      context: ./frontend
      args:
        - VITE_API_URL=http://localhost:8000
        - NODE_ENV=development

  playwright:
    build:
      context: ./frontend
      dockerfile: Dockerfile.playwright
      args:
        - VITE_API_URL=http://backend:8000
        - NODE_ENV=production
    ipc: host
    depends_on:
      - backend
      - mailcatcher
    env_file:
      - .env
    environment:
      - VITE_API_URL=http://backend:8000
      - MAILCATCHER_HOST=http://mailcatcher:1080
      # For the reports when run locally
      - PLAYWRIGHT_HTML_HOST=0.0.0.0
      - CI=${CI}
    volumes:
      - ./frontend/blob-report:/app/blob-report
      - ./frontend/test-results:/app/test-results
    ports:
      - 9323:9323

networks:
  traefik-public:
    # For local dev, don't expect an external Traefik network
    external: false

Description

In the development environment using Docker Compose, changes made to the source code are not automatically updating in the backend container. It is necessary to manually restart the container for the modifications to be applied, which interrupts the development workflow.

Operating System

Linux

Operating System Details

docker compose up -d

Python Version

python:3.10

Additional Context

No response

[niyazikemer]

I hope I understand you correctly, this is my way of development. (I'm a newbie)

• I use uv to install dependencies in the backend folder
  uv sync
  Start the app:
  docker compose watch
  Stop the back-end on the docker
  docker compose stop backend
  get in backend folder on the local environment
  cd backend
  activate the virtual environment
  source .venv/bin/activate
  start the FastApi on the local environment and work there, changes immediately effect the docker
  fastapi dev app/main.py --reload

Some sources:
development documentation

backend development documentation

[YuriiMotov]

just docker compose watch should also work (I tested and it works).

In current version of the template docker will sync changes and since FastAPI is run inside the container as

    command:
      - fastapi
      - run
      - --reload
      - "app/main.py"

(with--reload)
it will restart server on every update