Custom Images

dde works with any Docker image. The automatic dde layer detects whether the image is Alpine-based or Debian-based and adapts accordingly. This page shows examples for common non-PHP base images.

Node.js

docker-compose.yml

services:
  web:
    image: node:20-alpine
    working_dir: /app
    volumes:
      - .:/app
    command: npm run dev
    labels:
      - 'traefik.enable=true'
      - 'traefik.http.routers.web.rule=Host(`myapp.test`)'
      - 'traefik.http.routers.web.tls=true'
      - 'traefik.http.services.web.loadbalancer.server.port=3000'

The dde layer detects Alpine and installs su-exec + shadow. The entrypoint creates the dde user and execs npm run dev as the original command.

No built-in adapter applies (nginx/php-fpm/apache are not present), so the adapters step is a no-op.

Custom Adapter for Node.js

If your Node.js app writes to specific directories, create a project adapter:

.dde/adapters/node.sh

detect() {
    command -v node >/dev/null 2>&1
}

configure() {
    # Fix ownership of npm cache and app directories
    for dir in /home/dde/.npm /app/node_modules /app/.next; do
        [ -d "$dir" ] && chown -R dde:dde "$dir" 2>/dev/null || true
    done
}

Python

docker-compose.yml

services:
  web:
    image: python:3.12-slim
    working_dir: /app
    volumes:
      - .:/app
    command: python manage.py runserver 0.0.0.0:8000
    labels:
      - 'traefik.enable=true'
      - 'traefik.http.routers.web.rule=Host(`myapp.test`)'
      - 'traefik.http.routers.web.tls=true'
      - 'traefik.http.services.web.loadbalancer.server.port=8000'

For Debian-based Python images, dde installs gosu and creates the dde user. The loadbalancer.server.port label tells Traefik which port to route to.

Ruby / Rails

docker-compose.yml

services:
  web:
    build:
      context: .
      target: dev
    volumes:
      - .:/app
    labels:
      - 'traefik.enable=true'
      - 'traefik.http.routers.web.rule=Host(`myapp.test`)'
      - 'traefik.http.routers.web.tls=true'
      - 'traefik.http.services.web.loadbalancer.server.port=3000'

FROM ruby:3.3-slim as base
WORKDIR /app

FROM base as dev
RUN apt-get update && apt-get install -y build-essential libpq-dev

Go

docker-compose.yml

services:
  web:
    image: golang:1.22-alpine
    working_dir: /app
    volumes:
      - .:/app
    command: go run .
    labels:
      - 'traefik.enable=true'
      - 'traefik.http.routers.web.rule=Host(`myapp.test`)'
      - 'traefik.http.routers.web.tls=true'
      - 'traefik.http.services.web.loadbalancer.server.port=8080'

Multi-Service Projects

Projects with multiple containers get the dde layer applied to the first service with an image directive in the compose file. The runtime entrypoint override is generated for all services.

services:
  web:
    image: whatwedo/nginx:v2.6
    labels:
      - 'traefik.enable=true'
      - 'traefik.http.routers.web.rule=Host(`myapp.test`)'
      - 'traefik.http.routers.web.tls=true'

  worker:
    image: php:8.4-cli
    command: php bin/console messenger:consume

Both web and worker receive the dde entrypoint override with UID/GID environment variables, volume mounts for adapters, and the original command preservation.

Images Without a Package Manager

If your base image has no package manager (e.g., scratch, distroless, or minimal images), the automatic dde layer build will fail because it cannot install gosu/su-exec. In this case, you need to provide a dev-stage Dockerfile that starts from a full image:

FROM gcr.io/distroless/base as base
COPY myapp /app/myapp

FROM debian:bookworm-slim as dev
COPY --from=base /app/myapp /app/myapp
RUN apt-get update && apt-get install -y curl

Use target: dev in your compose build config to select the development stage.