Docker Compose Generator
Build docker-compose.yml files visually. Add services, set environment variables, volumes, and networks. Use templates to get started fast.
How to Use the Docker Compose Generator
- Choose a mode — start from scratch with Custom, pick a preset with Web Stack or Database, or load a full template.
- Add services — each service card lets you set the image, ports, volumes, environment variables, and dependencies.
- Copy or download — save as
docker-compose.ymland rundocker compose up -d.
Understanding Docker Compose
Docker Compose is the standard tool for running multi-container applications. Rather than managing each container manually with docker run flags, you describe your entire stack in a single YAML file. A typical web application needs at least two containers: one for the application server and one for the database. Compose handles the networking between them automatically — each service is reachable by its service name on the internal network.
Services, Images, and Builds
Each service in a Compose file runs from either a pre-built Docker image (e.g., postgres:15 from Docker Hub) or a locally built image defined by a Dockerfile. The build: . directive tells Compose to build from the Dockerfile in the current directory. Images from Docker Hub follow the format name:tag — always pin to a specific tag (like node:20-alpine) rather than latest to ensure reproducible builds.
Volumes and Persistent Data
Containers are ephemeral — when removed, all data inside is lost. Docker volumes solve this. Named volumes (declared in the top-level volumes: key and referenced as - db-data:/var/lib/postgresql/data) persist beyond the container lifecycle. Bind mounts (e.g., - ./src:/app/src) mount a host directory into the container, which is invaluable during development for live code reloading. In production, prefer named volumes for databases to avoid permission issues.
Environment Variables and Secrets
Environment variables configure services at runtime. You can set them inline (POSTGRES_PASSWORD: secret), reference a .env file with env_file: .env, or use Docker Secrets for production deployments. Never commit passwords in your docker-compose.yml — use a .env file that is listed in .gitignore. The environment: key supports ${VARIABLE_NAME} interpolation from the shell environment or .env file.
Networks and Service Discovery
Compose creates a default bridge network for all services in a file. Services communicate using their service names as hostnames — your Node.js app connects to PostgreSQL at postgres:5432, not localhost:5432. Custom networks let you isolate services: a frontend network between Nginx and the app, and a backend network between the app and the database, so Nginx cannot directly reach the database. Use the Dockerfile Generator to create optimized images for your services.