What Compose is for
Docker Compose defines a multi-container application in a single docker-compose.yml — your app, its database, a cache, a message queue — and brings the whole stack up with one docker compose up. It’s the standard way to run a realistic local development environment that mirrors production, without manually starting and linking containers. This builder lets you assemble that file by picking services and setting options, rather than hand-writing YAML (and fighting its indentation rules).
The pieces of a service
Each service in the file configures one container:
| Key | Defines |
|---|---|
image / build | What to run |
ports | HOST:CONTAINER port mapping |
environment | Env vars (config, credentials) |
volumes | Persistent storage / mounts |
depends_on | Startup order between services |
The builder ships templates for common services (Node, Python, Nginx, Postgres, MySQL, Mongo, Redis, Elasticsearch, RabbitMQ) with sensible defaults, plus a custom-service option for anything else.
The two gotchas that cost the most time
Port conflicts. docker compose up fails with “port already in use” when something on your host already holds that port. Change the host side of the mapping (the first number): 5433:5432 puts Postgres on host port 5433 while the container stays on 5432.
depends_on isn’t health. depends_on controls start order, not readiness — your app may start before the database is actually accepting connections. For true readiness, add a healthcheck to the dependency and depends_on: condition: service_healthy, or make your app retry the connection.
Persistence, the right way
Stateful services need named volumes (see FAQ) or you’ll lose data on every down. The generator wires these up for databases by default. Pair this with the .gitignore Generator so local volumes and .env files don’t get committed, and the YAML to JSON Converter if you need to inspect or transform the compose file programmatically.