Docker-Compose

Not everything in your stack is a container. Managed databases, SaaS APIs, VPN tunnels, Kubernetes intercepts, all sit outside Docker but still need to be wired into your local environment. Compose 2.36 introduced provider services to declare and manage these alongside your containers. The syntax A provider service replaces image: with a provider: block: services: api: image: my-api:latest tunnel: provider: type: telepresence options: namespace: avatars service: api port: 5732:api-80 Two parts: ...

LLMs are now first-class citizens in Compose. The models top-level key lets you declare which models your application needs and wire them into your services, all in the same Compose file. Basic usage Declare a model at the top level, reference it from a service: models: smollm: model: ai/smollm2 services: app: image: myapp models: - smollm When the stack starts, Compose ensures the model is available locally and connects the app service to it. The container receives endpoint information via environment variables. ...

Both entrypoint and command define what runs when a container starts. They look similar, but they play different roles, and confusing them leads to surprising behavior. The mental model When a container starts, Docker runs: <entrypoint> <command> entrypoint is the executable command is the default arguments passed to it If the image’s Dockerfile has ENTRYPOINT ["python"] and CMD ["app.py"], the container runs python app.py. Overriding from Compose Both can be overridden in Compose: ...

You’ve used secrets for sensitive data (Tip #22). For non-sensitive config files like nginx.conf or prometheus.yml, there’s a parallel feature: configs. Basic usage Define a config at the top level, reference it in a service: configs: nginx_conf: file: ./nginx.conf services: web: image: nginx configs: - source: nginx_conf target: /etc/nginx/nginx.conf The file is mounted read-only inside the container at the target path. No need to declare a volume mount manually. ...

A container is running but your app feels sluggish. Is it CPU-bound? Leaking memory? Stuck on a runaway process? Compose gives you two essential commands to find out: docker compose top and docker compose stats. docker compose top Show running processes inside each service’s container: docker compose top myapp-web-1 UID PID PPID C STIME TTY TIME CMD root 12345 12320 0 09:15 ? 00:00:02 nginx: master process nobody 12400 12345 0 09:15 ? 00:00:00 nginx: worker process myapp-api-1 UID PID PPID C STIME TTY TIME CMD node 12500 12480 2 09:15 ? 00:01:45 node server.js node 12600 12500 0 09:15 ? 00:00:12 node worker.js You see every process running inside each container with their CPU usage (C column) and CPU time. Perfect for spotting runaway workers or unexpected child processes. ...