Logs and Exec

Follow logs

Applications write to stdout and stderr; Docker captures that stream. Follow live output while reproducing a bug.

docker logs my-nginx
docker logs -f --tail 100 my-nginx

Logs with Compose

Name a service to focus, or omit it to see the whole stack.

docker compose logs -f web

Exec into a container

Start an interactive shell in a running container. Useful for checking files, packages, or connectivity.

docker exec -it my-nginx sh

Prefer logs first

Exec is powerful but temporary. Fix issues in the image, Compose file, or mounted config so the next container starts healthy without manual steps.