Docker Cheat Sheet

The commands I use for the handful of services that run as plain containers next to the Kubernetes cluster (media stack on the NAS, the odd test box).

Containers

Task	Command
Run detached, named, restart on boot	`docker run -d --name plex --restart unless-stopped -p 32400:32400 -v /data/media:/media plexinc/pms-docker`
List running / all	`docker ps` / `docker ps -a`
Logs, follow, last 200 lines	`docker logs -f --tail 200 plex`
Shell inside	`docker exec -it plex /bin/sh`
Stop / start / restart	`docker stop plex` · `docker start plex` · `docker restart plex`
Remove (stopped)	`docker rm plex`
Resource usage	`docker stats`
Inspect IP and mounts	`docker inspect plex \| jq '.[0].NetworkSettings.Networks, .[0].Mounts'`

Images

Task	Command
Pull / list	`docker pull nginx:1.27` / `docker images`
Build from the current directory	`docker build -t myapp:1.0 .`
Tag and push	`docker tag myapp:1.0 registry.lab/myapp:1.0` · `docker push registry.lab/myapp:1.0`
Remove unused images	`docker image prune -a`
History / size	`docker history myapp:1.0`

Volumes and networks

Task	Command
Named volume	`docker volume create pgdata` · `-v pgdata:/var/lib/postgresql/data`
Bind mount	`-v /srv/app/config:/config:ro`
List / inspect volumes	`docker volume ls` / `docker volume inspect pgdata`
User-defined bridge (containers resolve each other by name)	`docker network create lab` · `--network lab`
Host networking (no port mapping)	`--network host`
Inspect a network	`docker network inspect lab`

Compose

A minimal compose.yaml with the pieces that matter:

services:
  app:
    image: ghcr.io/example/app:1.4
    container_name: app
    restart: unless-stopped
    environment:
      TZ: Europe/Budapest
      PUID: "1000"
      PGID: "1000"
    ports:
      - "8080:8080"
    volumes:
      - ./config:/config
      - /data/media:/media:ro
    networks: [lab]
    healthcheck:
      test: ["CMD", "wget", "-qO-", "http://localhost:8080/health"]
      interval: 30s
      timeout: 5s
      retries: 3

networks:
  lab:
    external: true

Task	Command
Up (detached) / down	`docker compose up -d` / `docker compose down`
Pull new images and recreate	`docker compose pull && docker compose up -d`
Logs for one service	`docker compose logs -f app`
Recreate one service	`docker compose up -d --force-recreate app`
Validate / view merged config	`docker compose config`
Run a one-off command	`docker compose run --rm app sh`

Clean-up

docker system df                 # what is using the disk
docker container prune           # stopped containers
docker image prune -a            # images not used by any container
docker volume prune              # volumes not attached to any container (careful)
docker system prune -a --volumes # everything unused

Warning

docker volume prune deletes data that is not currently attached to a container. Stop a stack with docker compose down and its volumes are still attached only if you kept the service definitions; check docker volume ls first.

Handy one-liners

# IP of every running container
docker inspect -f '{{.Name}} {{range .NetworkSettings.Networks}}{{.IPAddress}}{{end}}' $(docker ps -q)

# Containers not set to restart automatically
docker inspect -f '{{.Name}} {{.HostConfig.RestartPolicy.Name}}' $(docker ps -aq) | grep -v unless-stopped

# Copy a file out of a container
docker cp plex:/config/Preferences.xml ./Preferences.xml

Last updated on October 17, 2026