Table of Contents

docker & docker-compose - Cheatsheet

Tags: #docker #dockercompose #cheatsheet

Last Reviewed: 16/08/2024

Usefull commands for docker and docker-compose

Quick Reference

CommandPurpose
docker-compose up -dStarts the Container and dettach (so you have your bash prompt back)
docker-compose downStops the Container
docker-compose psChecks the status of the Container
docker-exec -ti <container-name> /bin/bashOpens a Shell Prompt inside a Container (so you can troubleshoot)
docker save <image> > file.tarSaves an Image to a Tar file
Eg.: docker save nginx:latest > nginx_backup.tar
docker load < file.tarLoads a Tar file as an Image
docker stop $(docker ps -a -q)Stops all Containers. You can use “rm” instead of “stop” to remove them! 
docker build --tag <tag> .
To be run from the directory where “dockerfile” lives. Will create an Image with the tag provided. Eg.: docker build –tag tornscrapper:0.1 
docker images -a | grep none | awk '{ print $3; }' | xargs docker rmi
Delete dangling images and / or images that have a “none” tag.
Might be helpful if “docker image prune” doesn't remove those.

Cheatsheet

Commands

docker compose version
docker compose config
docker compose start
docker compose stop
docker compose restart
docker compose run
docker compose create
docker compose attach
docker compose pause
docker compose unpause
docker compose wait
docker compose up
docker compose down
docker compose ps
docker compose top
docker compose events
docker compose logs
docker compose images
docker compose build
docker compose push
docker compose cp
docker compose exec

Building

web:
  # build from Dockerfile
  build: .
  args:     # Add build arguments
    APP_HOME: app
  # build from custom Dockerfile
  build:
    context: ./dir
    dockerfile: Dockerfile.dev
  # build from image
  image: ubuntu
  image: ubuntu:14.04
  image: tutum/influxdb
  image: example-registry:4000/postgresql
  image: a4bc65fd

Ports

ports:
  - "3000"
  - "8000:80"  # host:container
# expose ports to linked services (not to host)
expose: ["3000"]

Environment Variables

# environment vars
environment:
  RACK_ENV: development
environment:
  - RACK_ENV=development
# environment vars from file
env_file: .env
env_file: [.env, .development.env]

Dependencies

# makes the `db` service available as the hostname `database`
# (implies depends_on)
links:
  - db:database
  - redis
# make sure `db` is alive before starting
depends_on:
  - db
# make sure `db` is healthy before starting
# and db-init completed without failure
depends_on:
  db:
    condition: service_healthy
  db-init:
    condition: service_completed_successfully

Other Options

# make this service extend another
extends:
  file: common.yml  # optional
  service: webapp
volumes:
  - /var/lib/mysql
  - ./_data:/var/lib/mysql
# automatically restart container
restart: unless-stopped
# always, on-failure, no (default)

Advanced Features

Labels

services:
  web:
    labels:
      com.example.description: "Accounting web app"

DNS Servers

services:
  web:
    dns: 8.8.8.8
    dns:
      - 8.8.8.8
      - 8.8.4.4

Devices

services:
  web:
    devices:
    - "/dev/ttyUSB0:/dev/ttyUSB0"

Healthcheck

# declare service healthy when `test` command succeeds
healthcheck:
  test: ["CMD", "curl", "-f", "http://localhost"]
  interval: 1m30s
  timeout: 10s
  retries: 3
  start_period: 40s

User

# specifying user
user: root
# specifying both user and group with ids
user: 0:0