Docker Cheat Sheet

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FROM ruby:2.2.2

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ENV APP_HOME/myapp
RUN mkdir $APP_HOME

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RUN bundle install

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WORKDIR /myapp

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VOLUME ["/data"]
# Specification for mount point

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ADD file.xyz /file.xyz
COPY --chown=user:group host_file.xyz /path/container_file.xyz

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ONBUILD RUN bundle install
# when used with another file

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EXPOSE 5900
CMD ["bundle", "exec", "rails", "server"]

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ENTRYPOINT exec top -b

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LABEL version="1.0"

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LABEL "com.example.vendor"="ACME Incorporated"
LABEL com.example.label-with-value="foo"

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LABEL description="This text illustrates \
that label-values can span multiple lines."

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# docker-compose.yml
version: '2'

services:
  web:
    build: .
    # build from Dockerfile
    context: ./Path
    dockerfile: Dockerfile
    ports:
     - "5000:5000"
    volumes:
     - .:/code
  redis:
    image: redis

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docker-compose start
docker-compose stop

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docker-compose pause
docker-compose unpause

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docker-compose ps
docker-compose up
docker-compose down

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web:
  # build from Dockerfile
  build: .

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  # build from custom Dockerfile
  build:
    context: ./dir
    dockerfile: Dockerfile.dev

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 # build from image
  image: ubuntu
  image: ubuntu:14.04
  image: tutum/influxdb
  image: example-registry:4000/postgresql
  image: a4bc65fd

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  ports:
    - "3000"
    - "8000:80"  # guest:host

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  # expose ports to linked services (not to host)
  expose: ["3000"]

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  # command to execute
  command: bundle exec thin -p 3000
  command: [bundle, exec, thin, -p, 3000]

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  # override the entrypoint
  entrypoint: /app/start.sh
  entrypoint: [php, -d, vendor/bin/phpunit]

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  # environment vars
  environment:
    RACK_ENV: development
  environment:
    - RACK_ENV=development

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

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  # makes the `db` service available as the hostname `database`
  # (implies depends_on)
  links:
    - db:database
    - redis

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  # make sure `db` is alive before starting
  depends_on:
    - db

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  # make this service extend another
  extends:
    file: common.yml  # optional
    service: webapp

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  volumes:
    - /var/lib/mysql
    - ./_data:/var/lib/mysql

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

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

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

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services:
  web:
    external_links:
      - redis_1
      - project_db_1:mysql

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services:
  web:
    extra_hosts:
      - "somehost:192.168.1.100"

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# To view list of all the services runnning in swarm
docker service ls 

# To see all running services
docker stack services stack_name

# to see all services logs
docker service logs stack_name service_name 

# To scale services quickly across qualified node
docker service scale stack_name_service_name=replicas

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# To clean or prune unused (dangling) images
docker image prune 

# To remove all images which are not in use containers , add - a
docker image prune -a 

# To Purne your entire system
docker system prune 

# To leave swarm
docker swarm leave

# To remove swarm ( deletes all volume data and database info)
docker stack rm stack_name 

# To kill all running containers
docker kill $(docekr ps -q )