Docker Commands

Set Environment Settings:

• DOCKER_CERT_PATH=C:\Users\jini\.docker\machine\certs
• DOCKER_HOST=tcp://192.168.99.100:2376
• DOCKER_TLS_VERIFY=1
• DOCKER_TOOLBOX_INSTALL_PATH= C:\Program Files\Docker Toolbox

Docker Lifecycle:

• docker run creates a container.
• docker stop stops it.
• docker start will start it again.
• docker restart restarts a container.
• docker rm deletes a container.
• docker kill sends a SIGKILL to a container.
• docker attach will connect to a running container.
• docker wait blocks until container stops.

If you want to run and then interact with a container, docker start then docker attach to get in.
If you want to poke around in an image, docker run -t -i to open a tty.

Docker Info:

• docker ps -a shows running and stopped containers.
• docker inspect looks at all the info on a container (including IP address).
• docker logs gets logs from container.
• docker events gets events from container.
• docker port shows public facing port of container.
• docker top shows running processes in container.
• docker diff shows changed files in the container’s FS.

Docker Images/Container Lifecycle:

• docker images shows all images.
• docker import creates an image from a tarball.
• docker build creates image from Dockerfile.
• docker commit creates image from a container.
• docker rmi removes an image.
• docker insert inserts a file from URL into image. (kind of odd, you’d think images would be immutable after create)
• docker load loads an image from a tar archive as STDIN, including images and tags (as of 0.7).
• docker save saves an image to a tar archive stream to STDOUT with all parent layers, tags & versions (as of 0.7).

Info

• docker history shows history of image.
• docker tag tags an image to a name (local or registry).

Docker Compose

Define and run multi-container applications with Docker.

• docker-compose --help
• create docker-compose.yml
version: '3'
services:
  eureka:
    restart: always
    build: ./micro1-eureka-server
    ports:
      - "8761:8761"
• docker-compose stop
docker-compose rm -f
docker-compose build
docker-compose up -d
docker-compose start
docker-compose ps
• Scaling containers running a given service
docker-compose scale eureka=3
• Healing, i.e., re-running containers that have stopped
docker-compose up --no-recreate

Docker Hub

Docker.io hosts its own index to a central registry which contains a large number of repositories.

• docker login to login to a registry.
• docker search searches registry for image.
• docker pull pulls an image from registry to local machine.
• docker push pushes an image to the registry from local machine.

Dockerfile

Instructions

•     .dockerignore
•     FROM Sets the Base Image for subsequent instructions.
•     MAINTAINER (deprecated - use LABEL instead)
•     RUN execute any commands in a new layer on top of the current image
•     CMD provide defaults for an executing container.
•     EXPOSE informs Docker that the container listens on the specified network ports at runtime.
•     ENV sets environment variable.
•     ADD copies new files, directories or remote file to container. Invalidates caches.
      Avoid ADD and use COPY instead.
•     COPY copies new files or directories to container. By default this copies as root regardless    of the USER/WORKDIR settings. Use --chown=: to give ownership to another user/group. (Same for ADD.)
•     ENTRYPOINT configures a container that will run as an executable.
•     VOLUME creates a mount point for externally mounted volumes or other containers.
•     USER sets the user name for following RUN / CMD / ENTRYPOINT commands.
•     WORKDIR sets the working directory.
•     ARG defines a build-time variable.
•     ONBUILD adds a trigger instruction when the image is used as the base for another build.
•     STOPSIGNAL sets the system call signal that will be sent to the container to exit.
•     LABEL apply key/value metadata to your images, containers, or daemons.

Tutorial: Flux7’s Dockerfile Tutorial

Examples: Examples

Best Practices: Best to look at http://github.com/wsargent/docker-devenv and the best practices / take 2 for more details.

Volumes:

Docker volumes are free-floating filesystems. They don’t have to be connected to a particular container.

Volumes are useful in situations where you can’t use links (which are TCP/IP only). For instance, if you need to have two docker instances communicate by leaving stuff on the filesystem.

You can mount them in several docker containers at once, using docker run -volume-from

Get Environment Settings
docker run --rm ubuntu env
Delete old containers
docker ps -a | grep 'weeks ago' | awk '{print $1}' | xargs docker rm
Delete stopped containers
docker rm `docker ps -a -q`
Show image dependencies
docker images -viz | dot -Tpng -o docker.png
Original
https://github.com/wsargent/docker-cheat-sheet/blob/master/README.md