docker-tips

My 🐳 Docker CLI Tips and Tricks

Installation

Linux

$ curl -sSL https://get.docker.com/ | sh
$ docker version

macOS

if you have Homebrew-Cask, just type:

$ brew cask install docker
$ docker version

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Containers

Starting and Stopping

• docker start starts a container so it is running.
• docker stop stops a running container.
• docker restart stops and starts a container.
• docker pause pauses a running container, "freezing" it in place.
• docker unpause will unpause a running container.
• docker wait blocks until running container stops.
• docker kill sends a SIGKILL to a running container.
• docker attach will connect to a running container.

CPU Constraints

The setting is a bit strange -- 1024 means 100% of the CPU, so if you want the container to take 50% of all CPU cores, you should specify 512

docker run -it -c 512 agileek/cpuset-test

Volumes

Lifecycle

$ docker volume create
$ docker volume rm

Info

$ docker volume ls
$ docker volume inspect

Exposing ports

Mapping the container port to the host port (only using localhost interface) using -p:

$ docker run -p 127.0.0.1:$HOSTPORT:$CONTAINERPORT --name CONTAINER -t someimage

Listens on the specified network ports at runtime by using EXPOSE:

$ EXPOSE <CONTAINERPORT>

To expose the container's port on your localhost's port:

$ iptables -t nat -A DOCKER -p tcp --dport <LOCALHOSTPORT> -j DNAT --to-destination <CONTAINERIP>:<PORT>

If you forget what you mapped the port to on the host container, use docker port to show it:

$ docker port CONTAINER $CONTAINERPORT

Tips

Prune

The new Data Management Commands have landed as of Docker 1.13:

$ docker system prune
$ docker volume prune
$ docker network prune
$ docker container prune
$ docker image prune

References

• Docker Reference documentation
• Docker Cheat Sheet
• Personal experience