docker cheatsheet

docker.md

example to create docker image in tar file

tar \
    --numeric-owner \
    --exclude=/boot \
    --exclude=/dev \
    --exclude=/pack \
    --exclude=/proc \
    --exclude=/sys \
    --exclude=/mnt \
    --exclude=/var/cache \
    --exclude=/usr/share/{foomatic,backgrounds,perl5,fonts,cups,qt4,groff,kde4,icons,pixmaps,emacs,gnome-background-properties,sounds,gnome,games,desktop-directories} \
    --exclude=/var/log \
    -zcvf \
    /pack/slax.tar.gz /

after load the image to docker

cat slax.tar.gz | docker import - slax

save the image as a tarball

docker save repositoryname:tag > repotag.tar

zip the image

gzip repotag.tar

copy the tarball to the new machine

scp repotag.tar.gz <foreign machine>

unzip The tarball

gunzip repotag.tar.gz

load the docker image

docker load < repotar.tar

find the Image ID

docker images

tag the image

docker tag repositoryname:tag

docker run -i -t --rm ubuntu /bin/bash

• -t flag assigns a pseudo-tty or terminal inside the new container.
• -i flag allows you to make an interactive connection by grabbing the standard input (STDIN) of the container.
• --rm flag automatically removes the container when the process exits. By default, containers are not deleted. This container exists until we keep the shell session and terminates when we exit the session (like an SSH session with a remote server).

docker run --name daemon -d ubuntu /bin/sh -c "while true; do echo hello world; sleep 1; done"

• --name daemon assigns daemon name to a new container. If you don’t specify a name explicitly, Docker will generate and assign it automatically.
• -d flag runs the container in the background (i.e., daemonizes it).

docker ps -a

• docker ps is a command to list containers.
• -a shows all containers (without -a flag ps will show only running containers).

check the logs and see what the daemon container is doing right now

docker logs -f daemon

let’s stop the daemon container

docker stop daemon

delete all containers

docker rm $(docker ps -a -q)

delete all images

docker rmi $(docker images -q)

to commit changes to existing Docker images

docker commit 782ce39021a0 wordpress:new2

• https://djangostars.com/blog/what-is-docker-and-how-to-use-it-with-python/
• https://github.com/alexryabtsev/docker-workshop/
• https://docs.docker.com/get-started/
• https://xebia.com/blog/create-the-smallest-possible-docker-container/