docker.md

Cgroups

https://dockerlabs.collabnix.com/advanced/security/cgroups/

Starting

// to run docker without sudo create the group 'docker' and add you 'user' to it like so # groupadd docker # usermod [user] -a -G docker

Creating

*Note that "Containers" are an instance of an "Image/Blueprint"

// search for images with # docker search [related_term] *Note that [related_term] doesn't have to be [container_name] but any [term] related to it *You can alse use the docker hub web site to search

// to download a docker image "blueprint" form docker hub use # docker pull [image_name] you can pull different version of an image using ':' after the name # docker pull [image_name]:[version]

// listing all docker images "blueprints" in the system # docker images or # docker image ls

// check if docker is running correctly with # docker run hello-world

// create a container with # docker run [container_name] [command_in_container]

// open interactive shell inside container with # docker run -it [container_name] sh ; or use if exists bash,zsh...

Building_Images

// to build an image you need a "Dockerfile" example :

	FROM python:3

	# set a directory for the app
	WORKDIR /usr/src/app

	# copy all the files to the container
	COPY . .

	# install dependencies
	RUN pip install --no-cache-dir -r requirements.txt

	# tell the port number the container should expose
	EXPOSE 5000

	# run the command
	CMD ["python", "./app.py"]

// building using 'docker build' # docker build -t [[your_dockerhub_nam]/[container_name_youwant]] [/path/to/Dockerfile] or . "for current dir"

Networking

// Creating a subnet # docker network --subnet "192.168.1.0/24" [net_name]

// Static address for container in subnet and hostname #docker run --net [net_name] --ip [ip] --hostname [hostname]

// running container in detached mode with '-d' and exposing its ports to random ports on the host with '-P' # docker run -d -P --name [custom_name_for_container] [container_image]

// you can also chose ports you want with '-p' instead of '-P' # docker run -p [host_port]:[container_port] --name [custom_name_for_container] [container_image]

// check port mapping #docker port [custom_container_name]/[token]

Status

// check for conatiners # docker ps ; for running ones # docker ps -a ; for all of them

Cleaning

// stop containers with # docker stop [custom_container_name]/[token]

// delete container right after exiting it # docker run --rm [container_name] [command_in_container] ; you can use -it with --rm

// delete exited containers with # docker rm $(docker -a -q -f status=exited) # docker container prune ; exactly the same as befor but easier # docker rmi ; for deleting ones that are no running

or copy container token from 'docker ps -a' and past it after 'rm'
# docker rm [token]