docker.md

layout	title
../../layouts/CheatSheet.astro	Docker Cheatsheet

Synopsis

Docker is a set of platform as a service products that use OS-level virtualization to deliver software in packages called containers. Containers are isolated from one another and bundle their own software, libraries and configuration files; they can communicate with each other through well-defined channels. All containers are run by a single operating-system kernel and are thus more lightweight than virtual machines. Containers are created from images that specify their precise contents. Images are often created by combining and modifying standard images downloaded from public repositories.

Run a new Container

Container is a running instance of an image. You can run a container from an image using the docker run command.

# Run a container from an image
docker run [OPTIONS] IMAGE[:TAG|@DIGEST] [COMMAND] [ARG...]

# Run a container from an image and attach to it
docker run -it [OPTIONS] IMAGE[:TAG|@DIGEST] [COMMAND] [ARG...]

Command	Description
docker run IMAGE	Start A New Container from an image
docker run --name CONTAINER IMAGE	Assign a name
docker run -p HOSTPORT:CONTAINERPORT IMAGE	Map a Port
docker run -P IMAGE	Map All ports
docker run -d IMAGE	Start Container in Background
docker run --hostname HOSTNAME IMAGE	Assign a Hostname
docker run --add-host HOSTNAME:IP IMAGE	Add a dns entry
docker run -v HOSTDIR:TARGETDIR IMAGE	Map a local Directory into the Container
docker run -it --entrypoint EXECUTABLE IMAGE	Change the Entrypoint

Manage Containers

Command	Description
docker ps	Show a list of running containers
docker ps -a	Show a list of all containers
docker rm CONTAINER	Delete a container
docker rm -f CONTAINER	Delete a running container
docker CONTAINER prune	Delete stopped containers
docker stop CONTAINER	Stop a running container
docker start CONTAINER	Start a stopped container
docker cp CONTAINER:SOURCE TARGET	Copy a file from a container to the host
docker cp TARGET CONTAINER:SOURCE	Copy a file from the host to a container
docker exec -it CONTAINER EXECUTABLE	Start a shell inside a running container
docker rename OLD_NAME NEW_NAME	Rename a container
docker commit CONTAINER	Create an image out of a container

Manage Images

Images are the building blocks of containers. You can manage images using the docker image command.

Command	Description
docker pull IMAGE[:TAG]	Download an image
docker push IMAGE	Upload an image to a repository
docker rmi IMAGE	Delete an image
docker images	Show list of all images
docker image prune	Delete dangling images
docker image prune -a	Delete all unused images
docker build DIRECTORY	Build an image from a Dockerfile
docker tag IMAGE NEWIMAGE	Tag an image
docker build -t IMAGE DIRECTORY	Build and tag an image from a Dockerfile
docker save IMAGE > FILE	Save an image to a .tar file
docker load -i TARFILE	Load an image from a .tar file

Info and Stats

Command	Description
docker logs CONTAINER	Show the logs of a container
docker stats	Show stats of a running container
docker top CONTAINER	Show processes of a container
docker version	Show installed docker version
docker inspect NAME	Get detailed info about an object
docker diff CONTAINER	Show all modified files in a container
docker port CONTAINER	Show mapped ports of a container

Docker compose

Docker compose is a tool for defining and running multi-container Docker applications. You can use it to run a single container or a complex application with multiple containers.

# Run a container from a docker-compose.yml file
docker-compose up

# Run a container in the background
docker-compose up -d

# Run a container with a custom docker-compose.yml file

docker-compose -f FILENAME.yml up

# Run a container with a custom docker-compose.yml file and a custom .env file
docker-compose -f FILENAME.yml --env-file .env up

Command	Description
docker compose build	Build all services from a docker-compose.yml file
docker compose up	Start all services
docker compose up NAME	Start named service and all dependencies
docker compose run NAME COMMAND	Run COMMAND in the service NAME
docker compose down	Stop all services
docker compose logs -f	see all logs for the services, following them

Docker Swarm

Docker Swarm is a native clustering tool for Docker. It turns a pool of Docker hosts into a single, virtual Docker host.

Command	Description
docker swarm init	Initialize a swarm
docker swarm join	Join a swarm
docker swarm leave	Leave a swarm
docker swarm join-token	Manage join tokens
docker node ls	List nodes
docker node inspect	Inspect a node
docker node promote	Promote a node
docker node demote	Demote a node
docker node update	Update a node
docker node rm	Remove a node
docker service ls	List services
docker service create	Create a new service
docker service inspect	Inspect a service
docker service logs	Fetch the logs of a service or task
docker service ps	List the tasks of a service
docker service rm	Remove a service
docker service scale	Scale a service
docker service update	Update a service

Docker Machine

Docker Machine is a tool for provisioning Docker hosts on your computer, on cloud providers, and inside your own data center. It creates servers, installs Docker on them, then configures the Docker client to talk to them.

Command	Description
docker-machine create	Create a machine
docker-machine ls	List machines
docker-machine ssh	Log into or run a command on a machine with SSH
docker-machine start	Start a machine
docker-machine stop	Stop a machine
docker-machine restart	Restart a machine
docker-machine regenerate-certs	Regenerate TLS Certificates for a machine
docker-machine env	Display the commands to set up the environment for the Docker client
docker-machine inspect	Inspect information about a machine
docker-machine ip	Get the IP address of a machine
docker-machine provision	Re-provision existing machines
docker-machine rm	Remove a machine
docker-machine scp	Copy files between machines
docker-machine ssh	Log into or run a command on a machine with SSH
docker-machine status	Get the status of a machine
docker-machine upgrade	Upgrade a machine to the latest version of Docker
docker-machine url	Get the URL of a machine
docker-machine help	Shows a list of commands or help for one command

Docker Registry

Dockers Registry is a tool to store and distribute Docker images. It is the default registry for Docker Hub.

Command	Description
docker login	Log in to a Docker registry
docker logout	Log out from a Docker registry
docker pull	Pull an image or a repository from a registry
docker push	Push an image or a repository to a registry
docker search	Search the Docker Hub for images
docker tag	Create a tag TARGET_IMAGE that refers to SOURCE_IMAGE

Dockerfile

A Dockerfile is a text document that contains all the commands a user could call on the command line to assemble an image. Using docker build users can create an automated build that executes several command-line instructions in succession.

Command	Description
FROM	Set the base image for subsequent instructions
RUN	Execute any commands in a new layer on top of the current image and commit the results
CMD	Provide defaults for an executing container
LABEL	Set metadata for an image
EXPOSE	Inform Docker that the container listens on the specified network ports at runtime
ENV	Set environment variables
ADD	Copy new files, directories or remote file URLs from SOURCE to the filesystem of the container at the path DEST
COPY	Copy new files or directories from SOURCE to the filesystem of the container at the path DEST
ENTRYPOINT	Configure a container that will run as an executable
VOLUME	Create a mount point with the specified name and mark it as holding externally mounted volumes from native host or other containers
USER	Set the user name (or UID) and optionally the user group (or GID) to use when running the image and for any RUN, CMD and ENTRYPOINT instructions that follow it in the Dockerfile
WORKDIR	Set the working directory for any RUN, CMD, ENTRYPOINT, COPY and ADD instructions that follow it in the Dockerfile
ARG	Define a variable that users can pass at build-time to the builder with the docker build command using the --build-arg <varname>=<value> flag
ONBUILD	Add a trigger instruction to an image
STOPSIGNAL	Set the system call signal that will be sent to the container to exit
HEALTHCHECK	Configure a test to perform to check that the container is still working
SHELL	Set the default shell for the shell-form of commands

Docker Hub

Docker Hub is a cloud-based registry service which allows you to link code repositories to Docker images. It offers automated builds, webhooks, and team collaboration features.

Command	Description
docker login	Log in to a Docker registry
docker logout	Log out from a Docker registry
docker pull	Pull an image or a repository from a registry
docker push	Push an image or a repository to a registry
docker search	Search the Docker Hub for images
docker tag	Create a tag TARGET_IMAGE that refers to SOURCE_IMAGE

Docker Networking

Docker networking is a feature that allows you to connect containers to each other and to the outside world. It allows you to create a network of containers that can communicate with each other and the outside world.

Command	Description
docker network create	Create a network
docker network connect	Connect a container to a network
docker network disconnect	Disconnect a container from a network
docker network inspect	Display detailed information on one or more networks
docker network ls	List networks
docker network prune	Remove all unused networks
docker network rm	Remove one or more networks

Docker Volumes

Docker volumes are the preferred mechanism for persisting data generated by and used by Docker containers. While bind mounts are dependent on the directory structure of the host machine, volumes are completely managed by Docker.

Command	Description
docker volume create	Create a volume
docker volume inspect	Display detailed information on one or more volumes
docker volume ls	List volumes
docker volume prune	Remove all unused local volumes
docker volume rm	Remove one or more volumes

Docker Secrets

Docker secrets are sensitive data which you don’t want to store in a Dockerfile or in your application’s source code unencrypted. Docker secrets are encrypted during transit and at rest in a Docker swarm. A given secret is only accessible to those services which have been granted explicit access to it, and only while those service tasks are running.

Command	Description
docker secret create	Create a secret
docker secret inspect	Display detailed information on one or more secrets
docker secret ls	List secrets
docker secret rm	Remove one or more secrets

Docker Stack

Docker stack is a set of interrelated services that share dependencies, and can be orchestrated and scaled together. A stack is defined in a docker-compose.yml file.

Command	Description
docker stack deploy	Deploy a new stack or update an existing one
docker stack ls	List stacks
docker stack ps	List the tasks in the stack
docker stack rm	Remove one or more stacks
docker stack services	List the services in the stack

Docker BuildKit

Docker BuildKit is a toolkit for converting source code to build artifacts in an efficient, expressive and repeatable manner. It provides a common set of operations for building container images and artifacts.

Command	Description
docker build	Build an image from a Dockerfile
docker buildx	Build with BuildKit

Docker Security

Docker security is a set of features that allow you to secure your Docker containers and images.

Command	Description
docker scan	Scan the image for vulnerabilities