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Docker Cheat Sheet – Most Important Docker Commands

Docker is a very popular tool introduced to make it easier for developers to create, deploy, and run applications using containers. A container is a utility provided by Docker to package and run an application in a loosely isolated environment. Containers are lightweight and contain everything needed to run an application, such as libraries and other dependencies packed by the developer during the application’s packaging process. This assures developers that their application can be run on any other machine. Here, we’re going to provide you with an ultimate Docker Cheat Sheet that will help you to learn Docker Commands easily.

This Docker command cheatsheet is a summary of commonly used Docker commands and their options, as well as other useful information related to Docker. It covers all the important commands required for Docker operations, including Docker installation, building, running, shipping, and cleaning up, as well as interaction with containers. This Docker cheat sheet is useful for both – DevOps freshers who’re learning Docker and experienced Docker users who need to recall a specific command or option but may not remember all the details.

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Docker Cheat Sheet – Table of Content

Pre-requisite: Docker, DockerHub

The below Docker cheat sheet contains commands to manage the docker containers, images, network, volumes, building running, and deploying containers and also covered commands related to Docker Compose.

Docker Commands Cheat Sheet

The Docker cheat sheet will help you as a reference guide from where you can quickly read of mostly used common commands of Docker. The cheat sheet will help as a handy guide for developers and other system administrations who are working with Docker. Let’s get started:

Installation Commands

Name

Command

Installation on Linux

curl -sSL https://gcurl -fsSL https://get.docker.com -o get-docker.sh && sudo sh get-docker.sh

Docker Login Commands

Name

Command

Log in to a Registry

docker login

Logout from a Registry

docker logout

Image Management Commands

Name

Command

Pulling an Image

docker image pull nginx

Pulling an Image Example

docker image pull <Name of The Image>:<Tag>

Image Transfer Commands

Name

Command

Pushing an Image

docker image push <usernameofregistry:Imagename: tag>

Pushing an Image Example

docker image push eon01/nginx localhost:5000/myadmin/nginx

Containers Management Commands

Name

Command

Starting Containers

docker container start nginx

Stopping Containers

docker container stop nginx

Restarting Containers

docker container restart nginx

Pausing Containers

docker container pause nginx

Unpausing Containers

docker container unpause nginx

Blocking a Container

docker container wait nginx

Sending SIGKILL Containers

docker container kill nginx

Sending another signal

docker container kill -s HUP nginx

Connecting to an Existing Container

docker container attach nginx

Check the Containers

docker ps

To see all running containers

docker container ls

Container Logs

docker logs infinite

‘tail -f’ Containers’ Logs

docker container logs infinite -f

Inspecting Containers

docker container inspect infinite

Inspecting Containers for certain

docker container inspect –format ‘{{ .NetworkSettings.IPAddress }}’ $(docker ps -q)

Containers Events

docker system events infinite

docker system events infinite

docker container port infinite

Running Processes

docker container top infinite

Container Resource Usage

docker container stats infinite

Inspecting changes to files or directories on a container’s filesystem

docker container diff infinite

Docker Image Management Commands

Name

Command

Listing Images

docker image ls

Building Images

docker build.

From a Remote GIT Repository

docker build github.com/creack/docker-firefox

Instead of Specifying a Context, You Can Pass a Single Dockerfile in the URL or Pipe the File in via STDIN

docker build – < Dockerfile

Building and Tagging

docker build -t eon/infinite.

Building a Dockerfile while Specifying the Build Context

docker build -f myOtherDockerfile.

Building from a Remote Dockerfile URI

curl example.com/remote/Dockerfile | docker build -f – .

Removing an Image

docker image rm nginx

Loading a Tarred Repository from a File or the Standard Input Stream

docker image load < ubuntu.tar.gz

Saving an Image to a Tar Archive

docker image save busybox > ubuntu.tar

Showing the History of an Image

docker image history

Creating an Image From a Container

docker container commit nginx

Tagging an Image

docker image tag nginx eon01/nginx

Pushing an Image

docker image push eon01/nginx

Docker Network Commands

Name

Command

Creating an Overlay Network

docker network create -d overlay MyOverlayNetwork

Creating a Bridge Network

docker network create -d bridge MyBridgeNetwork

Creating a Customized Overlay Network

docker network create -d overlay \

–subnet=192.168.0.0/16 \

–subnet=192.170.0.0/16 \

–gateway=192.168.0.100 \

–gateway=192.170.0.100 \

–ip-range=192.168.1.0/24 \

–aux-address=”my-router=192.168.1.5″

–aux-address=”my-switch=192.168.1.6″ \

–aux-address=”my-printer=192.170.1.5″

–aux-address=”my-nas=192.170.1.6″ \ MyOverlayNetwork

Removing a Network

docker network rm MyOverlayNetwork

Listing Networks

docker network ls

Getting Information About a Network

docker network inspect MyOverlayNetwork

Connecting a Running Container to a Network

docker network connect MyOverlayNetwork nginx

Connecting a Container to a Network When it Starts

docker container run -it -d –network=MyOverlayNetwork nginx

Disconnecting a Container from a Network

docker network disconnect MyOverlayNetwork nginx

Docker Exposing Ports Commands

Name

Command

Exposing Ports

EXPOSE <port_number>

Mapping Ports

docker run -p $HOST_PORT:$CONTAINER_PORT –name <container_name> -t <image>

Docker Commands Removing Containers, Images, Volumes, And Networks

Name

Command

Removing a Running Container

docker container rm nginx

Removing a Container and its Volume

docker container rm -v nginx

Removing all Exited Containers

docker container rm $(docker container ls -a -f status=exited -q)

Removing All Stopped Containers

docker container rm `docker container ls -a -q`

Removing a Docker Image

docker image rm nginx

Removing Dangling Images

docker image rm $(docker image ls -f dangling=true -q)

Removing all Images

docker image rm $(docker image ls -a -q)

Removing all Untagged Images

docker image rm -f $(docker image ls | grep “^” | awk “{print $3}”)

Stopping & Removing all Containers

docker container stop $(docker container ls -a -q) && docker container rm $(docker container ls -a -q)

Removing Dangling Volumes

docker volume rm $(docker volume ls -f dangling=true -q)

Removing all unused (containers, images, networks and volumes)

docker system prune -f

Clean all

docker system prune -a

Docker Swarm Commands

Name

Command

Installing Docker Swarm

curl -ssl https://get.docker.com | bash

Initializing the Swarm

docker swarm init –advertise-addr 192.168.10.1

Getting a Worker to Join the Swarm

docker swarm join-token worker

Getting a Manager to Join the Swarm

docker swarm join-token manager

Listing Services

docker service ls

Listing nodes

docker node ls

Creating a Service

docker service create –name vote -p 8080:80 instavote/vote

Listing Swarm Tasks

docker service ps

Scaling a Service

docker service scale vote=3

Updating a Service

docker service update –image instavote/vote:movies vote

Updating a Service

docker service update –force –update-parallelism 1 –update-delay 30s nginx

Docker file Commands

Command

Description

Example

FROM

Specifies the base image for the build

FROM ubuntu:latest

RUN

Executes a command inside the container during build time

RUN apt-get update && apt-get install -y curl

CMD

Specifies the default command to run when the container starts

CMD [“npm”, “start”]

EXPOSE

Informs Docker that the container listens on specific network ports at runtime

EXPOSE 80/tcp

ENV

Sets environment variables inside the container

ENV NODE_ENV=production

COPY

Copies files or directories from the build context into the container

COPY app.js /usr/src/app/

ADD

Similar to COPY but supports additional features like URL retrieval and decompression

ADD https://example.com/file.tar.gz /usr/src/

WORKDIR

Sets the working directory for subsequent instructions

WORKDIR /usr/src/app

ARG

Defines variables that users can pass at build-time to the builder with the docker build command

ARG VERSION=1.0

ENTRYPOINT

Configures a container to run as an executable

ENTRYPOINT [“python”, “app.py”]

VOLUME

Creates a mount point and assigns it to a specified volume

VOLUME /data

USER

Sets the user or UID to use when running the image

USER appuser

LABEL

Adds metadata to an image in the form of key-value pairs

LABEL version=”1.0″ maintainer=”John Doe

ONBUILD

Configures commands to run when the image is used as the base for another build

ONBUILD ADD . /app/src

Docker Volume Commands

Command

Description

Example

volume create

Creates a named volume

docker volume create mydata

volume ls

Lists the available volumes

docker volume ls

volume inspect

Displays detailed information about a volume

docker volume inspect mydata

volume rm

Removes one or more volumes

docker volume rm mydata

volume prune

Removes all unused volumes

docker volume prune

Docker CP commands

Command

Description

Example

docker cp [OPTIONS] SRC_PATH CONTAINER:DEST_PATH

Copies files or directories from the local filesystem to the specified container

docker cp myfile.txt mycontainer:/usr/src/app/

docker cp [OPTIONS] CONTAINER:SRC_PATH DEST_PATH

Copies files or directories from the specified container to the local filesystem

docker cp mycontainer:/usr/src/app/result.txt /tmp/result/

Docker Security Commands (Docker Scout)

Command

Description

Example

docker scout compare

[experimental] Compare two images and display differences

docker scout compare image1:tag image2:tag

docker scout cves

Display CVEs identified in a software artifact

docker scout cves image: tag

docker scout Quickview

Quick overview of an image

docker scout quickview image: tag

docker scout recommendations

Display available base image updates and remediation recommendations

docker scout recommendations image:tag

docker scout version

Show Docker Scout version information

docker scout version

Conclusion

In conclusion, this Docker cheat sheet helps you with a quick revision of all the Docker commands that are required for Docker operations, including Docker installation, building, running, shipping, and cleaning up, as well as interaction with containers.

FAQs on Docker CheatSheet

Q1. What is the architecture of Docker?

Answer:

Docker follows a client-server architecture. The Docker client communicates with the Docker daemon, which is responsible for building, running, and managing Docker containers. The client and daemon can run on the same host, or the client can connect to a remote daemon.

Q2. Which language is Docker built on?

Answer:

Docker is built using Go programming language because of its advantage of several features of the Linux kernel to deliver its functionality.

Q3. Does Docker require coding?

Answer:

No, Docker does not require any prior coding knowledge. It is a containerization platform that enables developers to package, deploy, and run applications using containers.

Q4. Are Docker secrets safe?

Answer:

You can use Docker secrets to centrally manage this data and securely transmit it to only those containers that need access to it. Secrets are encrypted during transit and at rest in a Docker swarm.

Q5. How many types of volumes are there in Docker?

Answer:

Docker supports three types of volumes:

a) Named Volumes: These are volumes with a user-defined name that can be used across multiple containers.

b) Bind Mounts: These are directories on the host machine that are mounted into a container, allowing direct access to the host’s file system.

c) tmpfs Mounts: These are volumes stored in the host’s memory, allowing fast read and write operations but with limited size and durability.

Q6. What is the flag in Docker?

Answer:

In Docker, a flag is a command-line option that modifies the behavior of a Docker command. Flags are used to provide additional instructions or parameters to Docker commands, allowing you to customize the execution according to your needs.

Q7. Why is Docker used in DevOps?

Answer:

Docker is widely used in DevOps practices due to its ability to create reproducible and portable environments. With Docker, developers can package their applications and dependencies into containers, ensuring consistent behavior across different stages of the software development lifecycle. Docker also facilitates the automation of deployment, testing, and scaling processes, enabling faster and more reliable software delivery in DevOps pipelines.

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