15 Commonly used docker commands with their syntax, explanation and examples

You can effortlessly enhance your docker skills by mastering some common docker commands.
Whether you are a beginner or looking to expand your knowledge, understanding these commands will significantly improve your docker experience.
In this article, we will provide a comprehensive guide on important docker commands that will streamline your workflow and enable you to efficiently manage your containers.
By following our step-by-step instructions and examples, you will be well-equipped to navigate the world of docker with ease.

Docker Image Management Commands

If you want to manage docker images efficiently, you need to familiarize yourself with the following commonly used docker image management commands:

The images will be downloaded from a repository. Default repository is docker hub but you can configure it to use your own private repository.

1. docker images

This command displays a list of all the images currently stored or downloaded on your local system. Example,

docker images

Example output will be

2. docker rmi

Use this command to remove one or more images from your local machine. Its syntax is

docker rmi image_id

3. docker tag

This command is used to add a new tag to an existing image. Example,

docker tag 406bsa29d5ab codippa

4. docker save

This command saves an image to a tar archive so that it can be shared or transferred from one device to another.
Example,

docker save -o image.tar 406bsa29d5ab

5. docker load

This command is used to load a docker image from a tar archive file.
This command allows you to import an image that has been saved using the docker save command. Example,

docker load /path/to/image.tar

This command will import the docker image contained in my_image.tar into your local docker environment, making it available for use.

By mastering these docker image management commands, you will be able to efficiently handle docker images on your system.

Docker Container Lifecycle Commands

Now, let’s probe the important docker commands that manage the lifecycle of containers.

1. docker run

This command creates and starts a container from a specified image. Example,

docker run 406bsa29d5ab

You can also set environment variables while running an image and the value of those variables may be used by your application to make it more dynamic.
Environment variables may be set using -e flag with docker run as shown below.

docker run -e DB_HOST=127.0.0.1 406bsa29d5ab

2. docker ps

Lists all running containers. Example,

docker ps will list only running containers.
To list both stopped and running containers, use -a flag as docker ps -a.

3. docker stop

Stops one or more running containers. Example,

docker stop s91c8831a4c9

where the value after stop is container id to be stopped.

4. docker rm

Removes one or more stopped containers. Example,

docker rm s91c8831a4c9

5. docker restart

Restarts one or more containers. Example,

docker restart s91c8831a4c9

6. docker cp

docker cp command can be used to copy a file from your local system into a docker container and vice-versa.
Its syntax is

docker cp <path to local file> container_name:<destination path in container>

Example,

docker cp /home/user/example.txt s91c8831a4c9:/home/app/example.txt

Similarly, you can also copy a file from docker container to your local system by interchanging second argument with first.

Mastering these docker container lifecycle commands will empower you to efficiently manage your containers throughout their lifecycle.

Docker Registry and Repository Commands

Unlike the local docker daemon, which stores images and containers on the host machine, docker registry is a service for hosting and distributing docker images.
docker Repository is a collection of related docker images tagged with a specific version.
Below are some commonly used docker commands related to interacting with docker Registry and Repository.

1. docker pull

This command is used to download images from docker Hub or any other registry. Example,

docker pull ubuntu

2. docker push

Push an image or a repository to a registry. Example,

docker push myrepo/myimage:latest

3. docker login

Command to log in to a docker registry. Example,

docker login docker.io

As stated earlier, if you do not issue this command, default registry is docker hub.

4. docker logout

Command to log out from a docker registry. Example,

docker logout docker.io

These commands are necessary for working with remote docker registries, managing images, and interacting with repositories to deploy and share docker applications effectively.

Conclusion

So, with these commonly used docker commands and their syntax, explanations, and examples in mind, you are well-equipped to efficiently manage your docker containers and images.
Whether you need to pull a new image, stop a running container, or rename a container, these commands provide you with the tools to streamline your docker workflow.
By mastering these commands, you can effectively navigate the world of containerization and harness the power of docker for your development and deployment needs.