Basic Docker Commands

Installation and Verification

Before you can start using Docker, install it on your system. Once installed, you can verify its version and ensure everything is up and running with these commands:

docker --version
docker info

Logging In

In case you have not yet created a docker account. Head over to their official website and create one. Then, login with your username. 

To log in to your account, simply type the following command.

docker login

Pulling Images

Docker images act as templates, for containers. These images are stored in a repository called Docker Hub. To retrieve an image you can use the command;

docker pull image_name:tag

For instance, to pull the latest Ubuntu image:

docker pull ubuntu:latest

Running Your First Container

Now lets make use of the image by executing a container. This is the part because containers are self images capable of running on their own. Here's how you can accomplish it;

docker run image_name:tag

For example, to run a basic Nginx web server container:

docker run nginx:latest

Listing Containers

You can see a list of running containers on your system using:

docker ps

If you want to see all containers, including the ones that are not currently running:

docker ps -a

Create Container

To create a container in docker, use the following command: 

Eg. 

docker create –name container-name -it ubuntu bash

Stopping and Starting Containers

To stop a running container, use the following command:

docker stop container_id

And to start a stopped container:

docker start container_id

Removing Containers

After a container has served its purpose, you can remove it using:

docker rm container_id

For example:

docker rm my_container

Managing Images

You can view a list of downloaded images on your system with:

docker images

If you want to remove an image:

docker rmi image_name:tag

Port Mapping

Containers often provide services that need access from the host or external network. You can map ports between the host and container using the -p flag:

docker run -p host_port:container_port image_name:tag

For instance:

docker run -p 8080:80 nginx:latest

Also see, kubernetes interview questions

Frequently Asked Questions

What is Docker?

Docker is a platform that developers can use to create, package and distribute applications, in the form of portable containers. These containers encapsulate all the components for a program to run including dependencies, libraries and configuration files.

What's the Difference Between a Docker Container and a Virtual Machine (VM)?

Both Docker containers and virtual machines offer isolation capabilities. However there are some distinctions. Containers are more lightweight compared to machines since they share the host operating system kernel. This results in resource consumption and faster performance. On the hand virtual machines include an operating system making them more resource intensive but providing stronger isolation.

How Can I Manage Multiple Containers?

To effectively handle containers Docker Compose comes into play. It serves as a tool specifically designed for defining and running Docker applications consisting of interconnected services. By utilizing a YAML file, for configuration management Docker Compose simplifies the management of applications.

What's the Difference Between Docker and Kubernetes?

While Kubernetes is a framework for executing and managing containers from numerous container runtimes, Docker is a container runtime. Numerous container runtimes, such as Docker, containerd, CRI-O, and any CRI (Container Runtime Interface) implementation, are supported by Kubernetes. Kubernetes can be compared to a "operating system" and Docker containers to "apps" that you put on the operating system. 

Conclusion

Now that you have a grasp of these basic Docker commands, you are ready to embark on your containerization journey. Docker greatly simplifies the process of development and deployment making it easier to create reliable and portable applications. By becoming proficient in these commands you are initiating the optimization of your development workflow and embracing the capabilities of containerization. Enjoy your experience, with Docker!

Recommended Readings:

• Docker Interview Questions: Beginner Level
   
• Docker Interview Questions: Intermediate Level
   
• Running Salt States And Commands In Docker Containers
   

You may refer to our Guided Path on Code Ninjas Studios for enhancing your skill set on DSA, Competitive Programming, System Design, etc. Check out essential interview questions, practice our available mock tests, look at the interview bundle for interview preparations, and so much more!

Happy Learning, Ninja!