Docker Interview Questions

Docker Interview Questions

What is Docker?

Docker is basically a computer program that mainly performs operating-system-level virtualization. This type of computer program was released in the year 2013. Docker is mainly used to run a computer package named container. Containers allow the developer to pack up all the applications with the parts it needs the most. The package parts are libraries and the other dependencies.

Docker is a little similar to the virtual machine. The virtual machine is used to create the whole virtual operating system. But the Docker is used to allow all the applications to adopt the same Linux Kernel. Docker is especially open-source which means anyone can contribute to the Docker to extend his or her own needs.

Practice Best Docker Interview Questions and Answers;

The use of Docker by the developers is increasing day by day. Docker has the potential for the organization by giving the developers and IT the freedom to build, manage and secure business applications. In the context above, we have presented the most important frequently asked Docker Interview Questions that will help you a lot.

So the following are some of the Docker Interview Questions that will help you to know more about Docker. apart from this, you can also download below the Docker Interview Questions PDF completely free.

Download Docker Interview Questions PDF

Below are the list of Best Docker Interview Questions and Answers

Firstly, Docker is a type of tool that is used to make the application, deploy and run in an easier way. The Docker uses the container to make the applications run easier. It is a type of the new generation of virtualization which is used to make the complex software accessible and confined compared to the other types of computer programs.

The following are the main differences between the Docker and the Virtual machine:

  • Docker has more potential as compared to the Virtual machine.
  • Docker container has the potential to share a single Kernel and all the application libraries.
  • The applications that are used inside the Docker are better than the applications that are used in the Virtual machine.

A docker container is a basic unit of software that packs up all the code to run the application in an easier and more reliable way. These type of containers are available in both the Linux and the window-based applications. Docker containers are the ones that are not tied to any of the individual infrastructures. They can just run on any of the computer and on any of the cloud.

The following are the main components of the Docker:

  • Container
  • Image
  • Platform image
  • Registry
  • Dockerfile

A docker image is a file that is comprised of multiple layers. It is used to execute code in the Docker container. An image is a combination of a file system and parameters. When dockers run the image, it becomes one or many instances of the container. Docker image is the package of executable files. It contains different code, libraries, runtime, binaries, and configuration files that are necessary to run the application.

A Docker Hub is the type of hosted registry solution that is being provided by Docker Inc. The Docker Hub allows you to link to code repositories, link to Docker clouds, stores manually pushed images and builds your image and tests them. Docker Hub will help you to provide these types of things so that you can easily set up the image to your hosts.

Docker cloud is a type of service that is being provided by the Docker. In the Docker clouds you can just carry out the following operations:

  • Nodes
  • Cloud Repository
  • Continuous Integration
  • Application deployment
  • Continuous Deployment

Docker swarm is a type of tool that is used for the clustering and arranging of the Docker containers. With the use of the Docker swarm, the administrator or the developer can establish and maintains the cluster of docker nodes. Docker Swarm also handles the standard Docker API.

A Dockerfile is a type of text document that contains the commands. A user could call on the command line to arrange an image. Dockerfile will give you the capabilities to create your own image.

A Dockerfile is mainly used to create an image. With the use of the Dockerfile, you can create an image again and again without going through the manual process.

Take Free: Docker MCQ & Quiz

The followings are the commands that are available in the Dockerfile:

If you want to create the Docker container, then you have to use a command and that is:

Docker run –t –I command name

The followings are the commands that are available in the Dockerfile:

  • Add
  • CMD
  • Entry point
  • ENV
  • FROM
  • RUN
  • USER

Docker mainly runs on the Linux and cloud platform.

In Linux there are also different types available on which Docker runs and they are:

  • Ubuntu 12.04, 13.04 et al
  • Fedora 19/20+
  • RHEL 6.5+
  • CENTOS 6+
  • ArchLinux
  • OpenSuse 12.3+
  • Crux 0.3+

The following are the types of clouds on which Docker runs:

  • Amazon EC2
  • Google Compute Engine
  • Microsoft Azure
  • Rackspace

No, if you are using the Docker container you will not lose any of the data. The data will be preserved in the Docker container until and unless the container is deleted

Docker is the latest and one of the most popular technologies that are used in the cloud era. With the help of the Docker container, more applications can run on the same old servers. These are the things that make the Docker container different from the other container technologies.

Below is one line command to stop all containers in docker.

docker stop $(docker ps -a -q)