Docker Interview Questions

Docker is a form of virtualizing the operating system in form of computer code level. Docker was entirely written in the Go language and was licensed under Apache license 2.0 in the form of binary. The first version of Docker was released back in 2013. Docker was developed and it is maintained by Docker. Inc. It supports different operating systems like windows, Mac OS, and Linux. It also support different platforms like x86-64 windows and architecture. It was initially released as an open source and was initially developed for UNIX in order to isolate Linux kernel features. Well, if you have got your dream job that is related Docker and you are not so sure about the questions that can be asked during the interview as well as the answers you are expected to give, stick around because we have prepared you some of the most important questions about Docker that you are likely going to be asked during the interview.

1. What is a Docker?

Ans. A Docker is a platform containerizing applications to isolate them from each other so that it can ensure more efficiency as well as high availability regardless of the environments like the development, testing as well as the production. The applications that are related to dependencies like jar files and libraries will be packaged as well as formed as a container that is called containerized application which works independently and does not need any dependency. Docker usually ensure that the application can be run irrespective of the external factors. The container in Docker normally gets the support from host operating system as well as from the Docker engine which supports all the operational as well as infrastructural related dependencies.

2. List and explain the components of Docker architecture.

Ans. This is a normally asked question asked during the interviews and you should actually expect it to be asked during your interview so be well prepared for it.

  • Docker client. This component usually perform build pull as well as run operations in order to establish the communication with the Docker host. The Docker command normally makes the use of Docker API in order to call the questions to be run.
  • Docker host. This is the component that contain the Docker daemon, containers as well as the images. The images are normally the kind of metadata for the apps which are containerized in the containers. The Docker daemon on the other hand establishes the needed connection with registry.
  • Registry. The registry is the component that normally store the Docker images. The public registry are Docker cloud and Docker hub and they be s used by any person.

3. What is a Docker container?

Ans. A Docker container is a sort of an encapsulation to the app which normally hold dependencies and share the kernel with other containers in a duration when the isolated processes on the operating systems are being ran. You can create a Docker container by creating a Docker image. The Docker images can be simply run after they have been created using the Docker commands. The Docker containers are like instances of the Docker images at the run time. The images can be stored in private hosts or public hosts for example Docker hub. Docker image is a set of files that can be ran in isolated process.

4. What are the different applications and functionalities of using Docker?

Ans. There are various functionalities as well as applications of using as well as implementing Docker and they include the following.

  • Docker enables the isolation of the app.
  • Docker simplifies the configuration as well as provide an easy way at infrastructure level configuration.
  • Docker manages the code pipeline with ease which helps provide a consistent environment and stability in the app.
  • Docker enables lots of debugging capabilities that helps provide useful functionalities to implement.
  • Docker lowers the utilization of a lot of servers in the form containerization.
  • Docker improves the productivity of a developer to concentrate on the business logic solely.
  • Docker enables the fast deployment in a form of virtualization at the level of operating system.

5. What is Docker registry?

Ans. A Docker registry is a place where the Docker images are stored and Docker Hub and Docker Cloud are the public registries where the hosted images can be hosted upon. The Docker hub is a default storage for the images. It is possible to set an own registry as per the requirement. It is also possible to use Docker Data Center (DDC) and the DDC do include the Docker Trusted Registry (DTR). The store of Docker is going to provide you with an option of buying as well as selling the Docker images.

6. What is the lifecycle of Docker container?

Ans. You should also be very prepared for this question because it is very common. Anyway, the lifecycle of the Docker container is as highlighted below:

  • Create the container.
  • The next thing is to run the Docker container
  • Pausing the container is the next thing.
  • Unpause the container.
  • Start your container.
  • Stop the container.
  • Restart your container.
  • Kill the container and finally‚Ķ
  • Destroy your container.

7. What are the vital Docker commands?

Ans. Below are some of the vital Docker commands.

  • Dockerd which is used to launch the Docker daemon.
  • Build command which is used to build an image file for the Docker.
  • Create command that has the function of creating a new container.
  • Kill command which has the function of killing the container.
  • Commit command that can be used to create a new image from changes in the containers.

8. What are Docker hub and Docker image?

Ans. To start with, a Docker image is set of files plus combination of parameters that can be used to create instances to run in different and separate containers as a process that is isolated. A Docker hub on the other hand is some kind of repository to the Docker images where the images are stored and can be accessed by the public.


Docker Interview Questions And Answers PDF

You can also download Docker interview questions and answers pdf from the link below :

Docker Interview Questions & Answers PDF

Hope the above will help you in preparing for Docker interviews.