Docker Interview Questions with Answers

Q1) What is Docker?

Docker can be defined as Containerization platform that packs all your applications, all the necessary dependencies combined to form containers. This will not only ensure the applications work seamlessly given any environment but also provides better efficiency to your Production ready applications. Docker wraps up bits and pieces of software with all the needed filesystems containing everything that needs to run the code, provide the runtime, system tools / libraries. This will ensure that the software is always run and executed the same, regardless of the environment.

Containers run on the same machine sharing the same Operating system Kernel, this makes it faster – as starting the applications is the only time that is required to start your Docker container (remember that the OS Kernel is already UP and running and uses the least of the RAM possible).

Q2) What is the advantage of Docker over hypervisors?

Docker is light weight and more efficient in terms of resource uses because it uses the host underlying kernel rather than creating its own hypervisor.

Q3) How is Docker different from other container technologies?

To start with, Docker is one of the upcoming and is a fresh project. Since its inception has been done in the Cloud era, it is way better many of the other competing Container technologies which have ruled their way until Docker came into existence. There is an active community that is running towards the better upbringing of Docker and it has also started extending its support to Windows and Mac OSX environments in the recent days. Other than these, below are the best possible reasons to highlight Docker as one of the better options to choose from than the existing Container technologies.

• There is no limitation on running Docker as the underlying infrastructure can be your laptop or else your Organization’s Public / Private cloud space
• Docker with its Container HUB forms the repository of all the containers that you are ever going to work, use and download. Sharing of applications is as well possible with the Containers that you create.
• Docker training is one of the best-documented technologies available in the Containerization space.

Q4) What is Docker image?

Docker image can be understood as a template from which Docker containers can be created as many as we want out of that single Docker image. Having said that, to put it in layman terms, Docker containers are created out of Docker images. Docker images are created with the build command, and this produces a container that starts when it is run. Docker images are stored in the Docker registry such as the public Docker registry (registry.hub.docker.com) as these are designed to be constituted with layers of other images, enabling just the minimal amount of data over the network.

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