Docker Interview Question and Answer
What is Docker and how does it work?
Docker is an open-source platform that allows developers to automate the deployment of applications inside containers. A container is a standalone executable package that includes everything needed to run a piece of software including the code, a runtime, libraries, environment variables and config files.
Docker works by using the host operating system's kernel to run containers. This allows containers to be isolated from one another and from the host system ensuring that they have no dependencies or conflicts with other applications on the host system. Docker also provides a shared library of pre-built images that can be pulled from a central repo and run immediately, making it easy for developers to quickly get started with their applications.
What is a Docker container?
A docker container is a packaged software solution that includes everything to run the application such as code, libraries, environment variables and more. We can say that a box holds all the parts needed to run specific software.
A docker container is a lightweight, standalone, and executable package of software that includes everything you need to run it.
What are the benefits of using Docker?
There are several benefits to using docker.
Portability:
Docker can run on any system that has docker installed.
Isolation:
Each container runs in its own isolated environment, which ensures that applications do not interfere with each other.
Scalability:
Docker makes it easy to scale applications by adding or removing containers as needed.
Ease of deployment:
Docker images can be stored in a central repo and pulled onto any system that has docker installed.
Version Control:
Docker images can be versioned so you can easily track changes and roll back to previous versions if needed.
What is the difference between Docker images and containers?
A docker image is a blueprint for creating a docker container. It contains the necessary code, libraries, dependencies, and configurations for running specific applications. An image can be thought of as a snapshot of a container and can be stored in a repo for later use.
A docker is a running instance of a docker image. When you launch a Docker container, you are creating an isolated and independent runtime environment based on the image. Containers can be started, stopped and deleted as needed and multiple containers can be run from the same image.
A docker image is a static template for creating a docker container while a docker container is a dynamic and isolated environment based on that image.
How does Docker ensure the consistency and reliability of containers?
docker ensures the consistency and reliability of containers in several way.
Image Versioning
Container Isolation
image layer
centralized management
What is a Dockerfile and how is it used?
A dockerfile is a script used to automate the creation of a Docker image. It contains a set of instructions that specify the base image to use, the dependencies to install, the files to copy and the commands to run. When you build a docker image using a dockerfile docker will execute each instruction in the file and create a new image based on the result. To use a Dockerfile, you simply create a file with the .dockerfile extension.
In short, a Dockerfile is a script that automates the creation of a Docker image, making it easy to recreate an application's environment and ensure consistency across different environments.
How can you share data between containers in Docker?
by using volumes, networking, tmpfs, or bind mounts, you can easily share data between containers and ensure that your applications have access to the data they need.
Write a command to run the container.
The given command is used to run the nginx.
docker run -d -p 80:80 nginx
- How can you delete the container?
The following command is used to delete the docker container.
docker rm web-server
- How can we interactively run ubuntu?
docker run -it ubuntu