Docker Interview Question

Introducing Docker

Docker is a very popular and powerful open source platform used to build, deploy and run applications. Docker allows you to separate the application/software from the underlying infrastructure.

1. What is a container?
A container is a standardized unit of software that comes with dependencies so that applications can be deployed quickly and reliably on different computing platforms.

Docker can be visualized as a large ship (docker) carrying huge containers.

Docker containers do not require a separate operating system to be installed. Docker only relies on or uses the resources of the kernel and its functions to allocate them to the CPU and memory, it relies on the kernel's functions and uses resource isolation for the CPU and memory, and separate namespaces to separate the application's view from the OS (operating system).

2. Why Learn Docker
Application development is more than just writing code! It involves a lot of behind the scenes work like using multiple frameworks and architectures for every stage of its lifecycle, which makes the process complex and challenging. Using the nature of containerization helps developers simplify and speed up the application workflow efficiently, while also giving them the freedom to develop using their own choice of technology and development environment.

• All these aspects form the core of DevOps, which makes it even more important for any developer to know these things to improve productivity, drive rapid development along with keeping in mind the factors of application scalability and more efficient resource management.
• Imagine a container as a lightweight box pre-installed with all the packages, dependencies, software required by your application, just deploy to production with minimal configuration changes.
• Many organizations like PayPal, Spotify, Uber etc. use Docker to simplify operations and bring infrastructure and security closer to create more secure applications.
• Portable, Containers can be deployed on multiple platforms like virtual machines, Kubernetes platform etc. as per the requirement of the desired scale or platform.