Introduction to Docker

Introduction to Docker

What is Docker?

Docker is a computer package with a program that is able to do operating system level tasks known as Virtualization.” Docker is industrialized by Docker, Inc.

Docker is a container management service where we can develop our application, package it, deploy and run with its dependencies in a container. Later we can ship this container easily to execute on other machines.

Why do we need to learn Docker?

Docker was initially released in March 2013 and after that, it has become the catchword for the modern technology where it is specially used for Agile-based projects.

We should be clear with two terms mentioned above Virtualization and Containerization. These two terms are much related to each other.

First communicate to you what is Virtualization?

Virtualization is a technical term that defines the process to introduce a Guest Operating system on the top priority of a Host operating system in a virtual environment. It gave various advantages like easy maintenance and recovery in case of failure and less cost as it reduced the need for extra hardware resources and infrastructures.

But nothing is perfect; virtualization also has some failures which made performance degradation as multiple virtual machines run on the same host. This caused the delay in the booting process and real time applications were affected. These drawbacks of virtualization rose in the evolution of new technology Containerization.

Now let me tell you about Containerization

Containerization has conveyed abstraction to the operating system, not the hardware like in virtualization, where there is no Guest OS. Here, Docker containers run by sharing a Linux Kernel, utilizes a host’s operating system, interact sharing needed libraries and resources, uses less memory, less CPU and take seconds to boot up.

Containerization sets applications as images that comprise everything that is required to execute them such as libraries, code, runtime environment, and configurations.

Applications of Docker

• Docker reduces the size of development providing a smaller footprint of the operating system through containers.
• With the help of containers, working seamlessly across applications has become easier for teams across different units such as QA, Operations and development.
• Docker containers can be deployed anywhere, used on any physical or virtual system like a developer’s laptop, in the cloud, or systems on premises.
• The containers are light weighted so they are scalable easily.

Example

Everything is centered on images in Docker, which is formed with a file system and parameters. For example, let’s execute the following command in Docker.

docker run hello-learning-docker

Here, the Docker command tells the Docker program on the OS for something needed to be done. Again, with the run command, we create an instance of the image that is then known as a container. At last “hello-learning-docker” represents the image from where the container is made.