Docker-yes, one of the hot topics of technical discussions in recent times. It is an open source, container-based technology and considered one of the disruptive innovations of recent times. Docker containers are isolated packages that contain the components required to run an application.
This chapter will describe container technology in detail and explain how it is different from virtual machines by comparing the benefits of both. It will give you an overview of Docker and its installation and configuration details; it will also cover how to create CentOS containers for application deployment. We will also cover Docker Hub and the basic architecture of Docker. We will see how to use the Tomcat image available on Docker Hub and create a sample image with a Java and Tomcat installation and a Dockerfile.
We will cover the following topics:
- Overview of Docker containers
- Understanding the difference between virtual machines and containers
- Installation and configuration of Docker on CentOS
- Creating your first Docker container
- Managing containers
Containers use OS-level virtualization, where the kernel is shared between isolated userspaces. Docker and OpenVZ are popular open source example of OS—level virtualization technologies.
Docker is an open source initiative to wrap code, the runtime environment, system tools, and libraries. Docker containers share the kernel they are running on and hence start instantly and in a lightweight manner. Docker containers run on Windows as well as Linux distributions. It is important to understand how containers and virtual machines are different.
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