Virtual machines are very common nowadays. They provide vast advantages for system administrators as they are the ones who turn physical machines to virtual machines. Every virtual machine contains its own memory and hard drive space. Containers is a new technology. Before we discuss how do containers work and Containers benefits, it is necessary that our readers should have knowledge about it.
Beginners Guide to How do Containers Work
Let’s start with the basics.
What Are Containers?
Containers basically is a method of operating system virtualization with which one can run an application and its dependent resources. With Container, you can easily package application code, configurations and dependencies into building blocks. These blocks deliver environmental consistency, operational efficiency, developer productivity, and version control.
Containers are the solution to the problem of how to run software reliably when shifted from one computing situation to another. The change in environment can be from developer’s laptop to test environment and from performance environment to production.
Solomon Hykes, Dockers creator while telling about the importance of Container said:
“You’re going to test using Python 2.7, and then it’s going to run on Python 3 in production and something weird will happen. You’ll run your tests on Debian and production is on Red Hat and all sorts of weird things happen.” Source: CIO from IDG
He further added that:
And it’s not just different software that can cause problems. “The network topology might be different, or the security policies and storage might be different but the software has to run on it.”
How Containers Work to Solve this Problem:
The container has a whole runtime environment i.e. an application, all its dependencies, libraries and other binaries. It also has configuration files used to run it and bundled it into one package. By containerizing the application platform and its dependencies, differences in OS distributions and underlying infrastructure are abstracted away.
Also Read: Things about OCS your boss wants to know
Containers share an operating system and use far fewer resources than their VM predecessor. Instead of creating a resource that reserves segments of your hardware, a container shares the installed operating system (Windows or Linux) and just segment off your application.
What are Dockers? How does it Work?
Docker is a popular open source project which is based on Linux containers. Docker is written in go and developed by Dotcloud. It provides a lightweight environment to run your application code. Docker has a well-organized workflow for moving your application from the developer’s laptop, test environment to production. It is incredibly fast and it can run on the host with compatible Linux Kernel.
Docker is based on a client-server architecture. Docker Daemon is actually responsible for all the actions that are related to containers. The daemon receives the commands from the Docker client through CLI or REST API’s. Docker client can be on the same host as a daemon or it can be present on any other host.
Images are the basic elements of Docker as containers are built up from images. These images are configured with applications. They are also used as templates for creating containers. Docker registry is a source for Docker images.
Benefits of Containers:
Containers have many benefits.
Containers allow portability and also reduces the organizational and technical frictions of moving an application between development, testing and production lifecycle. Containers encase all application file dependencies to it. It serves as a building block to be deployed at any computing resource which adds to containers benefits. This is beneficial for any organization as they will be able to deploy application reliably and consistently irrespective of the environment. In this way, there will be no need to configure each server and let you release new features in the more appropriate way.
With containers, one can get more from computing resources as with containers it is easier to run multiple applications on the same instances. Containers also help you specify the actual amount of memory, disk space and CPU. They have a faster boot time so one can quickly create and terminate applications or tasks encased in containers.
Containers Benefits are countless as Developer’s productivity is largely improved with the use of containers as there will be no cross service dependencies and conflicts. Each application component can be divided into different containers running a different microservice. Containers are isolated from one another, so you don’t have to worry about libraries or dependencies being in sync for each service. Developers can update each service individually as there are no library conflicts.
With containers, one can easily track version of application code and its dependencies. Docker container images have a Dockerfile that let you easily maintain and track versions of a container, inspect differences between versions, and roll-back to previous versions.