Why Docker?

What Are Microservices?

Before discussing Docker, it is important for you to understand what microservices are. Consider a very large application that is broken down into smaller services. Each of those services can be termed as microservices. Microservices are small processes that communicate with each other over a network. For example, consider an online shopping application that can be broken down into smaller microservices, such as the user-accounts service, product catalog, order server, and shopping cart server.

There are three major reasons for adopting a microservice architecture.

1. When applications are broken into smaller services, they are easier to build and maintain.
2. If you want to update a particular software, or you want a new technology stack in one of your modules or services, this is easy to perform because the dependency's concerns are smaller compared to the application as a whole.
3. If any of your modules or services go down, your overall application remains unaffected.

There are also several problems in adopting microservice architecture. When developing a large application that requires several microservices in one machine, you will require the same number of VMs as microservices. Each of these VMs contains dependencies for one microservice. The major disadvantage here is that in a virtual machine, there is a lot of wastage of resources, such as RAM, processor, and disk space, which are not completely utilized by the microservices running in those VMs. This is not an ideal way to implement the microservice architecture. In this case, Docker comes into play.

Docker and Microservices

Docker resolves this inefficiency problem by running several microservices in the same VM through running various containers for each microservice. Docker is an open-source application that helps you create, deploy, and run applications with the help of a container. Docker containers are small and lightweight VM alternatives that use the host operating system and use up relatively fewer resources.

To understand Docker, first, you must understand what is the problem statement that Docker is trying to resolve. Here, the problem is that after designing a project, it might run perfectly fine on your system initially, but has trouble opening on other systems and servers. As soon as you move the project to the production stage, on someone else's computer or on some other server, the project does not show the same level of performance, same level of working, or same optimization, even when you move that project from one place to another.

For example, when you develop a website by using ASP.net or PHP, and you work on it and move the project to the web server, there are some uncertainties that could occur. This includes images not properly loading, or perhaps a bit difference or glitch in the path. On the developer's machine, everything may work perfectly, but it might not work the same when moved to another machine.

How Does Docker Work?

Docker is specially designed to address the “It works on my machine” problem. Docker has compatibility with almost all the popular programming languages and common projects you may be working on. With Docker, you can be assured about getting a container that is absolutely tightly sealed, and these airtight containers are at the core of Docker. All your code is wrapped up by this container and the good thing is that these are completely portable. You can take a Docker container anywhere, and it works the same way it works on your own machine.

Docker also allows you to have social containers. The term “social container” means that these containers can be published on social media platforms. For example, when learning MySQL, you may find it challenging to install the core MySQL. Installing this program on your system may, in fact, be one of the primary challenges that you face, but it can easily be done with the help of Docker.

So, Docker is the software through which you create containers. In addition, these containers contain a number of useful features and tools. These containers are packed up with code, dependencies, configuration, processes, networking information, and also contain chunks of some of the operating system responsible for tweaking your code.

What Does Docker Do?

Docker can be divided into three primary functions:

• Client-and server-side application program.

Docker contains many features, including designing your container.  All of your codes and configuration will be already packed in, and you may move it anywhere you like.

• Service program.

Docker can act as a service, so that it can be deployed on any other server. You can deploy it on any place of your service of choice simply by taking your container.

• Platform for social networking.

You can share Docker images like any other item you might share on social media. For anybody who wants to start from a specific point in programming, they can start from whenever and wherever they want. Docker is a company managing and doing all these things for you.

Conclusion

This article discussed why you need Docker as a programmer and what Docker can do for you. With the help of Docker, you can host more applications on the same hardware, making it easier for you to quickly create ready-to-run containerized applications.