Once your application, including its logic and database, is developed, the next step is to put it into production. Many of us are familiar with the frustration of the "It works on my machine" problem. This occurs when the developer's setup works perfectly, but when the application is deployed to production, something crucial is missing or does not work as expected. Additionally, ensuring that the production environment can be reproduced exactly as intended can be a headache for the infrastructure team.

In the past, virtual machines were used to mitigate these issues. However, nowadays, more and more people are turning to Docker containers. These containers encapsulate all the requirements for the application environment, making deployment to production much simpler. Typically, the only requirement for deployment is having Docker installed on the production server. This makes the deployment process a breeze and ensures consistency between development and production environments.

Kubernetes is a tool that helps manage a bunch of containers. These containers are like individual performers, each doing their own thing. Kubernetes makes sure they're in the right place at the right time, scales them up if there's a big crowd, and even helps if one of them needs to take a break.

Docker

Think of Docker like a special box where you can put everything your application needs to work smoothly. This includes all the code, files, and settings. Once everything is neatly packed into this box, we call it a "container." In simple terms, Docker is a tool that helps developers wrap up their applications and all their dependencies into these lightweight containers. These containers work the same way no matter where they're run, making sure everything runs consistently.

Containers act like virtual environments that encapsulate all the necessary components of your application. They're self-contained packages that include your application's code, along with all the libraries, dependencies, and settings required for it to function properly. Imagine placing all these components into a special box—the container—ensuring your application remains isolated from its surroundings and operates consistently, regardless of the environment it's deployed in.

Docker simplifies this process by providing tools to create and manage these containers effortlessly. Developers can package their applications into these lightweight containers, which can then be easily distributed and run on any system that supports Docker. This consistency ensures that your application behaves the same way across different environments, eliminating compatibility issues and saving time during deployment and testing.

Docker is useful because it makes things a lot easier. For example, you can quickly set up the containers for testing, knowing they behave the same way everywhere. This saves time and headaches because you do not have to worry about differences between your computer and where your app is actually being used.

Kubernetes

Imagine Kubernetes like having a helpful assistant that takes care of all the behind-the-scenes things, so you can focus on making sure your application works the way it should. At its core, Kubernetes is a powerful tool that automates the deployment, scaling, and management of containerized applications. It is not just about managing individual containers; it is about orchestrating an entire ecosystem of interconnected components. Kubernetes plays a crucial role in making things easier. It helps manage all the different parts of an application, like web pages and databases, so they work well together.

Here is how it works: You tell Kubernetes what you want your application to look like using simple instructions. For example, you might say, "I want three copies of my web page running at all times." Kubernetes then takes care of setting up and managing these copies for you.

It also helps handle things like making sure your application is always available, even if one part of it stops working. It does this by keeping an eye on everything and fixing any problems automatically, so your users never notice a glitch.

And when your application needs to handle more traffic, Kubernetes can automatically add more copies to keep up with the demand.

Conclusion

In essence, Docker helps you create portable, self-sufficient containers for your applications, while Kubernetes helps you manage and scale those containers effectively in a production environment. They are often used together with Docker for containerization and Kubernetes for orchestration.