What are Kubernetes Containers

In this section, we are going to learn about what containers are. Before we dive into it, let's imagine that you want to transport all these goods that you see on the screen from one country to another. And you might be wondering, how do I transport a car, a few barrels, grains, a piano, and so many different items, from one country to another? They might require some different modes of transportation in all these things. This car might be transported in some other way, and the grains might be transported in some other way. But the thing is that we're transporting it from one place to another.

Understanding Containers

Imagine you need to transport various goods from one country to another. The challenge lies in the diverse nature of these items, each requiring a different mode of transportation. This is where a shipping container comes into play. You can pack all your goods into this standard container, which can then be transported efficiently over long distances, irrespective of the items inside.

Now, let's apply this concept to software applications. Suppose you've developed an application that works perfectly on your machine. However, when you share it with a friend, it fails to run on their machine. This is a common problem in software development, often leading to the infamous response, "But it works on my machine!"

Wouldn't it be great if you could package your application into a 'box' and share this box with your friend? This box would contain your application and all its dependencies, ensuring it runs flawlessly on any system. This is precisely what a container does.

Technological Definition of a Kubernetes Container

A container is a lightweight, portable, self-sufficient entity that encapsulates an application and its dependencies. It ensures the application runs constantly on virtually any hardware platform. Containers offer a streamlined approach to build, test, deploy, and redeploy applications across multiple environments, from a local laptop to an on-premise data center, and even to the cloud.

Benefits of Containers

Containers offer several advantages over traditional deployment methods:

1. Less Overhead: Containers require fewer system resources than traditional or virtual machine environments as they leverage the host operating system.
2. Increased Portability: Applications running in containers can be deployed quickly across multiple operating systems and hardware platforms.
3. Consistent Operations: Containers ensure applications run the same way, regardless of where they are deployed, solving the "It works on my machine" problem.
4. Efficiency: Containers enable rapid deployment, patching, or scaling of applications.
5. Support for Agile and DevOps: Containers accelerate development, testing, and production cycles, supporting agile methodologies and DevOps practices.

Scaling with Containers

Containers are not just about running applications; they also provide scalability. If you need to scale your application, you can create new containers. You can use a container orchestration engine like Kubernetes to manage multiple containers, which we'll explore in detail later in this course.

Conclusion

Containers offer a practical solution to many software development and deployment challenges. They provide an isolated environment for your application, ensuring it runs consistently across different systems. In the next section, we'll delve deeper into the infrastructure of containers and compare containers with virtual machines.