Application containerization has become the norm in the IT industry. It allows organizations or developers to encapsulate the application code and all its dependencies in a portable environment so that the app can be deployed virtually anywhere.

Kubernetes is a powerful, open-source orchestration service that can be used to manage containers in a containerized application.

In this article, we will dig deeper into both technologies and see how they complement each other.

How containers work

Before learning about containers, we first need to know why containers were designed.

In traditional app development, once an application or a service is developed, the next step is to deploy it, which can be a complex and time-consuming process. That’s because a successful app deployment requires a myriad of careful configurations, from resource allocation and dependency management to setting up environmental variables.

Another consideration is the portability of the application. If the developer needs to change the deployment environment or move to a new cloud provider, they need to go through the whole deployment process again from the ground up. Again, this is a tedious and time-consuming process that may lead to:

• Config drifts
• Production bugs

Containers successfully address this issue by bundling the application code base with all the dependencies—such as runtime, system tools, configuration files, and libraries—into a package called the container. This containerization creates a lightweight, secure, and immutable package known as the container image.

This image can then be used to deploy a containerized application in any environment, offering developers the freedom to develop an application without worrying about environmental constraints.

Advantages of containers

Developers like containers for a variety of reasons:

• Consistent environment. Containerization provides a consistent environment by bundling the application code and dependencies into a single package. This ensures consistency across the development, test, and production environments.
• Universal compatibility. Containers can be deployed virtually anywhere from Windows, Linux, and macOS to cloud providers and data centers. Even serverless deployments support containers.
• Portability. The container can be easily moved to a new environment with little to no modifications as all the required software and dependencies are packaged in a standardized container format. (Easily facilitate lift and shift scenarios.)
• Isolation. Containers feature strong isolation from external factors due to their containerized nature and sandboxed view of the underlying operating system resources (OS-level virtualization) such as CPU, memory, storage, and network resources.
• Scaling. The lightweight nature of containers contributes to rapid scaling capabilities: containers can be easily created and destroyed with limited resources to meet user demand.