Designing Your First Application in Kubernetes, Part 4: Configuration
I reviewed the basic setup for building applications in Kubernetes in part 1 of this blog series, and discussed processes as pods and controllers in part 2. In part 3, I explained how to configure networking services in Kubernetes to allow pods to communicate reliably with each other. In this installment, I’ll explain how to identify and manage the environment-specific configurations expected by your application to ensure its portability between environments.
Factoring out Configuration
One of the core design principles of any containerized app must be portability. We absolutely do not want to reengineer our containers or even the controllers that manage them for every environment. One very common reason why an application may work in one place but not another is problems with the environment-specific configuration expected by that app.
A well-designed application should treat configuration like an independent object, separate from the containers themselves, that’s provisioned to them at runtime. That way, when you move your app from one environment to another, you don’t need to rewrite any of your containers or controllers; you simply provide a configuration object appropriate to this new environment, leaving everything else untouched.
When we design applications, we need to identify what Continue reading
