When you create containers as read-only instances of your code, you quickly want a means to provide small changes in the form of flags or configuration. Perhaps, more importantly, you do not want to include private details such as API keys, passwords, or authentication tokens in your container images.
Kubernetes supports two resources to help and link in exactly this kind of information. The first is a ConfigMap, which can be used individually or across Pods for your application deployment, providing a single place to update and propagate configuration for your application. Kubernetes also supports the concept of a Secret, a far more locked down type of configuration that is more tightly controlled and exposed only where you need it.
For example, one might use a ConfigMap to control basic configuration of the example Redis deployment, and...