Labeling all the things

Labels are key-value pairs that are attached to resources, such as pods. They are intended to contain information that helps you to identify a particular resource.

You might add labels to your pods to identify the application that is being run, as well as other metadata, such as a version number, an environment name, or other labels that pertain to your application.

Labels are very flexible, as Kubernetes leaves it up to you to label your own resources as you see fit.

Once you begin working with Kubernetes, you will discover that you are able to add labels to almost every resource that you create.

The power of being able to add labels that reflect the architecture of your own application is that you are able to use selectors to query the resources using any combination of the labels that you have given your resources. This setup is shown in the following diagram:

You can add labels to many of the resources that you will create in Kubernetes and then query them with selectors.