Pushing and testing changes
During the course of development (for any project, not just Kubernetes Operators) it will likely become necessary to make changes to the code or other project files (such as resource manifests) and test those changes. In the case of this example, we will not be changing any code. Instead, we will redeploy the Operator with the proper metrics resources created to make the metrics visible, which we implemented in Chapter 5, Developing an Operator – Advanced Functionality.
Installing and configuring kube-prometheus
Metrics are not very useful without a tool to scrape and present them. This is what Prometheus is for, and it understands the metrics language in which we have implemented our own metrics. There are a number of other tools that can parse Prometheus metrics. In this tutorial, we will use kube-prometheus (https://github.com/prometheus-operator/kube-prometheus) to install a full end-to-end monitoring stack in our cluster. kube-prometheus...
