Summary

This chapter highlighted some additional options for functionality beyond the bare minimum that was established in Chapter 4, Developing an Operator with the Operator SDK. This list is obviously not exhaustive of every possibility for advanced features, but it is intended to showcase some of the most common additional features added to Operators. At this point, some of the patterns for feature development should start to become clear (for example, startup and initialization code usually goes in main.go, while features related to core logic can fit nicely with the controller code in nginxoperator_controller.go, or its own package).

The work done in this chapter shows some of the steps necessary in order to graduate an Operator from lower-level functionality to higher levels in the Capability Model. For example, metrics are a key aspect of a Level IV (Deep Insights) Operator and, therefore, something that is expected of the highest-function Operators available to users. In...