Learning Helm

Chapter 6. Advanced Chart Features

There is more to charts than metadata about the chart and a collection of templates. Charts can have dependencies, values can have schemas, Helm has life cycle hooks, you can sign charts, and more. In this chapter you will learn about other elements of charts, moving beyond templates.

These features provide powerful solutions to common problems that arise when building packages. The chapter starts by covering dependencies. Dependencies are a critical part of virtually every package management solution because they let you leverage existing packages in your solution and build on the work of others. It then goes on to cover schemas and validation, which are useful when you want to help chart users avoid issues before covering ways you can hook into processes Helm performs to execute custom actions. This chapter covers tests and testing as well—tests are vital in development because they ensure your software is running as expected. Helm provides security features that aid in mitigating some common threat paths, which are covered next. The chapter concludes by looking at how charts can be used to extend the Kubernetes API.

Throughout this chapter, you will see charts as examples you can reference at https://github.com/masterminds/learning-helm/blob/main/chapter6. They showcase different features covered in the chapter along with a Helm repository.

Chart Dependencies

Dependencies are a common element of package managers and their packages. Charts ...