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Common library

Most of our application Helm charts consume our Common library Helm chart.


The Common library chart is not meant to be installed directly, application charts use the Common library as a dependency.


In Helm 3, their team introduced the concept of a Library chart.

A library chart is a type of Helm chart that defines chart primitives or definitions which can be shared by Helm templates in other charts. This allows users to share snippets of code that can be re-used across charts, avoiding repetition and keeping charts DRY.

The common library was created because we saw many charts requiring only a few select configuration options in their Helm charts.


Take one of the many charts like sonarr or nzbget. Each of these charts only require setting service, port, persistence, ingress and image since state and app configuration is handled by the application itself.

In order to stay somewhat DRY (Don't Repeat Yourself) and keeping with Helm 3 usage for a Library chart, we saw this pattern and decided it was worth it for us to create a library. This means each one of these app charts has a dependency on what we call the common library.


To view the changelog for the common library see here.

Source code

The source code for our library chart can be found here.