Appendix A. Chart API Versions

This appendix covers the differences between chart API versions 2 and 1 (legacy).

The chart API version is specified in each chart’s Chart.yaml file and is used by Helm to determine how to parse the chart and which feature sets are made available.

For new charts, API version 2 should generally be used. However, many publicly available charts were created prior to the genesis of API version 2, and use 1, the legacy API version. Here we will go into detail on each of these API versions and the ways in which they are different.

API Version 2

Chart API version 2 is the current API version that was introduced in Helm 3. This is the default API version used when new charts are created using helm create.

Charts using API version 2 are guaranteed to be supported by Helm 3, but not necessarily by Helm 2. If you are only planning to support Helm 3 and above, it is recommended to just use this API version.

The Chart.yaml File

The following is an example of a Chart.yaml file for a chart using API version 2:

apiVersion: v2 1
name: lemon
version: 1.2.3
type: application
description: When life gives you lemons, do the DevOps
appVersion: 2.0.0
home: https://example.com
icon: https://example.com/img/lemon.png
sources:
  - https://github.com/myorg/mychart
keywords:
  - fruit
  - citrus
maintainers:
  - name: Carly Jenkins
    email: carly@mail.cj.example.com
    url: https://cj.example.com ...

Get Learning Helm now with O’Reilly online learning.

O’Reilly members experience live online training, plus books, videos, and digital content from 200+ publishers.