Description

User facing changes:

• Helm 4 brings Server Side Apply. If it is a first time chart install then server side apply will be used by default. Upgrades default to the apply method that was used in the latest release. To control the apply method for a specific packaged chart, a new field .Charts[x].ServerSideApply has been introduced with possible values true, false, auto . Auto will follow the default Helm behavior.
  • A good example of how this could effect some charts can be seen in the init package registry deployment. Server side apply caught that replicas were set even when they were controlled by the autoscaler, which led to a conflict error. To solve this we conditionally set replicas when the autoscaler is not enabled.
  • SSA enforces stricter field validation, if a field does not pass schema validation, you will receive an error instead of a warning.
• Helm now uses slog style logging.
• zarf tools helm is now a true copy of the Helm CLI. Previously, this command was a quasi fork of a subset of the Helm CLI and was not updated automatically. Zarf maintainer contributed to make this functionality possible #13617
• Helm's now uses kstatus as a backend for it's wait logic, since Zarf already used kstatus post Helm install the wait logic will be near identical to earlier Zarf versions. Zarf maintainers contributed this functionality to Helm in #13604

We will have to be very careful about merging this as there may be impacts to charts that we do not test for in the migration from Helm 3 to Helm 4. We want the experience to be seamless for users. I intend to make a R.C. release from this branch before merging into main.

Note that vendoring in the entirety of Helm instead of the current quasi fork bring binary size up about 5MB from 173M on main to 178M on this branch

Something interesting is that server side apply default to true during new installs, but "auto" during upgrades and rollbacks meaning that existing charts will use the existing strategy. I decided to add a new addition to the schema, serverSideApply, which accepts the field "true", "false", and "auto".

Related Issue

Fixes #2818
Fixes #2756
Fixes #4437

Checklist before merging

• Test, docs, adr added or updated as needed
• Contributor Guide Steps followed