Feature request: Zarf dev package templating

[zack-is-cool]

Is your feature request related to a problem? Please describe.

It would be beneficial if zarf had the ability to template out what would be in a package at create time and also at deploy time with input variables. It is sometimes difficult to determine what will happen with a complex zarf package with component imports, overrides etc.

Describe the solution you'd like

• Given I'm creating a zarf package
• When I type zarf dev package template create (or something like this) with --set variables or referencing a zarf.config
• Then Zarf will
  • template and print the Zarf package with templated ###ZARF_PKG_TMPLs rendered
  • template and print the values.yaml files with ###ZARF_VARs- defaults used if none provided by the user at create time
  • template and print all manifests that the helm charts would create with ###ZARF_VARs - defaults used if none provided by the user at create time
• When I type zarf dev package template deploy (or something like this) with --set variables or referencing a zarf.config
• Then Zarf will
  • template and print the Zarf package with templated ###ZARF_PKG_TMPLs rendered
  • template and print the values.yaml files with ###ZARF_VARs- possibly defaults used
  • template and print all manifests that the helm charts would create with ###ZARF_VARs - possibly defaults used if none provided by the user at deploy time

Additional context

I feel like this workflow eases the friction of needing to actually have a kubernetes cluster up and running and allows you to debug zarf package templating logic before applying anything to a cluster - similar to the way helm template works, but with the additional zarf templating on top of it.. This makes the feedback loop smaller when debugging a zarf package that is failing to deploy.

[JoeHCQ1]

I'll second this feature request. Not having an easy way to see the rendered yaml also made diagnosing this bug a bit tricky: #2692

Note that if the problem is in the values.yaml and it makes the yaml invalid, then a ctrl-c mid attempt to make it work will preserve the rendered yaml in your /tmp directory and you can view it there.

This command is also said to result in the full manifests because 'kind' is in all manifests:

zarf dev find-images . --flavor upstream --why "kind" > templated.txt

Final note: this zarf functionality should also be expanded into UDS since UDS is frequently the entrypoint to the package creation and deployment commands.