feat(appset): add support for missingkey=error in ApplicationSets (#13731)

[raxod502-plaid]

Closes #13731.

The implementation is pretty straightforward. I just introduce a new optional parameter goTemplateOptions which is a list of options for the template engine. They are passed as is. The new parameter is threaded through most places that goTemplate is.

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[codecov]

Codecov Report

Patch coverage: 84.61% and no project coverage change.

Comparison is base (d685f15) 49.25% compared to head (9d97eec) 49.25%.

Additional details and impacted files

@@           Coverage Diff           @@
##           master   #13733   +/-   ##
=======================================
  Coverage   49.25%   49.25%           
=======================================
  Files         251      251           
  Lines       43518    43521    +3     
=======================================
+ Hits        21435    21438    +3     
  Misses      19949    19949           
  Partials     2134     2134           

Impacted Files	Coverage Δ
.../apis/application/v1alpha1/applicationset_types.go	28.57% <ø> (ø)
applicationset/utils/utils.go	71.01% <64.70%> (+0.31%)	⬆️
...cationset/controllers/applicationset_controller.go	62.72% <100.00%> (ø)
applicationset/generators/cluster.go	80.34% <100.00%> (ø)
...licationset/generators/generator_spec_processor.go	60.39% <100.00%> (ø)
applicationset/generators/git.go	84.05% <100.00%> (ø)
applicationset/generators/scm_provider.go	33.53% <100.00%> (ø)
applicationset/generators/value_interpolation.go	80.00% <100.00%> (ø)
applicationset/webhook/webhook.go	65.71% <100.00%> (ø)

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[crenshaw-dev]

Could you update the git files generators docs to specifically call out this feature? To me, it has the most intuitive use case: I want to make sure my devs are fully populating their app.yaml file, and I want the AppSet to fail if they forget to set a field.

[crenshaw-dev]

Could you update the git files generators docs to specifically call out this feature? To me, it has the most intuitive use case: I want to make sure my devs are fully populating their app.yaml file, and I want the AppSet to fail if they forget to set a field.

[raxod502-plaid]

Sure thing - that would be this file, right? And specifically the Git Generator: Files subsection?

This feature will only work when using go templates, so do you think it is better to update all the examples to use go templates instead, or just to add an explanation of how to add the extra validation by migrating if you prefer?

[crenshaw-dev]

Yep, that's the file!

do you think it is better to update all the examples to use go templates instead

I do. We'll eventually want to deprecate and then remove fasttemplate support, since that library is no longer maintained.

[raxod502-plaid]

Updated! I think I translated all the syntax correctly but let me know if I made any mistakes.

[crenshaw-dev]

I tried to rebase, fingers crossed that I didn't break anything. 😬

[raxod502-plaid]

Thank you!