fix: correct issues with current upgrade logic for artifactOverrides with helm imageStrategy

[aaron-prindle]

Initially artifactsOverrides and imageStrategy were removed in skaffold v2 as we now use skaffold as a helm --post-renderer. In our upgrade.go for v2beta29 we had some logic added that would migrate people that used those fields to setValues and setValueTemplates. The upgrade.go logic here though did not work properly for multi-config projects as setValueTemplates has unfriendly behaviour when used with multi-config images as noted in #5317. As such this new PR changes upgrade.go to use all setValueTemplates replacements and adds a helm multi-config example as an integration test. This docs PR below might help to explain this a bit as well:
#8093

[codecov]

Codecov Report

Merging #8066 (a1cf201) into main (290280e) will decrease coverage by 3.98%.
The diff coverage is 53.28%.

❗ Current head a1cf201 differs from pull request most recent head cbf2e74. Consider uploading reports for the commit cbf2e74 to get more accurate results

@@            Coverage Diff             @@
##             main    #8066      +/-   ##
==========================================
- Coverage   70.48%   66.50%   -3.99%     
==========================================
  Files         515      597      +82     
  Lines       23150    29171    +6021     
==========================================
+ Hits        16317    19399    +3082     
- Misses       5776     8332    +2556     
- Partials     1057     1440     +383     

Impacted Files	Coverage Δ
cmd/skaffold/app/cmd/credits/export.go	0.00% <0.00%> (ø)
cmd/skaffold/app/cmd/deploy.go	40.90% <0.00%> (-12.94%)	⬇️
cmd/skaffold/app/cmd/test.go	44.44% <0.00%> (ø)
cmd/skaffold/app/exitcode.go	100.00% <ø> (+6.66%)	⬆️
cmd/skaffold/skaffold.go	0.00% <0.00%> (ø)
cmd/skaffold/app/cmd/inspect_tests.go	62.50% <14.28%> (-1.14%)	⬇️
cmd/skaffold/app/cmd/render.go	35.48% <18.18%> (-5.90%)	⬇️
cmd/skaffold/app/cmd/lsp.go	28.12% <28.12%> (ø)
cmd/skaffold/app/cmd/run.go	64.28% <33.33%> (-9.63%)	⬇️
cmd/skaffold/app/cmd/fix.go	56.41% <37.50%> (-20.07%)	⬇️
... and 394 more

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[gsquared94]

can you add a bit more detail about this hack? Like with an example of image value, and why we're setting BaseName to Repo.

[gsquared94]

is it possible that any other regular scenario will conflict with this conditional?

[aaron-prindle]

I don't believe there is realistically any regular scenario where this will conflict. I have tried with both artifact/artifactOverrides names of the format:

  artifacts:
  - image: gcr.io/aprindle-test-cluster/skaffold-helm

  artifacts:
  - image: skaffold-helm

and this works for both cases

[aaron-prindle]

Updated the comment to have more explanation:

	// this is a hack to properly support `imageStrategy=helm+explicitRegistry` from Skaffold v1.X.X which has the form:
	// image: "{{.Values.image.registry}}/{{.Values.image.repository}}:{{.Values.image.tag}}"
	// works by looking for intermediate helm replacement of the form image: <artifactName>/<artifactName>:<artifactName>
	// and treating that as just <artifact> by modifying the parsed representation.

[gsquared94]

lgtm, but please add some more text about the hack logic.