fix(ApplicationSet): Check strategy type to verify it's a progressive sync

[fcrespofastly]

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Description

From ArgoCD Progressive-Syncs manual argocd supports two strategies for applicationSets, AllAtOnce or RollingSync. Being AllAtOnce the default when no strategy is selected.

On the other hand, it seems that within the appset controller logic, there's a path in the code: https://github.com/argoproj/argo-cd/blob/master/applicationset/controllers/applicationset_controller.go#L213-L225

Where we do not check exhaustively the strategy type and thus:

strategy:
  type: AllAtOnce

Can cause an infinite reconciliation loop. See:

#14712
#22558

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[rumstead]

@fcrespofastly thanks for the PR! some build and linting errors need to be addressed. Additionally, please add some tests, especially one that reproduces the bug.

[jbmothiki]

Yola

[fcrespofastly]

Hey folks! Just a quick not to let you know that I'm still working on it last week with ArgoCon and KubeCon was a bit busy, so didn't have much time to work on this.

[codecov]

Codecov Report

Attention: Patch coverage is 55.55556% with 4 lines in your changes missing coverage. Please review.

Project coverage is 56.10%. Comparing base (c8c74b5) to head (a4e4b87).
Report is 6 commits behind head on master.

Files with missing lines	Patch %	Lines
...cationset/controllers/applicationset_controller.go	55.55%	4 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master   #22563      +/-   ##
==========================================
+ Coverage   56.05%   56.10%   +0.04%     
==========================================
  Files         343      343              
  Lines       57547    57551       +4     
==========================================
+ Hits        32259    32288      +29     
+ Misses      22643    22624      -19     
+ Partials     2645     2639       -6     

☔ View full report in Codecov by Sentry.
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[fcrespofastly]

Hey @rumstead 👋🏻

Updated the PR and added some tests. Let me know what you think. Does all of this make sense to you?

[rumstead]

Hey @rumstead 👋🏻

Updated the PR and added some tests. Let me know what you think. Does all of this make sense to you?

The code and tests make sense, I think it would be great if we can reproduce the bug via the reconcile loop and have a test that fails before your change and passes after. the current tests pass before and after your change.

[fcrespofastly]

Hey @rumstead 👋🏻
Updated the PR and added some tests. Let me know what you think. Does all of this make sense to you?

The code and tests make sense, I think it would be great if we can reproduce the bug via the reconcile loop and have a test that fails before your change and passes after. the current tests pass before and after your change.

Yeah I've been looking into it as well, it's just going to be tricky. To be clear with my change nothing should fail, it should still reconcile but not in a progressive sync fashion if not explicitly set.

[fcrespofastly]

Hey @rumstead !

Sorry for getting back to this late, being a few (good) days off !

Back to you comment I'm not sure how can I provide the tests you're asking. So I do appreciate if you can shed some light 💡

The bug this solves is an infinite reconciliation loop when the strategy type is set to AllAtOnce and no steps, but it does reconcile (nothing really fails, it's just someone could set strategy.type to AllAtOnce. This PR, effectively adds a more strict check, so to skip the progressive sync logic if the strategy type is not set to RollingSync.

Happy to discuss this further.

[rumstead]

Hey @rumstead !

Sorry for getting back to this late, being a few (good) days off !

Back to you comment I'm not sure how can I provide the tests you're asking. So I do appreciate if you can shed some light 💡

The bug this solves is an infinite reconciliation loop when the strategy type is set to AllAtOnce and no steps, but it does reconcile (nothing really fails, it's just someone could set strategy.type to AllAtOnce. This PR, effectively adds a more strict check, so to skip the progressive sync logic if the strategy type is not set to RollingSync.

Happy to discuss this further.

You can validate that progressive syncs doesn't happen when the AllAtOnce strategy is explicitly set on an applicationset by creating a test using the Reconcile function. You can assert on the values of the ApplicationStatus or even if the performProgressiveSyncs method was called.

[rumstead]

Hey @rumstead !
Sorry for getting back to this late, being a few (good) days off !
Back to you comment I'm not sure how can I provide the tests you're asking. So I do appreciate if you can shed some light 💡
The bug this solves is an infinite reconciliation loop when the strategy type is set to AllAtOnce and no steps, but it does reconcile (nothing really fails, it's just someone could set strategy.type to AllAtOnce. This PR, effectively adds a more strict check, so to skip the progressive sync logic if the strategy type is not set to RollingSync.
Happy to discuss this further.

You can validate that progressive syncs doesn't happen when the AllAtOnce strategy is explicitly set on an applicationset by creating a test using the Reconcile function. You can assert on the values of the ApplicationStatus or even if the performProgressiveSyncs method was called.

Ok, I was playing around with this today, and it seems too complicated to be worth it. I just have a few nits on comment verbiage, otherwise LGTM.

[fcrespofastly]

Hey @rumstead!

Thanks for the review! much appreciated!

Added your suggestion, not sure if there is anything else you wanted me to tackle/revisit?

[mubarak-j]

@rumstead is it possible to cherry pick this fix to the current version v2.14?

[rumstead]

/cherry-pick release-2.14