presync hook not running with apply

[Sajfer]

Hi.
I am trying to use the presync hook, but it does not seem to run when using helmfile apply, and only with helmfile sync.

In the documentation it seems like it should run on both apply and sync.
"Hooks associated to presync events are triggered before each release is applied to the remote cluster. This is the ideal event to execute any commands that may mutate the cluster state as it will not be run for read-only operations like lint, diff or template."

Is this the expected behavior?

[Sajfer]

@mumoshu is this a bug or the expected behaviour?

[mumoshu]

@Sajfer It should work for apply as well. We do call presync hooks from within the apply code path which invokes the some logic that backs helmfile sync

helmfile/pkg/app/app.go

Line 1376 in b1928e5

return subst.SyncReleases(&affectedReleases, helm, c.Values(), c.Concurrency(), &syncOpts)

which explicitly calls presync hooks

helmfile/pkg/state/state.go

Line 812 in d4a7b3b

if _, err := st.triggerPresyncEvent(release, "sync"); err != nil {

[gakesson]

@mumoshu I'm not sure @Sajfer has the same issue as I'm facing but I'm currently not able to use apply (even though I really would like to!) as the recommended operation because in case there is no diff to the release then the hook will not execute. I.e. any potential behavior changes induced by the hook may go missing during an upgrade.
So maybe what I'm after is a pre/post apply hook which will execute irrespective of sync being triggered on the release

[mumoshu]

@gakesson In terms of Helmfile, sync means it runs helm upgrade --install on the release. That said, the presync hook not being run on releases with no changes seems a correct behavior. If you need something that works for every release regardless of it has any changes or not, how about prepare?

[gakesson]

@mumoshu I don't object to the current behavior of presync hook only running when sync is in fact triggered on the release. It seems like a well-defined behavior, but it also means hooks become somewhat non-deterministic when using apply because the hook is entirely dependent on diffs in the release.
prepare could work but then we would need to have every hook script ignore further executions for non-mutating events/operations (repo, list, template etc.). In an ideal world I would like to have a preapply / postapply events so that specifying e.g. ["presync", "preapply"] would unconditionally run the hook once for the release before it being applied on the cluster.

[mumoshu]

@gakesson Thanks for the feedback. preapply that runs unconditionally sounds legit!

[mumoshu]

@Sajfer @gakesson Should we reuse this issue as a feature request for preapply?
Also, any of you willing to contribute a pull request to add that? Thanks!

[Sajfer]

That is fine for me.
I can see if I can figure out how to add that.

[Sajfer]

Just to clarify, what we want is a preapply command that runs everytime we apply, not just when there is changes?

[mumoshu]

@Sajfer Exactly!

[Sajfer]

I created a pullrequest against helmfile/helmfile, helmfile/helmfile#79