Daemon: Remove redundant call to AddClusterMember

[roosterfish]

When joining a new node to the cluster this action is already performed as part of the joinWithToken function on the control endpoint: https://github.com/canonical/microcluster/blob/main/internal/rest/resources/control.go#L104.

If the first node gets bootstrapped, trust for itself is added as part of StartAPI here https://github.com/canonical/microcluster/blob/main/internal/daemon/daemon.go#L374.

[roosterfish]

@masnax opening this as a draft PR because I am not sure if I am missing something else here.

[masnax]

Ah yes, I was wondering when someone would raise an eyebrow at this :)

This is part of what's going to be addressed by #89

Before we had so many hooks PreJoin, PostJoin, OnNewMember, etc., the main pattern I had used to actually run the hooks was to set the cluster notification header and re-use the same endpoint, but handle it differently.

The cluster notification header is set with the final argument here which applies this function as the proxy function for the client. This is sort of hinted at with the comment here.

Then, when we call AddClusterMember, we forego the default actions and instead run this block which executes the OnNewMember hook.

[masnax]

The final solution in #89 isn't ideal either, and I've been debating redoing that PR and just moving all the hooks over to their own set of endpoints to make things clear and distinct.

[roosterfish]

Appreciate the detailed response, so with the change in this PR it doesn't anymore send around the notification so it won't run the OnNewMemberHook(s) on the other cluster members?

This explains why I could still form a functioning cluster, but this is breaking the hooks then, haven't tested this.

I'll close it and keep an eye on #89. Let me know when you need a review.

[roosterfish]

This is sort of hinted at with the comment here.

Yeah I saw this but got confused by the "upgrade" in there.