[fix] Correctly setreplica_server_id on azurerm_postgresql_flexible_server_virtual_endpoint forazurerm_postgresql_flexible_servers that exist in separate resource groups

[bruceharrison1984]

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Description

This corrects a bug that occurs when the replica server doesn't exist in the same resource group as the source server. Previously, the endpoint would be flagged for changes on the second run. This corrects that issue.

Additionally, if the primary server was stopped it would also try to recreate the virtual endpoint. This also corrects that issue.

Anyone previously affected by this will see non-destructive changes on the first deploy, but the issue should correct it self there after.

This PR also removes the custom poller that was previously necessary. It appears Azure has changed the API so it is no longer necessary.

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Change Log

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• azurerm_postgresql_flexible_server_virtual_endpoint - fix bug that affected replicas deployed in different resource groups from the source server [postgresql_flexible_server_virtual_endpoint_resource incorrectly sets Replica Server ID #27453]

This is a (please select all that apply):

• Bug Fix
• New Feature (ie adding a service, resource, or data source)
• Enhancement
• Breaking Change

Related Issue(s)

Fixes #27453

Note

If this PR changes meaningfully during the course of review please update the title and description as required.

[jackofallops]

Hi @bruceharrison1984 - Thanks for this PR, it looks mostly good, but there are a few minor changes to take a look at below if you could?
Thanks

[jackofallops]

Are the server names we're looking for here guaranteed to be unique per subscription, or could we have a condition where there are multiple servers of the same name in different resource groups that could lead to an unexpected outcome here?

[bruceharrison1984]

The names may not be unique per subscription, however they must be unique per source server. Since we check that the replica name matches, as well as filter those results based on the source server ID we should be protected from selecting an incorrect replica. Even if the names matched, replicas must have unique names per source servers.

TLDR; For a given source server, all replicas associated with the source server must have unique names. By filtering on both conditions, we can confidently pick the correct one even if duplicate named replicas exist within the subscription.

https://github.com/hashicorp/terraform-provider-azurerm/pull/27509/files/94e28c5de14955a188f90192c06828946f9a6fcc#diff-6fceca959b7c5669ebd391456b3a69c7ff858802d5dc5e70a91c6237cd173ff0R258

I was worried about this as well, but I believe it is setup in a safe manner.

[jackofallops]

Since this is direct from the lookup API, we can't be sure it will be correctly cased for the expected state (since we validate the input), can we normalise it using servers.ParseFlexibleServerID() before setting the value into state.ReplicaServerId?

[bruceharrison1984]

I've updated the code to reflect your suggestion

[leonrob]

From a hashi customer... THANK YOU FOR THIS @bruceharrison1984