fix(consul-notify): normalize requirer socket path to basename

[hemanthnakkina]

The TCP health-check --socket-path is built from the unix_socket_filepath published by the requirer over the consul-notify relation, with the hypervisor/ content-interface directory prepended by the consul-client charm.

Older requirers (e.g. an openstack-hypervisor charm predating the content-interface socket-path fix) publish a value that contains a directory component such as data/shutdown.sock. When only the consul-client charm is refreshed, the relation databag still holds this stale value, so the rendered path becomes hypervisor/data/shutdown.sock, which does not exist in the snap namespace and makes every nic-down alert fail with ENOENT.

Normalize the requirer-provided value to its basename in the ConsulNotifyProvider, so consumers always receive just the socket file name regardless of the format published by the requirer. The rendered path is then always hypervisor/<filename>, decoupling consul-client from requirer upgrade ordering and stale relation data.

Default unit tests now feed a bare filename (the current contract); a dedicated test covers the old data/shutdown.sock format for backward compatibility.

Assisted-By: claude-opus-4.8

[Copilot]

Pull request overview

This PR updates the consul-notify provider to normalize the requirer-published UNIX socket path to a basename, ensuring the TCP health check always targets hypervisor/<filename> even when stale relation data contains an older data/<filename> format.

Changes:

• Normalize unix_socket_filepath to a basename in ConsulNotifyProvider for backward compatibility with older requirers.
• Update existing unit tests to use the “bare filename” contract.
• Add a dedicated unit test covering the legacy data/shutdown.sock relation value.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
lib/charms/consul_client/v0/consul_notify.py	Normalizes requirer-provided socket path to basename and bumps lib patch version.
tests/unit/test_charm.py	Updates socket-path test inputs to bare filenames and adds a backward-compatibility regression test.

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