Diagnosing problems with listener channel notifications not being handled properly by PostgREST connected to read replicas is difficult. Issues might be related to lost connections and listener not being connected to the right host after failover or database server restarts.
This patch adds logging of actual host:port used by libpq connection opened by the listener. It should make it easier to find out if PostgREST is connected to the right host.
Some helpers are provided for introspecting metrics already (used in JWT cache tests). This change provides facilities to additionally validate emited Observation events.
A new Spec module is also implemented, adding basic tests of schema cache reloading - their main goal is to excercise the new infrastructure.
- Create separate test suite for observability tests
- Create wrapper script `postgrest-test-observability`
- Add to CI and `postgrest-check`
- Move JWT cache tests under observability tests
Signed-off-by: Taimoor Zaeem <taimoorzaeem@gmail.com>