Fix GossipMembersMismatch misfiring with remote ruler eval (#2159)

* Fix GossipMembersMismatch misfiring with remote ruler eval

The alert doesn't take into account the queries that now have ruler-
prepended to their name. This PR fixes it

Signed-off-by: Dimitar Dimitrov <dimitar.dimitrov@grafana.com>

* Simpler regexes

* Update computed mixin

operations/mimir-mixin-compiled/alerts.yaml

@@ -352,7 +352,7 @@ groups:
       message: Mimir instance {{ $labels.pod }} in {{ $labels.cluster }}/{{ $labels.namespace
         }} sees incorrect number of gossip members.
     expr: |
-      avg by (cluster, namespace) (memberlist_client_cluster_members_count) != sum by (cluster, namespace) (up{job=~".+/(alertmanager|compactor|distributor|ingester.*|querier.*|ruler|store-gateway.*|cortex|mimir)"})
+      avg by (cluster, namespace) (memberlist_client_cluster_members_count) != sum by (cluster, namespace) (up{job=~".+/(alertmanager|compactor|distributor|ingester.*|querier.*|ruler|ruler-querier.*|store-gateway.*|cortex|mimir)"})
     for: 15m
     labels:
       severity: warning

operations/mimir-mixin/config.libsonnet

@@ -30,7 +30,7 @@
       ruler_query_frontend: '(ruler-query-frontend.*)',  // Match also custom ruler-query-frontend deployments.
       query_scheduler: 'query-scheduler.*',  // Not part of single-binary. Match also custom query-scheduler deployments.
       ruler_query_scheduler: 'ruler-query-scheduler.*',  // Not part of single-binary. Match also custom query-scheduler deployments.
-      ring_members: ['alertmanager', 'compactor', 'distributor', 'ingester.*', 'querier.*', 'ruler', 'store-gateway.*', 'cortex', 'mimir'],
+      ring_members: ['alertmanager', 'compactor', 'distributor', 'ingester.*', 'querier.*', 'ruler', 'ruler-querier.*', 'store-gateway.*', 'cortex', 'mimir'],
       store_gateway: '(store-gateway.*|cortex|mimir)',  // Match also per-zone store-gateway deployments.
       gateway: '(gateway|cortex-gw|cortex-gw-internal)',
       compactor: 'compactor.*|cortex|mimir',  // Match also custom compactor deployments.