Add Prometheus auth to armada multinode deployment

This adds a dynamically generated password for Prometheus to
build on the inclusion of basic auth for Prometheus in osh-infra

Depends-On: https://review.openstack.org/543553
Change-Id: I344b8326829c7816a5ce79529aa1a0f74df52dbd

tools/deployment/armada/generate-passwords.sh

@@ -55,6 +55,7 @@ passwords="BARBICAN_DB_PASSWORD \
     NOVA_RABBITMQ_USER_PASSWORD \
     NOVA_USER_PASSWORD \
     OPENSTACK_EXPORTER_USER_PASSWORD \
+    PROMETHEUS_ADMIN_PASSWORD \
     SWIFT_USER_PASSWORD"
 
 for password in $passwords

tools/deployment/armada/multinode/armada-lma.yaml

@@ -393,6 +393,11 @@ data:
     pod:
       replicas:
         prometheus: 2
+    endpoints:
+      monitoring:
+        auth:
+          admin:
+            password: ${PROMETHEUS_ADMIN_PASSWORD}
   source:
     type: local
     location: ${OSH_INFRA_PATH}
@@ -596,6 +601,10 @@ data:
         auth:
           admin:
             password: ${GRAFANA_ADMIN_PASSWORD}
+      monitoring:
+        auth:
+          admin:
+            password: ${PROMETHEUS_ADMIN_PASSWORD}
     labels:
       grafana:
         node_selector_key: openstack-control-plane