(PDB-5559) Grant read user to write user

To ensure old report partitions are removed promptly without blocking
commands and queries the write user needs the ability to cancel running
puppetdb queries. To do that the write user needs to be granted the read
user role.

Author: austb

manifests/database/postgresql.pp

@@ -99,5 +99,12 @@
       password_hash          => postgresql::postgresql_password($read_database_username, $read_database_password),
       database_owner         => $database_username
     }
+
+    -> postgresql_psql { "grant ${read_database_username} role to ${database_username}":
+      db      => $database_name,
+      command => "GRANT \"${read_database_username}\" TO \"${database_username}\"",
+      unless  => "SELECT oid, rolname FROM pg_roles WHERE
+                   pg_has_role( '${database_username}', oid, 'member') and rolname = '${read_database_username}'";
+    }
   }
 }