getDomainPostgresqlServer should take a domain

lib.nix

@@ -28,9 +28,8 @@ let
   getHostIps = hostname:
     filter (o: o != null) [ (getHostIpv4 hostname) (getHostIpv6 hostname) ];
 
-  getDomainPostgresqlServer = hostname:
-    let domain-name = entities.hosts."${hostname}".domain;
-    in getHostFqdn entities.domains."${domain-name}".postgresql-server;
+  getDomainPostgresqlServer = domain:
+    getHostFqdn entities.domains."${domain}".postgresql-server;
 
 in {
   inherit getHostSite getHostDomain getHostRealm getHostFqdn getHostIpv4