PostgreSQL host. Ignored when <a href="/nixpkgs/option/services.romm.database.createLocally"><a href="/nixpkgs/option/services.romm.database.createLocally" rel="nofollow">services.romm.database.createLocally</a></a> is set; the password for a remote database is passed as <code>DB_PASSWD</code> via <a href="/nixpkgs/option/services.romm.environmentFile"><a href="/nixpkgs/option/services.romm.environmentFile" rel="nofollow">services.romm.environmentFile</a></a>.