Revert "Remove superfluous hostName etc. options"

This reverts commit 553b552540.

modules/os.nix

@@ -11,6 +11,21 @@ in
       type = types.path;
     };
 
+    hostName = mkOption {
+      type = types.str;
+      default = null;
+    };
+
+    # domain = mkOption {
+    #   type = types.str;
+    #   default = "local";
+    # };
+
+    # searchDomains = mkOption {
+    #   type = types.listOf types.str;
+    #   default = [ cfg.domain ];
+    # };
+
     cert = mkOption {
       type = types.attrs;
       default = null;
@@ -38,6 +53,13 @@ in
     users.extraUsers.root.openssh.authorizedKeys.keys =
       cfg.adminAuthorizedKeys;
 
+    networking = {
+      hostName = cfg.hostName;
+      # domain = cfg.domain;
+      # search = cfg.searchDomains;
+      extraHosts = cfg.extraHosts;
+    };
+
    security.pki.certificateFiles = [ pki.ca.cert ];
     boot.kernel.sysctl = {
       "kernel.mm.transparent_hugepage.enabled" = "never";