nixos/dbus: always use socket activates user session

This removes the `services.dbus.socketActivated` and
`services.xserver.startDbusSession` options. Instead the user D-Bus
session is always socket activated.

nixos/doc/manual/release-notes/rl-2103.xml

@@ -59,7 +59,15 @@
 
   <itemizedlist>
    <listitem>
-    <para />
+    <para>
+     If the <varname>services.dbus</varname> module is enabled, then
+     the user D-Bus session is now always socket activated. The
+     associated options <varname>services.dbus.socketActivated</varname>
+     and <varname>services.xserver.startDbusSession</varname> have
+     therefore been removed and you will receive a warning if
+     they are present in your configuration. This change makes the
+     user D-Bus session available also for non-graphical logins.
+    </para>
    </listitem>
   </itemizedlist>
  </section>

nixos/modules/services/system/dbus.nix

@@ -19,6 +19,12 @@ in
 
 {
 
+  imports = [
+    (mkRemovedOptionModule
+      [ "services" "dbus" "socketActivated" ]
+      "The user D-Bus session is now always socket activated and this option can safely be removed.")
+  ];
+
   ###### interface
 
   options = {
@@ -51,14 +57,6 @@ in
           <filename><replaceable>pkg</replaceable>/share/dbus-1/services</filename>
         '';
       };
-
-      socketActivated = mkOption {
-        type = types.bool;
-        default = false;
-        description = ''
-          Make the user instance socket activated.
-        '';
-      };
     };
   };
 
@@ -108,7 +106,7 @@ in
         reloadIfChanged = true;
         restartTriggers = [ configDir ];
       };
-      sockets.dbus.wantedBy = mkIf cfg.socketActivated [ "sockets.target" ];
+      sockets.dbus.wantedBy = [ "sockets.target" ];
     };
 
     environment.pathsToLink = [ "/etc/dbus-1" "/share/dbus-1" ];

nixos/modules/services/x11/display-managers/default.nix

@@ -37,13 +37,6 @@ let
       . /etc/profile
       cd "$HOME"
 
-      ${optionalString cfg.startDbusSession ''
-        if test -z "$DBUS_SESSION_BUS_ADDRESS"; then
-          /run/current-system/systemd/bin/systemctl --user start dbus.socket
-          export `/run/current-system/systemd/bin/systemctl --user show-environment | grep '^DBUS_SESSION_BUS_ADDRESS'`
-        fi
-      ''}
-
       ${optionalString cfg.displayManager.job.logToJournal ''
         if [ -z "$_DID_SYSTEMD_CAT" ]; then
           export _DID_SYSTEMD_CAT=1

nixos/modules/services/x11/xserver.nix

@@ -151,6 +151,9 @@ in
       ./desktop-managers/default.nix
       (mkRemovedOptionModule [ "services" "xserver" "startGnuPGAgent" ]
         "See the 16.09 release notes for more information.")
+      (mkRemovedOptionModule
+        [ "services" "xserver" "startDbusSession" ]
+        "The user D-Bus session is now always socket activated and this option can safely be removed.")
     ];
 
 
@@ -296,14 +299,6 @@ in
         description = "DPI resolution to use for X server.";
       };
 
-      startDbusSession = mkOption {
-        type = types.bool;
-        default = true;
-        description = ''
-          Whether to start a new DBus session when you log in with dbus-launch.
-        '';
-      };
-
       updateDbusEnvironment = mkOption {
         type = types.bool;
         default = false;