···

       
36
       
 
       
{ config, pkgs, ... }:

     

       
37
       
 
       


     

       
38
       
 
       
{ services.xserver.enable = true;

     

       
39
       
-
       
  services.xserver.displayManager.kdm.enable = true;

     

       
40
       
-
       
  services.xserver.desktopManager.kde4.enable = true;

     

       
41
       
-
       
  environment.systemPackages = [ pkgs.kde4.kscreensaver ];

     

       
42
       
 
       
}

     

       
43
       
 
       
</programlisting>

     

       
44
       
 
       


     

···

       
36
       
 
       
{ config, pkgs, ... }:

     

       
37
       
 
       


     

       
38
       
 
       
{ services.xserver.enable = true;

     

       
39
       
+
       
  services.xserver.displayManager.sddm.enable = true;

     

       
40
       
+
       
  services.xserver.desktopManager.kde5.enable = true;

     

       
0
       
 
       

     

       
41
       
 
       
}

     

       
42
       
 
       
</programlisting>

     

       
43
       
 
       


     

···

       
25
       
 
       
<command>xterm</command> window.  Thus you should pick one or more of

     

       
26
       
 
       
the following lines:

     

       
27
       
 
       
<programlisting>

     

       
28
       
-
       
services.xserver.desktopManager.kde4.enable = true;

     

       
29
       
 
       
services.xserver.desktopManager.xfce.enable = true;

     

       
30
       
 
       
services.xserver.windowManager.xmonad.enable = true;

     

       
31
       
 
       
services.xserver.windowManager.twm.enable = true;

     
···

       
35
       
 
       


     

       
36
       
 
       
<para>NixOS’s default <emphasis>display manager</emphasis> (the

     

       
37
       
 
       
program that provides a graphical login prompt and manages the X

     

       
38
       
-
       
server) is SLiM.  You can select KDE’s <command>kdm</command> instead:

     

       
39
       
 
       
<programlisting>

     

       
40
       
-
       
services.xserver.displayManager.kdm.enable = true;

     

       
41
       
 
       
</programlisting>

     

       
42
       
 
       
</para>

     

       
43
       
 
       


     

···

       
25
       
 
       
<command>xterm</command> window.  Thus you should pick one or more of

     

       
26
       
 
       
the following lines:

     

       
27
       
 
       
<programlisting>

     

       
28
       
+
       
services.xserver.desktopManager.kde5.enable = true;

     

       
29
       
 
       
services.xserver.desktopManager.xfce.enable = true;

     

       
30
       
 
       
services.xserver.windowManager.xmonad.enable = true;

     

       
31
       
 
       
services.xserver.windowManager.twm.enable = true;

     
···

       
35
       
 
       


     

       
36
       
 
       
<para>NixOS’s default <emphasis>display manager</emphasis> (the

     

       
37
       
 
       
program that provides a graphical login prompt and manages the X

     

       
38
       
+
       
server) is SLiM.  You can select KDE’s <command>sddm</command> instead:

     

       
39
       
 
       
<programlisting>

     

       
40
       
+
       
services.xserver.displayManager.sddm.enable = true;

     

       
41
       
 
       
</programlisting>

     

       
42
       
 
       
</para>

     

       
43
       
 
       


     

···

       
41
       
 
       
		(DM is the program that provides a graphical login prompt

     

       
42
       
 
       
		 and manages the X server.)

     

       
43
       
 
       
	   	You can, for example, select KDE’s

     

       
44
       
-
       
        <command>kdm</command> instead:

     

       
45
       
 
       
        <programlisting>

     

       
46
       
-
       
            services.xserver.displayManager.kdm.enable = true;

     

       
47
       
 
       
        </programlisting>

     

       
48
       
 
       
    </para>

     

       
49
       
 
       


     

···

       
41
       
 
       
		(DM is the program that provides a graphical login prompt

     

       
42
       
 
       
		 and manages the X server.)

     

       
43
       
 
       
	   	You can, for example, select KDE’s

     

       
44
       
+
       
        <command>sddm</command> instead:

     

       
45
       
 
       
        <programlisting>

     

       
46
       
+
       
            services.xserver.displayManager.sddm.enable = true;

     

       
47
       
 
       
        </programlisting>

     

       
48
       
 
       
    </para>

     

       
49
       
 
       


     

···

       
65
       
 
       


     

       
66
       
 
       
</para>

     

       
67
       
 
       


     

       
68
       
-
       
<section xml:id="sec-option-declarations-eot"><title>Extensible Option 

     

       
69
       
 
       
    Types</title>

     

       
70
       
 
       


     

       
71
       
-
       
  <para>Extensible option types is a feature that allow to extend certain types 

     

       
72
       
 
       
    declaration through multiple module files.

     

       
73
       
-
       
    This feature only work with a restricted set of types, namely 

     

       
74
       
 
       
    <literal>enum</literal> and <literal>submodules</literal> and any composed

     

       
75
       
 
       
    forms of them.</para>

     

       
76
       
 
       


     

       
77
       
-
       
  <para>Extensible option types can be used for <literal>enum</literal> options 

     

       
78
       
-
       
    that affects multiple modules, or as an alternative to related 

     

       
79
       
 
       
    <literal>enable</literal> options.</para>

     

       
80
       
 
       


     

       
81
       
 
       
  <para>As an example, we will take the case of display managers. There is a

     

       
82
       
 
       
    central display manager module for generic display manager options and a

     

       
83
       
-
       
    module file per display manager backend (slim, kdm, gdm ...).

     

       
84
       
 
       
  </para>

     

       
85
       
 
       


     

       
86
       
 
       
  <para>There are two approach to this module structure:

     
···

       
96
       
 
       
  </para>

     

       
97
       
 
       


     

       
98
       
 
       
  <para>Both approachs have problems.</para>

     

       
99
       
-
       
    

     

       
100
       
 
       
  <para>Making backends independent can quickly become hard to manage. For

     

       
101
       
 
       
    display managers, there can be only one enabled at a time, but the type

     

       
102
       
 
       
    system can not enforce this restriction as there is no relation between

     
···

       
108
       
 
       
    central module will require to change the central module option every time

     

       
109
       
 
       
    a new backend is added or removed.</para>

     

       
110
       
 
       


     

       
111
       
-
       
  <para>By using extensible option types, it is possible to create a placeholder 

     

       
112
       
-
       
    option in the central module (<xref linkend='ex-option-declaration-eot-service' 

     

       
113
       
-
       
      />), and to extend it in each backend module (<xref 

     

       
114
       
-
       
      linkend='ex-option-declaration-eot-backend-slim' />, <xref 

     

       
115
       
-
       
      linkend='ex-option-declaration-eot-backend-kdm' />).</para>

     

       
116
       
-
       
 

     

       
117
       
 
       
  <para>As a result, <literal>displayManager.enable</literal> option values can

     

       
118
       
 
       
  be added without changing the main service module file and the type system

     

       
119
       
 
       
  automatically enforce that there can only be a single display manager

     

       
120
       
 
       
  enabled.</para>

     

       
121
       
 
       


     

       
122
       
-
       
<example xml:id='ex-option-declaration-eot-service'><title>Extensible type 

     

       
123
       
 
       
    placeholder in the service module</title>

     

       
124
       
 
       
<screen>

     

       
125
       
 
       
services.xserver.displayManager.enable = mkOption {

     
···

       
127
       
 
       
  type = with types; nullOr (enum [ ]);

     

       
128
       
 
       
};</screen></example>

     

       
129
       
 
       


     

       
130
       
-
       
<example xml:id='ex-option-declaration-eot-backend-slim'><title>Extending 

     

       
131
       
-
       
    <literal>services.xserver.displayManager.enable</literal> in the 

     

       
132
       
 
       
    <literal>slim</literal> module</title>

     

       
133
       
 
       
<screen>

     

       
134
       
 
       
services.xserver.displayManager.enable = mkOption {

     

       
135
       
 
       
  type = with types; nullOr (enum [ "slim" ]);

     

       
136
       
 
       
};</screen></example>

     

       
137
       
 
       


     

       
138
       
-
       
<example xml:id='ex-option-declaration-eot-backend-kdm'><title>Extending 

     

       
139
       
-
       
    <literal>services.foo.backend</literal> in the <literal>kdm</literal> 

     

       
140
       
 
       
    module</title>

     

       
141
       
 
       
<screen>

     

       
142
       
 
       
services.xserver.displayManager.enable = mkOption {

     

       
143
       
-
       
  type = with types; nullOr (enum [ "kdm" ]);

     

       
144
       
 
       
};</screen></example>

     

       
145
       
 
       


     

       
146
       
-
       
<para>The placeholder declaration is a standard <literal>mkOption</literal> 

     

       
147
       
-
       
  declaration, but it is important that extensible option declarations only use 

     

       
148
       
 
       
  the <literal>type</literal> argument.</para>

     

       
149
       
 
       


     

       
150
       
-
       
<para>Extensible option types work with any of the composed variants of 

     

       
151
       
-
       
  <literal>enum</literal> such as 

     

       
152
       
-
       
  <literal>with types; nullOr (enum [ "foo" "bar" ])</literal> 

     

       
153
       
 
       
  or <literal>with types; listOf (enum [ "foo" "bar" ])</literal>.</para>

     

       
154
       
 
       


     

       
155
       
 
       
</section>

     

···

       
65
       
 
       


     

       
66
       
 
       
</para>

     

       
67
       
 
       


     

       
68
       
+
       
<section xml:id="sec-option-declarations-eot"><title>Extensible Option

     

       
69
       
 
       
    Types</title>

     

       
70
       
 
       


     

       
71
       
+
       
  <para>Extensible option types is a feature that allow to extend certain types

     

       
72
       
 
       
    declaration through multiple module files.

     

       
73
       
+
       
    This feature only work with a restricted set of types, namely

     

       
74
       
 
       
    <literal>enum</literal> and <literal>submodules</literal> and any composed

     

       
75
       
 
       
    forms of them.</para>

     

       
76
       
 
       


     

       
77
       
+
       
  <para>Extensible option types can be used for <literal>enum</literal> options

     

       
78
       
+
       
    that affects multiple modules, or as an alternative to related

     

       
79
       
 
       
    <literal>enable</literal> options.</para>

     

       
80
       
 
       


     

       
81
       
 
       
  <para>As an example, we will take the case of display managers. There is a

     

       
82
       
 
       
    central display manager module for generic display manager options and a

     

       
83
       
+
       
    module file per display manager backend (slim, sddm, gdm ...).

     

       
84
       
 
       
  </para>

     

       
85
       
 
       


     

       
86
       
 
       
  <para>There are two approach to this module structure:

     
···

       
96
       
 
       
  </para>

     

       
97
       
 
       


     

       
98
       
 
       
  <para>Both approachs have problems.</para>

     

       
99
       
+
       


     

       
100
       
 
       
  <para>Making backends independent can quickly become hard to manage. For

     

       
101
       
 
       
    display managers, there can be only one enabled at a time, but the type

     

       
102
       
 
       
    system can not enforce this restriction as there is no relation between

     
···

       
108
       
 
       
    central module will require to change the central module option every time

     

       
109
       
 
       
    a new backend is added or removed.</para>

     

       
110
       
 
       


     

       
111
       
+
       
  <para>By using extensible option types, it is possible to create a placeholder

     

       
112
       
+
       
    option in the central module (<xref linkend='ex-option-declaration-eot-service'

     

       
113
       
+
       
      />), and to extend it in each backend module (<xref

     

       
114
       
+
       
      linkend='ex-option-declaration-eot-backend-slim' />, <xref

     

       
115
       
+
       
      linkend='ex-option-declaration-eot-backend-sddm' />).</para>

     

       
116
       
+
       


     

       
117
       
 
       
  <para>As a result, <literal>displayManager.enable</literal> option values can

     

       
118
       
 
       
  be added without changing the main service module file and the type system

     

       
119
       
 
       
  automatically enforce that there can only be a single display manager

     

       
120
       
 
       
  enabled.</para>

     

       
121
       
 
       


     

       
122
       
+
       
<example xml:id='ex-option-declaration-eot-service'><title>Extensible type

     

       
123
       
 
       
    placeholder in the service module</title>

     

       
124
       
 
       
<screen>

     

       
125
       
 
       
services.xserver.displayManager.enable = mkOption {

     
···

       
127
       
 
       
  type = with types; nullOr (enum [ ]);

     

       
128
       
 
       
};</screen></example>

     

       
129
       
 
       


     

       
130
       
+
       
<example xml:id='ex-option-declaration-eot-backend-slim'><title>Extending

     

       
131
       
+
       
    <literal>services.xserver.displayManager.enable</literal> in the

     

       
132
       
 
       
    <literal>slim</literal> module</title>

     

       
133
       
 
       
<screen>

     

       
134
       
 
       
services.xserver.displayManager.enable = mkOption {

     

       
135
       
 
       
  type = with types; nullOr (enum [ "slim" ]);

     

       
136
       
 
       
};</screen></example>

     

       
137
       
 
       


     

       
138
       
+
       
<example xml:id='ex-option-declaration-eot-backend-sdm'><title>Extending

     

       
139
       
+
       
    <literal>services.foo.backend</literal> in the <literal>sdm</literal>

     

       
140
       
 
       
    module</title>

     

       
141
       
 
       
<screen>

     

       
142
       
 
       
services.xserver.displayManager.enable = mkOption {

     

       
143
       
+
       
  type = with types; nullOr (enum [ "sddm" ]);

     

       
144
       
 
       
};</screen></example>

     

       
145
       
 
       


     

       
146
       
+
       
<para>The placeholder declaration is a standard <literal>mkOption</literal>

     

       
147
       
+
       
  declaration, but it is important that extensible option declarations only use

     

       
148
       
 
       
  the <literal>type</literal> argument.</para>

     

       
149
       
 
       


     

       
150
       
+
       
<para>Extensible option types work with any of the composed variants of

     

       
151
       
+
       
  <literal>enum</literal> such as

     

       
152
       
+
       
  <literal>with types; nullOr (enum [ "foo" "bar" ])</literal>

     

       
153
       
 
       
  or <literal>with types; listOf (enum [ "foo" "bar" ])</literal>.</para>

     

       
154
       
 
       


     

       
155
       
 
       
</section>

     

···

       
607
       
 
       
  # services.xserver.xkbOptions = "eurosign:e";

     

       
608
       
 
       


     

       
609
       
 
       
  # Enable the KDE Desktop Environment.

     

       
610
       
-
       
  # services.xserver.displayManager.kdm.enable = true;

     

       
611
       
-
       
  # services.xserver.desktopManager.kde4.enable = true;

     

       
612
       
 
       


     

       
613
       
 
       
  # Define a user account. Don't forget to set a password with ‘passwd’.

     

       
614
       
 
       
  # users.extraUsers.guest = {

     

···

       
607
       
 
       
  # services.xserver.xkbOptions = "eurosign:e";

     

       
608
       
 
       


     

       
609
       
 
       
  # Enable the KDE Desktop Environment.

     

       
610
       
+
       
  # services.xserver.displayManager.sddm.enable = true;

     

       
611
       
+
       
  # services.xserver.desktopManager.kde5.enable = true;

     

       
612
       
 
       


     

       
613
       
 
       
  # Define a user account. Don't forget to set a password with ‘passwd’.

     

       
614
       
 
       
  # users.extraUsers.guest = {

     

···

       
6
       
 
       
{

     

       
7
       
 
       
  services.xserver = {

     

       
8
       
 
       
    enable = true;

     

       
9
       
-
       
    displayManager.kdm.enable = true;

     

       
10
       
-
       
    desktopManager.kde4.enable = true;

     

       
11
       
 
       
    synaptics.enable = true; # for touchpad support on many laptops

     

       
12
       
 
       
  };

     

       
13
       
 
       


     

···

       
6
       
 
       
{

     

       
7
       
 
       
  services.xserver = {

     

       
8
       
 
       
    enable = true;

     

       
9
       
+
       
    displayManager.sddm.enable = true;

     

       
10
       
+
       
    desktopManager.kde5.enable = true;

     

       
11
       
 
       
    synaptics.enable = true; # for touchpad support on many laptops

     

       
12
       
 
       
  };

     

       
13
       
 
       


     

···

       
22
       
 
       
  };

     

       
23
       
 
       


     

       
24
       
 
       
  ###### implementation

     

       
25
       
-
       
  

     

       
26
       
 
       
  config = mkIf config.hardware.bluetooth.enable {

     

       
27
       
 
       


     

       
28
       
 
       
    environment.systemPackages = [ bluez-bluetooth pkgs.openobex pkgs.obexftp ];

     

···

       
22
       
 
       
  };

     

       
23
       
 
       


     

       
24
       
 
       
  ###### implementation

     

       
25
       
+
       


     

       
26
       
 
       
  config = mkIf config.hardware.bluetooth.enable {

     

       
27
       
 
       


     

       
28
       
 
       
    environment.systemPackages = [ bluez-bluetooth pkgs.openobex pkgs.obexftp ];

     

···

       
1
       
 
       
# This module declares the options to define a *display manager*, the

     

       
2
       
-
       
# program responsible for handling X logins (such as xdm, kdm, gdb, or

     

       
3
       
 
       
# SLiM).  The display manager allows the user to select a *session

     

       
4
       
 
       
# type*.  When the user logs in, the display manager starts the

     

       
5
       
 
       
# *session script* ("xsession" below) to launch the selected session

     

···

       
1
       
 
       
# This module declares the options to define a *display manager*, the

     

       
2
       
+
       
# program responsible for handling X logins (such as xdm, gdb, or

     

       
3
       
 
       
# SLiM).  The display manager allows the user to select a *session

     

       
4
       
 
       
# type*.  When the user logs in, the display manager starts the

     

       
5
       
 
       
# *session script* ("xsession" below) to launch the selected session

     

···

       
16
       
 
       
    services.xserver.enable = true;

     

       
17
       
 
       
    services.xserver.videoDrivers = [];

     

       
18
       
 
       


     

       
19
       
-
       
    # Enable KDM.  Any display manager will do as long as it supports XDMCP.

     

       
20
       
-
       
    services.xserver.displayManager.kdm.enable = true;

     

       
21
       
-
       
    services.xserver.displayManager.kdm.enableXDMCP = true;

     

       
22
       
-
       
    services.xserver.displayManager.kdm.extraConfig =

     

       
23
       
-
       
      ''

     

       
24
       
-
       
        [General]

     

       
25
       
-
       
        # We're headless, so don't bother starting an X server.

     

       
26
       
-
       
        StaticServers=

     

       
27
       
-
       


     

       
28
       
-
       
        [Xdmcp]

     

       
29
       
-
       
        Xaccess=${pkgs.writeText "Xaccess" "localhost"}

     

       
30
       
-
       
      '';

     

       
31
       
 
       


     

       
32
       
 
       
    systemd.sockets.terminal-server =

     

       
33
       
 
       
      { description = "Terminal Server Socket";

     

···

       
16
       
 
       
    services.xserver.enable = true;

     

       
17
       
 
       
    services.xserver.videoDrivers = [];

     

       
18
       
 
       


     

       
19
       
+
       
    # Enable GDM.  Any display manager will do as long as it supports XDMCP.

     

       
20
       
+
       
    services.xserver.displayManager.gdm.enable = true;

     

       
0
       
 
       

     

       
0
       
 
       

     

       
0
       
 
       

     

       
0
       
 
       

     

       
0
       
 
       

     

       
0
       
 
       

     

       
0
       
 
       

     

       
0
       
 
       

     

       
0
       
 
       

     

       
0
       
 
       

     

       
21
       
 
       


     

       
22
       
 
       
    systemd.sockets.terminal-server =

     

       
23
       
 
       
      { description = "Terminal Server Socket";

     

···

       
325
       
 
       


     

       
326
       
 
       
    kde = makeClosure ({ pkgs, ... }:

     

       
327
       
 
       
      { services.xserver.enable = true;

     

       
328
       
-
       
        services.xserver.displayManager.kdm.enable = true;

     

       
329
       
-
       
        services.xserver.desktopManager.kde4.enable = true;

     

       
330
       
 
       
      });

     

       
331
       
 
       


     

       
332
       
 
       
    xfce = makeClosure ({ pkgs, ... }:

     

···

       
325
       
 
       


     

       
326
       
 
       
    kde = makeClosure ({ pkgs, ... }:

     

       
327
       
 
       
      { services.xserver.enable = true;

     

       
328
       
+
       
        services.xserver.displayManager.sddm.enable = true;

     

       
329
       
+
       
        services.xserver.desktopManager.kde5.enable = true;

     

       
330
       
 
       
      });

     

       
331
       
 
       


     

       
332
       
 
       
    xfce = makeClosure ({ pkgs, ... }:

     

···

       
54
       
 
       
    client =

     

       
55
       
 
       
      { config, pkgs, ... }:

     

       
56
       
 
       
      { imports = [ ./common/x11.nix ];

     

       
57
       
-
       
        services.xserver.desktopManager.kde4.enable = true;

     

       
58
       
 
       
      };

     

       
59
       
 
       
  };

     

       
60
       
 
       


     

···

       
54
       
 
       
    client =

     

       
55
       
 
       
      { config, pkgs, ... }:

     

       
56
       
 
       
      { imports = [ ./common/x11.nix ];

     

       
57
       
+
       
        services.xserver.desktopManager.kde5.enable = true;

     

       
58
       
 
       
      };

     

       
59
       
 
       
  };

     

       
60
       
 
       


     

···

       
45
       
 
       
    client =

     

       
46
       
 
       
      { config, pkgs, ... }:

     

       
47
       
 
       
      { imports = [ ./common/x11.nix ];

     

       
48
       
-
       
        services.xserver.desktopManager.kde4.enable = true;

     

       
49
       
 
       
      };

     

       
50
       
 
       
  };

     

       
51
       
 
       


     

···

       
45
       
 
       
    client =

     

       
46
       
 
       
      { config, pkgs, ... }:

     

       
47
       
 
       
      { imports = [ ./common/x11.nix ];

     

       
48
       
+
       
        services.xserver.desktopManager.kde5.enable = true;

     

       
49
       
 
       
      };

     

       
50
       
 
       
  };

     

       
51