1{ config, lib, pkgs, ... }:
2
3with lib;
4
5let
6
7 dmcfg = config.services.xserver.displayManager;
8 xEnv = config.systemd.services."display-manager".environment;
9 cfg = dmcfg.lightdm;
10
11 inherit (pkgs) stdenv lightdm writeScript writeText;
12
13 # lightdm runs with clearenv(), but we need a few things in the enviornment for X to startup
14 xserverWrapper = writeScript "xserver-wrapper"
15 ''
16 #! /bin/sh
17 ${concatMapStrings (n: "export ${n}=\"${getAttr n xEnv}\"\n") (attrNames xEnv)}
18 exec ${dmcfg.xserverBin} ${dmcfg.xserverArgs}
19 '';
20
21 theme = pkgs.gnome3.gnome_themes_standard;
22 icons = pkgs.gnome3.defaultIconTheme;
23
24 # The default greeter provided with this expression is the GTK greeter.
25 # Again, we need a few things in the environment for the greeter to run with
26 # fonts/icons.
27 wrappedGtkGreeter = stdenv.mkDerivation {
28 name = "lightdm-gtk-greeter";
29 buildInputs = [ pkgs.makeWrapper ];
30
31 buildCommand = ''
32 # This wrapper ensures that we actually get themes
33 makeWrapper ${pkgs.lightdm_gtk_greeter}/sbin/lightdm-gtk-greeter \
34 $out/greeter \
35 --prefix PATH : "${pkgs.glibc}/bin" \
36 --set GDK_PIXBUF_MODULE_FILE "${pkgs.gdk_pixbuf}/lib/gdk-pixbuf-2.0/2.10.0/loaders.cache" \
37 --set GTK_PATH "${theme}:${pkgs.gtk3}" \
38 --set GTK_EXE_PREFIX "${theme}" \
39 --set GTK_DATA_PREFIX "${theme}" \
40 --set XDG_DATA_DIRS "${theme}/share:${icons}/share" \
41 --set XDG_CONFIG_HOME "${theme}/share"
42
43 cat - > $out/lightdm-gtk-greeter.desktop << EOF
44 [Desktop Entry]
45 Name=LightDM Greeter
46 Comment=This runs the LightDM Greeter
47 Exec=$out/greeter
48 Type=Application
49 EOF
50 '';
51 };
52
53 usersConf = writeText "users.conf"
54 ''
55 [UserList]
56 minimum-uid=500
57 hidden-users=${concatStringsSep " " dmcfg.hiddenUsers}
58 hidden-shells=/run/current-system/sw/bin/nologin
59 '';
60
61 lightdmConf = writeText "lightdm.conf"
62 ''
63 [LightDM]
64 greeter-user = ${config.users.extraUsers.lightdm.name}
65 greeters-directory = ${cfg.greeter.package}
66 sessions-directory = ${dmcfg.session.desktops}
67
68 [Seat:*]
69 xserver-command = ${xserverWrapper}
70 session-wrapper = ${dmcfg.session.script}
71 greeter-session = ${cfg.greeter.name}
72 ${cfg.extraSeatDefaults}
73 '';
74
75 gtkGreeterConf = writeText "lightdm-gtk-greeter.conf"
76 ''
77 [greeter]
78 theme-name = Adwaita
79 icon-theme-name = Adwaita
80 background = ${cfg.background}
81 '';
82
83in
84{
85 options = {
86 services.xserver.displayManager.lightdm = {
87
88 enable = mkOption {
89 default = false;
90 description = ''
91 Whether to enable lightdm as the display manager.
92 '';
93 };
94
95 greeter = mkOption {
96 description = ''
97 The LightDM greeter to login via. The package should be a directory
98 containing a .desktop file matching the name in the 'name' option.
99 '';
100 default = {
101 name = "lightdm-gtk-greeter";
102 package = wrappedGtkGreeter;
103 };
104 };
105
106 background = mkOption {
107 description = ''
108 The background image or color to use.
109 '';
110 };
111
112 extraSeatDefaults = mkOption {
113 type = types.lines;
114 default = "";
115 example = ''
116 greeter-show-manual-login=true
117 '';
118 description = "Extra lines to append to SeatDefaults section.";
119 };
120
121 };
122 };
123
124 config = mkIf cfg.enable {
125
126 services.xserver.displayManager.slim.enable = false;
127
128 services.xserver.displayManager.job = {
129 logsXsession = true;
130
131 # lightdm relaunches itself via just `lightdm`, so needs to be on the PATH
132 execCmd = ''
133 export PATH=${lightdm}/sbin:$PATH
134 exec ${lightdm}/sbin/lightdm --log-dir=/var/log --run-dir=/run
135 '';
136 };
137
138 environment.etc."lightdm/lightdm-gtk-greeter.conf".source = gtkGreeterConf;
139 environment.etc."lightdm/lightdm.conf".source = lightdmConf;
140 environment.etc."lightdm/users.conf".source = usersConf;
141
142 services.dbus.enable = true;
143 services.dbus.packages = [ lightdm ];
144
145 security.pam.services.lightdm = {
146 allowNullPassword = true;
147 startSession = true;
148 };
149 security.pam.services.lightdm-greeter = {
150 allowNullPassword = true;
151 startSession = true;
152 text = ''
153 auth required pam_env.so
154 auth required pam_permit.so
155
156 account required pam_permit.so
157
158 password required pam_deny.so
159
160 session required pam_env.so envfile=${config.system.build.pamEnvironment}
161 session required pam_unix.so
162 session optional ${pkgs.systemd}/lib/security/pam_systemd.so
163 '';
164 };
165
166 users.extraUsers.lightdm = {
167 createHome = true;
168 home = "/var/lib/lightdm-data";
169 group = "lightdm";
170 uid = config.ids.uids.lightdm;
171 };
172
173 users.extraGroups.lightdm.gid = config.ids.gids.lightdm;
174
175 services.xserver.displayManager.lightdm.background = mkDefault "${pkgs.nixos-artwork}/share/artwork/gnome/Gnome_Dark.png";
176
177 };
178}