aboutsummaryrefslogtreecommitdiff
path: root/gnu/services/dict.scm
diff options
context:
space:
mode:
Diffstat (limited to 'gnu/services/dict.scm')
0 files changed, 0 insertions, 0 deletions
generated by cgit
href='#n54'>54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 
;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2019, 2020 L  p R n  d n <guix@lprndn.info>
;;; Copyright © 2020 Ricardo Wurmus <rekado@elephly.net>
;;; Copyright © 2022 Maxim Cournoyer <maxim.cournoyer@gmail.com>
;;;
;;; This file is part of GNU Guix.
;;;
;;; GNU Guix is free software; you can redistribute it and/or modify it
;;; under the terms of the GNU General Public License as published by
;;; the Free Software Foundation; either version 3 of the License, or (at
;;; your option) any later version.
;;;
;;; GNU Guix is distributed in the hope that it will be useful, but
;;; WITHOUT ANY WARRANTY; without even the implied warranty of
;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;;; GNU General Public License for more details.
;;;
;;; You should have received a copy of the GNU General Public License
;;; along with GNU Guix.  If not, see <http://www.gnu.org/licenses/>.

(define-module (gnu services lightdm)
  #:use-module (gnu artwork)
  #:use-module (gnu packages admin)
  #:use-module (gnu packages display-managers)
  #:use-module (gnu packages freedesktop)
  #:use-module (gnu packages gnome)
  #:use-module (gnu packages vnc)
  #:use-module (gnu packages xorg)
  #:use-module (gnu services configuration)
  #:use-module (gnu services dbus)
  #:use-module (gnu services desktop)
  #:use-module (gnu services shepherd)
  #:use-module (gnu services xorg)
  #:use-module (gnu services)
  #:use-module (gnu system pam)
  #:use-module (gnu system shadow)
  #:use-module (guix diagnostics)
  #:use-module (guix gexp)
  #:use-module (guix i18n)
  #:use-module (guix records)
  #:use-module (ice-9 format)
  #:use-module (ice-9 match)
  #:use-module (srfi srfi-1)
  #:use-module (srfi srfi-26)
  #:export (lightdm-seat-configuration
            lightdm-seat-configuration?
            lightdm-seat-configuration-name
            lightdm-seat-configuration-type
            lightdm-seat-configuration-user-session
            lightdm-seat-configuration-autologin-user
            lightdm-seat-configuration-greeter-session
            lightdm-seat-configuration-xserver-command
            lightdm-seat-configuration-session-wrapper
            lightdm-seat-configuration-extra-config

            lightdm-gtk-greeter-configuration
            lightdm-gtk-greeter-configuration?
            lightdm-gtk-greeter-configuration-lightdm-gtk-greeter
            lightdm-gtk-greeter-configuration-assets
            lightdm-gtk-greeter-configuration-theme-name
            lightdm-gtk-greeter-configuration-icon-theme-name
            lightdm-gtk-greeter-configuration-cursor-theme-name
            lightdm-gtk-greeter-configuration-allow-debug
            lightdm-gtk-greeter-configuration-background
            lightdm-gtk-greeter-configuration-a11y-states
            lightdm-gtk-greeter-configuration-reader
            lightdm-gtk-greeter-configuration-extra-config

            lightdm-configuration
            lightdm-configuration?
            lightdm-configuration-lightdm
            lightdm-configuration-allow-empty-passwords?
            lightdm-configuration-xorg-configuration
            lightdm-configuration-greeters
            lightdm-configuration-seats
            lightdm-configuration-xdmcp?
            lightdm-configuration-xdmcp-listen-address
            lightdm-configuration-vnc-server?
            lightdm-configuration-vnc-server-command
            lightdm-configuration-vnc-server-listen-address
            lightdm-configuration-vnc-server-port
            lightdm-configuration-extra-config

            lightdm-service-type))

;;;
;;; Greeters.
;;;

(define list-of-file-likes?
  (list-of file-like?))

(define %a11y-states '(contrast font keyboard reader))

(define (a11y-state? value)
  (memq value %a11y-states))

(define list-of-a11y-states?
  (list-of a11y-state?))

(define-maybe boolean)

(define (serialize-boolean name value)
  (define (strip-trailing-? name)
    ;; field? -> field
    (let ((str (symbol->string name)))
      (if (string-suffix? "?" str)
          (string-drop-right str 1)
          str)))
  (format #f "~a=~:[false~;true~]~%" (strip-trailing-? name) value))

(define-maybe file-like)

(define (serialize-file-like name value)
  #~(format #f "~a=~a~%" '#$name #$value))

(define (serialize-list-of-a11y-states name value)
  (format #f "~a=~a~%" name (string-join (map symbol->string value) ";")))

(define (serialize-string name value)
  (format #f "~a=~a~%" name value))

(define (serialize-number name value)
  (format #f "~a=~a~%" name value))

(define (serialize-list-of-strings _ value)
  (string-join value "\n"))

(define-configuration lightdm-gtk-greeter-configuration
  (lightdm-gtk-greeter
   (file-like lightdm-gtk-greeter)
   "The lightdm-gtk-greeter package to use."
   empty-serializer)
  (assets
   (list-of-file-likes (list adwaita-icon-theme
                             gnome-themes-extra
                             ;; FIXME: hicolor-icon-theme should be in the
                             ;; packages of the desktop templates.
                             hicolor-icon-theme))
   "The list of packages complementing the greeter, such as package providing
icon themes."
   empty-serializer)
  (theme-name
   (string "Adwaita")
   "The name of the theme to use.")
  (icon-theme-name
   (string "Adwaita")
   "The name of the icon theme to use.")
  (cursor-theme-name
   (string "Adwaita")
   "The name of the cursor theme to use.")
  (cursor-theme-size
   (number 16)
   "The size to use for the cursor theme.")
  (allow-debugging?
   maybe-boolean
   "Set to #t to enable debug log level.")
  (background
   (file-like (file-append %artwork-repository
                           "/backgrounds/guix-checkered-16-9.svg"))
   "The background image to use.")
  ;; FIXME: This should be enabled by default, but it currently doesn't work,
  ;; failing to connect to D-Bus, causing the login to fail.
  (at-spi-enabled?
   (boolean #f)
   "Enable accessibility support through the Assistive Technology Service
Provider Interface (AT-SPI).")
  (a11y-states
   (list-of-a11y-states %a11y-states)
   "The accessibility features to enable, given as list of symbols.")
  (reader
   maybe-file-like
   "The command to use to launch a screen reader.")
  (extra-config
   (list-of-strings '())
   "Extra configuration values to append to the LightDM GTK Greeter
configuration file."))

(define (strip-record-type-name-brackets name)
  "Remove the '<' and '>' brackets from NAME, a symbol."
  (let ((name (symbol->string name)))
    (if (and (string-prefix? "<" name)
             (string-suffix? ">" name))
        (string->symbol (string-drop (string-drop-right name 1) 1))
        (error "unexpected record type name" name))))

(define (config->name config)
  "Return the constructor name (a symbol) from CONFIG."
  (strip-record-type-name-brackets
   (record-type-name (struct-vtable config))))

(define (greeter-configuration->greeter-fields config)
  "Return the fields of CONFIG, a greeter configuration."
  (match config
    ;; Note: register any new greeter configuration here.
    ((? lightdm-gtk-greeter-configuration?)
     lightdm-gtk-greeter-configuration-fields)))

(define (greeter-configuration->packages config)
  "Return the list of greeter packages, including assets, used by CONFIG, a
greeter configuration."
  (match config
    ;; Note: register any new greeter configuration here.
    ((? lightdm-gtk-greeter-configuration?)
     (cons (lightdm-gtk-greeter-configuration-lightdm-gtk-greeter config)
           (lightdm-gtk-greeter-configuration-assets config)))))

;;; TODO: Implement directly in (gnu services configuration), perhaps by
;;; making the FIELDS argument optional.
(define (serialize-configuration* config)
  "Like `serialize-configuration', but not requiring to provide a FIELDS
argument."
  (define fields (greeter-configuration->greeter-fields config))
  (serialize-configuration config fields))

(define (greeter-configuration->conf-name config)
  "Return the file name of CONFIG, a greeter configuration."
  (format #f "~a.conf" (greeter-configuration->greeter-session config)))

(define (greeter-configuration->file config)
  "Serialize CONFIG into a file under the output directory, so that it can be
easily added to XDG_CONF_DIRS."
  (computed-file
   (greeter-configuration->conf-name config)
   #~(begin
       (call-with-output-file #$output
         (lambda (port)
           (format port (string-append
                         "[greeter]\n"
                         #$(serialize-configuration* config))))))))


;;;
;;; Seats.
;;;

(define seat-name? string?)

(define (serialize-seat-name _ value)
  (format #f "[Seat:~a]~%" value))

(define (seat-type? type)
  (memq type '(local xremote)))

(define (serialize-seat-type name value)
  (format #f "~a=~a~%" name value))

(define-maybe seat-type)

(define (greeter-session? value)
  (memq value '(lightdm-gtk-greeter)))

(define (serialize-greeter-session name value)
  (format #f "~a=~a~%" name value))

(define-maybe greeter-session)

(define-maybe string)

;;; Note: all the fields except for the seat name should be 'maybe's, since
;;; the real default value is set by the %lightdm-seat-default define later,
;;; and this avoids repeating ourselves in the serialized configuration file.
(define-configuration lightdm-seat-configuration
  (name
   seat-name
   "The name of the seat.  An asterisk (*) can be used in the name
to apply the seat configuration to all the seat names it matches.")
  (user-session
   maybe-string
   "The session to use by default.  The session name must be provided as a
lowercase string, such as @code{\"gnome\"}, @code{\"ratpoison\"}, etc.")
  (type
   (seat-type 'local)
   "The type of the seat, either the @code{local} or @code{xremote} symbol.")
  (autologin-user
   maybe-string
   "The username to automatically log in with by default.")
  (greeter-session
   (greeter-session 'lightdm-gtk-greeter)
   "The greeter session to use, specified as a symbol.  Currently, only
@code{lightdm-gtk-greeter} is supported.")
  ;; Note: xserver-command must be lazily computed, so that it can be
  ;; overridden via 'lightdm-configuration-xorg-configuration'.
  (xserver-command
   maybe-file-like
   "The Xorg server command to run.")
  (session-wrapper
   (file-like (xinitrc))
   "The xinitrc session wrapper to use.")
  (extra-config
   (list-of-strings '())
   "Extra configuration values to append to the seat configuration section."))

(define (greeter-session->greater-configuration-pred identifier)
  "Return the predicate to check if a configuration is of the type specifying
a greeter identified by IDENTIFIER."
  (match identifier
    ;; Note: register any new greeter identifier here.
    ('lightdm-gtk-greeter
     lightdm-gtk-greeter-configuration?)))

(define (greeter-configuration->greeter-session config)
  "Given CONFIG, a greeter configuration object, return its identifier,
a symbol."
  (let ((suffix "-configuration")
        (greeter-conf-name (config->name config)))
    (string->symbol (string-drop-right (symbol->string greeter-conf-name)
                                       (string-length suffix)))))

(define list-of-seat-configurations?
  (list-of lightdm-seat-configuration?))


;;;
;;; LightDM.
;;;

(define (greeter-configuration? config)
  (or (lightdm-gtk-greeter-configuration? config)
      ;; Note: register any new greeter configuration here.
      ))

(define (list-of-greeter-configurations? greeter-configs)
  (and ((list-of greeter-configuration?) greeter-configs)
       ;; Greeter configurations must also not be provided more than once.
       (let* ((types (map (compose record-type-name struct-vtable)
                          greeter-configs))
              (dupes (filter (lambda (type)
                               (< 1 (count (cut eq? type <>) types)))
                             types)))
         (unless (null? dupes)
           (leave (G_ "duplicate greeter configurations: ~a~%") dupes)))))

(define-configuration/no-serialization lightdm-configuration
  (lightdm
   (file-like lightdm)
   "The lightdm package to use.")
  (allow-empty-passwords?
   (boolean #f)
   "Whether users not having a password set can login.")
  (debug?
   (boolean #f)
   "Enable verbose output.")
  (xorg-configuration
   (xorg-configuration (xorg-configuration))
   "The default Xorg server configuration to use to generate the Xorg server
start script.  It can be refined per seat via the @code{xserver-command} of
the @code{<lightdm-seat-configuration>} record, if desired.")
  (greeters
   (list-of-greeter-configurations (list (lightdm-gtk-greeter-configuration)))
   "The LightDM greeter configurations specifying the greeters to use.")
  (seats
   (list-of-seat-configurations (list (lightdm-seat-configuration
                                       (name "*"))))
   "The seat configurations to use.  A LightDM seat is akin to a user.")
  (xdmcp?
   (boolean #f)
   "Whether a XDMCP server should listen on port UDP 177.")
  (xdmcp-listen-address
   maybe-string
   "The host or IP address the XDMCP server listens for incoming connections.
When unspecified, listen on for any hosts/IP addresses.")
  (vnc-server?
   (boolean #f)
   "Whether a VNC server is started.")
  (vnc-server-command
   (file-like (file-append tigervnc-server "/bin/Xvnc"))
   "The Xvnc command to use for the VNC server, it's possible to provide extra
options not otherwise exposed along the command, for example to disable
security:
@lisp
(vnc-server-command
 (file-append tigervnc-server \"/bin/Xvnc\"
             \" -SecurityTypes None\" ))
@end lisp

Or to set a PasswordFile for the classic (unsecure) VncAuth mechanism:
@lisp
(vnc-server-command
 (file-append tigervnc-server \"/bin/Xvnc\"
             \" -PasswordFile /var/lib/lightdm/.vnc/passwd\"))
@end lisp
The password file should be manually created using the @command{vncpasswd}
command.

Note that LightDM will create new sessions for VNC users, which means they
need to authenticate in the same way as local users would.
")
  (vnc-server-listen-address
   maybe-string
   "The host or IP address the VNC server listens for incoming connections.
When unspecified, listen for any hosts/IP addresses.")
  (vnc-server-port
   (number 5900)
   "The TCP port the VNC server should listen to.")
  (extra-config
   (list-of-strings '())
   "Extra configuration values to append to the LightDM configuration file."))

(define (lightdm-configuration->greeters-config-dir config)
  "Return a directory containing all the serialized greeter configurations
from CONFIG, a <lightdm-configuration> object."
  (file-union "etc-lightdm"
              (append-map (lambda (g)
                            `((,(greeter-configuration->conf-name g)
                               ,(greeter-configuration->file g))))
                          (lightdm-configuration-greeters config))))

(define (lightdm-configuration->packages config)
  "Return all the greeter packages and their assets defined in CONFIG, a
<lightdm-configuration> object, as well as the lightdm package itself."
  (cons (lightdm-configuration-lightdm config)
        (append-map greeter-configuration->packages
                    (lightdm-configuration-greeters config))))

(define (validate-lightdm-configuration config)
  "Sanity check CONFIG, a <lightdm-configuration> record instance."
  ;; This is required to make inter-field validations, such as between the
  ;; seats and greeters.
  (let* ((seats (lightdm-configuration-seats config))
         (greeter-sessions (delete-duplicates
                            (map lightdm-seat-configuration-greeter-session
                                 seats)
                            eq?))
         (greeter-configurations (lightdm-configuration-greeters config))
         (missing-greeters
          (filter-map
           (lambda (id)
             (define pred (greeter-session->greater-configuration-pred id))
             (if (find pred greeter-configurations)
                 #f                     ;happy path
                 id))
           greeter-sessions)))
    (unless (null? missing-greeters)
      (leave (G_ "no greeter configured for seat greeter sessions: ~a~%")
             missing-greeters))))

(define (lightdm-configuration-file config)
  (match-record config <lightdm-configuration>
    (xorg-configuration seats
     xdmcp? xdmcp-listen-address
     vnc-server? vnc-server-command vnc-server-listen-address vnc-server-port
     extra-config)
    (apply
     mixed-text-file
     "lightdm.conf" "
#
# General configuration
#
[LightDM]
greeter-user=lightdm
sessions-directory=/run/current-system/profile/share/xsessions\
:/run/current-system/profile/share/wayland-sessions
remote-sessions-directory=/run/current-system/profile/share/remote-sessions
"
     #~(string-join '#$extra-config "\n")
     "
#
# XDMCP Server configuration
#
[XDMCPServer]
enabled=" (if xdmcp? "true" "false") "\n"
(if (maybe-value-set? xdmcp-listen-address)
    (format #f "xdmcp-listen-address=~a" xdmcp-listen-address)
    "") "

#
# VNC Server configuration
#
[VNCServer]
enabled=" (if vnc-server? "true" "false") "
command=" vnc-server-command "
port=" (number->string vnc-server-port) "\n"
(if (maybe-value-set? vnc-server-listen-address)
    (format #f "vnc-server-listen-address=~a" vnc-server-listen-address)
    "") "

#
# Seat configuration.
#
"
     (map (lambda (seat)
            ;; This complication exists to propagate a default value for
            ;; the 'xserver-command' field of the seats.  Having a
            ;; 'xorg-configuration' field at the root of the
            ;; lightdm-configuration enables the use of
            ;; 'set-xorg-configuration' and can be more convenient.
            (let ((seat* (if (maybe-value-set?
                              (lightdm-seat-configuration-xserver-command seat))
                             seat
                             (lightdm-seat-configuration
                              (inherit seat)
                              (xserver-command (xorg-start-command
                                                xorg-configuration))))))
              (serialize-configuration seat*
                                       lightdm-seat-configuration-fields)))
          seats))))

(define %lightdm-accounts
  (list (user-group (name "lightdm") (system? #t))
        (user-account
         (name "lightdm")
         (group "lightdm")
         (system? #t)
         (comment "LightDM user")
         (home-directory "/var/lib/lightdm")
         (shell (file-append shadow "/sbin/nologin")))))

(define %lightdm-activation
  ;; Ensure /var/lib/lightdm is owned by the "lightdm" user.  Adapted from the
  ;; %gdm-activation.
  (with-imported-modules '((guix build utils))
    #~(begin
        (use-modules (guix build utils))

        (define (ensure-ownership directory)
          (let* ((lightdm (getpwnam "lightdm"))
                 (uid (passwd:uid lightdm))
                 (gid (passwd:gid lightdm))
                 (st  (stat directory #f)))
            ;; Recurse into directory only if it has wrong ownership.
            (when (and st
                       (or (not (= uid (stat:uid st)))
                           (not (= gid (stat:gid st)))))
              (for-each (lambda (file)
                          (chown file uid gid))
                        (find-files directory #:directories? #t)))))

        (when (not (stat "/var/lib/lightdm-data" #f))
          (mkdir-p "/var/lib/lightdm-data"))
        (for-each ensure-ownership
                  '("/var/lib/lightdm"
                    "/var/lib/lightdm-data")))))

(define (lightdm-pam-service config)
  "Return a PAM service for @command{lightdm}."
  (unix-pam-service "lightdm"
                    #:login-uid? #t
                    #:allow-empty-passwords?
                    (lightdm-configuration-allow-empty-passwords? config)))

(define (lightdm-greeter-pam-service)
  "Return a PAM service for @command{lightdm-greeter}."
  (pam-service
   (name "lightdm-greeter")
   (auth (list
          ;; Load environment from /etc/environment and ~/.pam_environment.
          (pam-entry (control "required") (module "pam_env.so"))
          ;; Always let the greeter start without authentication.
          (pam-entry (control "required") (module "pam_permit.so"))))
   ;; No action required for account management
   (account (list (pam-entry (control "required") (module "pam_permit.so"))))
   ;; Prohibit changing password.
   (password (list (pam-entry (control "required") (module "pam_deny.so"))))
   ;; Setup session.
   (session (list (pam-entry (control "required") (module "pam_unix.so"))))))

(define (lightdm-autologin-pam-service)
  "Return a PAM service for @command{lightdm-autologin}}."
  (pam-service
   (name "lightdm-autologin")
   (auth
    (list
     ;; Block login if user is globally disabled.
     (pam-entry (control "required") (module "pam_nologin.so"))
     (pam-entry (control "required") (module "pam_succeed_if.so")
                (arguments (list "uid >= 1000")))
     ;; Allow access without authentication.
     (pam-entry (control "required") (module "pam_permit.so"))))
   ;; Stop autologin if account requires action.
   (account (list (pam-entry (control "required") (module "pam_unix.so"))))
   ;; Prohibit changing password.
   (password (list (pam-entry (control "required") (module "pam_deny.so"))))
   ;; Setup session.
   (session (list (pam-entry (control "required") (module "pam_unix.so"))))))

(define (lightdm-pam-services config)
  (list (lightdm-pam-service config)
        (lightdm-greeter-pam-service)
        (lightdm-autologin-pam-service)))

(define (lightdm-shepherd-service config)
  "Return a <lightdm-service> for LightDM using CONFIG."

  (validate-lightdm-configuration config)

  (define lightdm-command
    #~(list #$(file-append (lightdm-configuration-lightdm config)
                           "/sbin/lightdm")
            #$@(if (lightdm-configuration-debug? config)
                   #~("--debug")
                   #~())
            "--config"
            #$(lightdm-configuration-file config)))

  (define lightdm-paths
    (let ((lightdm (lightdm-configuration-lightdm config)))
      #~(string-join
         '#$(map (lambda (dir)
                   (file-append lightdm dir))
                 '("/bin" "/sbin" "/libexec"))
         ":")))

  (define greeters-config-dir
    (lightdm-configuration->greeters-config-dir config))

  (define data-dirs
    ;; LightDM itself needs to be in XDG_DATA_DIRS for the accountsservice
    ;; interface it provides to be picked up.  The greeters must also be in
    ;; XDG_DATA_DIRS to be found.
    (let ((packages (lightdm-configuration->packages config)))
      #~(string-join '#$(map (cut file-append <> "/share") packages)
                     ":")))

  (list
   (shepherd-service
    (documentation "LightDM display manager")
    (requirement '(pam dbus-system user-processes host-name))
    (provision '(lightdm display-manager xorg-server))
    (respawn? #f)
    (start
     ;; Note: sadly, environment variables defined for 'lightdm' are
     ;; cleared and/or overridden by /etc/profile by its spawned greeters,
     ;; so an out-of-band means such as /etc is required.
     #~(make-forkexec-constructor #$lightdm-command
                                  ;; Lightdm needs itself in its PATH.
                                  #:environment-variables
                                  (list
                                   ;; It knows to look for greeter
                                   ;; configurations in XDG_CONFIG_DIRS...
                                   (string-append "XDG_CONFIG_DIRS="
                                                  #$greeters-config-dir)
                                   ;; ... and for greeter .desktop files as
                                   ;; well as lightdm accountsservice
                                   ;; interface in XDG_DATA_DIRS.
                                   (string-append "XDG_DATA_DIRS="
                                                  #$data-dirs)
                                   (string-append "PATH=" #$lightdm-paths))))
    (stop #~(make-kill-destructor)))))

(define lightdm-service-type
  (handle-xorg-configuration
   lightdm-configuration
   (service-type
    (name 'lightdm)
    (default-value (lightdm-configuration))
    (extensions
     (list (service-extension pam-root-service-type lightdm-pam-services)
           (service-extension shepherd-root-service-type
                              lightdm-shepherd-service)
           (service-extension activation-service-type
                              (const %lightdm-activation))
           (service-extension dbus-root-service-type
                              (compose list lightdm-configuration-lightdm))
           (service-extension polkit-service-type
                              (compose list lightdm-configuration-lightdm))
           (service-extension account-service-type
                              (const %lightdm-accounts))
           ;; Add 'lightdm' to the system profile, so that its
           ;; 'share/accountsservice' D-Bus service extension directory can be
           ;; found via the 'XDG_DATA_DIRS=/run/current-system/profile/share'
           ;; environment variable set in the wrapper of the
           ;; libexec/accounts-daemon binary of the accountsservice package.
           ;; This daemon is spawned by D-Bus, and there's little we can do to
           ;; affect its environment.  For more reading, see:
           ;; https://github.com/NixOS/nixpkgs/issues/45059.
           (service-extension profile-service-type
                              lightdm-configuration->packages)
           ;; This is needed for the greeter itself to find its configuration,
           ;; because XDG_CONF_DIRS gets overridden by /etc/profile.
           (service-extension
            etc-service-type
            (lambda (config)
              `(("lightdm"
                 ,(lightdm-configuration->greeters-config-dir config)))))))
    (description "Run @code{lightdm}, the LightDM graphical login manager."))))


;;;
;;; Generate documentation.
;;;
(define (generate-doc)
  (configuration->documentation 'lightdm-configuration)
  (configuration->documentation 'lightdm-gtk-greeter-configuration)
  (configuration->documentation 'lightdm-seat-configuration))
generated by cgit