aboutsummaryrefslogtreecommitdiff
path: root/gnu/system/shadow.scm
blob: 236807c70aa83957a65dd62bcf1daa1274b619f6 (about) (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
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
;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2013, 2014, 2015, 2016, 2017 Ludovic Courtès <ludo@gnu.org>
;;; Copyright © 2016 Alex Griffin <a@ajgrf.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 system shadow)
  #:use-module (guix records)
  #:use-module (guix gexp)
  #:use-module (guix store)
  #:use-module (guix modules)
  #:use-module (guix sets)
  #:use-module (guix ui)
  #:use-module (gnu services)
  #:use-module (gnu services shepherd)
  #:use-module ((gnu system file-systems)
                #:select (%tty-gid))
  #:use-module ((gnu packages admin)
                #:select (shadow))
  #:use-module (gnu packages bash)
  #:use-module (gnu packages guile-wm)
  #:use-module (srfi srfi-1)
  #:use-module (srfi srfi-26)
  #:use-module (srfi srfi-34)
  #:use-module (srfi srfi-35)
  #:export (user-account
            user-account?
            user-account-name
            user-account-password
            user-account-uid
            user-account-group
            user-account-supplementary-groups
            user-account-comment
            user-account-home-directory
            user-account-create-home-directory?
            user-account-shell
            user-account-system?

            user-group
            user-group?
            user-group-name
            user-group-password
            user-group-id
            user-group-system?

            default-skeletons
            skeleton-directory
            %base-groups
            %base-user-accounts

            account-service-type
            account-service))

;;; Commentary:
;;;
;;; Utilities for configuring the Shadow tool suite ('login', 'passwd', etc.)
;;;
;;; Code:

(define-record-type* <user-account>
  user-account make-user-account
  user-account?
  (name           user-account-name)
  (password       user-account-password (default #f))
  (uid            user-account-uid (default #f))
  (group          user-account-group)             ; number | string
  (supplementary-groups user-account-supplementary-groups
                        (default '()))            ; list of strings
  (comment        user-account-comment (default ""))
  (home-directory user-account-home-directory)
  (create-home-directory? user-account-create-home-directory? ;Boolean
                          (default #t))
  (shell          user-account-shell              ; gexp
                  (default (file-append bash "/bin/bash")))
  (system?        user-account-system?            ; Boolean
                  (default #f)))

(define-record-type* <user-group>
  user-group make-user-group
  user-group?
  (name           user-group-name)
  (password       user-group-password (default #f))
  (id             user-group-id (default #f))
  (system?        user-group-system?              ; Boolean
                  (default #f)))


(define %base-groups
  ;; Default set of groups.
  (let-syntax ((system-group (syntax-rules ()
                               ((_ args ...)
                                (user-group (system? #t) args ...)))))
    (list (system-group (name "root") (id 0))
          (system-group (name "wheel"))           ; root-like users
          (system-group (name "users"))           ; normal users
          (system-group (name "nogroup"))         ; for daemons etc.

          ;; The following groups are conventionally used by things like udev to
          ;; control access to hardware devices.
          (system-group (name "tty") (id %tty-gid))
          (system-group (name "dialout"))
          (system-group (name "kmem"))
          (system-group (name "input"))           ; input devices, from udev
          (system-group (name "video"))
          (system-group (name "audio"))
          (system-group (name "netdev"))          ; used in avahi-dbus.conf
          (system-group (name "lp"))
          (system-group (name "disk"))
          (system-group (name "floppy"))
          (system-group (name "cdrom"))
          (system-group (name "tape"))
          (system-group (name "kvm")))))          ; for /dev/kvm

(define %base-user-accounts
  ;; List of standard user accounts.  Note that "root" is a special case, so
  ;; it's not listed here.
  (list (user-account
         (name "nobody")
         (uid 65534)
         (group "nogroup")
         (shell (file-append shadow "/sbin/nologin"))
         (home-directory "/nonexistent")
         (create-home-directory? #f)
         (system? #t))))

(define (default-skeletons)
  "Return the default skeleton files for /etc/skel.  These files are copied by
'useradd' in the home directory of newly created user accounts."
  (define copy-guile-wm
    (with-imported-modules '((guix build utils))
      #~(begin
          (use-modules (guix build utils))
          (copy-file (car (find-files #+guile-wm "wm-init-sample.scm"))
                     #$output))))

  (let ((profile (plain-file "bash_profile" "\
# Honor per-interactive-shell startup file
if [ -f ~/.bashrc ]; then . ~/.bashrc; fi\n"))
        (bashrc  (plain-file "bashrc" "\
# Bash initialization for interactive non-login shells and
# for remote shells (info \"(bash) Bash Startup Files\").

# Export 'SHELL' to child processes.  Programs such as 'screen'
# honor it and otherwise use /bin/sh.
export SHELL

if [ -n \"$SSH_CLIENT\" -a -z \"`type -P cat`\" ]
then
    # We are being invoked from a non-interactive SSH session
    # (as in \"ssh host command\") but 'cat' cannot be found
    # in $PATH.  Source /etc/profile so we get $PATH and other
    # essential variables.
    source /etc/profile
fi

# Adjust the prompt depending on whether we're in 'guix environment'.
if [ -n \"$GUIX_ENVIRONMENT\" ]
then
    PS1='\\u@\\h \\w [env]\\$ '
else
    PS1='\\u@\\h \\w\\$ '
fi
alias ls='ls -p --color'
alias ll='ls -l'
alias grep='grep --color'\n"))
        (zlogin    (plain-file "zlogin" "\
# Honor system-wide environment variables
source /etc/profile\n"))
        (guile-wm  (computed-file "guile-wm" copy-guile-wm))
        (xdefaults (plain-file "Xdefaults" "\
XTerm*utf8: always
XTerm*metaSendsEscape: true\n"))
        (gdbinit   (plain-file "gdbinit" "\
# Tell GDB where to look for separate debugging files.
set debug-file-directory ~/.guix-profile/lib/debug\n")))
    `((".bash_profile" ,profile)
      (".bashrc" ,bashrc)
      (".zlogin" ,zlogin)
      (".Xdefaults" ,xdefaults)
      (".guile" ,(plain-file "dot-guile"
                             (string-append
                              "(use-modules (ice-9 readline))\n\n"
                              ";; Enable completion at the REPL.\n"
                              "(activate-readline)\n")))
      (".guile-wm" ,guile-wm)
      (".gdbinit" ,gdbinit))))

(define (skeleton-directory skeletons)
  "Return a directory containing SKELETONS, a list of name/derivation tuples."
  (computed-file "skel"
                 (with-imported-modules '((guix build utils))
                   #~(begin
                       (use-modules (ice-9 match)
                                    (guix build utils))

                       (mkdir #$output)
                       (chdir #$output)

                       ;; Note: copy the skeletons instead of symlinking
                       ;; them like 'file-union' does, because 'useradd'
                       ;; would just copy the symlinks as is.
                       (for-each (match-lambda
                                   ((target source)
                                    (copy-recursively source target)))
                                 '#$skeletons)
                       #t))))

(define (assert-valid-users/groups users groups)
  "Raise an error if USERS refer to groups not listed in GROUPS."
  (let ((groups (list->set (map user-group-name groups))))
    (define (validate-supplementary-group user group)
      (unless (set-contains? groups group)
        (raise (condition
                (&message
                 (message
                  (format #f (G_ "supplementary group '~a' \
of user '~a' is undeclared")
                          group
                          (user-account-name user))))))))

    (for-each (lambda (user)
                (unless (set-contains? groups (user-account-group user))
                  (raise (condition
                          (&message
                           (message
                            (format #f (G_ "primary group '~a' \
of user '~a' is undeclared")
                                    (user-account-group user)
                                    (user-account-name user)))))))

                (for-each (cut validate-supplementary-group user <>)
                          (user-account-supplementary-groups user)))
              users)))


;;;
;;; Service.
;;;

(define (user-group->gexp group)
  "Turn GROUP, a <user-group> object, into a list-valued gexp suitable for
'active-groups'."
  #~(list #$(user-group-name group)
          #$(user-group-password group)
          #$(user-group-id group)
          #$(user-group-system? group)))

(define (user-account->gexp account)
  "Turn ACCOUNT, a <user-account> object, into a list-valued gexp suitable for
'activate-users'."
  #~`(#$(user-account-name account)
      #$(user-account-uid account)
      #$(user-account-group account)
      #$(user-account-supplementary-groups account)
      #$(user-account-comment account)
      #$(user-account-home-directory account)
      #$(user-account-create-home-directory? account)
      ,#$(user-account-shell account)             ; this one is a gexp
      #$(user-account-password account)
      #$(user-account-system? account)))

(define (account-activation accounts+groups)
  "Return a gexp that activates ACCOUNTS+GROUPS, a list of <user-account> and
<user-group> objects.  Raise an error if a user account refers to a undefined
group."
  (define accounts
    (filter user-account? accounts+groups))

  (define user-specs
    (map user-account->gexp accounts))

  (define groups
    (filter user-group? accounts+groups))

  (define group-specs
    (map user-group->gexp groups))

  (assert-valid-users/groups accounts groups)

  ;; Add users and user groups.
  #~(begin
      (setenv "PATH"
              (string-append #$(@ (gnu packages admin) shadow) "/sbin"))
      (activate-users+groups (list #$@user-specs)
                             (list #$@group-specs))))

(define (account-shepherd-service accounts+groups)
  "Return a Shepherd service that creates the home directories for the user
accounts among ACCOUNTS+GROUPS."
  (define accounts
    (filter user-account? accounts+groups))

  ;; Create home directories only once 'file-systems' is up.  This makes sure
  ;; they are created in the right place if /home lives on a separate
  ;; partition.
  ;;
  ;; XXX: We arrange for this service to stop right after it's done its job so
  ;; that 'guix system reconfigure' knows that it can reload it fearlessly
  ;; (and thus create new home directories).  The cost of this hack is that
  ;; there's a small window during which first-time logins could happen before
  ;; the home directory has been created.
  (list (shepherd-service
         (requirement '(file-systems))
         (provision '(user-homes))
         (modules '((gnu build activation)))
         (start (with-imported-modules (source-module-closure
                                        '((gnu build activation)))
                  #~(lambda ()
                      (activate-user-home
                       (list #$@(map user-account->gexp accounts)))
                      #f)))                       ;stop
         (stop #~(const #f))
         (respawn? #f)
         (documentation "Create user home directories."))))

(define (shells-file shells)
  "Return a file-like object that builds a shell list for use as /etc/shells
based on SHELLS.  /etc/shells is used by xterm, polkit, and other programs."
  (computed-file "shells"
                 #~(begin
                     (use-modules (srfi srfi-1))

                     (define shells
                       (delete-duplicates (list #$@shells)))

                     (call-with-output-file #$output
                       (lambda (port)
                         (display "\
/bin/sh
/run/current-system/profile/bin/sh
/run/current-system/profile/bin/bash\n" port)
                         (for-each (lambda (shell)
                                     (display shell port)
                                     (newline port))
                                   shells))))))
(define (etc-files arguments)
  "Filter out among ARGUMENTS things corresponding to skeletons, and return
the /etc/skel directory for those."
  (let ((skels (filter pair? arguments))
        (users (filter user-account? arguments)))
    `(("skel" ,(skeleton-directory skels))
      ("shells" ,(shells-file (map user-account-shell users))))))

(define account-service-type
  (service-type (name 'account)

                ;; Concatenate <user-account>, <user-group>, and skeleton
                ;; lists.
                (compose concatenate)
                (extend append)

                (extensions
                 (list (service-extension activation-service-type
                                          account-activation)
                       (service-extension shepherd-root-service-type
                                          account-shepherd-service)
                       (service-extension etc-service-type
                                          etc-files)))))

(define (account-service accounts+groups skeletons)
  "Return a <service> that takes care of user accounts and user groups, with
ACCOUNTS+GROUPS as its initial list of accounts and groups."
  (service account-service-type
           (append skeletons accounts+groups)))

;;; shadow.scm ends here