aboutsummaryrefslogtreecommitdiff
path: root/gnu/services/rsync.scm
blob: e85dd509346451601a143f28c81e35f9b31959f0 (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
;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2017 Oleg Pykhalov <go.wigust@gmail.com>
;;; Copyright © 2021, 2023 Ludovic Courtès <ludo@gnu.org>
;;; Copyright © 2023 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 rsync)
  #:use-module ((gnu build linux-container) #:select (%namespaces))
  #:use-module (gnu services)
  #:use-module (gnu services base)
  #:use-module (gnu services shepherd)
  #:autoload   (gnu system file-systems) (file-system-mapping)
  #:use-module (gnu system shadow)
  #:use-module (gnu packages admin)
  #:use-module (gnu packages linux)
  #:use-module (gnu packages rsync)
  #:use-module (guix records)
  #:use-module (guix gexp)
  #:use-module (guix diagnostics)
  #:use-module (guix i18n)
  #:use-module (guix least-authority)
  #:use-module (srfi srfi-1)
  #:use-module (srfi srfi-26)
  #:use-module (ice-9 match)
  #:export (rsync-configuration
            rsync-configuration?
            rsync-configuration-modules

            rsync-module
            rsync-module?
            rsync-module-name
            rsync-module-file-name
            rsync-module-comment
            rsync-module-read-only
            rsync-module-timeout

            rsync-service-type))

;;;; Commentary:
;;;
;;; This module implements a service that to run instance of Rsync,
;;; files synchronization tool.
;;;
;;;; Code:

(define-with-syntax-properties (warn-share-field-deprecation (value properties))
  (unless (unspecified? value)
    (warning (source-properties->location properties)
             (G_ "the 'share-path' and 'share-comment' fields is deprecated, \
please use 'modules' instead~%")))
  value)

(define-record-type* <rsync-configuration>
  rsync-configuration
  make-rsync-configuration
  rsync-configuration?
  (package       rsync-configuration-package              ; file-like
                 (default rsync))
  (address       rsync-configuration-address              ; string | #f
                 (default #f))
  (port-number   rsync-configuration-port-number          ; integer
                 (default 873))
  (pid-file      rsync-configuration-pid-file             ; string
                 (default "/var/run/rsyncd/rsyncd.pid"))
  (lock-file     rsync-configuration-lock-file            ; string
                 (default "/var/run/rsyncd/rsyncd.lock"))
  (log-file      rsync-configuration-log-file             ; string
                 (default "/var/log/rsyncd.log"))
  (use-chroot?   rsync-configuration-use-chroot?          ; boolean
                 (sanitize warn-share-field-deprecation)
                 (default *unspecified*))
  (modules       rsync-configuration-actual-modules ;list of <rsync-module>
                 (default %default-modules))  ;TODO: eventually remove default
  (share-path    rsync-configuration-share-path           ; string
                 (sanitize warn-share-field-deprecation)
                 (default *unspecified*))
  (share-comment rsync-configuration-share-comment        ; string
                 (sanitize warn-share-field-deprecation)
                 (default *unspecified*))
  (read-only?    rsync-configuration-read-only?           ; boolean
                 (sanitize warn-share-field-deprecation)
                 (default *unspecified*))
  (timeout       rsync-configuration-timeout              ; integer
                 (sanitize warn-share-field-deprecation)
                 (default *unspecified*))
  (user          rsync-configuration-user                 ; string
                 (default "root"))
  (group         rsync-configuration-group                ; string
                 (default "root"))
  (uid           rsync-configuration-uid                  ; string
                 (default "rsyncd"))
  (gid           rsync-configuration-gid                  ; string
                 (default "rsyncd")))

;; Rsync "module": a directory exported the rsync protocol.
(define-record-type* <rsync-module>
  rsync-module make-rsync-module
  rsync-module?
  (name          rsync-module-name)               ;string
  (file-name     rsync-module-file-name)          ;string
  (comment       rsync-module-comment             ;string
                 (default ""))
  (read-only?    rsync-module-read-only?          ;boolean
                 (default #t))
  (chroot?       rsync-module-chroot?             ;boolean
                 (default #t))
  (timeout       rsync-module-timeout             ;integer
                 (default 300)))

(define %default-modules
  ;; Default modules, provided for backward compatibility.
  (list (rsync-module (name "files")
                      (file-name "/srv/rsyncd")
                      (comment "Rsync share")
                      (read-only? #f))))          ;yes, that was the default

(define (rsync-configuration-modules config)
  (match-record config <rsync-configuration>
    (modules
     share-path share-comment use-chroot? read-only? timeout) ;deprecated
    (if (unspecified? share-path)
        (rsync-configuration-actual-modules config)
        (list (rsync-module                       ;backward compatibility
               (name "files")
               (file-name share-path)
               (comment "Rsync share")
               (chroot?
                (if (unspecified? use-chroot?) #t use-chroot?))
               (read-only?
                (if (unspecified? read-only?) #f read-only?))
               (timeout
                (if (unspecified? timeout) 300 timeout)))))))

(define (rsync-account config)
  "Return the user accounts and user groups for CONFIG."
  (let ((rsync-user (if (rsync-configuration-uid config)
                        (rsync-configuration-uid config)
                        (rsync-configuration-user config)))
        (rsync-group (if (rsync-configuration-gid config)
                         (rsync-configuration-gid config)
                         (rsync-configuration-group config))))
    (list (user-group (name rsync-group) (system? #t))
          (user-account
           (name rsync-user)
           (system? #t)
           (group rsync-group)
           (comment "rsyncd privilege separation user")
           (home-directory (string-append "/var/run/"
                                          rsync-user))
           (shell (file-append shadow "/sbin/nologin"))))))

(define (rsync-activation config)
  "Return the activation GEXP for CONFIG."
  (with-imported-modules '((guix build utils))
    #~(begin
        (let ((user  (getpw (if #$(rsync-configuration-uid config)
                                #$(rsync-configuration-uid config)
                                #$(rsync-configuration-user config))))
              (group (getpw (if #$(rsync-configuration-gid config)
                                #$(rsync-configuration-gid config)
                                #$(rsync-configuration-group config)))))
          (mkdir-p (dirname #$(rsync-configuration-pid-file config)))
          (for-each (lambda (directory)
                      (mkdir-p directory)
                      (chown directory (passwd:uid user) (group:gid group)))
                    '#$(map rsync-module-file-name
                            (rsync-configuration-modules config)))))))

(define (rsync-config-file config)
  ;; Return the rsync configuration file corresponding to CONFIG.
  (define (module-config module)
    (match-record module <rsync-module>
      (name file-name comment chroot? read-only? timeout)
      (list "[" name "]\n"
            "  path = " file-name "\n"
            "  use chroot = " (if chroot? "true" "false") "\n"
            "  comment = " comment "\n"
            "  read only = " (if read-only? "true" "false") "\n"
            "  timeout = " (number->string timeout) "\n")))

  (define modules
    (rsync-configuration-modules config))

  (match-record config <rsync-configuration>
    (package address port-number pid-file lock-file log-file
             user group uid gid)
    (unless (string=? user "root")
      (cond
       ((<= port-number 1024)
        (error (string-append "rsync-service: to run on port "
                              (number->string port-number)
                              ", user must be root.")))
       ((find rsync-module-chroot? modules)
        (error (string-append "rsync-service: to run in a chroot"
                              ", user must be root.")))
       (uid
        (error "rsync-service: to use uid, user must be root."))
       (gid
        (error "rsync-service: to use gid, user must be root."))))

    (apply mixed-text-file "rsync.conf"
           "# Generated by 'rsync-service'.\n\n"
           "pid file = " pid-file "\n"
           "lock file = " lock-file "\n"
           "log file = " log-file "\n"
           (if address (string-append "address = " address "\n") "")
           "port = " (number->string port-number) "\n"
           (if uid (string-append "uid = " uid "\n") "")
           "gid = " (if gid gid "nogroup") "\n"   ; no group nobody
           "\n\n"
           (append-map module-config modules))))

(define (rsync-shepherd-service config)
  "Return a <shepherd-service> for rsync with CONFIG."

  ;; XXX: Predicates copied from (gnu services ssh).
  (define inetd-style?
    #~(and (defined? 'make-inetd-constructor)
           (not (string=? (@ (shepherd config) Version) "0.9.0"))))

  (define ipv6-support?
    #~(catch 'system-error
        (lambda ()
          (let ((sock (socket AF_INET6 SOCK_STREAM 0)))
            (close-port sock)
            #t))
        (const #f)))

  (define (module->file-system-mapping module)
    "Return the <file-system-mapping> record corresponding to MODULE, an
<rsync-module> object."
    (match-record module <rsync-module>
      (file-name read-only?)
      (file-system-mapping
       (source file-name)
       (target source)
       (writable? (not read-only?)))))

  (match-record config <rsync-configuration>
    (package log-file modules pid-file port-number user group)
    ;; Run the rsync daemon in its own 'mnt' namespace, to guard against
    ;; change to mount points it may be serving.
    (let* ((config-file (rsync-config-file config))
           (rsync-command #~(list #$(least-authority-wrapper
                                     (file-append rsync "/bin/rsync")
                                     #:name "rsync"
                                     #:namespaces (fold delq %namespaces
                                                        '(net user))
                                     #:mappings
                                     (append (list (file-system-mapping
                                                    (source "/var/run/rsyncd")
                                                    (target source)
                                                    (writable? #t))
                                                   (file-system-mapping
                                                    (source (dirname log-file))
                                                    (target source)
                                                    (writable? #t))
                                                   (file-system-mapping
                                                    (source config-file)
                                                    (target source)))
                                             (map module->file-system-mapping
                                                  modules)))
                                  "--config" #$config-file "--daemon")))
      (list (shepherd-service
             (provision '(rsync))
             (documentation "Run rsync daemon.")
             (actions (list (shepherd-configuration-action config-file)))
             (start #~(if #$inetd-style?
                          (make-inetd-constructor
                           #$rsync-command
                           (cons (endpoint
                                  (make-socket-address AF_INET INADDR_ANY
                                                       #$port-number))
                                 (if #$ipv6-support?
                                     (list
                                      (endpoint
                                       (make-socket-address AF_INET6 IN6ADDR_ANY
                                                            #$port-number)))
                                     '()))
                           #:service-name-stem "rsync"
                           #:user #$user
                           #:group #$group)
                          (make-forkexec-constructor #$rsync-command
                                                     #:pid-file #$pid-file
                                                     #:user #$user
                                                     #:group #$group)))
             (stop #~(if #$inetd-style?
                         (make-inetd-destructor)
                         (make-kill-destructor))))))))

(define rsync-service-type
  (service-type
   (name 'rsync)
   (extensions
    (list (service-extension shepherd-root-service-type rsync-shepherd-service)
          (service-extension account-service-type rsync-account)
          (service-extension activation-service-type rsync-activation)))
   (default-value (rsync-configuration))
   (description
    "Run the rsync file copying tool in daemon mode.  This allows remote hosts
to keep synchronized copies of the files exported by rsync.")))