summaryrefslogtreecommitdiff
path: root/gnu/services/dns.scm
blob: 2ed7b9e22f32eb59354d27d0ce4af7ece2c0bf4f (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
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
;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2017 Julien Lepiller <julien@lepiller.eu>
;;;
;;; 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 dns)
  #:use-module (gnu services)
  #:use-module (gnu services configuration)
  #:use-module (gnu services shepherd)
  #:use-module (gnu system shadow)
  #:use-module (gnu packages admin)
  #:use-module (gnu packages dns)
  #:use-module (guix packages)
  #:use-module (guix records)
  #:use-module (guix gexp)
  #:use-module (srfi srfi-1)
  #:use-module (srfi srfi-34)
  #:use-module (srfi srfi-35)
  #:use-module (ice-9 match)
  #:use-module (ice-9 regex)
  #:export (knot-service-type
            knot-acl-configuration
            knot-key-configuration
            knot-keystore-configuration
            knot-zone-configuration
            knot-remote-configuration
            knot-policy-configuration
            knot-configuration
            define-zone-entries
            zone-file
            zone-entry))

;;;
;;; Knot DNS.
;;;

(define-record-type* <knot-key-configuration>
  knot-key-configuration make-knot-key-configuration
  knot-key-configuration?
  (id        knot-key-configuration-id
             (default ""))
  (algorithm knot-key-configuration-algorithm
             (default #f)); one of #f, or an algorithm name
  (secret    knot-key-configuration-secret
             (default "")))

(define-record-type* <knot-acl-configuration>
  knot-acl-configuration make-knot-acl-configuration
  knot-acl-configuration?
  (id      knot-acl-configuration-id
           (default ""))
  (address knot-acl-configuration-address
           (default '()))
  (key     knot-acl-configuration-key
           (default '()))
  (action  knot-acl-configuration-action
           (default '()))
  (deny?   knot-acl-configuration-deny?
           (default #f)))

(define-record-type* <zone-entry>
  zone-entry make-zone-entry
  zone-entry?
  (name  zone-entry-name
         (default "@"))
  (ttl   zone-entry-ttl
         (default ""))
  (class zone-entry-class
         (default "IN"))
  (type  zone-entry-type
         (default "A"))
  (data  zone-entry-data
         (default "")))

(define-record-type* <zone-file>
  zone-file make-zone-file
  zone-file?
  (entries zone-file-entries
           (default '()))
  (origin  zone-file-origin
           (default ""))
  (ns      zone-file-ns
           (default "ns"))
  (mail    zone-file-mail
           (default "hostmaster"))
  (serial  zone-file-serial
           (default 1))
  (refresh zone-file-refresh
           (default "2d"))
  (retry   zone-file-retry
           (default "15m"))
  (expiry  zone-file-expiry
           (default "2w"))
  (nx      zone-file-nx
           (default "1h")))
(define-record-type* <knot-keystore-configuration>
  knot-keystore-configuration make-knot-keystore-configuration
  knot-keystore-configuration?
  (id knot-keystore-configuration-id
      (default ""))
  (backend knot-keystore-configuration-backend
           (default 'pem))
  (config  knot-keystore-configuration-config
           (default "/var/lib/knot/keys/keys")))

(define-record-type* <knot-policy-configuration>
  knot-policy-configuration make-knot-policy-configuration
  knot-policy-configuration?
  (id                   knot-policy-configuration-id
                        (default ""))
  (keystore             knot-policy-configuration-keystore
                        (default "default"))
  (manual?              knot-policy-configuration-manual?
                        (default #f))
  (single-type-signing? knot-policy-configuration-single-type-signing?
                        (default #f))
  (algorithm            knot-policy-configuration-algorithm
                        (default "ecdsap256sha256"))
  (ksk-size             knot-policy-configuration-ksk-size
                        (default 256))
  (zsk-size             knot-policy-configuration-zsk-size
                        (default 256))
  (dnskey-ttl           knot-policy-configuration-dnskey-ttl
                        (default 'default))
  (zsk-lifetime         knot-policy-configuration-zsk-lifetime
                        (default "30d"))
  (propagation-delay    knot-policy-configuration-propagation-delay
                        (default "1d"))
  (rrsig-lifetime       knot-policy-configuration-rrsig-lifetime
                        (default "14d"))
  (rrsig-refresh        knot-policy-configuration-rrsig-refresh
                        (default "7d"))
  (nsec3?               knot-policy-configuration-nsec3?
                        (default #f))
  (nsec3-iterations     knot-policy-configuration-nsec3-iterations
                        (default 5))
  (nsec3-salt-length    knot-policy-configuration-nsec3-salt-length
                        (default 8))
  (nsec3-salt-lifetime  knot-policy-configuration-nsec3-salt-lifetime
                        (default "30d")))

(define-record-type* <knot-zone-configuration>
  knot-zone-configuration make-knot-zone-configuration
  knot-zone-configuration?
  (domain           knot-zone-configuration-domain
                    (default ""))
  (file             knot-zone-configuration-file
                    (default "")) ; the file where this zone is saved.
  (zone             knot-zone-configuration-zone
                    (default (zone-file))) ; initial content of the zone file
  (master           knot-zone-configuration-master
                    (default '()))
  (ddns-master      knot-zone-configuration-ddns-master
                    (default #f))
  (notify           knot-zone-configuration-notify
                    (default '()))
  (acl              knot-zone-configuration-acl
                    (default '()))
  (semantic-checks? knot-zone-configuration-semantic-checks?
                    (default #f))
  (disable-any?     knot-zone-configuration-disable-any?
                    (default #f))
  (zonefile-sync    knot-zone-configuration-zonefile-sync
                    (default 0))
  (dnssec-policy    knot-zone-configuration-dnssec-policy
                    (default #f))
  (serial-policy    knot-zone-configuration-serial-policy
                    (default 'increment)))

(define-record-type* <knot-remote-configuration>
  knot-remote-configuration make-knot-remote-configuration
  knot-remote-configuration?
  (id  knot-remote-configuration-id
       (default ""))
  (address knot-remote-configuration-address
           (default '()))
  (via     knot-remote-configuration-via
           (default '()))
  (key     knot-remote-configuration-key
           (default #f)))

(define-record-type* <knot-configuration>
  knot-configuration make-knot-configuration
  knot-configuration?
  (knot          knot-configuration-knot
                 (default knot))
  (run-directory knot-configuration-run-directory
                 (default "/var/run/knot"))
  (listen-v4     knot-configuration-listen-v4
                 (default "0.0.0.0"))
  (listen-v6     knot-configuration-listen-v6
                 (default "::"))
  (listen-port   knot-configuration-listen-port
                 (default 53))
  (keys          knot-configuration-keys
                 (default '()))
  (keystores     knot-configuration-keystores
                 (default '()))
  (acls          knot-configuration-acls
                 (default '()))
  (remotes       knot-configuration-remotes
                 (default '()))
  (policies      knot-configuration-policies
                 (default '()))
  (zones         knot-configuration-zones
                 (default '())))

(define-syntax define-zone-entries
  (syntax-rules ()
    ((_ id (name ttl class type data) ...)
     (define id (list (make-zone-entry name ttl class type data) ...)))))

(define (error-out msg)
  (raise (condition (&message (message msg)))))

(define (verify-knot-key-configuration key)
  (unless (knot-key-configuration? key)
    (error-out "keys must be a list of only knot-key-configuration."))
  (let ((id (knot-key-configuration-id key)))
    (unless (and (string? id) (not (equal? id "")))
      (error-out "key id must be a non empty string.")))
  (unless (memq '(#f hmac-md5 hmac-sha1 hmac-sha224 hmac-sha256 hmac-sha384 hmac-sha512)
                (knot-key-configuration-algorithm key))
          (error-out "algorithm must be one of: #f, 'hmac-md5, 'hmac-sha1,
'hmac-sha224, 'hmac-sha256, 'hmac-sha384 or 'hmac-sha512")))

(define (verify-knot-keystore-configuration keystore)
  (unless (knot-keystore-configuration? keystore)
    (error-out "keystores must be a list of only knot-keystore-configuration."))
  (let ((id (knot-keystore-configuration-id keystore)))
    (unless (and (string? id) (not (equal? id "")))
      (error-out "keystore id must be a non empty string.")))
  (unless (memq '(pem pkcs11)
                (knot-keystore-configuration-backend keystore))
          (error-out "backend must be one of: 'pem or 'pkcs11")))

(define (verify-knot-policy-configuration policy)
  (unless (knot-keystore-configuration? policy)
    (error-out "policies must be a list of only knot-policy-configuration."))
  (let ((id (knot-policy-configuration-id policy)))
    (unless (and (string? id) (not (equal? id "")))
      (error-out "policy id must be a non empty string."))))

(define (verify-knot-acl-configuration acl)
  (unless (knot-acl-configuration? acl)
    (error-out "acls must be a list of only knot-acl-configuration."))
  (let ((id (knot-acl-configuration-id acl))
        (address (knot-acl-configuration-address acl))
        (key (knot-acl-configuration-key acl))
        (action (knot-acl-configuration-action acl)))
    (unless (and (string? id) (not (equal? id "")))
      (error-out "acl id must be a non empty string."))
    (unless (and (list? address)
                 (fold (lambda (x1 x2) (and (string? x1) (string? x2))) "" address))
      (error-out "acl address must be a list of strings.")))
  (unless (boolean? (knot-acl-configuration-deny? acl))
    (error-out "deny? must be #t or #f.")))

(define (verify-knot-zone-configuration zone)
  (unless (knot-zone-configuration? zone)
    (error-out "zones must be a list of only knot-zone-configuration."))
  (let ((domain (knot-zone-configuration-domain zone)))
    (unless (and (string? domain) (not (equal? domain "")))
      (error-out "zone domain must be a non empty string."))))

(define (verify-knot-remote-configuration remote)
  (unless (knot-remote-configuration? remote)
    (error-out "remotes must be a list of only knot-remote-configuration."))
  (let ((id (knot-remote-configuration-id remote)))
    (unless (and (string? id) (not (equal? id "")))
      (error-out "remote id must be a non empty string."))))

(define (verify-knot-configuration config)
  (unless (package? (knot-configuration-knot config))
    (error-out "knot configuration field must be a package."))
  (unless (string? (knot-configuration-run-directory config))
    (error-out "run-directory must be a string."))
  (unless (list? (knot-configuration-keys config))
    (error-out "keys must be a list of knot-key-configuration."))
  (for-each (lambda (key) (verify-knot-key-configuration key))
            (knot-configuration-keys config))
  (unless (list? (knot-configuration-keystores config))
    (error-out "keystores must be a list of knot-keystore-configuration."))
  (for-each (lambda (keystore) (verify-knot-keystore-configuration keystore))
            (knot-configuration-keystores config))
  (unless (list? (knot-configuration-acls config))
    (error-out "acls must be a list of knot-acl-configuration."))
  (for-each (lambda (acl) (verify-knot-acl-configuration acl))
            (knot-configuration-acls config))
  (unless (list? (knot-configuration-zones config))
    (error-out "zones must be a list of knot-zone-configuration."))
  (for-each (lambda (zone) (verify-knot-zone-configuration zone))
            (knot-configuration-zones config))
  (unless (list? (knot-configuration-policies config))
    (error-out "policies must be a list of knot-policy-configuration."))
  (for-each (lambda (policy) (verify-knot-policy-configuration policy))
            (knot-configuration-policies config))
  (unless (list? (knot-configuration-remotes config))
    (error-out "remotes must be a list of knot-remote-configuration."))
  (for-each (lambda (remote) (verify-knot-remote-configuration remote))
            (knot-configuration-remotes config))
  #t)

(define (format-string-list l)
  "Formats a list of string in YAML"
  (if (eq? l '())
      ""
      (let ((l (reverse l)))
        (string-append
          "["
          (fold (lambda (x1 x2)
                  (string-append (if (symbol? x1) (symbol->string x1) x1) ", "
                                 (if (symbol? x2) (symbol->string x2) x2)))
                (car l) (cdr l))
          "]"))))

(define (knot-acl-config acls)
  (with-output-to-string
    (lambda ()
      (for-each
        (lambda (acl-config)
          (let ((id (knot-acl-configuration-id acl-config))
                (address (knot-acl-configuration-address acl-config))
                (key (knot-acl-configuration-key acl-config))
                (action (knot-acl-configuration-action acl-config))
                (deny? (knot-acl-configuration-deny? acl-config)))
            (format #t "    - id: ~a\n" id)
            (unless (eq? address '())
              (format #t "      address: ~a\n" (format-string-list address)))
            (unless (eq? key '())
              (format #t "      key: ~a\n" (format-string-list key)))
            (unless (eq? action '())
              (format #t "      action: ~a\n" (format-string-list action)))
            (format #t "      deny: ~a\n" (if deny? "on" "off"))))
        acls))))

(define (knot-key-config keys)
  (with-output-to-string
    (lambda ()
      (for-each
        (lambda (key-config)
          (let ((id (knot-key-configuration-id key-config))
                (algorithm (knot-key-configuration-algorithm key-config))
                (secret (knot-key-configuration-secret key-config)))
            (format #t     "    - id: ~a\n" id)
            (if algorithm
                (format #t "      algorithm: ~a\n" (symbol->string algorithm)))
            (format #t     "      secret: ~a\n" secret)))
        keys))))

(define (knot-keystore-config keystores)
  (with-output-to-string
    (lambda ()
      (for-each
        (lambda (keystore-config)
          (let ((id (knot-keystore-configuration-id keystore-config))
                (backend (knot-keystore-configuration-backend keystore-config))
                (config (knot-keystore-configuration-config keystore-config)))
            (format #t "    - id: ~a\n" id)
            (format #t "      backend: ~a\n" (symbol->string backend))
            (format #t "      config: \"~a\"\n" config)))
        keystores))))

(define (knot-policy-config policies)
  (with-output-to-string
    (lambda ()
      (for-each
        (lambda (policy-config)
          (let ((id (knot-policy-configuration-id policy-config))
                (keystore (knot-policy-configuration-keystore policy-config))
                (manual? (knot-policy-configuration-manual? policy-config))
                (single-type-signing? (knot-policy-configuration-single-type-signing?
                                        policy-config))
                (algorithm (knot-policy-configuration-algorithm policy-config))
                (ksk-size (knot-policy-configuration-ksk-size policy-config))
                (zsk-size (knot-policy-configuration-zsk-size policy-config))
                (dnskey-ttl (knot-policy-configuration-dnskey-ttl policy-config))
                (zsk-lifetime (knot-policy-configuration-zsk-lifetime policy-config))
                (propagation-delay (knot-policy-configuration-propagation-delay
                                     policy-config))
                (rrsig-lifetime (knot-policy-configuration-rrsig-lifetime
                                  policy-config))
                (nsec3? (knot-policy-configuration-nsec3? policy-config))
                (nsec3-iterations (knot-policy-configuration-nsec3-iterations
                                    policy-config))
                (nsec3-salt-length (knot-policy-configuration-nsec3-salt-length
                                     policy-config))
                (nsec3-salt-lifetime (knot-policy-configuration-nsec3-salt-lifetime
                                       policy-config)))
            (format #t "    - id: ~a\n" id)
            (format #t "      keystore: ~a\n" keystore)
            (format #t "      manual: ~a\n" (if manual? "on" "off"))
            (format #t "      single-type-signing: ~a\n" (if single-type-signing?
                                                             "on" "off"))
            (format #t "      algorithm: ~a\n" algorithm)
            (format #t "      ksk-size: ~a\n" (number->string ksk-size))
            (format #t "      zsk-size: ~a\n" (number->string zsk-size))
            (unless (eq? dnskey-ttl 'default)
              (format #t "      dnskey-ttl: ~a\n" dnskey-ttl))
            (format #t "      zsk-lifetime: ~a\n" zsk-lifetime)
            (format #t "      propagation-delay: ~a\n" propagation-delay)
            (format #t "      rrsig-lifetime: ~a\n" rrsig-lifetime)
            (format #t "      nsec3: ~a\n" (if nsec3? "on" "off"))
            (format #t "      nsec3-iterations: ~a\n"
                    (number->string nsec3-iterations))
            (format #t "      nsec3-salt-length: ~a\n"
                    (number->string nsec3-salt-length))
            (format #t "      nsec3-salt-lifetime: ~a\n" nsec3-salt-lifetime)))
        policies))))

(define (knot-remote-config remotes)
  (with-output-to-string
    (lambda ()
      (for-each
        (lambda (remote-config)
          (let ((id (knot-remote-configuration-id remote-config))
                (address (knot-remote-configuration-address remote-config))
                (via (knot-remote-configuration-via remote-config))
                (key (knot-remote-configuration-key remote-config)))
            (format #t "    - id: ~a\n" id)
            (unless (eq? address '())
              (format #t "      address: ~a\n" (format-string-list address)))
            (unless (eq? via '())
              (format #t "      via: ~a\n" (format-string-list via)))
            (if key
              (format #t "      key: ~a\n" key))))
        remotes))))

(define (serialize-zone-entries entries)
  (with-output-to-string
    (lambda ()
      (for-each
        (lambda (entry)
          (let ((name (zone-entry-name entry))
                (ttl (zone-entry-ttl entry))
                (class (zone-entry-class entry))
                (type (zone-entry-type entry))
                (data (zone-entry-data entry)))
            (format #t "~a ~a ~a ~a ~a\n" name ttl class type data)))
        entries))))

(define (serialize-zone-file zone domain)
  (computed-file (string-append domain ".zone")
    #~(begin
        (call-with-output-file #$output
          (lambda (port)
            (format port "$ORIGIN ~a.\n"
                    #$(zone-file-origin zone))
            (format port "@ IN SOA ~a ~a (~a ~a ~a ~a ~a)\n"
                    #$(zone-file-ns zone)
                    #$(zone-file-mail zone)
                    #$(zone-file-serial zone)
                    #$(zone-file-refresh zone)
                    #$(zone-file-retry zone)
                    #$(zone-file-expiry zone)
                    #$(zone-file-nx zone))
            (format port "~a\n"
                    #$(serialize-zone-entries (zone-file-entries zone))))))))

(define (knot-zone-config zone)
  (let ((content (knot-zone-configuration-zone zone)))
    #~(with-output-to-string
        (lambda ()
          (let ((domain #$(knot-zone-configuration-domain zone))
                (file #$(knot-zone-configuration-file zone))
                (master (list #$@(knot-zone-configuration-master zone)))
                (ddns-master #$(knot-zone-configuration-ddns-master zone))
                (notify (list #$@(knot-zone-configuration-notify zone)))
                (acl (list #$@(knot-zone-configuration-acl zone)))
                (semantic-checks? #$(knot-zone-configuration-semantic-checks? zone))
                (disable-any? #$(knot-zone-configuration-disable-any? zone))
                (dnssec-policy #$(knot-zone-configuration-dnssec-policy zone))
                (serial-policy '#$(knot-zone-configuration-serial-policy zone)))
            (format #t "    - domain: ~a\n" domain)
            (if (eq? master '())
                ;; This server is a master
                (if (equal? file "")
                  (format #t "      file: ~a\n"
                    #$(serialize-zone-file content
                                           (knot-zone-configuration-domain zone)))
                  (format #t "      file: ~a\n" file))
                ;; This server is a slave (has masters)
                (begin
                  (format #t "      master: ~a\n"
                          #$(format-string-list
                              (knot-zone-configuration-master zone)))
                  (if ddns-master (format #t "      ddns-master ~a\n" ddns-master))))
            (unless (eq? notify '())
              (format #t "      notify: ~a\n"
                      #$(format-string-list
                          (knot-zone-configuration-notify zone))))
            (unless (eq? acl '())
              (format #t "      acl: ~a\n"
                      #$(format-string-list
                          (knot-zone-configuration-acl zone))))
            (format #t "      semantic-checks: ~a\n" (if semantic-checks? "on" "off"))
            (format #t "      disable-any: ~a\n" (if disable-any? "on" "off"))
            (if dnssec-policy
                (begin
                  (format #t "      dnssec-signing: on\n")
                  (format #t "      dnssec-policy: ~a\n" dnssec-policy)))
            (format #t "      serial-policy: ~a\n"
                    (symbol->string serial-policy)))))))

(define (knot-config-file config)
  (verify-knot-configuration config)
  (computed-file "knot.conf"
    #~(begin
        (call-with-output-file #$output
          (lambda (port)
            (format port "server:\n")
            (format port "    rundir: ~a\n" #$(knot-configuration-run-directory config))
            (format port "    user: knot\n")
            (format port "    listen: ~a@~a\n"
                    #$(knot-configuration-listen-v4 config)
                    #$(knot-configuration-listen-port config))
            (format port "    listen: ~a@~a\n"
                    #$(knot-configuration-listen-v6 config)
                    #$(knot-configuration-listen-port config))
            (format port "\nkey:\n")
            (format port #$(knot-key-config (knot-configuration-keys config)))
            (format port "\nkeystore:\n")
            (format port #$(knot-keystore-config (knot-configuration-keystores config)))
            (format port "\nacl:\n")
            (format port #$(knot-acl-config (knot-configuration-acls config)))
            (format port "\nremote:\n")
            (format port #$(knot-remote-config (knot-configuration-remotes config)))
            (format port "\npolicy:\n")
            (format port #$(knot-policy-config (knot-configuration-policies config)))
            (unless #$(eq? (knot-configuration-zones config) '())
              (format port "\nzone:\n")
              (format port "~a\n"
                      (string-concatenate
                        (list #$@(map knot-zone-config
                                      (knot-configuration-zones config)))))))))))

(define %knot-accounts
  (list (user-group (name "knot") (system? #t))
        (user-account
          (name "knot")
          (group "knot")
          (system? #t)
          (comment "knot dns server user")
          (home-directory "/var/empty")
          (shell (file-append shadow "/sbin/nologin")))))

(define (knot-activation config)
  #~(begin
      (use-modules (guix build utils))
      (define (mkdir-p/perms directory owner perms)
        (mkdir-p directory)
        (chown directory (passwd:uid owner) (passwd:gid owner))
        (chmod directory perms))
      (mkdir-p/perms #$(knot-configuration-run-directory config)
                     (getpwnam "knot") #o755)
      (mkdir-p/perms "/var/lib/knot" (getpwnam "knot") #o755)
      (mkdir-p/perms "/var/lib/knot/keys" (getpwnam "knot") #o755)
      (mkdir-p/perms "/var/lib/knot/keys/keys" (getpwnam "knot") #o755)))

(define (knot-shepherd-service config)
  (let* ((config-file (knot-config-file config))
         (knot (knot-configuration-knot config)))
    (list (shepherd-service
            (documentation "Run the Knot DNS daemon.")
            (provision '(knot dns))
            (requirement '(networking))
            (start #~(make-forkexec-constructor
                       (list (string-append #$knot "/sbin/knotd")
                             "-c" #$config-file)))
            (stop #~(make-kill-destructor))))))

(define knot-service-type
  (service-type (name 'knot)
                (extensions
                  (list (service-extension shepherd-root-service-type
                                           knot-shepherd-service)
                        (service-extension activation-service-type
                                           knot-activation)
                        (service-extension account-service-type
                                           (const %knot-accounts))))))