File: mosquitto.conf

package info (click to toggle)
mosquitto 1.4.10-3%2Bdeb9u4
  • links: PTS, VCS
  • area: main
  • in suites: stretch
  • size: 3,968 kB
  • sloc: ansic: 18,665; python: 3,996; xml: 3,803; cpp: 1,502; makefile: 718; sh: 221; perl: 70
file content (830 lines) | stat: -rw-r--r-- 37,375 bytes parent folder | download
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
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
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
# Config file for mosquitto
#
# See mosquitto.conf(5) for more information.
#
# Default values are shown, uncomment to change.
#
# Use the # character to indicate a comment, but only if it is the 
# very first character on the line.

# =================================================================
# General configuration
# =================================================================

# Time in seconds to wait before resending an outgoing QoS=1 or 
# QoS=2 message.
#retry_interval 20

# Time in seconds between updates of the $SYS tree.
# Set to 0 to disable the publishing of the $SYS tree.
#sys_interval 10

# Time in seconds between cleaning the internal message store of 
# unreferenced messages. Lower values will result in lower memory 
# usage but more processor time, higher values will have the 
# opposite effect.
# Setting a value of 0 means the unreferenced messages will be 
# disposed of as quickly as possible.
#store_clean_interval 10

# Write process id to a file. Default is a blank string which means 
# a pid file shouldn't be written.
# This should be set to /var/run/mosquitto.pid if mosquitto is
# being run automatically on boot with an init script and 
# start-stop-daemon or similar.
#pid_file

# When run as root, drop privileges to this user and its primary 
# group.
# Leave blank to stay as root, but this is not recommended.
# If run as a non-root user, this setting has no effect.
# Note that on Windows this has no effect and so mosquitto should 
# be started by the user you wish it to run as.
#user mosquitto

# The maximum number of QoS 1 and 2 messages currently inflight per 
# client.
# This includes messages that are partway through handshakes and 
# those that are being retried. Defaults to 20. Set to 0 for no 
# maximum. Setting to 1 will guarantee in-order delivery of QoS 1 
# and 2 messages.
#max_inflight_messages 20

# The maximum number of QoS 1 and 2 messages to hold in a queue 
# above those that are currently in-flight.  Defaults to 100. Set 
# to 0 for no maximum (not recommended).
# See also queue_qos0_messages.
#max_queued_messages 100

# Set to true to queue messages with QoS 0 when a persistent client is
# disconnected. These messages are included in the limit imposed by
# max_queued_messages.
# Defaults to false.
# This is a non-standard option for the MQTT v3.1 spec but is allowed in
# v3.1.1.
#queue_qos0_messages false

# This option sets the maximum publish payload size that the broker will allow.
# Received messages that exceed this size will not be accepted by the broker.
# The default value is 0, which means that all valid MQTT messages are
# accepted. MQTT imposes a maximum payload size of 268435455 bytes. 
#message_size_limit 0

# This option controls whether a client is allowed to connect with a zero
# length client id or not. This option only affects clients using MQTT v3.1.1
# and later. If set to false, clients connecting with a zero length client id
# are disconnected. If set to true, clients will be allocated a client id by
# the broker. This means it is only useful for clients with clean session set
# to true.
#allow_zero_length_clientid true

# If allow_zero_length_clientid is true, this option allows you to set a prefix
# to automatically generated client ids to aid visibility in logs.
#auto_id_prefix

# This option allows persistent clients (those with clean session set to false)
# to be removed if they do not reconnect within a certain time frame.
#
# This is a non-standard option in MQTT V3.1 but allowed in MQTT v3.1.1.
#
# Badly designed clients may set clean session to false whilst using a randomly
# generated client id. This leads to persistent clients that will never
# reconnect. This option allows these clients to be removed.
#
# The expiration period should be an integer followed by one of h d w m y for
# hour, day, week, month and year respectively. For example
#
# persistent_client_expiration 2m
# persistent_client_expiration 14d
# persistent_client_expiration 1y
#
# The default if not set is to never expire persistent clients.
#persistent_client_expiration

# If a client is subscribed to multiple subscriptions that overlap, e.g. foo/#
# and foo/+/baz , then MQTT expects that when the broker receives a message on
# a topic that matches both subscriptions, such as foo/bar/baz, then the client
# should only receive the message once.
# Mosquitto keeps track of which clients a message has been sent to in order to
# meet this requirement. The allow_duplicate_messages option allows this
# behaviour to be disabled, which may be useful if you have a large number of
# clients subscribed to the same set of topics and are very concerned about
# minimising memory usage.
# It can be safely set to true if you know in advance that your clients will
# never have overlapping subscriptions, otherwise your clients must be able to
# correctly deal with duplicate messages even when then have QoS=2.
#allow_duplicate_messages false

# The MQTT specification requires that the QoS of a message delivered to a
# subscriber is never upgraded to match the QoS of the subscription. Enabling
# this option changes this behaviour. If upgrade_outgoing_qos is set true,
# messages sent to a subscriber will always match the QoS of its subscription.
# This is a non-standard option explicitly disallowed by the spec.
#upgrade_outgoing_qos false

# This option affects the scenario when a client subscribes to a topic that has
# retained messages. It is possible that the client that published the retained
# message to the topic had access at the time they published, but that access
# has been subsequently removed. If check_retain_source is set to true, the
# default, the source of a retained message will be checked for access rights
# before it is republished. When set to false, no check will be made and the
# retained message will always be published. This affects all listeners.
#check_retain_source true

# =================================================================
# Default listener
# =================================================================

# IP address/hostname to bind the default listener to. If not
# given, the default listener will not be bound to a specific 
# address and so will be accessible to all network interfaces.
# bind_address ip-address/host name
#bind_address

# Port to use for the default listener.
#port 1883

# The maximum number of client connections to allow. This is 
# a per listener setting.
# Default is -1, which means unlimited connections.
# Note that other process limits mean that unlimited connections 
# are not really possible. Typically the default maximum number of 
# connections possible is around 1024.
#max_connections -1

# Choose the protocol to use when listening.
# This can be either mqtt or websockets.
# Websockets support is currently disabled by default at compile time.
# Certificate based TLS may be used with websockets, except that
# only the cafile, certfile, keyfile and ciphers options are supported.
#protocol mqtt

# When a listener is using the websockets protocol, it is possible to serve
# http data as well. Set http_dir to a directory which contains the files you
# wish to serve. If this option is not specified, then no normal http
# connections will be possible.
#http_dir

# Set use_username_as_clientid to true to replace the clientid that a client
# connected with with its username. This allows authentication to be tied to
# the clientid, which means that it is possible to prevent one client
# disconnecting another by using the same clientid.
# If a client connects with no username it will be disconnected as not
# authorised when this option is set to true.
# Do not use in conjunction with clientid_prefixes.
# See also use_identity_as_username.
#use_username_as_clientid

# -----------------------------------------------------------------
# Certificate based SSL/TLS support
# -----------------------------------------------------------------
# The following options can be used to enable SSL/TLS support for 
# this listener. Note that the recommended port for MQTT over TLS
# is 8883, but this must be set manually.
#
# See also the mosquitto-tls man page.

# At least one of cafile or capath must be defined. They both 
# define methods of accessing the PEM encoded Certificate 
# Authority certificates that have signed your server certificate 
# and that you wish to trust.
# cafile defines the path to a file containing the CA certificates.
# capath defines a directory that will be searched for files
# containing the CA certificates. For capath to work correctly, the
# certificate files must have ".crt" as the file ending and you must run
# "c_rehash <path to capath>" each time you add/remove a certificate.
#cafile
#capath

# Path to the PEM encoded server certificate.
#certfile

# Path to the PEM encoded keyfile.
#keyfile

# This option defines the version of the TLS protocol to use for this listener.
# The default value allows v1.2, v1.1 and v1.0, if they are all supported by
# the version of openssl that the broker was compiled against. For openssl >=
# 1.0.1 the valid values are tlsv1.2 tlsv1.1 and tlsv1. For openssl < 1.0.1 the
# valid values are tlsv1.
#tls_version

# By default a TLS enabled listener will operate in a similar fashion to a
# https enabled web server, in that the server has a certificate signed by a CA
# and the client will verify that it is a trusted certificate. The overall aim
# is encryption of the network traffic. By setting require_certificate to true,
# the client must provide a valid certificate in order for the network
# connection to proceed. This allows access to the broker to be controlled
# outside of the mechanisms provided by MQTT.
#require_certificate false

# If require_certificate is true, you may set use_identity_as_username to true
# to use the CN value from the client certificate as a username. If this is
# true, the password_file option will not be used for this listener.
#use_identity_as_username false

# If you have require_certificate set to true, you can create a certificate
# revocation list file to revoke access to particular client certificates. If
# you have done this, use crlfile to point to the PEM encoded revocation file.
#crlfile

# If you wish to control which encryption ciphers are used, use the ciphers
# option. The list of available ciphers can be optained using the "openssl
# ciphers" command and should be provided in the same format as the output of
# that command.
# If unset defaults to DEFAULT:!aNULL:!eNULL:!LOW:!EXPORT:!SSLv2:@STRENGTH
#ciphers DEFAULT:!aNULL:!eNULL:!LOW:!EXPORT:!SSLv2:@STRENGTH

# -----------------------------------------------------------------
# Pre-shared-key based SSL/TLS support
# -----------------------------------------------------------------
# The following options can be used to enable PSK based SSL/TLS support for
# this listener. Note that the recommended port for MQTT over TLS is 8883, but
# this must be set manually.
#
# See also the mosquitto-tls man page and the "Certificate based SSL/TLS
# support" section. Only one of certificate or PSK encryption support can be
# enabled for any listener.

# The psk_hint option enables pre-shared-key support for this listener and also
# acts as an identifier for this listener. The hint is sent to clients and may
# be used locally to aid authentication. The hint is a free form string that
# doesn't have much meaning in itself, so feel free to be creative.
# If this option is provided, see psk_file to define the pre-shared keys to be
# used or create a security plugin to handle them.
#psk_hint

# Set use_identity_as_username to have the psk identity sent by the client used
# as its username. Authentication will be carried out using the PSK rather than
# the MQTT username/password and so password_file will not be used for this
# listener.
#use_identity_as_username false

# When using PSK, the encryption ciphers used will be chosen from the list of
# available PSK ciphers. If you want to control which ciphers are available,
# use the "ciphers" option.  The list of available ciphers can be optained
# using the "openssl ciphers" command and should be provided in the same format
# as the output of that command.
#ciphers

# =================================================================
# Extra listeners
# =================================================================

# Listen on a port/ip address combination. By using this variable 
# multiple times, mosquitto can listen on more than one port. If 
# this variable is used and neither bind_address nor port given, 
# then the default listener will not be started.
# The port number to listen on must be given. Optionally, an ip 
# address or host name may be supplied as a second argument. In 
# this case, mosquitto will attempt to bind the listener to that 
# address and so restrict access to the associated network and 
# interface. By default, mosquitto will listen on all interfaces.
# Note that for a websockets listener it is not possible to bind to a host
# name.
# listener port-number [ip address/host name]
#listener

# The maximum number of client connections to allow. This is 
# a per listener setting.
# Default is -1, which means unlimited connections.
# Note that other process limits mean that unlimited connections 
# are not really possible. Typically the default maximum number of 
# connections possible is around 1024.
#max_connections -1

# The listener can be restricted to operating within a topic hierarchy using
# the mount_point option. This is achieved be prefixing the mount_point string
# to all topics for any clients connected to this listener. This prefixing only
# happens internally to the broker; the client will not see the prefix.
#mount_point

# Choose the protocol to use when listening.
# This can be either mqtt or websockets.
# Certificate based TLS may be used with websockets, except that only the
# cafile, certfile, keyfile and ciphers options are supported.
#protocol mqtt

# When a listener is using the websockets protocol, it is possible to serve
# http data as well. Set http_dir to a directory which contains the files you
# wish to serve. If this option is not specified, then no normal http
# connections will be possible.
#http_dir

# Set use_username_as_clientid to true to replace the clientid that a client
# connected with with its username. This allows authentication to be tied to
# the clientid, which means that it is possible to prevent one client
# disconnecting another by using the same clientid.
# If a client connects with no username it will be disconnected as not
# authorised when this option is set to true.
# Do not use in conjunction with clientid_prefixes.
# See also use_identity_as_username.
#use_username_as_clientid

# -----------------------------------------------------------------
# Certificate based SSL/TLS support
# -----------------------------------------------------------------
# The following options can be used to enable certificate based SSL/TLS support
# for this listener. Note that the recommended port for MQTT over TLS is 8883,
# but this must be set manually.
#
# See also the mosquitto-tls man page and the "Pre-shared-key based SSL/TLS
# support" section. Only one of certificate or PSK encryption support can be
# enabled for any listener.

# At least one of cafile or capath must be defined to enable certificate based
# TLS encryption. They both define methods of accessing the PEM encoded
# Certificate Authority certificates that have signed your server certificate
# and that you wish to trust.
# cafile defines the path to a file containing the CA certificates.
# capath defines a directory that will be searched for files
# containing the CA certificates. For capath to work correctly, the
# certificate files must have ".crt" as the file ending and you must run
# "c_rehash <path to capath>" each time you add/remove a certificate.
#cafile
#capath

# Path to the PEM encoded server certificate.
#certfile

# Path to the PEM encoded keyfile.
#keyfile

# By default an TLS enabled listener will operate in a similar fashion to a
# https enabled web server, in that the server has a certificate signed by a CA
# and the client will verify that it is a trusted certificate. The overall aim
# is encryption of the network traffic. By setting require_certificate to true,
# the client must provide a valid certificate in order for the network
# connection to proceed. This allows access to the broker to be controlled
# outside of the mechanisms provided by MQTT.
#require_certificate false

# If require_certificate is true, you may set use_identity_as_username to true
# to use the CN value from the client certificate as a username. If this is
# true, the password_file option will not be used for this listener.
#use_identity_as_username false

# If you have require_certificate set to true, you can create a certificate
# revocation list file to revoke access to particular client certificates. If
# you have done this, use crlfile to point to the PEM encoded revocation file.
#crlfile

# If you wish to control which encryption ciphers are used, use the ciphers
# option. The list of available ciphers can be optained using the "openssl
# ciphers" command and should be provided in the same format as the output of
# that command.
#ciphers

# -----------------------------------------------------------------
# Pre-shared-key based SSL/TLS support
# -----------------------------------------------------------------
# The following options can be used to enable PSK based SSL/TLS support for
# this listener. Note that the recommended port for MQTT over TLS is 8883, but
# this must be set manually.
#
# See also the mosquitto-tls man page and the "Certificate based SSL/TLS
# support" section. Only one of certificate or PSK encryption support can be
# enabled for any listener.

# The psk_hint option enables pre-shared-key support for this listener and also
# acts as an identifier for this listener. The hint is sent to clients and may
# be used locally to aid authentication. The hint is a free form string that
# doesn't have much meaning in itself, so feel free to be creative.
# If this option is provided, see psk_file to define the pre-shared keys to be
# used or create a security plugin to handle them.
#psk_hint

# Set use_identity_as_username to have the psk identity sent by the client used
# as its username. Authentication will be carried out using the PSK rather than
# the MQTT username/password and so password_file will not be used for this
# listener.
#use_identity_as_username false

# When using PSK, the encryption ciphers used will be chosen from the list of
# available PSK ciphers. If you want to control which ciphers are available,
# use the "ciphers" option.  The list of available ciphers can be optained
# using the "openssl ciphers" command and should be provided in the same format
# as the output of that command.
#ciphers

# =================================================================
# Persistence
# =================================================================

# If persistence is enabled, save the in-memory database to disk 
# every autosave_interval seconds. If set to 0, the persistence 
# database will only be written when mosquitto exits. See also
# autosave_on_changes.
# Note that writing of the persistence database can be forced by 
# sending mosquitto a SIGUSR1 signal.
#autosave_interval 1800

# If true, mosquitto will count the number of subscription changes, retained
# messages received and queued messages and if the total exceeds
# autosave_interval then the in-memory database will be saved to disk.
# If false, mosquitto will save the in-memory database to disk by treating
# autosave_interval as a time in seconds.
#autosave_on_changes false

# Save persistent message data to disk (true/false).
# This saves information about all messages, including 
# subscriptions, currently in-flight messages and retained 
# messages.
# retained_persistence is a synonym for this option.
#persistence false

# The filename to use for the persistent database, not including 
# the path.
#persistence_file mosquitto.db

# Location for persistent database. Must include trailing /
# Default is an empty string (current directory).
# Set to e.g. /var/lib/mosquitto/ if running as a proper service on Linux or
# similar.
#persistence_location

# =================================================================
# Logging
# =================================================================

# Places to log to. Use multiple log_dest lines for multiple 
# logging destinations.
# Possible destinations are: stdout stderr syslog topic file
#
# stdout and stderr log to the console on the named output.
#
# syslog uses the userspace syslog facility which usually ends up 
# in /var/log/messages or similar.
#
# topic logs to the broker topic '$SYS/broker/log/<severity>', 
# where severity is one of D, E, W, N, I, M which are debug, error, 
# warning, notice, information and message. Message type severity is used by
# the subscribe/unsubscribe log_types and publishes log messages to
# $SYS/broker/log/M/susbcribe or $SYS/broker/log/M/unsubscribe.
#
# The file destination requires an additional parameter which is the file to be
# logged to, e.g. "log_dest file /var/log/mosquitto.log". The file will be
# closed and reopened when the broker receives a HUP signal. Only a single file
# destination may be configured.
#
# Note that if the broker is running as a Windows service it will default to
# "log_dest none" and neither stdout nor stderr logging is available.
# Use "log_dest none" if you wish to disable logging.
#log_dest stderr

# If using syslog logging (not on Windows), messages will be logged to the
# "daemon" facility by default. Use the log_facility option to choose which of
# local0 to local7 to log to instead. The option value should be an integer
# value, e.g. "log_facility 5" to use local5.
#log_facility

# Types of messages to log. Use multiple log_type lines for logging
# multiple types of messages.
# Possible types are: debug, error, warning, notice, information, 
# none, subscribe, unsubscribe, websockets, all.
# Note that debug type messages are for decoding the incoming/outgoing
# network packets. They are not logged in "topics".
#log_type error
#log_type warning
#log_type notice
#log_type information

# Change the websockets logging level. This is a global option, it is not
# possible to set per listener. This is an integer that is interpreted by
# libwebsockets as a bit mask for its lws_log_levels enum. See the
# libwebsockets documentation for more details. "log_type websockets" must also
# be enabled.
#websockets_log_level 0

# If set to true, client connection and disconnection messages will be included
# in the log.
#connection_messages true

# If set to true, add a timestamp value to each log message.
#log_timestamp true

# =================================================================
# Security
# =================================================================

# If set, only clients that have a matching prefix on their 
# clientid will be allowed to connect to the broker. By default, 
# all clients may connect.
# For example, setting "secure-" here would mean a client "secure-
# client" could connect but another with clientid "mqtt" couldn't.
#clientid_prefixes

# Boolean value that determines whether clients that connect 
# without providing a username are allowed to connect. If set to 
# false then a password file should be created (see the 
# password_file option) to control authenticated client access. 
# Defaults to true.
#allow_anonymous true

# In addition to the clientid_prefixes, allow_anonymous and TLS 
# authentication options, username based authentication is also 
# possible. The default support is described in "Default 
# authentication and topic access control" below. The auth_plugin 
# allows another authentication method to be used.
# Specify the path to the loadable plugin and see the 
# "Authentication and topic access plugin options" section below.
#auth_plugin

# -----------------------------------------------------------------
# Default authentication and topic access control
# -----------------------------------------------------------------

# Control access to the broker using a password file. This file can be
# generated using the mosquitto_passwd utility. If TLS support is not compiled
# into mosquitto (it is recommended that TLS support should be included) then
# plain text passwords are used, in which case the file should be a text file
# with lines in the format:
# username:password
# The password (and colon) may be omitted if desired, although this 
# offers very little in the way of security.
# 
# See the TLS client require_certificate and use_identity_as_username options
# for alternative authentication options.
#password_file

# Access may also be controlled using a pre-shared-key file. This requires
# TLS-PSK support and a listener configured to use it. The file should be text
# lines in the format:
# identity:key
# The key should be in hexadecimal format without a leading "0x".
#psk_file

# Control access to topics on the broker using an access control list
# file. If this parameter is defined then only the topics listed will
# have access.
# If the first character of a line of the ACL file is a # it is treated as a
# comment.
# Topic access is added with lines of the format:
#
# topic [read|write|readwrite] <topic>
# 
# The access type is controlled using "read", "write" or "readwrite". This
# parameter is optional (unless <topic> contains a space character) - if not
# given then the access is read/write.  <topic> can contain the + or #
# wildcards as in subscriptions.
# 
# The first set of topics are applied to anonymous clients, assuming
# allow_anonymous is true. User specific topic ACLs are added after a 
# user line as follows:
#
# user <username>
#
# The username referred to here is the same as in password_file. It is
# not the clientid.
#
#
# If is also possible to define ACLs based on pattern substitution within the
# topic. The patterns available for substition are:
#
# %c to match the client id of the client
# %u to match the username of the client
#
# The substitution pattern must be the only text for that level of hierarchy.
#
# The form is the same as for the topic keyword, but using pattern as the
# keyword.
# Pattern ACLs apply to all users even if the "user" keyword has previously
# been given.
#
# If using bridges with usernames and ACLs, connection messages can be allowed
# with the following pattern:
# pattern write $SYS/broker/connection/%c/state
#
# pattern [read|write|readwrite] <topic>
#
# Example:
#
# pattern write sensor/%u/data
#
#acl_file

# -----------------------------------------------------------------
# Authentication and topic access plugin options
# -----------------------------------------------------------------

# If the auth_plugin option above is used, define options to pass to the
# plugin here as described by the plugin instructions. All options named
# using the format auth_opt_* will be passed to the plugin, for example:
#
# auth_opt_db_host
# auth_opt_db_port 
# auth_opt_db_username
# auth_opt_db_password


# =================================================================
# Bridges
# =================================================================

# A bridge is a way of connecting multiple MQTT brokers together.
# Create a new bridge using the "connection" option as described below. Set
# options for the bridges using the remaining parameters. You must specify the
# address and at least one topic to subscribe to.
# Each connection must have a unique name.
# The address line may have multiple host address and ports specified. See
# below in the round_robin description for more details on bridge behaviour if
# multiple addresses are used.
# The direction that the topic will be shared can be chosen by 
# specifying out, in or both, where the default value is out. 
# The QoS level of the bridged communication can be specified with the next
# topic option. The default QoS level is 0, to change the QoS the topic
# direction must also be given.
# The local and remote prefix options allow a topic to be remapped when it is
# bridged to/from the remote broker. This provides the ability to place a topic
# tree in an appropriate location. 
# For more details see the mosquitto.conf man page.
# Multiple topics can be specified per connection, but be careful 
# not to create any loops.
# If you are using bridges with cleansession set to false (the default), then
# you may get unexpected behaviour from incoming topics if you change what
# topics you are subscribing to. This is because the remote broker keeps the
# subscription for the old topic. If you have this problem, connect your bridge
# with cleansession set to true, then reconnect with cleansession set to false
# as normal.
#connection <name>
#address <host>[:<port>] [<host>[:<port>]]
#topic <topic> [[[out | in | both] qos-level] local-prefix remote-prefix]

# Set the version of the MQTT protocol to use with for this bridge. Can be one
# of mqttv31 or mqttv311. Defaults to mqttv31.
#bridge_protocol_version mqttv31

# If a bridge has topics that have "out" direction, the default behaviour is to
# send an unsubscribe request to the remote broker on that topic. This means
# that changing a topic direction from "in" to "out" will not keep receiving
# incoming messages. Sending these unsubscribe requests is not always
# desirable, setting bridge_attempt_unsubscribe to false will disable sending
# the unsubscribe request.
#bridge_attempt_unsubscribe true

# If the bridge has more than one address given in the address/addresses
# configuration, the round_robin option defines the behaviour of the bridge on
# a failure of the bridge connection. If round_robin is false, the default
# value, then the first address is treated as the main bridge connection. If
# the connection fails, the other secondary addresses will be attempted in
# turn. Whilst connected to a secondary bridge, the bridge will periodically
# attempt to reconnect to the main bridge until successful.
# If round_robin is true, then all addresses are treated as equals. If a
# connection fails, the next address will be tried and if successful will
# remain connected until it fails
#round_robin false

# Set the client id to use on the remote end of this bridge connection. If not
# defined, this defaults to 'name.hostname' where name is the connection name
# and hostname is the hostname of this computer.
# This replaces the old "clientid" option to avoid confusion. "clientid"
# remains valid for the time being.
#remote_clientid

# Set the clientid to use on the local broker. If not defined, this defaults to
# 'local.<clientid>'. If you are bridging a broker to itself, it is important
# that local_clientid and clientid do not match.
#local_clientid

# Set the clean session variable for this bridge.
# When set to true, when the bridge disconnects for any reason, all 
# messages and subscriptions will be cleaned up on the remote 
# broker. Note that with cleansession set to true, there may be a 
# significant amount of retained messages sent when the bridge 
# reconnects after losing its connection.
# When set to false, the subscriptions and messages are kept on the 
# remote broker, and delivered when the bridge reconnects.
#cleansession false

# If set to true, publish notification messages to the local and remote brokers
# giving information about the state of the bridge connection. Retained
# messages are published to the topic $SYS/broker/connection/<clientid>/state
# unless the notification_topic option is used.
# If the message is 1 then the connection is active, or 0 if the connection has
# failed.
#notifications true

# Choose the topic on which notification messages for this bridge are
# published. If not set, messages are published on the topic
# $SYS/broker/connection/<clientid>/state
#notification_topic 

# Set the keepalive interval for this bridge connection, in 
# seconds.
#keepalive_interval 60

# Set the start type of the bridge. This controls how the bridge starts and
# can be one of three types: automatic, lazy and once. Note that RSMB provides
# a fourth start type "manual" which isn't currently supported by mosquitto.
#
# "automatic" is the default start type and means that the bridge connection
# will be started automatically when the broker starts and also restarted
# after a short delay (30 seconds) if the connection fails.
#
# Bridges using the "lazy" start type will be started automatically when the
# number of queued messages exceeds the number set with the "threshold"
# parameter. It will be stopped automatically after the time set by the
# "idle_timeout" parameter. Use this start type if you wish the connection to
# only be active when it is needed.
#
# A bridge using the "once" start type will be started automatically when the
# broker starts but will not be restarted if the connection fails.
#start_type automatic

# Set the amount of time a bridge using the automatic start type will wait
# until attempting to reconnect.  Defaults to 30 seconds.
#restart_timeout 30

# Set the amount of time a bridge using the lazy start type must be idle before
# it will be stopped. Defaults to 60 seconds.
#idle_timeout 60

# Set the number of messages that need to be queued for a bridge with lazy
# start type to be restarted. Defaults to 10 messages.
# Must be less than max_queued_messages.
#threshold 10

# If try_private is set to true, the bridge will attempt to indicate to the
# remote broker that it is a bridge not an ordinary client. If successful, this
# means that loop detection will be more effective and that retained messages
# will be propagated correctly. Not all brokers support this feature so it may
# be necessary to set try_private to false if your bridge does not connect
# properly.
#try_private true

# Set the username to use when connecting to a broker that requires
# authentication.
# This replaces the old "username" option to avoid confusion. "username"
# remains valid for the time being.
#remote_username

# Set the password to use when connecting to a broker that requires
# authentication. This option is only used if remote_username is also set.
# This replaces the old "password" option to avoid confusion. "password"
# remains valid for the time being.
#remote_password

# -----------------------------------------------------------------
# Certificate based SSL/TLS support
# -----------------------------------------------------------------
# Either bridge_cafile or bridge_capath must be defined to enable TLS support
# for this bridge.
# bridge_cafile defines the path to a file containing the
# Certificate Authority certificates that have signed the remote broker
# certificate.
# bridge_capath defines a directory that will be searched for files containing
# the CA certificates. For bridge_capath to work correctly, the certificate
# files must have ".crt" as the file ending and you must run "c_rehash <path to
# capath>" each time you add/remove a certificate.
#bridge_cafile
#bridge_capath

# Path to the PEM encoded client certificate, if required by the remote broker.
#bridge_certfile

# Path to the PEM encoded client private key, if required by the remote broker.
#bridge_keyfile

# When using certificate based encryption, bridge_insecure disables
# verification of the server hostname in the server certificate. This can be
# useful when testing initial server configurations, but makes it possible for
# a malicious third party to impersonate your server through DNS spoofing, for
# example. Use this option in testing only. If you need to resort to using this
# option in a production environment, your setup is at fault and there is no
# point using encryption.
#bridge_insecure false

# -----------------------------------------------------------------
# PSK based SSL/TLS support
# -----------------------------------------------------------------
# Pre-shared-key encryption provides an alternative to certificate based
# encryption. A bridge can be configured to use PSK with the bridge_identity
# and bridge_psk options. These are the client PSK identity, and pre-shared-key
# in hexadecimal format with no "0x". Only one of certificate and PSK based
# encryption can be used on one
# bridge at once.
#bridge_identity
#bridge_psk


# =================================================================
# External config files
# =================================================================

# External configuration files may be included by using the 
# include_dir option. This defines a directory that will be searched
# for config files. All files that end in '.conf' will be loaded as
# a configuration file. It is best to have this as the last option
# in the main file. This option will only be processed from the main
# configuration file. The directory specified must not contain the 
# main configuration file.
#include_dir

# =================================================================
# rsmb options - unlikely to ever be supported
# =================================================================

#ffdc_output
#max_log_entries
#trace_level
#trace_output