1# Config file for mosquitto
2#
3# See mosquitto.conf(5) for more information.
4#
5# Default values are shown, uncomment to change.
6#
7# Use the # character to indicate a comment, but only if it is the
8# very first character on the line.
9
10# =================================================================
11# General configuration
12# =================================================================
13
14# Use per listener security settings.
15#
16# It is recommended this option be set before any other options.
17#
18# If this option is set to true, then all authentication and access control
19# options are controlled on a per listener basis. The following options are
20# affected:
21#
22# acl_file
23# allow_anonymous
24# allow_zero_length_clientid
25# auto_id_prefix
26# password_file
27# plugin
28# plugin_opt_*
29# psk_file
30#
31# Note that if set to true, then a durable client (i.e. with clean session set
32# to false) that has disconnected will use the ACL settings defined for the
33# listener that it was most recently connected to.
34#
35# The default behaviour is for this to be set to false, which maintains the
36# setting behaviour from previous versions of mosquitto.
37#per_listener_settings false
38
39
40# This option controls whether a client is allowed to connect with a zero
41# length client id or not. This option only affects clients using MQTT v3.1.1
42# and later. If set to false, clients connecting with a zero length client id
43# are disconnected. If set to true, clients will be allocated a client id by
44# the broker. This means it is only useful for clients with clean session set
45# to true.
46#allow_zero_length_clientid true
47
48# If allow_zero_length_clientid is true, this option allows you to set a prefix
49# to automatically generated client ids to aid visibility in logs.
50# Defaults to 'auto-'
51#auto_id_prefix auto-
52
53# This option affects the scenario when a client subscribes to a topic that has
54# retained messages. It is possible that the client that published the retained
55# message to the topic had access at the time they published, but that access
56# has been subsequently removed. If check_retain_source is set to true, the
57# default, the source of a retained message will be checked for access rights
58# before it is republished. When set to false, no check will be made and the
59# retained message will always be published. This affects all listeners.
60#check_retain_source true
61
62# QoS 1 and 2 messages will be allowed inflight per client until this limit
63# is exceeded.  Defaults to 0. (No maximum)
64# See also max_inflight_messages
65#max_inflight_bytes 0
66
67# The maximum number of QoS 1 and 2 messages currently inflight per
68# client.
69# This includes messages that are partway through handshakes and
70# those that are being retried. Defaults to 20. Set to 0 for no
71# maximum. Setting to 1 will guarantee in-order delivery of QoS 1
72# and 2 messages.
73#max_inflight_messages 20
74
75# For MQTT v5 clients, it is possible to have the server send a "server
76# keepalive" value that will override the keepalive value set by the client.
77# This is intended to be used as a mechanism to say that the server will
78# disconnect the client earlier than it anticipated, and that the client should
79# use the new keepalive value. The max_keepalive option allows you to specify
80# that clients may only connect with keepalive less than or equal to this
81# value, otherwise they will be sent a server keepalive telling them to use
82# max_keepalive. This only applies to MQTT v5 clients. The default, and maximum
83# value allowable, is 65535.
84#
85# Set to 0 to allow clients to set keepalive = 0, which means no keepalive
86# checks are made and the client will never be disconnected by the broker if no
87# messages are received. You should be very sure this is the behaviour that you
88# want.
89#
90# For MQTT v3.1.1 and v3.1 clients, there is no mechanism to tell the client
91# what keepalive value they should use. If an MQTT v3.1.1 or v3.1 client
92# specifies a keepalive time greater than max_keepalive they will be sent a
93# CONNACK message with the "identifier rejected" reason code, and disconnected.
94#
95#max_keepalive 65535
96
97# For MQTT v5 clients, it is possible to have the server send a "maximum packet
98# size" value that will instruct the client it will not accept MQTT packets
99# with size greater than max_packet_size bytes. This applies to the full MQTT
100# packet, not just the payload. Setting this option to a positive value will
101# set the maximum packet size to that number of bytes. If a client sends a
102# packet which is larger than this value, it will be disconnected. This applies
103# to all clients regardless of the protocol version they are using, but v3.1.1
104# and earlier clients will of course not have received the maximum packet size
105# information. Defaults to no limit. Setting below 20 bytes is forbidden
106# because it is likely to interfere with ordinary client operation, even with
107# very small payloads.
108#max_packet_size 0
109
110# QoS 1 and 2 messages above those currently in-flight will be queued per
111# client until this limit is exceeded.  Defaults to 0. (No maximum)
112# See also max_queued_messages.
113# If both max_queued_messages and max_queued_bytes are specified, packets will
114# be queued until the first limit is reached.
115#max_queued_bytes 0
116
117# Set the maximum QoS supported. Clients publishing at a QoS higher than
118# specified here will be disconnected.
119#max_qos 2
120
121# The maximum number of QoS 1 and 2 messages to hold in a queue per client
122# above those that are currently in-flight.  Defaults to 1000. Set
123# to 0 for no maximum (not recommended).
124# See also queue_qos0_messages.
125# See also max_queued_bytes.
126#max_queued_messages 1000
127#
128# This option sets the maximum number of heap memory bytes that the broker will
129# allocate, and hence sets a hard limit on memory use by the broker.  Memory
130# requests that exceed this value will be denied. The effect will vary
131# depending on what has been denied. If an incoming message is being processed,
132# then the message will be dropped and the publishing client will be
133# disconnected. If an outgoing message is being sent, then the individual
134# message will be dropped and the receiving client will be disconnected.
135# Defaults to no limit.
136#memory_limit 0
137
138# This option sets the maximum publish payload size that the broker will allow.
139# Received messages that exceed this size will not be accepted by the broker.
140# The default value is 0, which means that all valid MQTT messages are
141# accepted. MQTT imposes a maximum payload size of 268435455 bytes.
142#message_size_limit 0
143
144# This option allows the session of persistent clients (those with clean
145# session set to false) that are not currently connected to be removed if they
146# do not reconnect within a certain time frame. This is a non-standard option
147# in MQTT v3.1. MQTT v3.1.1 and v5.0 allow brokers to remove client sessions.
148#
149# Badly designed clients may set clean session to false whilst using a randomly
150# generated client id. This leads to persistent clients that connect once and
151# never reconnect. This option allows these clients to be removed.  This option
152# allows persistent clients (those with clean session set to false) to be
153# removed if they do not reconnect within a certain time frame.
154#
155# The expiration period should be an integer followed by one of h d w m y for
156# hour, day, week, month and year respectively. For example
157#
158# persistent_client_expiration 2m
159# persistent_client_expiration 14d
160# persistent_client_expiration 1y
161#
162# The default if not set is to never expire persistent clients.
163#persistent_client_expiration
164
165# Write process id to a file. Default is a blank string which means
166# a pid file shouldn't be written.
167# This should be set to /var/run/mosquitto/mosquitto.pid if mosquitto is
168# being run automatically on boot with an init script and
169# start-stop-daemon or similar.
170#pid_file
171
172# Set to true to queue messages with QoS 0 when a persistent client is
173# disconnected. These messages are included in the limit imposed by
174# max_queued_messages and max_queued_bytes
175# Defaults to false.
176# This is a non-standard option for the MQTT v3.1 spec but is allowed in
177# v3.1.1.
178#queue_qos0_messages false
179
180# Set to false to disable retained message support. If a client publishes a
181# message with the retain bit set, it will be disconnected if this is set to
182# false.
183#retain_available true
184
185# Disable Nagle's algorithm on client sockets. This has the effect of reducing
186# latency of individual messages at the potential cost of increasing the number
187# of packets being sent.
188#set_tcp_nodelay false
189
190# Time in seconds between updates of the $SYS tree.
191# Set to 0 to disable the publishing of the $SYS tree.
192#sys_interval 10
193
194# The MQTT specification requires that the QoS of a message delivered to a
195# subscriber is never upgraded to match the QoS of the subscription. Enabling
196# this option changes this behaviour. If upgrade_outgoing_qos is set true,
197# messages sent to a subscriber will always match the QoS of its subscription.
198# This is a non-standard option explicitly disallowed by the spec.
199#upgrade_outgoing_qos false
200
201# When run as root, drop privileges to this user and its primary
202# group.
203# Set to root to stay as root, but this is not recommended.
204# If set to "mosquitto", or left unset, and the "mosquitto" user does not exist
205# then it will drop privileges to the "nobody" user instead.
206# If run as a non-root user, this setting has no effect.
207# Note that on Windows this has no effect and so mosquitto should be started by
208# the user you wish it to run as.
209#user mosquitto
210
211# =================================================================
212# Listeners
213# =================================================================
214
215# Listen on a port/ip address combination. By using this variable
216# multiple times, mosquitto can listen on more than one port. If
217# this variable is used and neither bind_address nor port given,
218# then the default listener will not be started.
219# The port number to listen on must be given. Optionally, an ip
220# address or host name may be supplied as a second argument. In
221# this case, mosquitto will attempt to bind the listener to that
222# address and so restrict access to the associated network and
223# interface. By default, mosquitto will listen on all interfaces.
224# Note that for a websockets listener it is not possible to bind to a host
225# name.
226#
227# On systems that support Unix Domain Sockets, it is also possible
228# to create a # Unix socket rather than opening a TCP socket. In
229# this case, the port number should be set to 0 and a unix socket
230# path must be provided, e.g.
231# listener 0 /tmp/mosquitto.sock
232#
233# listener port-number [ip address/host name/unix socket path]
234listener 1883
235
236# By default, a listener will attempt to listen on all supported IP protocol
237# versions. If you do not have an IPv4 or IPv6 interface you may wish to
238# disable support for either of those protocol versions. In particular, note
239# that due to the limitations of the websockets library, it will only ever
240# attempt to open IPv6 sockets if IPv6 support is compiled in, and so will fail
241# if IPv6 is not available.
242#
243# Set to `ipv4` to force the listener to only use IPv4, or set to `ipv6` to
244# force the listener to only use IPv6. If you want support for both IPv4 and
245# IPv6, then do not use the socket_domain option.
246#
247#socket_domain
248
249# Bind the listener to a specific interface. This is similar to
250# the [ip address/host name] part of the listener definition, but is useful
251# when an interface has multiple addresses or the address may change. If used
252# with the [ip address/host name] part of the listener definition, then the
253# bind_interface option will take priority.
254# Not available on Windows.
255#
256# Example: bind_interface eth0
257#bind_interface
258
259# When a listener is using the websockets protocol, it is possible to serve
260# http data as well. Set http_dir to a directory which contains the files you
261# wish to serve. If this option is not specified, then no normal http
262# connections will be possible.
263#http_dir
264
265# The maximum number of client connections to allow. This is
266# a per listener setting.
267# Default is -1, which means unlimited connections.
268# Note that other process limits mean that unlimited connections
269# are not really possible. Typically the default maximum number of
270# connections possible is around 1024.
271#max_connections -1
272
273# The listener can be restricted to operating within a topic hierarchy using
274# the mount_point option. This is achieved be prefixing the mount_point string
275# to all topics for any clients connected to this listener. This prefixing only
276# happens internally to the broker; the client will not see the prefix.
277#mount_point
278
279# Choose the protocol to use when listening.
280# This can be either mqtt or websockets.
281# Certificate based TLS may be used with websockets, except that only the
282# cafile, certfile, keyfile, ciphers, and ciphers_tls13 options are supported.
283#protocol mqtt
284
285# Set use_username_as_clientid to true to replace the clientid that a client
286# connected with its username. This allows authentication to be tied to
287# the clientid, which means that it is possible to prevent one client
288# disconnecting another by using the same clientid.
289# If a client connects with no username it will be disconnected as not
290# authorised when this option is set to true.
291# Do not use in conjunction with clientid_prefixes.
292# See also use_identity_as_username.
293# This does not apply globally, but on a per-listener basis.
294#use_username_as_clientid
295
296# Change the websockets headers size. This is a global option, it is not
297# possible to set per listener. This option sets the size of the buffer used in
298# the libwebsockets library when reading HTTP headers. If you are passing large
299# header data such as cookies then you may need to increase this value. If left
300# unset, or set to 0, then the default of 1024 bytes will be used.
301#websockets_headers_size
302
303# -----------------------------------------------------------------
304# Certificate based SSL/TLS support
305# -----------------------------------------------------------------
306# The following options can be used to enable certificate based SSL/TLS support
307# for this listener. Note that the recommended port for MQTT over TLS is 8883,
308# but this must be set manually.
309#
310# See also the mosquitto-tls man page and the "Pre-shared-key based SSL/TLS
311# support" section. Only one of certificate or PSK encryption support can be
312# enabled for any listener.
313
314# Both of certfile and keyfile must be defined to enable certificate based
315# TLS encryption.
316
317# Path to the PEM encoded server certificate.
318#certfile
319
320# Path to the PEM encoded keyfile.
321#keyfile
322
323# If you wish to control which encryption ciphers are used, use the ciphers
324# option. The list of available ciphers can be optained using the "openssl
325# ciphers" command and should be provided in the same format as the output of
326# that command. This applies to TLS 1.2 and earlier versions only. Use
327# ciphers_tls1.3 for TLS v1.3.
328#ciphers
329
330# Choose which TLS v1.3 ciphersuites are used for this listener.
331# Defaults to "TLS_AES_256_GCM_SHA384:TLS_CHACHA20_POLY1305_SHA256:TLS_AES_128_GCM_SHA256"
332#ciphers_tls1.3
333
334# If you have require_certificate set to true, you can create a certificate
335# revocation list file to revoke access to particular client certificates. If
336# you have done this, use crlfile to point to the PEM encoded revocation file.
337#crlfile
338
339# To allow the use of ephemeral DH key exchange, which provides forward
340# security, the listener must load DH parameters. This can be specified with
341# the dhparamfile option. The dhparamfile can be generated with the command
342# e.g. "openssl dhparam -out dhparam.pem 2048"
343#dhparamfile
344
345# By default an TLS enabled listener will operate in a similar fashion to a
346# https enabled web server, in that the server has a certificate signed by a CA
347# and the client will verify that it is a trusted certificate. The overall aim
348# is encryption of the network traffic. By setting require_certificate to true,
349# the client must provide a valid certificate in order for the network
350# connection to proceed. This allows access to the broker to be controlled
351# outside of the mechanisms provided by MQTT.
352#require_certificate false
353
354# cafile and capath define methods of accessing the PEM encoded
355# Certificate Authority certificates that will be considered trusted when
356# checking incoming client certificates.
357# cafile defines the path to a file containing the CA certificates.
358# capath defines a directory that will be searched for files
359# containing the CA certificates. For capath to work correctly, the
360# certificate files must have ".crt" as the file ending and you must run
361# "openssl rehash <path to capath>" each time you add/remove a certificate.
362#cafile
363#capath
364
365
366# If require_certificate is true, you may set use_identity_as_username to true
367# to use the CN value from the client certificate as a username. If this is
368# true, the password_file option will not be used for this listener.
369#use_identity_as_username false
370
371# -----------------------------------------------------------------
372# Pre-shared-key based SSL/TLS support
373# -----------------------------------------------------------------
374# The following options can be used to enable PSK based SSL/TLS support for
375# this listener. Note that the recommended port for MQTT over TLS is 8883, but
376# this must be set manually.
377#
378# See also the mosquitto-tls man page and the "Certificate based SSL/TLS
379# support" section. Only one of certificate or PSK encryption support can be
380# enabled for any listener.
381
382# The psk_hint option enables pre-shared-key support for this listener and also
383# acts as an identifier for this listener. The hint is sent to clients and may
384# be used locally to aid authentication. The hint is a free form string that
385# doesn't have much meaning in itself, so feel free to be creative.
386# If this option is provided, see psk_file to define the pre-shared keys to be
387# used or create a security plugin to handle them.
388#psk_hint
389
390# When using PSK, the encryption ciphers used will be chosen from the list of
391# available PSK ciphers. If you want to control which ciphers are available,
392# use the "ciphers" option.  The list of available ciphers can be optained
393# using the "openssl ciphers" command and should be provided in the same format
394# as the output of that command.
395#ciphers
396
397# Set use_identity_as_username to have the psk identity sent by the client used
398# as its username. Authentication will be carried out using the PSK rather than
399# the MQTT username/password and so password_file will not be used for this
400# listener.
401#use_identity_as_username false
402
403
404# =================================================================
405# Persistence
406# =================================================================
407
408# If persistence is enabled, save the in-memory database to disk
409# every autosave_interval seconds. If set to 0, the persistence
410# database will only be written when mosquitto exits. See also
411# autosave_on_changes.
412# Note that writing of the persistence database can be forced by
413# sending mosquitto a SIGUSR1 signal.
414#autosave_interval 1800
415
416# If true, mosquitto will count the number of subscription changes, retained
417# messages received and queued messages and if the total exceeds
418# autosave_interval then the in-memory database will be saved to disk.
419# If false, mosquitto will save the in-memory database to disk by treating
420# autosave_interval as a time in seconds.
421#autosave_on_changes false
422
423# Save persistent message data to disk (true/false).
424# This saves information about all messages, including
425# subscriptions, currently in-flight messages and retained
426# messages.
427# retained_persistence is a synonym for this option.
428#persistence false
429
430# The filename to use for the persistent database, not including
431# the path.
432#persistence_file mosquitto.db
433
434# Location for persistent database.
435# Default is an empty string (current directory).
436# Set to e.g. /var/lib/mosquitto if running as a proper service on Linux or
437# similar.
438#persistence_location
439
440
441# =================================================================
442# Logging
443# =================================================================
444
445# Places to log to. Use multiple log_dest lines for multiple
446# logging destinations.
447# Possible destinations are: stdout stderr syslog topic file dlt
448#
449# stdout and stderr log to the console on the named output.
450#
451# syslog uses the userspace syslog facility which usually ends up
452# in /var/log/messages or similar.
453#
454# topic logs to the broker topic '$SYS/broker/log/<severity>',
455# where severity is one of D, E, W, N, I, M which are debug, error,
456# warning, notice, information and message. Message type severity is used by
457# the subscribe/unsubscribe log_types and publishes log messages to
458# $SYS/broker/log/M/susbcribe or $SYS/broker/log/M/unsubscribe.
459#
460# The file destination requires an additional parameter which is the file to be
461# logged to, e.g. "log_dest file /var/log/mosquitto.log". The file will be
462# closed and reopened when the broker receives a HUP signal. Only a single file
463# destination may be configured.
464#
465# The dlt destination is for the automotive `Diagnostic Log and Trace` tool.
466# This requires that Mosquitto has been compiled with DLT support.
467#
468# Note that if the broker is running as a Windows service it will default to
469# "log_dest none" and neither stdout nor stderr logging is available.
470# Use "log_dest none" if you wish to disable logging.
471#log_dest stderr
472
473# Types of messages to log. Use multiple log_type lines for logging
474# multiple types of messages.
475# Possible types are: debug, error, warning, notice, information,
476# none, subscribe, unsubscribe, websockets, all.
477# Note that debug type messages are for decoding the incoming/outgoing
478# network packets. They are not logged in "topics".
479#log_type error
480#log_type warning
481#log_type notice
482#log_type information
483
484
485# If set to true, client connection and disconnection messages will be included
486# in the log.
487#connection_messages true
488
489# If using syslog logging (not on Windows), messages will be logged to the
490# "daemon" facility by default. Use the log_facility option to choose which of
491# local0 to local7 to log to instead. The option value should be an integer
492# value, e.g. "log_facility 5" to use local5.
493#log_facility
494
495# If set to true, add a timestamp value to each log message.
496#log_timestamp true
497
498# Set the format of the log timestamp. If left unset, this is the number of
499# seconds since the Unix epoch.
500# This is a free text string which will be passed to the strftime function. To
501# get an ISO 8601 datetime, for example:
502# log_timestamp_format %Y-%m-%dT%H:%M:%S
503#log_timestamp_format
504
505# Change the websockets logging level. This is a global option, it is not
506# possible to set per listener. This is an integer that is interpreted by
507# libwebsockets as a bit mask for its lws_log_levels enum. See the
508# libwebsockets documentation for more details. "log_type websockets" must also
509# be enabled.
510#websockets_log_level 0
511
512
513# =================================================================
514# Security
515# =================================================================
516
517# If set, only clients that have a matching prefix on their
518# clientid will be allowed to connect to the broker. By default,
519# all clients may connect.
520# For example, setting "secure-" here would mean a client "secure-
521# client" could connect but another with clientid "mqtt" couldn't.
522#clientid_prefixes
523
524# Boolean value that determines whether clients that connect
525# without providing a username are allowed to connect. If set to
526# false then a password file should be created (see the
527# password_file option) to control authenticated client access.
528#
529# Defaults to false, unless there are no listeners defined in the configuration
530# file, in which case it is set to true, but connections are only allowed from
531# the local machine.
532allow_anonymous true
533
534# -----------------------------------------------------------------
535# Default authentication and topic access control
536# -----------------------------------------------------------------
537
538# Control access to the broker using a password file. This file can be
539# generated using the mosquitto_passwd utility. If TLS support is not compiled
540# into mosquitto (it is recommended that TLS support should be included) then
541# plain text passwords are used, in which case the file should be a text file
542# with lines in the format:
543# username:password
544# The password (and colon) may be omitted if desired, although this
545# offers very little in the way of security.
546#
547# See the TLS client require_certificate and use_identity_as_username options
548# for alternative authentication options. If a plugin is used as well as
549# password_file, the plugin check will be made first.
550#password_file
551
552# Access may also be controlled using a pre-shared-key file. This requires
553# TLS-PSK support and a listener configured to use it. The file should be text
554# lines in the format:
555# identity:key
556# The key should be in hexadecimal format without a leading "0x".
557# If an plugin is used as well, the plugin check will be made first.
558#psk_file
559
560# Control access to topics on the broker using an access control list
561# file. If this parameter is defined then only the topics listed will
562# have access.
563# If the first character of a line of the ACL file is a # it is treated as a
564# comment.
565# Topic access is added with lines of the format:
566#
567# topic [read|write|readwrite|deny] <topic>
568#
569# The access type is controlled using "read", "write", "readwrite" or "deny".
570# This parameter is optional (unless <topic> contains a space character) - if
571# not given then the access is read/write.  <topic> can contain the + or #
572# wildcards as in subscriptions.
573#
574# The "deny" option can used to explicity deny access to a topic that would
575# otherwise be granted by a broader read/write/readwrite statement. Any "deny"
576# topics are handled before topics that grant read/write access.
577#
578# The first set of topics are applied to anonymous clients, assuming
579# allow_anonymous is true. User specific topic ACLs are added after a
580# user line as follows:
581#
582# user <username>
583#
584# The username referred to here is the same as in password_file. It is
585# not the clientid.
586#
587#
588# If is also possible to define ACLs based on pattern substitution within the
589# topic. The patterns available for substition are:
590#
591# %c to match the client id of the client
592# %u to match the username of the client
593#
594# The substitution pattern must be the only text for that level of hierarchy.
595#
596# The form is the same as for the topic keyword, but using pattern as the
597# keyword.
598# Pattern ACLs apply to all users even if the "user" keyword has previously
599# been given.
600#
601# If using bridges with usernames and ACLs, connection messages can be allowed
602# with the following pattern:
603# pattern write $SYS/broker/connection/%c/state
604#
605# pattern [read|write|readwrite] <topic>
606#
607# Example:
608#
609# pattern write sensor/%u/data
610#
611# If an plugin is used as well as acl_file, the plugin check will be
612# made first.
613#acl_file
614
615# -----------------------------------------------------------------
616# External authentication and topic access plugin options
617# -----------------------------------------------------------------
618
619# External authentication and access control can be supported with the
620# plugin option. This is a path to a loadable plugin. See also the
621# plugin_opt_* options described below.
622#
623# The plugin option can be specified multiple times to load multiple
624# plugins. The plugins will be processed in the order that they are specified
625# here. If the plugin option is specified alongside either of
626# password_file or acl_file then the plugin checks will be made first.
627#
628# If the per_listener_settings option is false, the plugin will be apply to all
629# listeners. If per_listener_settings is true, then the plugin will apply to
630# the current listener being defined only.
631#
632# This option is also available as `auth_plugin`, but this use is deprecated
633# and will be removed in the future.
634#
635#plugin
636
637# If the plugin option above is used, define options to pass to the
638# plugin here as described by the plugin instructions. All options named
639# using the format plugin_opt_* will be passed to the plugin, for example:
640#
641# This option is also available as `auth_opt_*`, but this use is deprecated
642# and will be removed in the future.
643#
644# plugin_opt_db_host
645# plugin_opt_db_port
646# plugin_opt_db_username
647# plugin_opt_db_password
648
649
650# =================================================================
651# Bridges
652# =================================================================
653
654# A bridge is a way of connecting multiple MQTT brokers together.
655# Create a new bridge using the "connection" option as described below. Set
656# options for the bridges using the remaining parameters. You must specify the
657# address and at least one topic to subscribe to.
658#
659# Each connection must have a unique name.
660#
661# The address line may have multiple host address and ports specified. See
662# below in the round_robin description for more details on bridge behaviour if
663# multiple addresses are used. Note that if you use an IPv6 address, then you
664# are required to specify a port.
665#
666# The direction that the topic will be shared can be chosen by
667# specifying out, in or both, where the default value is out.
668# The QoS level of the bridged communication can be specified with the next
669# topic option. The default QoS level is 0, to change the QoS the topic
670# direction must also be given.
671#
672# The local and remote prefix options allow a topic to be remapped when it is
673# bridged to/from the remote broker. This provides the ability to place a topic
674# tree in an appropriate location.
675#
676# For more details see the mosquitto.conf man page.
677#
678# Multiple topics can be specified per connection, but be careful
679# not to create any loops.
680#
681# If you are using bridges with cleansession set to false (the default), then
682# you may get unexpected behaviour from incoming topics if you change what
683# topics you are subscribing to. This is because the remote broker keeps the
684# subscription for the old topic. If you have this problem, connect your bridge
685# with cleansession set to true, then reconnect with cleansession set to false
686# as normal.
687#connection <name>
688#address <host>[:<port>] [<host>[:<port>]]
689#topic <topic> [[[out | in | both] qos-level] local-prefix remote-prefix]
690
691# If you need to have the bridge connect over a particular network interface,
692# use bridge_bind_address to tell the bridge which local IP address the socket
693# should bind to, e.g. `bridge_bind_address 192.168.1.10`
694#bridge_bind_address
695
696# If a bridge has topics that have "out" direction, the default behaviour is to
697# send an unsubscribe request to the remote broker on that topic. This means
698# that changing a topic direction from "in" to "out" will not keep receiving
699# incoming messages. Sending these unsubscribe requests is not always
700# desirable, setting bridge_attempt_unsubscribe to false will disable sending
701# the unsubscribe request.
702#bridge_attempt_unsubscribe true
703
704# Set the version of the MQTT protocol to use with for this bridge. Can be one
705# of mqttv50, mqttv311 or mqttv31. Defaults to mqttv311.
706#bridge_protocol_version mqttv311
707
708# Set the clean session variable for this bridge.
709# When set to true, when the bridge disconnects for any reason, all
710# messages and subscriptions will be cleaned up on the remote
711# broker. Note that with cleansession set to true, there may be a
712# significant amount of retained messages sent when the bridge
713# reconnects after losing its connection.
714# When set to false, the subscriptions and messages are kept on the
715# remote broker, and delivered when the bridge reconnects.
716#cleansession false
717
718# Set the amount of time a bridge using the lazy start type must be idle before
719# it will be stopped. Defaults to 60 seconds.
720#idle_timeout 60
721
722# Set the keepalive interval for this bridge connection, in
723# seconds.
724#keepalive_interval 60
725
726# Set the clientid to use on the local broker. If not defined, this defaults to
727# 'local.<clientid>'. If you are bridging a broker to itself, it is important
728# that local_clientid and clientid do not match.
729#local_clientid
730
731# If set to true, publish notification messages to the local and remote brokers
732# giving information about the state of the bridge connection. Retained
733# messages are published to the topic $SYS/broker/connection/<clientid>/state
734# unless the notification_topic option is used.
735# If the message is 1 then the connection is active, or 0 if the connection has
736# failed.
737# This uses the last will and testament feature.
738#notifications true
739
740# Choose the topic on which notification messages for this bridge are
741# published. If not set, messages are published on the topic
742# $SYS/broker/connection/<clientid>/state
743#notification_topic
744
745# Set the client id to use on the remote end of this bridge connection. If not
746# defined, this defaults to 'name.hostname' where name is the connection name
747# and hostname is the hostname of this computer.
748# This replaces the old "clientid" option to avoid confusion. "clientid"
749# remains valid for the time being.
750#remote_clientid
751
752# Set the password to use when connecting to a broker that requires
753# authentication. This option is only used if remote_username is also set.
754# This replaces the old "password" option to avoid confusion. "password"
755# remains valid for the time being.
756#remote_password
757
758# Set the username to use when connecting to a broker that requires
759# authentication.
760# This replaces the old "username" option to avoid confusion. "username"
761# remains valid for the time being.
762#remote_username
763
764# Set the amount of time a bridge using the automatic start type will wait
765# until attempting to reconnect.
766# This option can be configured to use a constant delay time in seconds, or to
767# use a backoff mechanism based on "Decorrelated Jitter", which adds a degree
768# of randomness to when the restart occurs.
769#
770# Set a constant timeout of 20 seconds:
771# restart_timeout 20
772#
773# Set backoff with a base (start value) of 10 seconds and a cap (upper limit) of
774# 60 seconds:
775# restart_timeout 10 30
776#
777# Defaults to jitter with a base of 5 and cap of 30
778#restart_timeout 5 30
779
780# If the bridge has more than one address given in the address/addresses
781# configuration, the round_robin option defines the behaviour of the bridge on
782# a failure of the bridge connection. If round_robin is false, the default
783# value, then the first address is treated as the main bridge connection. If
784# the connection fails, the other secondary addresses will be attempted in
785# turn. Whilst connected to a secondary bridge, the bridge will periodically
786# attempt to reconnect to the main bridge until successful.
787# If round_robin is true, then all addresses are treated as equals. If a
788# connection fails, the next address will be tried and if successful will
789# remain connected until it fails
790#round_robin false
791
792# Set the start type of the bridge. This controls how the bridge starts and
793# can be one of three types: automatic, lazy and once. Note that RSMB provides
794# a fourth start type "manual" which isn't currently supported by mosquitto.
795#
796# "automatic" is the default start type and means that the bridge connection
797# will be started automatically when the broker starts and also restarted
798# after a short delay (30 seconds) if the connection fails.
799#
800# Bridges using the "lazy" start type will be started automatically when the
801# number of queued messages exceeds the number set with the "threshold"
802# parameter. It will be stopped automatically after the time set by the
803# "idle_timeout" parameter. Use this start type if you wish the connection to
804# only be active when it is needed.
805#
806# A bridge using the "once" start type will be started automatically when the
807# broker starts but will not be restarted if the connection fails.
808#start_type automatic
809
810# Set the number of messages that need to be queued for a bridge with lazy
811# start type to be restarted. Defaults to 10 messages.
812# Must be less than max_queued_messages.
813#threshold 10
814
815# If try_private is set to true, the bridge will attempt to indicate to the
816# remote broker that it is a bridge not an ordinary client. If successful, this
817# means that loop detection will be more effective and that retained messages
818# will be propagated correctly. Not all brokers support this feature so it may
819# be necessary to set try_private to false if your bridge does not connect
820# properly.
821#try_private true
822
823# Some MQTT brokers do not allow retained messages. MQTT v5 gives a mechanism
824# for brokers to tell clients that they do not support retained messages, but
825# this is not possible for MQTT v3.1.1 or v3.1. If you need to bridge to a
826# v3.1.1 or v3.1 broker that does not support retained messages, set the
827# bridge_outgoing_retain option to false. This will remove the retain bit on
828# all outgoing messages to that bridge, regardless of any other setting.
829#bridge_outgoing_retain true
830
831# If you wish to restrict the size of messages sent to a remote bridge, use the
832# bridge_max_packet_size option. This sets the maximum number of bytes for
833# the total message, including headers and payload.
834# Note that MQTT v5 brokers may provide their own maximum-packet-size property.
835# In this case, the smaller of the two limits will be used.
836# Set to 0 for "unlimited".
837#bridge_max_packet_size 0
838
839
840# -----------------------------------------------------------------
841# Certificate based SSL/TLS support
842# -----------------------------------------------------------------
843# Either bridge_cafile or bridge_capath must be defined to enable TLS support
844# for this bridge.
845# bridge_cafile defines the path to a file containing the
846# Certificate Authority certificates that have signed the remote broker
847# certificate.
848# bridge_capath defines a directory that will be searched for files containing
849# the CA certificates. For bridge_capath to work correctly, the certificate
850# files must have ".crt" as the file ending and you must run "openssl rehash
851# <path to capath>" each time you add/remove a certificate.
852#bridge_cafile
853#bridge_capath
854
855
856# If the remote broker has more than one protocol available on its port, e.g.
857# MQTT and WebSockets, then use bridge_alpn to configure which protocol is
858# requested. Note that WebSockets support for bridges is not yet available.
859#bridge_alpn
860
861# When using certificate based encryption, bridge_insecure disables
862# verification of the server hostname in the server certificate. This can be
863# useful when testing initial server configurations, but makes it possible for
864# a malicious third party to impersonate your server through DNS spoofing, for
865# example. Use this option in testing only. If you need to resort to using this
866# option in a production environment, your setup is at fault and there is no
867# point using encryption.
868#bridge_insecure false
869
870# Path to the PEM encoded client certificate, if required by the remote broker.
871#bridge_certfile
872
873# Path to the PEM encoded client private key, if required by the remote broker.
874#bridge_keyfile
875
876# -----------------------------------------------------------------
877# PSK based SSL/TLS support
878# -----------------------------------------------------------------
879# Pre-shared-key encryption provides an alternative to certificate based
880# encryption. A bridge can be configured to use PSK with the bridge_identity
881# and bridge_psk options. These are the client PSK identity, and pre-shared-key
882# in hexadecimal format with no "0x". Only one of certificate and PSK based
883# encryption can be used on one
884# bridge at once.
885#bridge_identity
886#bridge_psk
887
888
889# =================================================================
890# External config files
891# =================================================================
892
893# External configuration files may be included by using the
894# include_dir option. This defines a directory that will be searched
895# for config files. All files that end in '.conf' will be loaded as
896# a configuration file. It is best to have this as the last option
897# in the main file. This option will only be processed from the main
898# configuration file. The directory specified must not contain the
899# main configuration file.
900# Files within include_dir will be loaded sorted in case-sensitive
901# alphabetical order, with capital letters ordered first. If this option is
902# given multiple times, all of the files from the first instance will be
903# processed before the next instance. See the man page for examples.
904#include_dir
905