翻译：mosquitto 配置文件 - window版

配置文件路径

"C:\Program Files\Mosquitto\mosquitto.conf"

参考：https://mosquitto.org/man/mosquitto-conf-5.html

版本：mosquitto-2.0.14

翻译

mosquitto.conf 文件翻译（谷歌翻译）

# mosquitto 的配置文件
#
# 参见 mosquitto.conf(5) 了解更多信息。
#
# 显示默认值，取消注释更改。
#
# 使用 # 字符表示注释，但前提是它是行中的第一个字符。

通用配置

# ================================================== ================
# 通用配置
# ================================================== ================

# 使用每个监听器的安全设置。
#
# 建议将此选项设置在任何其他选项之前。
#
# 如果此选项设置为 true，则所有身份验证和访问控制选项都基于每个侦听器进行控制。 以下选项受到影响：
#
# password_file（密码文件） acl_file（访问控制列表文件） psk_file（预共享密钥模式文件） 
# auth_plugin（认证插件） auth_opt_*（认证选项） allow_anonymous（允许匿名）
# auto_id_prefix（认证ID前缀） allow_zero_length_clientid（允许零长度的客户端 ID）
#
# 请注意，如果设置为 true，则已断开连接的持久客户端（即，将干净会话设置为 false）将使用为其最近连接到的侦听器定义的 ACL 设置。
#
# 默认行为是将 this 设置为 false，这将保持以前版本的 mosquitto 的设置行为。
# per_listener_settings false


# 此选项控制是否允许客户端使用零长度客户端 ID 进行连接。 
# 此选项仅影响使用 MQTT v3.1.1 及更高版本的客户端。 
# 如果设置为 false，则使用零长度客户端 ID 连接的客户端将断开连接。 
# 如果设置为 true，则代理将为客户端分配一个客户端 ID。 
# 这意味着它只对 clean session 设置为 true 的客户端有用。
#allow_zero_length_clientid true

# 如果 allow_zero_length_clientid 为 true，则此选项允许您为自动生成的客户端 ID 设置前缀，以帮助查看日志。 
# 默认为“auto_”
# auto_id_prefix auto_

# 这个选项会影响到客户订阅有保留信息的主题时的情况。
# 有可能向该主题发布保留信息的客户在发布时有访问权限，但随后该访问权限被取消。
# 如果check_retain_source被设置为 "true"，默认情况下，在重新发布之前，保留信息的来源将被检查访问权限。
# 当设置为false时，将不进行检查，保留的消息将始终被发布。这影响到所有监听器。
#check_retain_source true

# 每个客户的QoS 1和2信息将被允许在机上发送，直到超过这个限制。 
# 默认为0。（没有最大值）
# 另见max_inflight_messages。
#max_inflight_bytes 0

# 每个客户端当前传输的 QoS 1 和 2 消息的最大数量。 
# 这包括在握手过程中的消息和正在重试的消息。 默认为 20。
# 设置为 0 表示没有最大值。 
# 设置为 1 将保证 QoS 1 和 2 消息的有序传递。
#max_inflight_messages 20

# 对于MQTT v5客户端，可以让服务器发送一个 "server keepalive"值，它将覆盖客户端设置的keepalive值。
# 这旨在作为一种机制，说明服务器将比它预期的时间更早地断开客户端的连接，并且客户端应该使用新的keepalive值。
# max_keepalive选项允许你指定客户端只能用小于或等于这个值的keepalive进行连接，否则他们将被发送一个服务器keepalive，告诉他们使用max_keepalive。
# 这只适用于MQTT v5客户端。允许的最大值是65535。不要设置低于10。
#max_keepalive 65535

# 对于MQTT v5客户端，可以让服务器发送一个 "最大数据包大小 "的值，该值将指示客户端不接受大小超过max_packet_size字节的MQTT数据包。
# 这适用于整个MQTT数据包，而不仅仅是有效载荷。
# 将该选项设置为一个正值将把最大的数据包大小设置为该字节数。
# 如果一个客户端发送的数据包大于这个值，它将被断开连接。
# 这适用于所有客户，无论他们使用的协议版本如何，但v3.1.1和更早的客户当然不会收到最大数据包大小信息。
# 默认为无限制。禁止设置低于20字节，因为它可能会干扰普通的客户端操作，即使是非常小的有效载荷。
#max_packet_size 0

# 高于当前传输中的 QoS 1 和 2 消息将按客户端排队，直到超过此限制。 
# 默认为 0。（无最大值）
# 另见 max_queued_messages。
# 如果同时指定了 max_queued_messages 和 max_queued_bytes，则数据包将排队直到达到第一个限制。
#max_queued_bytes 0

# 设置支持的最大QoS。以高于此处指定的QoS发布的客户将被断开连接。
#max_qos 2

# 每个客户端队列中保存的 QoS 1 和 2 消息的最大数量，高于当前正在传输的消息。 
# 默认为 1000。设置为 0 表示没有最大值（不推荐）。 
# 另请参阅 queue_qos0_messages。 
# 另见 max_queued_bytes。
#max_queued_messages 1000

# 此选项设置代理将分配的最大堆内存字节数，从而对代理使用的内存设置硬限制。 超过此值的内存请求将被拒绝。
# 效果将根据被拒绝的内容而有所不同。
# 如果正在处理传入的消息，则该消息将被丢弃并且发布客户端将断开连接。
# 如果正在发送传出消息，则单个消息将被丢弃并且接收客户端将断开连接。
# 默认为无限制。
#memory_limit 0

# 此选项设置代理将允许的最大发布负载大小。
# 代理将不接受接收到的超过此大小的消息。
# 默认值为 0，表示接受所有有效的 MQTT 消息。
# MQTT 规定的最大负载大小为 268435455（FFFFFFF） 字节。
#message_size_limit 0

# 如果持久客户端（clean session设置为 false 的客户端）未在特定时间范围内重新连接，则此选项允许将其删除。
#
# 这是 MQTT V3.1 中的非标准选项，但在 MQTT v3.1.1 中是允许的。
#
# 设计不当的客户端可能会在使用随机生成的客户端 ID 时将 clean session 设置为 false。
# 这导致永远不会重新连接的持久客户端。
# 此选项允许删除这些客户端。
#
# 过期时间应该是一个整数，后跟 h d w m y 之一，分别表示小时、天、周、月和年。 例如
#
#persistent_client_expiration 2m
#persistent_client_expiration 14d
#persistent_client_expiration 1y
#
# 如果未设置，则默认为永不过期的持久客户端。
#persistent_client_expiration

# 将进程ID写到文件中。
# 默认是一个空白字符串，这意味着不应该写入pid文件。
# 如果mosquitto在开机时通过init脚本和start-stop-daemon或类似的方式自动运行，则应将此设置为/var/run/mosquitto/mosquitto.pid。
#pid_file

# 设置为 "true"，当一个持久性客户断开连接时，用QoS 0排队等待消息。
# 这些消息包括在max_queued_messages和max_queued_bytes的限制中
# 默认为false。这是MQTT v3.1规范中的一个非标准选项，但在v3.1.1中是允许的。
#queue_qos0_messages false

# 设置为 false 以禁用保留消息支持。如果客户发布
# 设置了保留位的消息，如果设置为将断开连接
# 错误的。
#retain_available 真

# 在客户端套接字上禁用 Nagle 算法。 这具有减少单个消息的延迟的效果，但可能会增加发送的数据包数量。
#set_tcp_nodelay false

# $SYS 树的更新间隔时间（秒）。设置为0表示禁用 $SYS 树的发布。
#sys_interval 10

# MQTT规范要求，交付给订阅者的消息的QoS永远不会被升级以匹配订阅的QoS。
# 启用该选项可以改变这一行为。
# 如果upgrade_outgoing_qos被设置为 "true"，发送给订阅者的消息将总是与订阅的QoS相匹配。
# 这是一个非标准的选项，被规范明确禁止。
#upgrade_outgoing_qos false

# 以 root 身份运行时，删除此用户及其主要组的权限。
# 设置为 root 以保持 root 身份，但不推荐这样做。
# 如果设置为“mosquitto”，或未设置，并且“mosquitto”用户不存在，那么它会将权限授予“nobody”用户。
# 如果以非 root 用户身份运行，则此设置无效。
# 请注意，在 Windows 上这不起作用，因此 mosquitto 应该由您希望它运行的用户启动。
#user mosquitto

Listeners

# ================================================== ================
# Listeners
# ================================================== ================

# 侦听端口/IP 地址组合。
# 通过多次使用这个变量，mosquitto 可以监听多个端口。
# 如果使用了这个变量并且没有给出 bind_address 和 port，那么默认的监听器将不会被启动。
# 必须给出监听的端口号。
# 可选地，可以提供 IP 地址或主机名作为第二个参数。
# 在这种情况下，mosquitto 将尝试将侦听器绑定到该地址，从而限制对相关网络和接口的访问。
# 默认情况下，mosquitto 将侦听所有接口。
# 请注意，对于 websockets 侦听器，不可能绑定到主机名。
#
# 在支持 Unix 域套接字的系统上，也可以创建 Unix 套接字而不是打开 TCP 套接字。
# 在这种情况下，端口号应设置为 0，并且必须提供 unix 套接字路径，例如
# listener 0 /tmp/mosquitto.sock
#
# 监听 端口号[IP地址 / 主机名 / unix套接字路径]
#listener

# 默认情况下，监听器将尝试监听所有支持的IP协议版本。
# 如果你没有一个IPv4或IPv6接口，你可能希望禁用对这些协议版本的支持。
# 特别要注意的是，由于websockets库的限制，只有在编译了IPv6支持的情况下，它才会尝试打开IPv6套接字，所以如果IPv6不可用，就会失败。
#
# 设置为 `ipv4` 以强制侦听器仅使用 IPv4，或设置为 `ipv6` 以强制侦听器仅使用 IPv6。
# 如果您希望同时支持 IPv4 和 IPv6，则不要使用 socket_domain 选项。
#
#socket_domain

# 将侦听器绑定到特定接口。
# 这类似于侦听器定义的 [ip 地址/主机名] 部分，但在接口具有多个地址或地址可能更改时很有用。
# 如果与侦听器定义的 [ip 地址/主机名] 部分一起使用，则 bind_interface 选项将优先。
# 在 Windows 上不可用。
#
# 示例：bind_interface eth0
#bind_interface

# 当侦听器使用 websockets 协议时，也可以提供 http 数据。
# 将 http_dir 设置为包含您希望提供的文件的目录。
# 如果未指定此选项，则无法进行正常的 http 连接。
#http_dir

# 允许的最大客户端连接数。
# 这是每个侦听器的设置。
# 默认为 -1，表示无限连接。
# 请注意，其他进程限制意味着无限制的连接实际上是不可能的。
# 通常，可能的默认最大连接数约为 1024。
#max_connections -1

# 可以使用 mount_point 选项将侦听器限制为在主题层次结构内运行。
# 这是通过为连接到此侦听器的任何客户端的所有主题添加 mount_point 字符串前缀来实现的。
# 这种前缀只发生在代理内部；客户端将看不到前缀。
#mount_point

# 选择收听时使用的协议。
# 这可以是 mqtt 或 websockets。
# 基于证书的 TLS 可与 websockets 一起使用，但仅支持 cafile、certfile、keyfile、ciphers 和 ciphers_tls13 选项。
#protocol MQTT

# 将 use_username_as_clientid 设置为 true 以用其用户名替换客户端连接的 clientid。
# 这允许将身份验证绑定到 clientid，这意味着可以防止一个客户端使用相同的 clientid 断开另一个客户端的连接。
# 如果客户端连接时没有用户名，当此选项设置为 true 时，它将被视为未授权而断开连接。
# 不要与 clientid_prefixes 一起使用。
# 另请参阅 use_identity_as_username。
#use_username_as_clientid

# 更改 websockets 标头大小。
# 这是一个全局选项，无法为每个侦听器设置。
# 此选项设置读取 HTTP 标头时 libwebsockets 库中使用的缓冲区的大小。
# 如果您要传递大标题数据（例如 cookie），则可能需要增加此值。
# 如果未设置或设置为 0，则将使用默认值 1024 字节。
#websockets_headers_size

基于证书的 SSL/TLS 支持

# ------------------------------------------------- ----------------
# 基于证书的 SSL/TLS 支持
# ------------------------------------------------- ----------------
# 以下选项可用于启用基于证书的 SSL/TLS 支持
# 对于这个监听器。请注意，MQTT over TLS 的推荐端口是 8883，
# 但这必须手动设置。
#
# 另请参阅 mosquitto-tls 手册页和“基于预共享密钥的 SSL/TLS”
# 支持”部分。只能支持证书或 PSK 加密之一
# 为任何监听器启用。

# certfile 和 keyfile 都必须定义以启用基于证书的
# TLS 加密。

# PEM 编码的服务器证书的路径。
#证书文件

# PEM 编码的密钥文件的路径。
#keyfile

# 如果您希望控制使用哪些加密密码，请使用 ciphers 选项。
# 可以使用“openssl ciphers”命令选择可用密码的列表，并且应以与该命令的输出相同的格式提供。
# 这仅适用于 TLS 1.2 和更早版本。
# 将 ciphers_tls1.3 用于 TLS v1.3。
#ciphers

# 选择用于此侦听器的 TLS v1.3 密码套件。
# 默认为“TLS_AES_256_GCM_SHA384:TLS_CHACHA20_POLY1305_SHA256:TLS_AES_128_GCM_SHA256”
#ciphers_tls1.3

# 如果您将 require_certificate 设置为 true，则可以创建证书撤销列表文件以撤销对特定客户端证书的访问。
# 如果您已完成此操作，请使用 crlfile 指向 PEM 编码的撤销文件。
#crlfile

# 为了允许使用提供前向安全性的临时 DH 密钥交换，侦听器必须加载 DH 参数。
# 这可以用 dhparamfile 选项指定。
# dhparamfile 可以使用命令生成，例如 “openssl dhparam -out dhparam.pem 2048”
#dhparamfile

# 默认情况下，启用 TLS 的侦听器将以与启用 https 的 Web 服务器类似的方式运行，因为服务器具有由 CA 签署的证书，客户端将验证它是否是受信任的证书。
# 总体目标是加密网络流量。
# 通过将 require_certificate 设置为 true，客户端必须提供有效的证书才能继续进行网络连接。
# 这允许在 MQTT 提供的机制之外控制对代理的访问。
#require_certificate false

# cafile 和 capath 定义了访问 PEM 编码的证书颁发机构证书的方法，这些证书在检查传入的客户端证书时将被视为受信任。
# cafile 定义包含 CA 证书的文件的路径。
# capath 定义了一个目录，用于搜索包含 CA 证书的文件。
# 要使 capath 正常工作，证书文件必须以“.crt”作为文件结尾，并且每次添加/删除证书时都必须运行“openssl rehash <path to capath>”。
#cafile
#capath


# 如果 require_certificate 为 true，您可以将 use_identity_as_username 设置为 true 以使用来自客户端证书的 CN 值作为用户名。
# 如果这是真的，password_file 选项将不会用于此侦听器。
#use_identity_as_username false

基于预共享密钥的 SSL/TLS 支持

# ------------------------------------------------- ----------------
# 基于预共享密钥的 SSL/TLS 支持
# ------------------------------------------------- ----------------
# 以下选项可用于启用基于 PSK 的 SSL/TLS 支持
# 这个监听器。请注意，MQTT over TLS 的推荐端口是 8883，
# 但这必须手动设置。
#
# 另请参阅 mosquitto-tls 手册页和“基于证书的 SSL/TLS 支持”部分。
# 任何侦听器只能启用证书或 PSK 加密支持之一。

# psk_hint 选项为此侦听器启用预共享密钥支持，并且还充当此侦听器的标识符。
# 提示被发送到客户端，并且可以在本地使用以帮助身份验证。
# 提示是一个自由形式的字符串，它本身没有多大意义，所以请随意发挥创意。
# 如果提供此选项，请参阅 psk_file 以定义要使用的预共享密钥或创建安全插件来处理它们。
#psk_hint

# 使用 PSK 时，将从可用 PSK 密码列表中选择使用的加密密码。
# 如果您想控制哪些密码可用，请使用“密码”选项。
# 可以使用“openssl ciphers”命令选择可用密码的列表，并且应以与该命令的输出相同的格式提供。
#密码

# 设置 use_identity_as_username 以将客户端发送的 psk 身份用作其用户名。
# 身份验证将使用 PSK 而不是 MQTT 用户名/密码执行，因此 password_file 将不会用于此侦听器。
#use_identity_as_username 假

持久化

# ================================================== ================
# 持久化
# ================================================== ================

# 如果启用了持久性，则每隔 autosave_interval 秒将内存数据库保存到磁盘。
# 如果设置为 0，持久化数据库只会在 mosquitto 退出时写入。
# 另请参阅 autosave_on_changes。
# 请注意，可以通过向 mosquitto 发送 SIGUSR1 信号来强制写入持久性数据库。
#autosave_interval 1800

# 如果为 true，mosquitto 将计算订阅更改、接收到的保留消息和排队消息的数量，如果总数超过 autosave_interval，则内存数据库将保存到磁盘。
# 如果为 false，mosquitto 会将 autosave_interval 视为以秒为单位的时间，从而将内存数据库保存到磁盘。
#autosave_on_changes false

# 将持久消息数据保存到磁盘（真/假）。
# 这会保存有关所有消息的信息，包括订阅、当前传输中的消息和保留的消息。
# reserved_persistence 是此选项的同义词。
#persistence false

# 用于持久数据库的文件名，不包括路径。
#persistence_file mosquitto.db

# 持久数据库的位置。
# 默认为空字符串（当前目录）。
# 设置为例如 /var/lib/mosquitto 如果在 Linux 或类似设备上作为适当的服务运行。
#persistence_location

日志

# ================================================== ================
# 日志
# ================================================== ================

# 日志存放的地方。
# 将多个 log_dest 行用于多个日志记录目的地。
# 可能的目的地是： stdout stderr syslog topic file dlt
#
# stdout 和 stderr 日志到命名输出的控制台。
#
# syslog 使用用户空间 syslog 工具，它通常以
# 在 /var/log/messages 或类似文件中。
#
# 主题日志到代理主题 '$SYS/broker/log/<severity>',
# 其中严重性是 D、E、W、N、I、M 之一，它们是调试、错误、
# 警告、通知、信息和消息。消息类型严重性由
# 订阅/取消订阅 log_types 并将日志消息发布到
# $SYS/broker/log/M/susbcribe 或 $SYS/broker/log/M/unsubscribe。
#
# 文件目的地需要一个额外的参数，它是要发送的文件是
# 登录，例如“log_dest 文件 /var/log/mosquitto.log”。该文件将是
# 当经纪人收到 HUP 信号时关闭并重新打开。只有一个文件
# 目的地可以配置。
#
# dlt 目标用于汽车“诊断日志和跟踪”工具。
# 这要求 Mosquitto 已经编译并支持 DLT。
#
# 请注意，如果代理作为 Windows 服务运行，它将默认为
# "log_dest none" 并且 stdout 和 stderr 日志都不可用。
# 如果您想禁用日志记录，请使用“log_dest none”。
#log_dest stderr

# 要记录的消息类型。使用多个 log_type 行进行日志记录
# 多种类型的消息。
# 可能的类型有：调试、错误、警告、通知、信息、
# 无，订阅，取消订阅，websockets，所有。
# 请注意，调试类型消息用于解码传入/传出
# 网络数据包。他们没有登录“主题”。
#log_type 错误
#log_type 警告
#log_type 通知
#log_type 信息


# 如果设置为true，将包含客户端连接和断开消息
# 在日志中。
#connection_messages true

# 如果使用 syslog 日志记录（不在 Windows 上），消息将被记录到
# 默认情况下“守护进程”工具。使用 log_facility 选项选择哪个
# local0 到 local7 改为登录。选项值应该是一个整数
# 值，例如“log_facility 5”使用local5。
#log_facility

# 如果设置为true，则为每条日志消息添加一个时间戳值。
#log_timestamp true

# 设置日志时间戳的格式。如果不设置，这是数量
# 自 Unix 时代以来的秒数。
# 这是一个自由文本字符串，将传递给 strftime 函数。到
# 获取 ISO 8601 日期时间，例如：
# log_timestamp_format %Y-%m-%dT%H:%M:%S
#log_timestamp_format

# 更改 websockets 日志级别。这是一个全局选项，它不是
# 可以设置每个监听器。这是一个整数，由
# libwebsockets 作为其 lws_log_levels 枚举的位掩码。见
# libwebsockets 文档了解更多详情。 “log_type websockets”也必须
# 启用。
#websockets_log_level 0

安全

# ================================================== ================
# 安全
# ================================================== ================

# 如果设置，则仅允许在其 clientid 上具有匹配前缀的客户端连接到代理。
# 默认情况下，所有客户端都可以连接。
# 例如，在此处设置“secure-”意味着客户端“secure-client”可以连接，而另一个客户端 ID 为“mqtt”的客户端则无法连接。
#clientid_prefixes

# 判断客户端是否连接的布尔值
# 不提供用户名允许连接。如果设置为
# false 那么应该创建一个密码文件（参见
# password_file 选项）来控制经过身份验证的客户端访问。
#
# 默认为 false，除非配置文件中没有定义监听器，在这种情况下它被设置为 true，但只允许来自本地机器的连接。
#allow_anonymous false

默认身份验证和主题访问控制

# ------------------------------------------------- ----------------
# 默认身份验证和主题访问控制
# ------------------------------------------------- ----------------

# 使用密码文件控制对代理的访问。
# 可以使用 mosquitto_passwd 实用程序生成此文件。
# 如果 TLS 支持没有被编译成 mosquitto（建议应该包括 TLS 支持），
# 那么使用纯文本密码，在这种情况下，文件应该是一个文本文件，
# 行格式为： username:password
# 密码（和冒号 ) 可以根据需要省略，尽管这在安全性方面提供的很少。
#
# 有关替代身份验证选项，请参阅 TLS 客户端 require_certificate 和 use_identity_as_username 选项。
# 如果使用 auth_plugin 以及 password_file，将首先进行 auth_plugin 检查。
#password_file

# 也可以使用预共享密钥文件来控制访问。
# 这需要 TLS-PSK 支持和配置为使用它的侦听器。
# 该文件应该是以下格式的文本行： identity:key
# 密钥应该是没有前导“0x”的十六进制格式。
# 如果还使用了 auth_plugin，则将首先进行 auth_plugin 检查。
#psk_file

# 使用访问控制列表文件控制对代理上主题的访问。
# 如果定义了此参数，则只有列出的主题才能访问。 
# 如果 ACL 文件的一行的第一个字符是 #，则将其视为注释。
# 使用以下格式的行添加主题访问：
#
# topic [read|write|readwrite|deny] <topic>
#
# 访问类型使用“read”、“write”、“readwrite”或“deny”控制。
# 此参数是可选的（除非 <topic> 包含空格字符） - 如果未给出，则访问权限为 read/write。
# <topic> 可以像订阅一样包含 + 或 # 通配符。
#
# “deny”选项可用于明确拒绝访问主题，否则该主题将被更广泛的 read/write/readwrite 语句授予。
# 任何“拒绝”主题都在授予 read/write 访问权限的主题之前处理。
#
# 第一组主题应用于匿名客户端，假设 allow_anonymous 为真。
# 用户特定主题 ACL 添加到用户行之后，如下所示：
#
# user <username>
#
# 这里所指的 username 与password_file 中的相同。这不是客户端 ID。
#
#
# 如果还可以根据主题内的模式替换定义 ACL。 可用于替换的模式有：
#
# %c 匹配客户端的 client id
# %u 匹配客户端的 username
#
# 替换模式必须是该层次结构级别的唯一文本。
#
# 形式与主题关键字相同，但使用模式作为关键字。
# 即使之前已经给出了“user”关键字，模式 ACL 也适用于所有用户。
#
# 如果使用具有用户名和 ACL 的网桥，则可以允许连接消息
# 使用以下模式：
# 模式写入 $SYS/broker/connection/%c/state
#
# pattern [read|write|readwrite] <topic>
#
# 例子：
#
# pattern write sensor/%u/data
#
# 如果使用 auth_plugin 和 acl_file，将首先进行 auth_plugin 检查。
#acl_file

外部认证和主题访问插件选项

# ------------------------------------------------- ----------------
# 外部认证和主题访问插件选项
# ------------------------------------------------- ----------------

# auth_plugin 选项可以支持外部身份验证和访问控制。
# 这是可加载插件的路径。
# 另请参阅下面描述的 auth_opt_* 选项。
#
# 可以多次指定 auth_plugin 选项以加载多个插件。
# 插件将按照它们在此处指定的顺序进行处理。
# 如果 auth_plugin 选项与 password_file 或 acl_file 中的任一个一起指定，则将首先进行插件检查。
#
#auth_plugin

# 如果使用了上面的 auth_plugin 选项，请按照插件说明中的说明在此处定义要传递给插件的选项。
# 所有使用 auth_opt_* 格式命名的选项都将传递给插件，例如：
#
# auth_opt_db_host
# auth_opt_db_port
# auth_opt_db_username
# auth_opt_db_password

Bridges

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

# 桥接器是一种将多个 MQTT 代理连接在一起的方式。
# 使用“连接”选项创建一个新桥，如下所述。
# 使用其余参数设置桥接选项。
# 您必须指定要订阅的地址和至少一个主题。
#
# 每个连接必须有一个唯一的名称。
#
# 地址行可以指定多个主机地址和端口。
# 如果使用多个地址，请参阅下面的 round_robin 描述以获取有关桥接行为的更多详细信息。
# 请注意，如果您使用 IPv6 地址，则需要指定端口。
#
# 可以通过指定 out、in 或两者来选择共享主题的方向，其中默认值为 out。
# 可以使用下一个主题选项指定桥接通信的 QoS 级别。
# 默认的 QoS 级别为 0，要更改 QoS，还必须给出主题方向。
#
# 本地和远程前缀选项允许主题在桥接到/从远程代理桥接时重新映射。
# 这提供了将主题树放置在适当位置的能力。
#
# 有关更多详细信息，请参阅 mosquitto.conf 手册页。
#
# 每个连接可以指定多个主题，但注意不要创建任何循环。
#
# 如果您使用的网桥将 cleansession 设置为 false（默认值），那么如果您更改订阅的主题，您可能会从传入的主题中获得意外行为。
# 这是因为远程代理保留对旧主题的订阅。
# 如果您遇到此问题，请在将 cleansession 设置为 true 的情况下连接您的网桥，然后像往常一样在将 cleansession 设置为 false 的情况下重新连接。
#connection <名称>
#address <主机>[:<端口>] [<主机>[:<端口>]]
#topic <topic> [[[out | in | both] qos等级] 本地前缀 远程前缀]

# 如果您需要让网桥通过特定的网络接口连接，请使用 bridge_bind_address 告诉网桥套接字应该绑定到哪个本地 IP 地址，
# 例如 `bridge_bind_address 192.168.1.10`
# bridge_bind_address

# 如果桥的主题具有“出”方向，则默认行为是向该主题的远程代理发送取消订阅请求。
# 这意味着将主题方向从“输入”更改为“输出”将不会继续接收传入消息。
# 发送这些取消订阅请求并不总是可取的，将 bridge_attempt_unsubscribe 设置为 false 将禁用发送取消订阅请求。
# bridge_attempt_unsubscribe 真

# 设置要用于此网桥的 MQTT 协议的版本。
# 可以是 mqttv50、mqttv311 或 mqttv31 之一。
# 默认为 mqttv311。
# bridge_protocol_version mqttv311

# 为这个网桥设置干净的会话变量。
# 当设置为 true 时，当网桥因任何原因断开连接时，远程代理上的所有消息和订阅都将被清除。
# 请注意，将 cleansession 设置为 true，当网桥在失去连接后重新连接时，可能会发送大量保留的消息。
# 设置为 false 时，订阅和消息将保留在远程代理上，并在网桥重新连接时传送。
# cleansession false

# 设置使用延迟启动类型的网桥在停止之前必须处于空闲状态的时间量。 默认为 60 秒。
#idle_timeout 60

# 设置此桥接连接的保活时间间隔，以秒为单位
# keepalive_interval 60

# 设置要在本地代理上使用的 clientid。
# 如果未定义，则默认为“local.<clientid>”。
# 如果您将代理桥接到自身，则 local_clientid 和 clientid 不匹配很重要。
# local_clientid

# 如果设置为 true，则向本地和远程代理发布通知消息，提供有关桥接连接状态的信息。
# 除非使用 notification_topic 选项，否则保留的消息将发布到主题 $SYS/broker/connection/<clientid>/state。
# 如果消息为 1，则连接处于活动状态，如果连接失败，则为 0。 这使用了最后的遗嘱和遗嘱功能。
#notifications true

# 选择发布此桥的通知消息的主题。
# 如果未设置，消息将发布到主题 $SYS/broker/connection/<clientid>/state
#notification_topic

# 设置要在此桥连接的远程端使用的客户端 ID。
# 如果未定义，则默认为“name.hostname”，其中 name 是连接名称，hostname 是这台计算机的主机名。
# 这取代了旧的“clientid”选项以避免混淆。
# “clientid”暂时保持有效。
#remote_clientid

# 设置连接到需要身份验证的代理时使用的密码。
# 仅当还设置了 remote_username 时才使用此选项。
# 这取代了旧的“密码”选项以避免混淆。
# “密码”暂时有效。
# remote_password

# 设置连接到需要身份验证的代理时使用的用户名。
# 这取代了旧的“用户名”选项以避免混淆。
# “用户名”暂时保持有效。
# remote_username

# 设置使用自动启动类型的网桥在尝试重新连接之前等待的时间。
# 此选项可以配置为使用以秒为单位的恒定延迟时间，或者使用基于“Decorrelated Jitter”的退避机制，这会在重启发生时增加一定程度的随机性。
#
# 设置一个固定的超时时间为 20 秒：
# restart_timeout 20
#
# 将退避设置为 10 秒的基础（起始值）和 30 秒的上限（上限）：
# restart_timeout 10 30
#
# 默认为以 5 为基数和 30 为上限的抖动
#restart_timeout 5 30

# 如果网桥在 address/addresses 配置中给出了多个地址，round_robin 选项定义网桥在网桥连接失败时的行为。
# 如果round_robin 为false，即默认值，则第一个地址被视为主桥连接。
# 如果连接失败，将依次尝试其他辅助地址。
# 当连接到次要桥时，桥会定期尝试重新连接到主桥，直到成功。
# 如果 round_robin 为真，则所有地址都被视为相等。
# 如果连接失败，将尝试下一个地址，如果成功将保持连接直到失败
# round_robin false

# 设置网桥的启动类型。
# 这控制了桥接的启动方式，可以是以下三种类型之一：automatic、lazy、once。
# 请注意，RSMB 提供了第四种启动类型“手册”，目前 mosquitto 不支持该启动类型。
#
# “automatic”是默认的启动类型，意味着当代理启动时桥连接将自动启动，如果连接失败，也会在短暂延迟（30 秒）后重新启动。
#
# 当排队消息的数量超过使用“阈值”参数设置的数量时，使用“延迟”启动类型的网桥将自动启动。
# 它会在“idle_timeout”参数设置的时间过后自动停止。
# 如果您希望连接仅在需要时处于活动状态，请使用此启动类型。
#
# 使用“once”启动类型的网桥将在代理启动时自动启动，但如果连接失败则不会重新启动。
#start_type automatic

# 设置需要排队等待延迟启动类型的网桥重新启动的消息数。
# 默认为 10 条消息。
# 必须小于 max_queued_messages。
#threshold 10

# 如果 try_private 设置为 true，则网桥将尝试向远程代理指示它是网桥而不是普通客户端。
# 如果成功，这意味着循环检测将更有效并且保留的消息将被正确传播。
# 并非所有代理都支持此功能，因此如果您的网桥连接不正确，则可能需要将 try_private 设置为 false。
#try_private true

# 一些 MQTT 代理不允许保留消息。
# MQTT v5 为代理提供了一种机制来告诉客户端他们不支持保留消息，但这对于 MQTT v3.1.1 或 v3.1 来说是不可能的。
# 如果您需要桥接到不支持保留消息的 v3.1.1 或 v3.1 代理，请将 bridge_outgoing_retain 选项设置为 false。
# 无论任何其他设置如何，这都会删除到该网桥的所有传出消息上的保留位。
#bridge_outgoing_retain true

# 如果您希望限制发送到远程网桥的消息的大小，请使用 bridge_max_packet_size 选项。
# 这设置了整个消息的最大字节数，包括标题和有效负载。
# 请注意，MQTT v5 代理可能会提供他们自己的最大数据包大小属性。
# 在这种情况下，将使用两个限制中较小的一个。
# 设置为 0 表示“无限制”。
#bridge_max_packet_size 0

基于证书的 SSL/TLS 支持

# ------------------------------------------------- ----------------
# 基于证书的 SSL/TLS 支持
# ------------------------------------------------- ----------------
# 必须定义 bridge_cafile 或 bridge_capath 才能为该网桥启用 TLS 支持。
# bridge_cafile 定义包含已签署远程代理证书的证书颁发机构证书的文件的路径。
# bridge_capath 定义了一个目录，用于搜索包含 CA 证书的文件。
# 要使bridge_capath 正常工作，证书文件必须以“.crt”作为文件结尾，并且每次添加/删除证书时都必须运行“openssl rehash <path to capath>”。
#bridge_cafile
#bridge_capath


# 如果远程代理在其端口上有多个可用协议，例如 MQTT 和 WebSockets，然后使用 bridge_alpn 配置请求的协议。
# 请注意，WebSockets 对网桥的支持尚不可用。
#bridge_alpn

# 使用基于证书的加密时，bridge_insecure 会禁用服务器证书中服务器主机名的验证。
# 这在测试初始服务器配置时很有用，但会使恶意第三方通过 DNS 欺骗等方式冒充您的服务器。
# 仅在测试中使用此选项。
# 如果您需要在生产环境中使用此选项，则您的设置有问题，使用加密毫无意义。
#bridge_insecure false

# PEM 编码的客户端证书的路径，如果远程代理需要。
#bridge_certfile

# PEM 编码的客户端私钥的路径，如果远程代理需要。
#bridge_keyfile

基于 PSK 的 SSL/TLS 支持

# ------------------------------------------------- ----------------
# 基于 PSK 的 SSL/TLS 支持
# ------------------------------------------------- ----------------
# 预共享密钥加密提供了基于证书加密的替代方案。
# 可以将网桥配置为使用带有 bridge_identity 和 bridge_psk 选项的 PSK。
# 这些是客户端 PSK 标识和十六进制格式的预共享密钥，没有“0x”。
# 一次只能在一个网桥上使用基于证书和 PSK 的加密之一。
#bridge_identity
#bridge_psk

外部配置文件

# ================================================== ================
# 外部配置文件
# ================================================== ================

# 可以使用 include_dir 选项包含外部配置文件。
# 这定义了一个将搜索配置文件的目录。
# 所有以“.conf”结尾的文件都将作为配置文件加载。
# 最好将此作为主文件中的最后一个选项。
# 此选项将仅从主配置文件中处理。
# 指定的目录不得包含主配置文件。
# include_dir 中的文件将按区分大小写的字母顺序加载，大写字母在前。
# 如果多次给出此选项，则第一个实例中的所有文件将在下一个实例之前处理。
# 有关示例，请参见手册页。 include_dir

原文

# 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

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

# Use per listener security settings.
#
# It is recommended this option be set before any other options.
#
# If this option is set to true, then all authentication and access control
# options are controlled on a per listener basis. The following options are
# affected:
#
# password_file acl_file psk_file auth_plugin auth_opt_* allow_anonymous
# auto_id_prefix allow_zero_length_clientid
#
# Note that if set to true, then a durable client (i.e. with clean session set
# to false) that has disconnected will use the ACL settings defined for the
# listener that it was most recently connected to.
#
# The default behaviour is for this to be set to false, which maintains the
# setting behaviour from previous versions of mosquitto.
#per_listener_settings false


# 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.
# Defaults to 'auto-'
#auto_id_prefix auto-

# 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

# QoS 1 and 2 messages will be allowed inflight per client until this limit
# is exceeded.  Defaults to 0. (No maximum)
# See also max_inflight_messages
#max_inflight_bytes 0

# 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

# For MQTT v5 clients, it is possible to have the server send a "server
# keepalive" value that will override the keepalive value set by the client.
# This is intended to be used as a mechanism to say that the server will
# disconnect the client earlier than it anticipated, and that the client should
# use the new keepalive value. The max_keepalive option allows you to specify
# that clients may only connect with keepalive less than or equal to this
# value, otherwise they will be sent a server keepalive telling them to use
# max_keepalive. This only applies to MQTT v5 clients. The maximum value
# allowable is 65535. Do not set below 10.
#max_keepalive 65535

# For MQTT v5 clients, it is possible to have the server send a "maximum packet
# size" value that will instruct the client it will not accept MQTT packets
# with size greater than max_packet_size bytes. This applies to the full MQTT
# packet, not just the payload. Setting this option to a positive value will
# set the maximum packet size to that number of bytes. If a client sends a
# packet which is larger than this value, it will be disconnected. This applies
# to all clients regardless of the protocol version they are using, but v3.1.1
# and earlier clients will of course not have received the maximum packet size
# information. Defaults to no limit. Setting below 20 bytes is forbidden
# because it is likely to interfere with ordinary client operation, even with
# very small payloads.
#max_packet_size 0

# QoS 1 and 2 messages above those currently in-flight will be queued per
# client until this limit is exceeded.  Defaults to 0. (No maximum)
# See also max_queued_messages.
# If both max_queued_messages and max_queued_bytes are specified, packets will
# be queued until the first limit is reached.
#max_queued_bytes 0

# Set the maximum QoS supported. Clients publishing at a QoS higher than
# specified here will be disconnected.
#max_qos 2

# The maximum number of QoS 1 and 2 messages to hold in a queue per client
# above those that are currently in-flight.  Defaults to 1000. Set
# to 0 for no maximum (not recommended).
# See also queue_qos0_messages.
# See also max_queued_bytes.
#max_queued_messages 1000
#
# This option sets the maximum number of heap memory bytes that the broker will
# allocate, and hence sets a hard limit on memory use by the broker.  Memory
# requests that exceed this value will be denied. The effect will vary
# depending on what has been denied. If an incoming message is being processed,
# then the message will be dropped and the publishing client will be
# disconnected. If an outgoing message is being sent, then the individual
# message will be dropped and the receiving client will be disconnected.
# Defaults to no limit.
#memory_limit 0

# 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 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

# 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/mosquitto.pid if mosquitto is
# being run automatically on boot with an init script and
# start-stop-daemon or similar.
#pid_file

# 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 and max_queued_bytes
# 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

# Set to false to disable retained message support. If a client publishes a
# message with the retain bit set, it will be disconnected if this is set to
# false.
#retain_available true

# Disable Nagle's algorithm on client sockets. This has the effect of reducing
# latency of individual messages at the potential cost of increasing the number
# of packets being sent.
#set_tcp_nodelay false

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

# 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

# When run as root, drop privileges to this user and its primary
# group.
# Set to root to stay as root, but this is not recommended.
# If set to "mosquitto", or left unset, and the "mosquitto" user does not exist
# then it will drop privileges to the "nobody" user instead.
# 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

Listeners

# =================================================================
# 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.
#
# On systems that support Unix Domain Sockets, it is also possible
# to create a # Unix socket rather than opening a TCP socket. In
# this case, the port number should be set to 0 and a unix socket
# path must be provided, e.g.
# listener 0 /tmp/mosquitto.sock
#
# listener port-number [ip address/host name/unix socket path]
#listener

# By default, a listener will attempt to listen on all supported IP protocol
# versions. If you do not have an IPv4 or IPv6 interface you may wish to
# disable support for either of those protocol versions. In particular, note
# that due to the limitations of the websockets library, it will only ever
# attempt to open IPv6 sockets if IPv6 support is compiled in, and so will fail
# if IPv6 is not available.
#
# Set to `ipv4` to force the listener to only use IPv4, or set to `ipv6` to
# force the listener to only use IPv6. If you want support for both IPv4 and
# IPv6, then do not use the socket_domain option.
#
#socket_domain

# Bind the listener to a specific interface. This is similar to
# the [ip address/host name] part of the listener definition, but is useful
# when an interface has multiple addresses or the address may change. If used
# with the [ip address/host name] part of the listener definition, then the
# bind_interface option will take priority.
# Not available on Windows.
#
# Example: bind_interface eth0
#bind_interface

# 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

# 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, ciphers, and ciphers_tls13 options are supported.
#protocol mqtt

# 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

# Change the websockets headers size. This is a global option, it is not
# possible to set per listener. This option sets the size of the buffer used in
# the libwebsockets library when reading HTTP headers. If you are passing large
# header data such as cookies then you may need to increase this value. If left
# unset, or set to 0, then the default of 1024 bytes will be used.
#websockets_headers_size

Certificate based SSL/TLS support

# -----------------------------------------------------------------
# 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.

# Both of certfile and keyfile must be defined to enable certificate based
# TLS encryption.

# Path to the PEM encoded server certificate.
#certfile

# Path to the PEM encoded keyfile.
#keyfile

# 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. This applies to TLS 1.2 and earlier versions only. Use
# ciphers_tls1.3 for TLS v1.3.
#ciphers

# Choose which TLS v1.3 ciphersuites are used for this listener.
# Defaults to "TLS_AES_256_GCM_SHA384:TLS_CHACHA20_POLY1305_SHA256:TLS_AES_128_GCM_SHA256"
#ciphers_tls1.3

# 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

# To allow the use of ephemeral DH key exchange, which provides forward
# security, the listener must load DH parameters. This can be specified with
# the dhparamfile option. The dhparamfile can be generated with the command
# e.g. "openssl dhparam -out dhparam.pem 2048"
#dhparamfile

# 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

# cafile and capath define methods of accessing the PEM encoded
# Certificate Authority certificates that will be considered trusted when
# checking incoming client certificates.
# 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
# "openssl rehash <path to capath>" each time you add/remove a certificate.
#cafile
#capath


# 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

Pre-shared-key based SSL/TLS support

# -----------------------------------------------------------------
# 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

# 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

# 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

Persistence

# =================================================================
# 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.
# 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

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

# Places to log to. Use multiple log_dest lines for multiple
# logging destinations.
# Possible destinations are: stdout stderr syslog topic file dlt
#
# 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.
#
# The dlt destination is for the automotive `Diagnostic Log and Trace` tool.
# This requires that Mosquitto has been compiled with DLT support.
#
# 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

# 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


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

# 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

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

# Set the format of the log timestamp. If left unset, this is the number of
# seconds since the Unix epoch.
# This is a free text string which will be passed to the strftime function. To
# get an ISO 8601 datetime, for example:
# log_timestamp_format %Y-%m-%dT%H:%M:%S
#log_timestamp_format

# 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

Security

# =================================================================
# 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 false, unless there are no listeners defined in the configuration
# file, in which case it is set to true, but connections are only allowed from
# the local machine.
#allow_anonymous false


### Default authentication and topic access control

# -----------------------------------------------------------------
# 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. If an auth_plugin is used as well as
# password_file, the auth_plugin check will be made first.
#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".
# If an auth_plugin is used as well, the auth_plugin check will be made first.
#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|deny] <topic>
#
# The access type is controlled using "read", "write", "readwrite" or "deny".
# 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 "deny" option can used to explicity deny access to a topic that would
# otherwise be granted by a broader read/write/readwrite statement. Any "deny"
# topics are handled before topics that grant read/write access.
#
# 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
#
# If an auth_plugin is used as well as acl_file, the auth_plugin check will be
# made first.
#acl_file

External authentication and topic access plugin options

# -----------------------------------------------------------------
# External authentication and topic access plugin options
# -----------------------------------------------------------------

# External authentication and access control can be supported with the
# auth_plugin option. This is a path to a loadable plugin. See also the
# auth_opt_* options described below.
#
# The auth_plugin option can be specified multiple times to load multiple
# plugins. The plugins will be processed in the order that they are specified
# here. If the auth_plugin option is specified alongside either of
# password_file or acl_file then the plugin checks will be made first.
#
#auth_plugin

# 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

# =================================================================
# 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. Note that if you use an IPv6 address, then you
# are required to specify a port.
#
# 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]

# If you need to have the bridge connect over a particular network interface,
# use bridge_bind_address to tell the bridge which local IP address the socket
# should bind to, e.g. `bridge_bind_address 192.168.1.10`
#bridge_bind_address

# 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

# Set the version of the MQTT protocol to use with for this bridge. Can be one
# of mqttv50, mqttv311 or mqttv31. Defaults to mqttv311.
#bridge_protocol_version mqttv311

# 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

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

# 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

# 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.
# This uses the last will and testament feature.
#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 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 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

# 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 amount of time a bridge using the automatic start type will wait
# until attempting to reconnect.
# This option can be configured to use a constant delay time in seconds, or to
# use a backoff mechanism based on "Decorrelated Jitter", which adds a degree
# of randomness to when the restart occurs.
#
# Set a constant timeout of 20 seconds:
# restart_timeout 20
#
# Set backoff with a base (start value) of 10 seconds and a cap (upper limit) of
# 60 seconds:
# restart_timeout 10 30
#
# Defaults to jitter with a base of 5 and cap of 30
#restart_timeout 5 30

# 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 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 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

# Some MQTT brokers do not allow retained messages. MQTT v5 gives a mechanism
# for brokers to tell clients that they do not support retained messages, but
# this is not possible for MQTT v3.1.1 or v3.1. If you need to bridge to a
# v3.1.1 or v3.1 broker that does not support retained messages, set the
# bridge_outgoing_retain option to false. This will remove the retain bit on
# all outgoing messages to that bridge, regardless of any other setting.
#bridge_outgoing_retain true

# If you wish to restrict the size of messages sent to a remote bridge, use the
# bridge_max_packet_size option. This sets the maximum number of bytes for
# the total message, including headers and payload.
# Note that MQTT v5 brokers may provide their own maximum-packet-size property.
# In this case, the smaller of the two limits will be used.
# Set to 0 for "unlimited".
#bridge_max_packet_size 0

Certificate based SSL/TLS support

# -----------------------------------------------------------------
# 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 "openssl rehash
# <path to capath>" each time you add/remove a certificate.
#bridge_cafile
#bridge_capath


# If the remote broker has more than one protocol available on its port, e.g.
# MQTT and WebSockets, then use bridge_alpn to configure which protocol is
# requested. Note that WebSockets support for bridges is not yet available.
#bridge_alpn

# 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

# 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

PSK based SSL/TLS support

# -----------------------------------------------------------------
# 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 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.
# Files within include_dir will be loaded sorted in case-sensitive
# alphabetical order, with capital letters ordered first. If this option is
# given multiple times, all of the files from the first instance will be
# processed before the next instance. See the man page for examples.
#include_dir