环境信息：
1. Linux Centos7.2 环境，CPU 2核，内存8G.
2. mosquitto版本：mosquitto-1.5.4
官网：http://mosquitto.org/download/
libwebsockets官网： https://libwebsockets.org/网址:yii666.com
本环境搭建，主要用到了mosquitto，么有涉及websocket的内容，所以，这里不做安装介绍。
搭建过程：文章地址https://www.yii666.com/article/764248.html
1. 安装mosquitto-1.5.4
下载解压缩mosquitto-1.5.4.tar.gz。然后执行make
[root@ws2 mosquitto-1.5.]# make
set -e; for d in lib client src; do make -C ${d}; done
make[]: Entering directory `/opt/mosquitto-1.5./lib'
cc -Wall -ggdb -O2 -I. -I.. -I../lib -fPIC -DWITH_TLS -DWITH_TLS_PSK -DWITH_THREADING -DWITH_SOCKS -c mosquitto.c -o mosquitto.o
In file included from mosquitto.c:::
mosquitto_internal.h::: fatal error: openssl/ssl.h: No such file or directory
# include <openssl/ssl.h>
^
compilation terminated.
make[]: *** [mosquitto.o] Error
make[]: Leaving directory `/opt/mosquitto-1.5./lib'
make: *** [mosquitto] Error
上述错误是因为没有安装openssl-devel。安装上openssl-devel即可解决： yum install openssl-devel
make -C cpp
make[]: Entering directory `/opt/mosquitto-1.5./lib/cpp'
g++ -Wall -ggdb -O2 -I. -I.. -I../lib -fPIC -c mosquittopp.cpp -o mosquittopp.o
make[]: g++: Command not found
make[]: *** [mosquittopp.o] Error
make[]: Leaving directory `/opt/mosquitto-1.5./lib/cpp'
make[]: *** [all] Error
make[]: Leaving directory `/opt/mosquitto-1.5./lib'
上述错误是因为没有安装gcc-c++. 安装上gcc-c++即可解决： yum install gcc-c++
cc -I.. -Wall -ggdb -O2 -c mosquitto_passwd.c -o mosquitto_passwd.o
cc mosquitto_passwd.o -o mosquitto_passwd -lcrypto
make[]: Leaving directory `/opt/mosquitto-1.5./src'
set -e; for d in man; do make -C ${d}; done
make[]: Entering directory `/opt/mosquitto-1.5./man'
make[]: Nothing to be done for `all'.
make[]: Leaving directory `/opt/mosquitto-1.5./man'
上述错误是因为没有安装c-ares-devel. 安装上c-ares-devel即可解决： yum install c-ares-devel
解决上面的问题，可以一次安装下面的所有的依赖：yum -y install gcc gcc-c++ openssl-devel c-ares-devel libuuid-devel wget cmake
[root@ws2 mosquitto-1.5.]# yum -y install gcc gcc-c++ openssl-devel c-ares-devel libuuid-devel wget cmake
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
Package gcc-4.8.-.el7.x86_64 already installed and latest version
Package gcc-c++-4.8.-.el7.x86_64 already installed and latest version
Package :openssl-devel-1.0.2k-.el7.x86_64 already installed and latest version
Package c-ares-devel-1.10.-.el7.x86_64 already installed and latest version
Package libuuid-devel-2.23.-.el7.x86_64 already installed and latest version
Package wget-1.14-.el7_4..x86_64 already installed and latest version
Package cmake-2.8.12.2-.el7.x86_64 already installed and latest version
2. 配置mosquitto
进入/etc/mosquitto目录
[root@ws2 mosquitto]# cp mosquitto.conf.example mosquitto.conf
[root@ws2 mosquitto]# cp pwfile.example pwfile
vi mosquitto.conf，做下面配置
allow_anonymous true
password_file /etc/mosquitto/pwfile
然后，在文件最末尾补充（mosquitto服务监听的端口）：
port 1883 listener 9090 protocol websockets
3. 启动mosquitto
[root@ws2 mosquitto]# mosquitto -c /etc/mosquitto/mosquitto.conf
Error: Websockets support not available.
Error found at /etc/mosquitto/mosquitto.conf:.
Error: Unable to open configuration file.
这个错误，是因为我没有安装websockets模块，另外，config.mk里面的websocket没有配置为YES。所以将配置中websocket的注释掉即可。
#listener
#protocol websockets
再次启动：
[root@ws2 mosquitto]# mosquitto -c /etc/mosquitto/mosquitto.conf
: mosquitto version 1.5. starting
: Config loaded from /etc/mosquitto/mosquitto.conf.
: Opening ipv4 listen socket on port .
: Opening ipv6 listen socket on port .
: Error: Invalid user 'mosquitto'.
上述错误显示没有mosquitto用户，创建用户并添加组。
[root@ws2 mosquitto]# groupadd mosquitto
[root@ws2 mosquitto]# useradd -g mosquitto mosquitto
最后再次启动：
[root@ws2 mosquitto]# mosquitto -c /etc/mosquitto/mosquitto.conf
: mosquitto version 1.5. starting
: Config loaded from /etc/mosquitto/mosquitto.conf.
: Opening ipv4 listen socket on port .
: Opening ipv6 listen socket on port .
此时，mosquitto以前台服务的方式在运行。。。如何使用，请看帮助信息：
[root@ws2 mosquitto]# mosquitto --help
mosquitto version 1.5. mosquitto is an MQTT v3.1.1 broker. Usage: mosquitto [-c config_file] [-d] [-h] [-p port] -c : specify the broker config file.
-d : put the broker into the background after starting.
-h : display this help.
-p : start the broker listening on the specified port.
Not recommended in conjunction with the -c option.
-v : verbose mode - enable all logging types. This overrides
any logging options given in the config file. See http://mosquitto.org/ for more information.
4. 测试验证
[root@ws2 ~]# mosquitto_sub -t rulee
mosquitto_sub: error while loading shared libraries: libmosquitto.so.: cannot open shared object file: No such file or directory
此处错误，表明动态库没有配合好路径，参照下面的操作（主要是红色的两行指令）：
[root@ws2 ~]# cat /etc/ld.so.conf
include ld.so.conf.d/*.conf
[root@ws2 ~]#
[root@ws2 ~]# echo "/usr/local/lib" >> /etc/ld.so.conf
[root@ws2 ~]#
[root@ws2 ~]# vi /etc/ld.so.conf
include ld.so.conf.d/*.conf
/usr/local/lib
[root@ws2 ~]# ldconfig
然后再次订阅一个rulee的topic：
然后，再启动一个终端，进行发布消息操作：
[root@ws2 ~]# mosquitto_pub -h localhost -t rulee -m "hello rule engine"
在上面的订阅窗口已经收到这个发布的消息
[root@ws2 ~]# mosquitto_sub -t rulee
hello rule engine
安全控制：
上面的操作，是针对无安全控制的，下面，进行带安全控制的配置，进入/etc/mosquitto目录：
[root@ws2 mosquitto]# cp mosquitto.conf.example mosquitto.conf
[root@ws2 mosquitto]# cp pwfile.example pwfile
[root@ws2 mosquitto]# cp aclfile.example aclfile
vi mosquitto.conf，做下面配置文章来源地址:https://www.yii666.com/article/764248.html
allow_anonymous false
password_file /etc/mosquitto/pwfile
acl_file /etc/mosquitto/aclfile
然后，在文件最末尾补充监听端口（若没有配置的话）： port 1883
添加安全用户信息：
[root@ws2 mosquitto]# mosquitto_passwd -c /etc/mosquitto/pwfile shihuc
Password:
Reenter password:
重新启动mosquitto服务：
[root@ws2 mosquitto]# mosquitto -d -c /etc/mosquitto/mosquitto.conf
订阅：
[root@ws2 ~]# mosquitto_sub -t rulee
hello rule engine
Connection Refused: not authorised.
[root@ws2 ~]#
[root@ws2 ~]#
[root@ws2 ~]# mosquitto_sub -t /taikang/rulee -u shihuc -P shihuc
发布：
[root@ws2 ~]# mosquitto_pub -h localhost -t /taikang/rulee -m "hello rule engine with auth"
Connection Refused: not authorised.
Error: The connection was refused.
[root@ws2 ~]#
[root@ws2 ~]#
[root@ws2 ~]# mosquitto_pub -u shihuc -P shihuc -h localhost -t /taikang/rulee -m "hello rule engine with auth"
[root@ws2 ~]#