MQTT server construction - mosquitto1.4.4 installation guide
mosquito
mosquitto is an open source message broker service software that implements the MQTT v3.1 protocol.
It provides a very lightweight message data transmission protocol, works in a publish/subscribe mode, and can be used for message communication between IoT devices, middleware, and APP clients.
mosquitto official website
http://mosquitto.org/
For the mqtt protocol, please refer to
http://docs.oasis-open.org/mqtt/mqtt/v3.1.1/os/mqtt-v3.1.1-os.html
Basic preparation
Linux kernel version: Centos 6.5_final_64bit
Install the basic software
yum install gcc -c++ yum install cmake yum install openssl-devel // mosquitto supports openssl by default
Downloader
Official website download
wget http://mosquitto.org/files/source/mosquitto-1.4.4.tar.gz tar -xzvf mosquitto-1.4.4.tar.gz cd mosquitto - 1.4 . 4
编译安装
编译选项
当前的程序目录可直接编译，在编译之前需根据需要做一定的配置，否则会出现 xxx.h找不到的情况。
vim config.mk
config.mk包括了多个选项, 可按需关闭或开启，但一旦开启则需要先安装对应的模块
模块说明
|
选项
|
说明
|
make出错信息
|
WITH_SRV
|
启用c-areas库的支持，一个支持异步DNS查找的库见http://c-ares.haxx.se |
missing ares.h
|
WITH_UUID
|
启用lib-uuid支持，支持为每个连接的客户端生成唯一的uuid
|
missing uuid.h
|
WITH_WEBSOCKETS
|
启用websocket支持，需安装libwebsockets对于需要使用websocket协议的应用开启 |
missing libwebsockets.h
|
安装c-areas
wget http://c-ares.haxx.se/download/c-ares-1.10.0.tar.gz tar xvf c-ares-1.10.0.tar.gz cd c-ares-1.10.0 ./configure make sudo make install
安装lib-uuid
yum install libuuid-devel
安装libwebsockets
wget https://github.com/warmcat/libwebsockets/archive/v1.3-chrome37-firefox30.tar.gz tar zxvf v1.3-chrome37-firefox30.tar.gz cd libwebsockets-1.3-chrome37-firefox30 mkdir build; cd build; cmake .. -DLIB_SUFFIX=64 make install
//若遇到以上模块无法安装的情况，可将对应模块选项关闭即可，但相应功能也将无法提供；
开始安装mosquitto
make make install
至此程序已经安装完毕！
程序文件将默认安装到以下位置
| 路径 | 程序文件 |
| /usr/local/sbin | mosquiotto server |
| /etc/mosquitto | configuration |
| /usr/local/bin | utility command |
修正链接库路径
由于操作系统版本及架构原因，很容易出现安装之后的链接库无法被找到，如启动mosquitto客户端可能出现找不到
libmosquitto.so.1文件，因此需要添加链接库路径
//添加路径 vim /etc/ld.so.conf.d/liblocal.conf /usr/local/lib64 /usr/local/lib
//刷新 ldconfig
启动与测试
创建用户
mosquitto默认以mosquitto用户启动，可以通过配置文件修改
groupadd mosquitto
useradd -g mosuqitto mosquiotto
程序配置
mv /etc/mosquitto/mosquitto.conf.example /etc/mosquitto/mosquitto.conf
配置项说明
# 服务进程的PID #pid_file /var/run/mosquitto.pid # 服务进程的系统用户 #user mosquitto # 服务绑定的IP地址 #bind_address # 服务绑定的端口号 #port 1883 # 允许的最大连接数，-1表示没有限制 #max_connections -1 # 允许匿名用户 #allow_anonymous true
//关于详细配置可参考
http://mosquitto.org/man/mosquitto-conf-5.html
启动
mosquitto -c /etc/mosquitto/mosquitto.conf -d
成功将启动1883端口监听
客户端测试
新建两个shell端口A/B
A 订阅主题：
mosquitto_sub -t location
B 推送消息：
mosquitto_pub -t location -h localhost -m "new location"
可以在A窗口看到由B推送的消息，此外服务端窗口也可以看到客户端连接和端口的日志
1443083396: New client connected from 127.0.0.1 as mosqpub/31924-iZ94eb8yq (c1, k60). 1443083396: Client mosqpub/31924-iZ94eb8yq disconnected.、
FAQ
启动mosquitto报错
error while loading shared libraries: libwebsockets.so.4.0.0: cannot open shared object file: No such file or directory
或者
error while loading shared libraries: libmosquitto.so.1: cannot open shared object file: No such file or directory
解决方法
找不到链接库，通过locate或find命令找到libwebsockets.so.4.0.0，将其目录添加至ldconfg配置中：
vim /etc/ld.so.conf.d/liblocal.conf /usr/local/lib64 /usr/local/lib ldconfig //执行ln -s 添加软连接的方式也可行
编译找不到openssl/ssl.h
解决方法
yum install openssl-devel
编译报错
mosquitto.c:871: error: ‘struct mosquitto’ has no member named ‘achan’
找不到areas.h
解决方法
安装 c-areas模块(见上文)或将config.mk中WITH_SRV选项关闭
make test 提示不支持协议
Address family not supported by protocol
一般是指所访问的地址类型不被支持，比如IPV6，忽略该错误即可
参考文档
mosquitto1.4 搭建日记
https://goochgooch.wordpress.com/2014/08/01/building-mosquitto-1-4/
Ubuntu下搭建教程(日文)
http://qiita.com/aquaviter/items/cb3051cf42a3a3c4a4d9
使mosquitto支持websockets
https://www.justinribeiro.com/chronicle/2014/10/22/mosquitto-libwebsockets-google-compute-engine-setup/
使用JS实现mqtt-websocket
http://jpmens.net/2014/07/03/the-mosquitto-mqtt-broker-gets-websockets-support/