MQTT研究之mosquitto：【环境搭建】

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/

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：

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-1.5.4]# make
set -e; for d in lib client src; do make -C ${d}; done
make[1]: Entering directory `/opt/mosquitto-1.5.4/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:27:0:
mosquitto_internal.h:28:27: fatal error: openssl/ssl.h: No such file or directory
 #  include <openssl/ssl.h>
                           ^
compilation terminated.
make[1]: *** [mosquitto.o] Error 1
make[1]: Leaving directory `/opt/mosquitto-1.5.4/lib'
make: *** [mosquitto] Error 2

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[2]: Entering directory `/opt/mosquitto-1.5.4/lib/cpp'
g++ -Wall -ggdb -O2  -I. -I.. -I../lib -fPIC -c mosquittopp.cpp -o mosquittopp.o
make[2]: g++: Command not found
make[2]: *** [mosquittopp.o] Error 127
make[2]: Leaving directory `/opt/mosquitto-1.5.4/lib/cpp'
make[1]: *** [all] Error 2
make[1]: Leaving directory `/opt/mosquitto-1.5.4/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[1]: Leaving directory `/opt/mosquitto-1.5.4/src'
set -e; for d in man; do make -C ${d}; done
make[1]: Entering directory `/opt/mosquitto-1.5.4/man'
make[1]: Nothing to be done for `all'.
make[1]: Leaving directory `/opt/mosquitto-1.5.4/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-1.5.4]# 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-4.8.5-28.el7.x86_64 already installed and latest version
Package gcc-c++-4.8.5-28.el7.x86_64 already installed and latest version
Package 1:openssl-devel-1.0.2k-12.el7.x86_64 already installed and latest version
Package c-ares-devel-1.10.0-3.el7.x86_64 already installed and latest version
Package libuuid-devel-2.23.2-52.el7.x86_64 already installed and latest version
Package wget-1.14-15.el7_4.1.x86_64 already installed and latest version
Package cmake-2.8.12.2-2.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:874.
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 9090
#protocol websockets

再次启动：

[root@ws2 mosquitto]# mosquitto -c /etc/mosquitto/mosquitto.conf
1544435834: mosquitto version 1.5.4 starting
1544435834: Config loaded from /etc/mosquitto/mosquitto.conf.
1544435834: Opening ipv4 listen socket on port 1883.
1544435834: Opening ipv6 listen socket on port 1883.
1544435834: 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
1544436204: mosquitto version 1.5.4 starting
1544436204: Config loaded from /etc/mosquitto/mosquitto.conf.
1544436204: Opening ipv4 listen socket on port 1883.
1544436204: Opening ipv6 listen socket on port 1883.

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 1.5.4

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.1: 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

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 ~]#