MQTT publisher and subscriber with PHP. nothing special just my mqtt project trial template
$ sudo apt-get install php-pear
$ sudo apt-get install php7-dev
$ sudo apt-add-repository ppa:mosquitto-dev/mosquitto-ppa
$ sudo apt-get update
$ sudo apt-get install libmosquitto-dev
$ sudo apt-get install mosquitto mosquitto-clients
$ sudo pecl install Mosquitto-alpha
Add extension=mosquitto.so to php.ini