Monit: Apache2, MySQL and PHP-FPM

lamp.mon

# Apache2
check process apache2 with pidfile /var/run/apache2/apache2.pid
   group www-data
   start program = "/bin/systemctl start apache2" with timeout 30 seconds
   stop program = "/bin/systemctl stop apache2"
   if failed host localhost port 80 with protocol http 
       and request "/server-status" for 2 times within 2 cycles then restart
    depend apache_bin
    depend apache_rc
 
check file apache_bin with path /usr/sbin/apache2
    group www-data
    include /etc/monit/templates/rootbin
 
check file apache_rc with path /etc/init.d/apache2
    group www-data
    include /etc/monit/templates/rootbin
 
# MySQL
check process mysql with pidfile /var/run/mysqld/mysqld.pid
   group mysql
   start program = "/bin/systemctl start mysql"
   stop program = "/bin/systemctl stop mysql"
   if failed host localhost port 3306 protocol mysql with timeout 15 seconds for 2 times within 3 cycles then restart
   if failed unixsocket /var/run/mysqld/mysqld.sock protocol mysql for 2 times within 3 cycles then restart
   if 2 restarts with 2 cycles then timeout
    depend mysql_bin
    depend mysql_rc
 
check file mysql_bin with path /usr/sbin/mysqld
    group mysql
    include /etc/monit/templates/rootbin
 
check file mysql_rc with path /etc/init.d/mysql
    group mysql
    include /etc/monit/templates/rootbin

 
# PHP-FPM
check process php7.2-fpm with pidfile /var/run/php/php7.2-fpm.pid
   start program = "/bin/systemctl start php7.2-fpm" with timeout 30 seconds
   stop program = "/bin/systemctl stop php7.2-fpm"
   if failed host example.tld port 80 protocol http 
      and request "/index.php"
   then restart
   if 2 restarts within 2 cycles then timeout

server-status is not an ordinary file. It is part of Apache2. You have to enable mod_status: a2enmod status