• Check the latest release on: https://community.ubnt.com/t5/UniFi-Updates-Blog/bg-p/Blog_UniFi
• Click on latest articles and select the latest version.
• Scroll down and download: UniFi.unix.zip
• Save the zip in: /var/tmp
• You need the latest Java release from Oracle: http://www.java.com/en/download/manual.jsp
• Download the x64 RPM

mongodb-server requires EPEL repository

yum install mongodb-server unzip
yum localinstall jre-8u45-linux-x64.rpm

Make sure you have a minimum of 4GB in /opt

cd /opt
unzip /var/tmp/UniFi.unix.zip

/etc/init.d/unifi

#!/bin/bash
# chkconfig: 2345 95 20
# description: UniFi system
# processname: unifi

UNIFI_PATH=/opt/UniFi

ctrl_start() {
  java -jar $UNIFI_PATH/lib/ace.jar start &
}

ctrl_stop() {
  java -jar $UNIFI_PATH/lib/ace.jar stop &
}

ctrl_restart() {
  ctrl_stop
  sleep 1
  ctrl_start
}

case "$1" in
  start) echo -n "starting UniFi system: "
         ctrl_start
         echo "service started"
         ;;
  stop) echo -n "stopping UniFi system: "
        ctrl_stop
        echo "service stopped"
        ;;
  restart) echo -n "restarting UniFi system: "
           ctrl_restart
           echo "service restarted"
           ;;
  *) echo "usage: $0 {start|stop|restart}"
     ;;
esac

exit 0

/etc/firewalld/services/unifi.xml

<?xml version="1.0" encoding="utf-8"?>
<service>
  <short>unifi</short>
  <description>UniFi ports</description>
  <port protocol="tcp" port="8080"/>
  <port protocol="tcp" port="8081"/>
  <port protocol="tcp" port="8880"/>
  <port protocol="tcp" port="8843"/>
  <port protocol="tcp" port="8443"/>
  <port protocol="tcp" port="27117"/>
  <port protocol="udp" port="3478"/>
</service>

firewall-cmd --permanent --zone=management --add-service=unifi
firewall-cmd --reload

/etc/init.d/unifi start

Go with your browser to: http://your.domain.com:8080