Nmap scan report for test (192.168.88.65)
Host is up (0.0023s latency).
Not shown: 998 closed ports
PORT     STATE SERVICE
111/tcp  open  rpcbind
3306/tcp open  mysql

Nmap scan report for localhost (127.0.0.1)
Host is up (0.0000030s latency).
Other addresses for localhost (not scanned): 127.0.0.1
Not shown: 996 closed ports
PORT     STATE SERVICE
25/tcp   open  smtp
111/tcp  open  rpcbind
3306/tcp open  mysql
8000/tcp open  http-alt

root @ debian /root ### iptables -I INPUT -p tcp --dport 8000 -j ACCEPT
root @ debian /root ### iptables-save

# Generated by iptables-save v1.4.21 on Mon Mar  6 10:11:58 2017
*filter
:INPUT ACCEPT [57:123601]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [44:124193]
-A INPUT -p tcp -m tcp --dport 8000 -j ACCEPT
-A INPUT -p tcp -m tcp --dport 8000 -j ACCEPT
-A INPUT -p tcp -m tcp --dport 8000 -j ACCEPT
-A INPUT -p tcp -m tcp --dport 8000 -j ACCEPT
-A INPUT -p tcp -m tcp --dport 8000 -j ACCEPT
-A INPUT -p tcp -m tcp --dport 8000 --tcp-flags FIN,SYN,RST,ACK SYN -j ACCEPT
COMMIT
# Completed on Mon Mar  6 10:11:58 2017

Name: http (or any name you want)
Protocol: TCP
Host IP: (blank)
Host Port: 8888 (or any port you want)
Guest IP: (blank)
Guest Port: 8000 (match your web app port)