#! /usr/bin/env python

import sys
from subprocess import Popen, PIPE
import syslog
import mysql.connector


mysql_opts = {
    "host": "localhost",
    "user": "dyndns_insert",
    "password": "your_password",
    "db": "dyndns"
}
    
# file to store new ip
proxy_pass = "/var/cache/nginx/proxy_pass"

# remote open port
port = 443

def insert_into_database(ip):
    try:
        ip = {"ip": ip}
        insert_ip = ("INSERT INTO ip (ipv4) VALUES (%(ip)s)") 
        connection = mysql.connector.connect(**mysql_opts)
        cursor = connection.cursor()
        cursor.execute(insert_ip, (ip))
        connection.commit()
        cursor.close()
        connection.close()
        syslog.syslog(syslog.LOG_DEBUG, "Update database")
    except mysql.connector.errors.Error as error:
        syslog.syslog(syslog.LOG_ERR, "%s" % error)
        

def get_ip():
    lines = ""
    for line in sys.stdin:
        if line.startswith("Subject"):
            try:
                ip = line.split(" ")[2].strip()
                syslog.syslog(syslog.LOG_DEBUG, "Get new ip: %s" % ip)
                return ip
            except IndexError as error:
                syslog.syslog(syslog.LOG_ERR, "Missing ip in subject")

def update_proxy_pass(ip):
    with open(proxy_pass, "w") as fd:
        fd.write("proxy_pass https://%s:%d;" % (ip, port))
        return True

def reload_nginx():
    cmd = ["sudo", "/etc/init.d/nginx", "reload"]
    process = Popen(cmd, stdout=PIPE, stderr=PIPE)
    status, error = process.communicate()
    if error:
        syslog.syslog(syslog.LOG_ERR, error)
    if status:
        syslog.syslog(syslog.LOG_DEBUG, status)


if __name__ == "__main__":
    ip = get_ip()
    if ip:
        insert_into_database(ip)
        if update_proxy_pass(ip):
            reload_nginx()