Get IP Address for ddclient from a TP-LINK Router

README.md

Get IP Address for use in ddclient from a TP-LINK Router

Retrieve the local IP address by screen scraping the router's web page using a ruby script from a server behind the router

To use in ddclient:

use=cmd, cmd="ROUTER_IP=<YOUR ROUTER IP ADDRESS> ROUTER_USER=<USERNAME> ROUTER_PASS=<PASSWORD> /path/to/getRouterIPAddress.rb"

getRouterIPAddress.rb

#!/usr/bin/ruby

require 'base64'
require 'uri'
require 'net/http'

ROUTER_IP = ENV['ROUTER_IP']
ROUTER_USER = ENV['ROUTER_USER']
ROUTER_PASS = ENV['ROUTER_PASS']

# get ip from router
def routerIP
    uri = URI("http://"+ROUTER_IP+"/data/map_internet_info_form.json")
    req = Net::HTTP::Post.new(uri)
    req['Referer'] = "http://"+ROUTER_IP+"/userRpm/BasicNetworkMapRpm.htm"
    req['Cookie'] = URI::encode("Authorization=Basic "+Base64.strict_encode64(ROUTER_USER+':'+ROUTER_PASS))
    req.set_form_data('operation' => 'read')
    res = Net::HTTP.start(uri.hostname, uri.port) do |http|
      http.request(req)
    end

    case res
    when Net::HTTPSuccess, Net::HTTPRedirection
puts res.body
        res.body.each_line do |line|
            # "wan_ip": "0.0.0.0"
            line.match /wan_ip".*"(\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3})"/ do |matchdata|
                return matchdata[1]
            end
        end
    else
        puts res.value
    end
    return nil
end

puts routerIP()