myjsonip.com in Go

This is a site that allows you to quickly get information relative to your hosts. IP address and agent are the only things implemented so far.

How to use the site

You are able to query the site for your WAN IP address or agent and it will return it in json (default), yaml or xml depending on the route.

HTTP Method	URI	What is returned?
GET	/	IP Address (JSON)
GET	/ip/:format	IP Address
GET	/agent/:format	Agent
GET	/all/:format	IP Address + Agent

Examples:

http://myjsonip.com/ip or http://myjsonip.com/ip/json

{"ip":"172.22.52.123"}

http://myjsonip.com/ip/yaml:

---
ip: 172.22.52.123

http://myjsonip.com/ip/xml:

<?xml version="1.0" encoding="UTF-8"?>
<myjsonip.com>
  <ip>127.0.0.1</ip>
</myjsonip.com>

I have x interfaces on my server with NATs, how can I leverage this site to get each interface WAN IP?

I use the following script in production in order to quickly look up all interfaces or a single interface WAN IP. A few examples of how to use the script:

How to grab the WAN IP for ALL interfaces: $ find_wan_ip.rb

How to grab the WAN IP for a single interface: $ find_wan_ip.rb 192.168.2.5

How to grab the WAN IP for multiple interfaces: $ find_wan_ip.rb 192.168.2.5 192.168.2.6

require 'net/http'
require 'json'
require 'resolv'
require 'socket'

# Grab all interfaces that have valid IPv4 addresses
interfaces = Socket.getifaddrs.map do |i|
  next if i.addr.ipv4_loopback? || i.addr.ipv6_loopback?
  next unless i.addr.ipv4?
  x = [ i.name, i.addr.ip_address ]
  x
end.compact

# Build hash for looking up interface names by IP
ip_to_int = interfaces.inject({}) do |memo,x|
  name   = x[0]
  lan_ip = x[1]
  memo[lan_ip] = name
  memo
end

# Parse the command line to see if any IP addresses where passed.
ip_addresses = ARGV.each.map do |x|
  if x =~ Resolv::IPv4::Regex && ip_to_int.keys.include?(x)
    x
  else
    next
  end
end.compact

# If no IP addresses where passed, grab the WAN IP of all interfaces
ip_addresses = interfaces.map { |x| x[1] } if ip_addresses.empty?

# Setup our http connection. This is used to discover the public/WAN IP.
uri  = URI('http://myjsonip.com/ip')
http = Net::HTTP.new(uri.host, uri.port)
http.open_timeout = 2
http.read_timeout = 2

ip_addresses.each do |ip|
  failed_request = false
  no_ip = false
  lan_ip = ip
  interface_name = ip_to_int[lan_ip]

  # This makes sure we use this interface when making outbound connections.
  http.local_host = lan_ip

  begin
    res = http.get('/')
  rescue Net::OpenTimeout, Errno::EHOSTUNREACH, Errno::ECONNREFUSED => e
    failed_request = true
    no_ip = true
  end

  wan_ip   = JSON.load(res.body)['ip'] unless failed_request
  # If the WAN IP is 50.56.18.108 it means that no NAT is setup and it's defaulting to our firewall's IP.
  wan_ip = nil if no_ip
  puts "%s:%s:%s" % [interface_name, lan_ip, wan_ip]
end

Contributing

1. Fork it ( https://github.com/jasonwbarnett/myjsonip.com-go/fork )
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create a new Pull Request