Getting hostname or IP address in Ruby on Rails

Question

I support the Ruby on Rails application and am looking for a convenient way to find the host name or IP address of the field in which I am included (since the virtual machine and new instances can have different host names or IP addresses). Is there a quick and easy way to do this in Ruby on Rails?

Edit: the answer below is correct, but the explanation provided by Craig is helpful (see also the link provided in the answer):

The code [below] does NOT connect or send any packets (64.233.187.99, which is google). Since UDP is a stateless protocol, connect () simply makes a system call that determines how to route packets based on the address and the interface (and therefore the IP address) it needs to bind. addr () returns an array containing the family (AF_INET), local port, and local address (which is what we want) of the socket.

Answer 1

From coderrr.wordpress.com :

require 'socket' def local_ip orig, Socket.do_not_reverse_lookup = Socket.do_not_reverse_lookup, true # turn off reverse DNS resolution temporarily UDPSocket.open do |s| s.connect '64.233.187.99', 1 s.addr.last end ensure Socket.do_not_reverse_lookup = orig end # irb:0> local_ip # => "192.168.0.127" 

Answer 2

Hostname

An easy way to get the hostname in Ruby:

 require 'socket' hostname = Socket.gethostname 

The trap is that it depends on the host, knowing its own name, because it uses the gethostname or uname system call, so it will not work for the original problem.

Functionally, this is identical to the hostname response without calling an external program. The host name may or may not be fully qualified, depending on the configuration of the machine.

---

IP address

Since ruby ​​1.9, you can also use the Socket library to get a list of local addresses. ip_address_list returns an array of AddrInfo objects. How you choose it, it will depend on what you want to do and how many interfaces you have, but here is an example that simply selects the first IP address of an IP address without a loop as a string:

 require 'socket' ip_address = Socket.ip_address_list.find { |ai| ai.ipv4? && !ai.ipv4_loopback? }.ip_address 

Answer 3

Try the following:

 host = `hostname`.strip # Get the hostname from the shell and removing trailing \n puts host # Output the hostname 

Answer 4

Usually a server has several interfaces, at least one private and one public.

Since all the answers here concern this simple scenario, a cleaner way is to ask Socket for the current ip_address_list() , as in:

 require 'socket' def my_first_private_ipv4 Socket.ip_address_list.detect{|intf| intf.ipv4_private?} end def my_first_public_ipv4 Socket.ip_address_list.detect{|intf| intf.ipv4? and !intf.ipv4_loopback? and !intf.ipv4_multicast? and !intf.ipv4_private?} end 

Both return an Addrinfo object, so if you need a string, you can use the ip_address() method, as in:

 ip= my_first_public_ipv4.ip_address unless my_first_public_ipv4.nil? 

You can easily develop a more suitable solution for your case by changing the Addrinfo methods used to filter the required interface address.

Answer 5

This IP address used here is Google, but you can use any available IP address.

 require "socket" local_ip = UDPSocket.open {|s| s.connect("64.233.187.99", 1); s.addr.last} 

Answer 6

Simplest host_with_port in .rb controller

 host_port= request.host_with_port 

Answer 7

Put the selection in the backticks:

 `dig #{request.host} +short`.strip # dig gives a newline at the end 

Or just request.host if you don't care if it is IP or not.

Answer 8

The accepted answer works, but you need to create a socket for each request, and it does not work if the server is on the local network and / or is not connected to the Internet. Below, I believe it will always work, as it analyzes the request header.

 request.env["SERVER_ADDR"] 

Answer 9

As in the answer, using hostname using the external uname command on UNIX / LINUX:

 hostname = `uname -n`.chomp.sub(/\..*/,'') # stripping off "\n" and the network name if present 

for the IP addresses used (your computer may have several network interfaces), you can use something like this:

  # on a Mac: ip_addresses = `ifconfig | grep 'inet ' | grep -v 127.0.0.1 | cut -d' ' -f 2`.split => ['10.2.21.122','10.8.122.12'] # on Linux: ip_addresses = `ifconfig -a | grep 'inet ' | grep -v 127.0.0.1 | cut -d':' -f 2 | cut -d' ' -f 1`.split => ['10.2.21.122','10.8.122.12'] 

Answer 10

You will likely have multiple IP addresses on each machine (127.0.0.1, 192.168.0.1, etc.). If you use * NIX as the OS, I would suggest using hostname and then starting DNS to look at it. You should be able to use / etc / hosts to determine the local host name in order to resolve the IP address for this machine. Windows has similar functionality, but I have not used it since Windows 95 was the edge of the bleeding.

Another option is to click on a search service, for example WhatIsMyIp.com . These guys will refuse you your real IP address. This can also be configured using the Perl script on the local server, if you prefer. I believe that 3 lines or so of code to output the remote IP from% ENV should cover you.

Answer 11

 io = IO.popen('hostname') hostname = io.readlines io = IO.popen('ifconfig') ifconfig = io.readlines ip = ifconfig[11].scan(/\ \d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}\ /) 

A few answers with require 'socket' look good. Those who have request.blah_blah_blah suppose you use Rails.

IO should be available all the time. The only problem with this script is that if ifconfig is displayed in another homestead on your systems, you will get different results for IP. The look of the host should be as firm as Sears.

Answer 12

try: Request.remote_ip

remote_ip ()

Determine the source IP address. REMOTE_ADDR is standard, but if the user is behind a proxy server. HTTP_CLIENT_IP and / or HTTP_X_FORWARDED_FOR are set by proxies, so check them if REMOTE_ADDR is a proxy. HTTP_X_FORWARDED_FOR can be a comma separated list in case of multiple integer proxies; The last address that is not a reliable IP source.

Update: Unfortunately, I did not read the documentation correctly.