If you use virtual hosts and have had to test your site on a variety of devices you know it can be a pain. On a desktop or laptop you can edit your hosts file to route requests to the correct IP, but how can you do this on iPads, iPhones, etc.? Luckily 37signals has released a free DNS service called xip.io that makes this really easy.

The best way to show how xip.io works is by example. From the xip.io website:

10.0.0.1.xip.io              resolves to   10.0.0.1
www.10.0.0.1.xip.io     resolves to   10.0.0.1
mysite.10.0.0.1.xip.io   resolves to   10.0.0.1
foo.bar.10.0.0.1.xip.io  resolves to   10.0.0.1

So if you have a virtual host for "mysite", in apache you can add the following server alias to your virtual host configuration:

ServerAlias mysite.10.0.0.1.xip.io

Or even

ServerAlias mysite.*.xip.io

After restarting apache you can visit http://mysite.10.0.0.1.xip.io from any device and the IP should be resolved correctly to 10.0.0.1.

For more info on xip.io and a link to the github page visit http://xip.io/.

Hopefully this will make testing your concrete5 sites that use a virtual host easier!