I have two PHP applications on the same Apache server. At some point, application A needs to call a URL on application B.
So let’s say a script located at http://somedomain.com/app1/action need to download http://somedomain.com/app2/action using file_get_contents() (the domain is the same for both applications)
I was wondering how does PHP handle this? Is the request going through the whole internet, as if it was a call to an external URL? Or is it somehow optimizing it and accessing the application on the server directly?
I think it depends from your DNS resolution and is not related to PHP.
If your network is properly configured, you should be able to access the site on your local network even by calling the public url.
To be sure about your request not leaving the server, you could use the
localhost( or127.0.0.1) address. You can also use the local ip address to access it over the local network.