HTTP request on localhost failing

Question

I have a Wordpress instance on my development box with the WP REST API plugin installed. I am attempting to create my own plugin to use wp_remote_get() to communicate with my own custom PHP application on the same box.

I have set up my hosts file with the name of the custom PHP application. I have written a simple cURL request which is able to connect.

$curl = curl_init();

curl_setopt( $curl, CURLOPT_RETURNTRANSFER, 1 );
curl_setopt( $curl, CURLOPT_HEADER, 1 );
curl_setopt( $curl, CURLOPT_POST, false );
curl_setopt( $curl, CURLOPT_URL, "http://foo.richard.local/notify/$post_id" );

$curlData = curl_exec( $curl );

However when I try to use wp_remote_get() i'm getting a WP_Error

$response = wp_remote_get(
    "http://foo.richard.local/notify/$post_id"
);

if ( is_wp_error( $response ) ) {
    $errorResponse = $response->get_error_message();
}

Operation timed out after 5514 milliseconds with 0 bytes received

I have increased the timeout, but I'm still getting the same response.

I have installed the excellent Core Control plugin to verify the HTTP configuration settings.

The https_local_ssl_verify and https_ssl_verify filters have been set in my plugin.

The Core Control External HTTP Access Logger looks like this:

Answer 1

To make wp_remote_get() work you need to check your php.ini file. In your php.ini file you need to set allow_url_include = On, which by default is set as allow_url_include = Off. Otherwise wp_remote_get() will not work.

Reference: allow_url_include