WordPress is used for a small website in my workplace. The server must use a proxy to connect to the web, and this is necessary for many plugins and for updates.
As explained in the documentation, the proxy is declared in wp-config.php
define('WP_PROXY_HOST', 'myCache.fr');
define('WP_PROXY_PORT', '3128');
Since 3.8.1, the Dashboard does not show any update available (even if now 3.9.1 is out). No error message is displayed either.
I had to run wireshark to see what was happening :
- WordPress sends a POST request to https://api.wordpress.org/plugins/info/1.0
- Squid proxy answers Error 501 : “Unsupported Request Method and Protocol”
It seems that the proxy does not support HTTPS POST requests. So I had to find where the https URL was defined in WordPress. It turns out it is in wp-includes/update.php. But the URLs are defined as http, and the following code is used (in three different places) to convert it to https if ssl is available :
if ( $ssl = wp_http_supports( array( 'ssl' ) ) ) $url = set_url_scheme( $url, 'https' );
I thus commented those :
/**if ( $ssl = wp_http_supports( array( 'ssl' ) ) ) $url = set_url_scheme( $url, 'https' );*/
And I could update the server. Of course, I will have to do that again after each update…
As a better workaround, you can install php curl extension, libcurl will be used as the default transport handler instead “stream” and it behave correctly with https post and proxies.
Thanks a lot, I’ll try that !
Missing the php curl extension was my problem – once that was installed, the site was able to reach out to get plugins etc via a proxy using a https url etc etc.