We are currently running an old Jenkins version (2.263.3).

Our JDK tool definitions all use "Extract .zip/.tar.gz" with a file URL pointing to a location on the controller (under /opt/jenkins-tool-installers).

This works fine.

We are now setting up a new Jenkins controller, running version 2.479.2.

While tool installers configured the same way still work, the tool management interface reports all of those file URLs as malformed.

This is because the checking code uses ProxyConfiguration.newHttpRequestBuilder to access them, which only supports HTTP or HTTPS URLs.

But the installation does not use the same method to access the zip/tarball, and this supports file URLs (and, I assume, other schemes like FTP).

Note: the actual installation tries to access the URL from the agent first, before trying from the controller. It would be useful to have a checkbox or dropdown to configure that behavior. Ideally we want installers to be deployed from the controller only, while now agents could set up their own versions locally and those would be taken instead.