Proxy setup but not working

[Jaap Vermeulen]

Hi,

It looks like I'm behind a finicky proxy server that doesn't like Jenkins' HTTP requests.  This is for Jenkins 2.46.1 on Windows, although the same results are seen on Linux.

The proxy configuration is correct, and when testing using the 'Validate Proxy' button, it reports success, including for the 'http://updates.jenkins-ci.org/update-center.json' URL.

But when I try to run a 'Check Now', it fails miserably:

java.io.IOException: Server returned HTTP response code: 403 for URL: http://ftp-nyc.osuosl.org/pub/jenkins/updates/stable-2.46/update-center.json
	at sun.net.www.protocol.http.HttpURLConnection.getInputStream0(Unknown Source)
	at sun.net.www.protocol.http.HttpURLConnection.getInputStream(Unknown Source)
	at hudson.model.DownloadService.loadJSON(DownloadService.java:171)
	at hudson.model.UpdateSite.updateDirectlyNow(UpdateSite.java:190)

etc. etc.

When verifying the URL the request was redirected to using the 'Validate Proxy' button, again it reports success (http://ftp-nyc.osuosl.org/pub/jenkins/updates/stable-2.46/update-center.json).

So what's going on? I tried to take a look with Fiddler, but it doesn't see the HTTP requests that Jenkins is issuing (only the '500' error response when the 'Check Now' fails).

My guess is that the *actual* request submitted by Jenkins (using jetty it seems) has header information (either present or missing) that causes the proxy to reject the request. Does anyone have a good way of logging the actual requests (with headers) and/or other ways of figuring out what is going on here? I tried enabling FINE logging, but it still doesn't show me what is exactly being requested (with headers).

Thanks,

Jaap