I have a working setup with apache 2.2 server acting as a remote proxy.
I'm using proxytunnel with two chained proxies: proxytunnel -q -X -p localproxy:8080 -r remoteproxy:443 -d destination:22
I had to apply a patch for SSL to work though: https://issues.apache.org/bugzilla/show_bug.cgi?id=29744
I'm now trying to do the same using the apache 2.4 server (SSL issue is resolved in 2.4 apparently). The connection establishes immediately but after cca 20 seconds apache (remoteproxy) resets the connection to the local proxy, thus killing my SSH session. Keepalives didn't help.
I tried raising the log level LogLevel debug
in the general apache config, but i'm not seeing any useful info.
Is there a way to debug the mod_proxy itself in a more detailed manner?
There's new feature to 2.4 called reqtimeout_module. You have to comment all the statements in /etc/apache2/mods-available/reqtimeout.conf and restart the server.
You can also check http://httpd.apache.org/docs/current/mod/mod_reqtimeout.html for more detailed info.
As mention before, disabling the mod_reqtimeout does the trick. I did it by adding
RequestReadTimeout header=0 body=0
to the vhost configuration.