Hello, I have an operational setup where Apache httpd is proxying secure
websockets traffic to an Apache Tomcat server. In other words, I'm using
ProxyPass to pass traffic along to a WSS url.
I'm now having some issues trying to throw mod_headers into the mix. I'm
attempting to manipulate the "Upgrade" header like so in my Apache httpd
Virtual Host:
< LocationMatch "/somewhere" >
RequestHeader set Upgrade websocket
ProxyPass wss://192.168.1.77/some_url_on_tomcat
< / LocationMatch >
So, supposing the client sends something funky for Upgrade like "WebSocket"
(as an older version of a certain websocket library does), this
RequestHeader directive should, by my understanding, replace it with
"websocket".
However, when I place %{Upgrade}i in both my Apache httpd and Apache Tomcat
access logs, I'm finding that the modified Upgrade header appears only in
my httpd access logs, Tomcat says it is getting the original unmodified
value!
This is rather perplexing to me as my understanding is that RequestHeader
should permanently alter that request header. The Tomcat setup I have is
very straightforward and there should be no surprises there.
I've tried changing my RequestHeader usage to do an unset and add I've also
tried adding the "early" directive to the end of RequestHeader, but that
does not alter the behavior.
It sure seems like the problem is with how Apache httpd is passing things
along somehow, but my research hasn't come up with an answer that explains
it or offers a resolution. Am I missing something here?
Versions: Apache httpd 2.4.18 / Apache Tomcat 8.5.24
Many thanks,
~Mark
