[naviserver-devel] Naviserver as reverse proxy - header fields

[David O. <da...@qc...>]

Hi,

We've been looking at using Naviserver as a reverse proxy so it can serve
up fastpath requests, and also forward requests to an upstream app server
when required.

There was a couple of issues we came across that I'd like to ask about.
The proxy server code follows the same basic idea as Gustaf's post here:
http://sourceforge.net/p/naviserver/mailman/message/31063859/

1. Host header fields.
When we forward a request upstream using ns_ssl I couldn't find a way of
getting the Host header field to be forwarded untouched by ns_ssl.

I pass the query headers into ns_ssl which include a Host field containing
the host originally request by the client, and ns_ssl always overwrites it
with the value of the upstream Host. I don't think this behaviour is wrong
by any means, but, in Apache for example, there is an option which turns on
the behaviour we were looking for - proxyPreserveHost
http://httpd.apache.org/docs/2.2/mod/mod_proxy.html#proxypreservehost

Could there be scope for such an argument for ns_ssl (and ns_http as well I
guess) or is there a better way to deal with this?
Something like this:
https://bitbucket.org/davidqc/nsssl/branches/compare/davidqc/nsssl:tip%0Dnaviserver/nsssl:default#diff


2. Duplicate headers added by ns_respond.
Once upstream has replied to the proxy, the response is passed back to the
client using ns_respond with the headers we received from upstream. What we
are seeing is duplicate content-type and content-length headers being
received by the client.
It seems like this may be because Ns_ConnUpdateHeaders is using a case
sensitive Ns_SetUpdate to update the content-type header. So if
content-type already exists, it will add Content-Type as well.

Should this behaviour be that a case insensitive Ns_SetIUpdate is used like
the following or are there other ways around this?:
https://bitbucket.org/davidqc/naviserver/branches/compare/davidqc/naviserver:tip%0Dnaviserver/naviserver:default#diff


Thanks
-- 
David Osborne
Qcode Software Limited
http://www.qcode.co.uk