Like many people I use Apache's mod_proxy to proxy from *:80 to a bunch of servers running upon 127.0.0.1:XX.
(I've mentioned this too often; but in short I have a bunch of sites all running with thttpd under their own UID).
Why do I use apache soley as a reverse proxy, instead of pound, varnish, nginx, or lighttpd? After all it is pretty heavy-weight. Well the answer to that is that I have a bunch of mod_rewrite rules.
So I'm wondering, could I drop apache if I were to hack together a simple network proxy that would listen upon port 80, reading requests, and directing them to local servers? The answer to that is plainly "yes". There are many reverse-proxies around and writing them isn't hard.
So what would be the point? Imagine a reverse-proxy that understood mod_rewrite rules. That would rock.
In short we'd have to define three things:
- Matching vhost name.
- Destination to proxy to.
- (Optionally) the mod_rewrite rules
Given something like this:
LISTEN 1.2.3.4:80
host example.net or host www.example.net
{
#redirect traffic here
proxy_to 127.0.0.1 1011
RewriteRule /about /cgi-bin/index.cgi
}
When the proxy received an incoming request to http://example.net/about it would actually send the request /cgi-bin/index.cgi to the host 127.0.0.1:1011.
That seems neither too complex nor too impossible.
The hard part would be emulating mod_rewrite 100%. Especially chained requests. I would be willing to write the trivial version, but I suspect the full emulation would be a job of diminishing returns. Am I right?
ObSubject: You crossed the line first, sir. - "The Dark Knight"
Nginx's rewrite module is pretty powerful.
No need to reinvent the wheel :)
The problem is that Apache's mod_rewrite is the defacto standard for such things.
Anything and everything from wordpress, to phpbb, and mediawiki includes such rules. Nothing else, except for Apache/Apache 2.x, understands them.
Yes other servers have similar features. But no that doesn't make it necessarily easy to convert.
As mentioned nginx is pretty powerful as reverse-proxy(i think it's a defacto standard right now). From my experience with migration from apache to nginx rewrite rules almost the same(little difference in keywords) won't take much time to fix and pretty straight-forward.
I really have the feeling you are reinventing the wheel. Things like nginx and lighttpd are perfect for this kind of use, and they have powerful rewrite engines.
I think perhaps I'm not making my point clearly enough:
I think you've all convinced me that either my suggestion of a mod_rewrite syntax-port, rather than anything else, is not something that seems useful to others.
For the moment I'll keep Apache2 and I will example using nginx instead in the near future.
I do personally think that mod_rewrite is the defacto standard and having to reinvent the wheel by porting such rules to different servers is a bigger waste of time than having a proxy.
That said I can understand the argument :)
(If I were ignoring your mod_rewrite desires I would of course just say "use haproxy", but...)
If you want to get 100% compatibility with mod_rewrite, you might be best to just rip the heart out of mod_rewrite itself into an abstract url-rewriting library. Who knows, the mod_rewrite maintainers might be interested in factoring out the central rewrite engine.
Tbh. I would rather have some kind of converter that converts from mod_rewrite format to lighttpd/nginx rules
I think it is a marvelous idea.
Said that, if the idea is to be fully compatible, maybe that your invent needs to XSload mod_rewrite.c :)
I wish that light reverse proxy with full apache > 1.3 rewrite compatibility.
Load existing mapfiles and existing apache2 prg's, could be a plus.
Greetings
To be honest, having a reverse proxy capable of Apache rewrite rules would be pretty sweet.
Porting/implementing something like this in Nginx would be AWESOME (yes, I know that it already has powerful rewrite rules) but it also could take a long time and perhaps there is a reason nobody tried/succeeded to do it yet.
I for one could enjoy very much a small/minimalistic perl daemon can understand Apache rewrite rules. I'm sure such a project wouldn't go unnoticed.