Better Living Through Reverse Proxies
Thu May 30 15:59:02 EDT 2013
- Putting Apache in Front of Domino
- Better Living Through Reverse Proxies
- Domino's Server-Side User Security
- A Partially-Successful Venture Into Improving Reverse Proxies With Domino
- PSA: Reverse-Proxy Regression in Domino 12.0.1
A while ago, I set up Apache as a reverse proxy in front of Domino. Initially, that was in order to serve a WordPress site on the same server, but since then it has more than proven its worth in other ways, mostly in the areas of fault tolerance and SSL support.
IBM recognizes those benefits, which is why Domino 9 on Windows comes bundled with IHS; however, I am a responsible admin, so I don't run Windows on my main servers. Fortunately, stock Apache does the job nicely... or it does usually. Filled with enthusiasm for this kind of setup, I rolled out a small Linode VM dedicated entirely to running Apache as a proxy (sort of like their NodeBalancers, but manual). Unfortunately, I started running into a problem where sometimes sites fronted by it (such as this one) would not properly include their host information and would instead load the main I Know Some Guys site, which is the default on Domino. I wasn't able to find a fix that actually worked, so I decided to use that as an excuse to switch to a cute little number named Nginx.
So far, my experience with Nginx has been fantastic. The config files are like a cleaned-up version of Apache's and it matches it for each feature I've needed (namely, load balancing, easy config, and multiple SSL certificates). As a nice bonus, I didn't have to do any of the config massaging I had to for Apache in order to get XSP's funky resource-aggregation rules to work. If you have the means, I highly recommend it.
My latest foray into proxying also gave me an opportunity to look back into my main bugbears with the setup: Domino tracking the proxy server's IP instead of the original requester's and its lack of knowledge of SSL (which causes it to redirect from an SSL login page to a non-SSL one). Fortunately, it turns out that these problems have been sort-of-solved for years via a notes.ini setting added as part of Domino's terminal WebSphere infection: HTTPEnableConnectorHeaders.
By enabling that on my Domino server, I was able to start providing some of those headers. The remote-host headers ("$WSRA" and "$WSRH") work perfectly: setting that to the incoming host causes Domino to act just like that was the original requester, namely filling that in for the REMOTE_HOST field in classic and facesContext.getExternalContext().getRequest().getRemoteAddr() in XPages.
Unfortunately, I was stymied when I set "$WSIS" to True. Though it does indeed cause Domino to acknowledge that the incoming request is via SSL, it does it TOO well: Domino appears to revert to its behavior of only acknowledging a single SSL site, so it caused requests to essentially ignore the Host (and "$WSSN") headers. So that problem remains unsolved.
Still, I feel pretty good about my switch to Nginx and my abuse of the HTTP connector headers and look forward to tinkering some more. For reference, here is the config I use for the standard HTTP proxy ("arcturus" is the short name I gave for the main upstream target):
server {
listen 80;
location / {
proxy_pass http://arcturus;
proxy_next_upstream error timeout invalid_header http_500 http_502 http_503 http_504;
proxy_redirect off;
proxy_buffering off;
proxy_set_header Host $host;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header $WSRA $remote_addr;
proxy_set_header $WSRH $remote_addr;
proxy_set_header $WSSN $host;
}
}