After setting up both Railo and ColdFusion web apps behind Nginx, I wanted to prove to myself that the configuration was functioning how I thought it should. The apps worked, but there were several issues I was concerned about.
Here’s the configuration I wanted to test:
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First off, I had a doubt regarding how Nginx was selecting which location directive to use for each file requested from the documentation I’ve read. What I wanted to ensure is that Nginx was serving the static files, and proxying only the CFML files.
A deeper issue here is whether or not the proxy_pass directive contains a URI. If it does, you can’t use a regex to filter a location for CFML files only. A few examples will explain this better:
This configuration contains a URI in the proxy_pass directive, namely /domain.com/. You cannot use a regex in the location directive to filter the request, so in my case, the location directive simply had to point to the root ( recursively in the way Nginx works, so essentially this directive will process any file under the root ).
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This configuration also contains a URI in the proxy_pass directive, the trailing slash. Again, no regex in the location is possible.
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This config does not have a URI component in the proxy_pass directive, no trailing slash and no subdirectory are present here. In this case, we CAN apply a regex filter to pass only those files we want to our application server.
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The tradeoff here is that if we use a filter to ensure only CFML files are pass to our app server, then we need to additionally configure each virtual host in Tomcat’s server.xml ( assuming multiple hosts per server ) so that Tomcat can locate the files.
If you’d rather configure each server only in Nginx, as I did with my CF11 install, then another approach might be to use a regex to filter all your static files. Hence:
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With the essential background information out of the way, the question that arose was this. Is Nginx actually serving the static files, as I hoped, or are they all being passed to ColdFusion? The documention I found here and there seemed contradictory.
Here’s one way to test this using curl on the command line to fetch the response headers, with the output I got using the above settings:
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See the difference? The image is being cached on the browser and the headers are being set as per the static file location block, while index.cfm isn’t being cached. The
expires epoch; directive tells the browser to set the expires date to 01 Jan 1970, a date in the past means don’t cache this, while the
expires modified +90d; tells the browser to set the expires date 90 days from the Last-Modified date.
Another way to see these headers is via Developer Tools in Chrome ( or a comparable tool in any other modern browser ). Open a Dev Tools window while browsing the web page you’d like to check, refresh the page, go to the Network tab, and click on any file to see the headers. This approach will give you a better overview of how your Nginx settings are serving and caching each file involved in an http request.
After some thought and study, I decided to change my initial approach to caching static content to one that will help guarentee any content that I modify is served fresh from the server rather that stale from the cache. Here’s what I came up with, for now, for a particular business application that I am still developing:
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The users who access this site every day will only need to re-download static content once a day, an additional second or two once a day won’t hurt them. In the version of Nginx I’m currently using, enabling gzip disables etags. For now, I’d rather have etag enabled, so I’m disabling gzip for static content, but leaving it enabled for the dynamically generated content that is returned from the proxied app server.
Resources for further reading: