proxy_pass only if a file exists
francis at daoine.org
Sat May 4 21:25:30 UTC 2013
On Tue, Apr 30, 2013 at 10:25:34AM -0400, mrtn wrote:
> I need to make sure a file actually exists before proxy_pass-ing the request
> to an upstream server. I don't serve existing files directly using Nginx
> because there are some application-specific logic i need to perform on the
> application server for such requests.
I confess I don't fully understand that -- if file X exists on the local
filesystem, then ignore it and proxy_pass to server Y; but if it doesn't,
then don't proxy_pass and do something else instead, which is presumably
better than caching the 404 from server Y.
But that's ok; I don't have to understand it.
> I've looked at try_files, but it seems like it will serve the file
> straightaway once it is found, which is not what I want here.
Correct. try_files serves the first file found, or else rewrites to the
> Another way
> is to use if (!-f $request_filename), but as mentioned here:
> http://wiki.nginx.org/Pitfalls#Check_IF_File_Exists, it's
> a terrible way to check the existence of a file.
The entire purpose of "-f" is to check whether the thing named is a file.
The common case is something like "if it is a file, serve it; else do
something different", and now that try_files exists, "-f" is not the
best way to achieve the common case.
> Is there a feasible yet efficient way?
It sounds like "-f" is what you want, perhaps following the example
shown on http://wiki.nginx.org/IfIsEvil
Francis Daly francis at daoine.org
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