Nginx – WebDav mirroring with Apache/Nginx

(Back to the days when I used Subversion) I had similar problem with proxying to Apache SVN from Nginx SSL frontend. Suppose Nginx SSL frontend is https ://host and we'd like to proxy connections to the internal Apache SVN server http ://svn

The problem occurs when you try to copy a resource is with Destination header:

COPY /path HTTP/1.1
Host: host
Destination: https://host/another_path

As you can see Destination header still contains https schema. The fix is pretty evident --

location / {
    # to avoid 502 Bad Gateway:
    # http://vanderwijk.info/Members/ivo/articles/ComplexSVNSetupFix
    set $destination $http_destination;

    if ($destination ~* ^https(.+)$) {
         set $destination http$1;
    }

    proxy_set_header Destination $destination;
    proxy_set_header Host $host;
    proxy_set_header X-Forwarded-For $remote_addr;

    proxy_pass http://svn;
}

The problem you see is a combination of two actual problems:

• The problem in nginx core, which results in request body being read incorrectly in some cases. In your case, this problem is triggered by the auth request module. This problem is under investigation.

• The bug in dav module which causes nginx to dereference null pointer if request body wasn't read under dav module's control. The bug doesn't manifest itself under normal conditions, but due to the above problem you've hit it.