Configuring WebDAVContrib with FCGI

FCGI is a standard extension protocol understood by all major web server implementations (for example, Lighttpd, Nginx, Apache and IIS all support it).

The WebDAVContrib distribution includes a FCGI server script, in tools/webdav.fcgi (or =virtualhosts-webdav.fcgi if you are using =VirtualHostingContrib), which can be used with any web server that supports FCGI. The following examples show it being used with Lighttpd, Nginx and Apache. Note that these are generic examples, and will require customisation for your site.

Note that the default configuration of the WebDAV FCGI module uses BasicAuth to obtain authentication information about the user. For this reason it is important that you configure your WebDAV service to use SSL. However configuration of SSL is beyond the scope of this guide.

Let's say we have Foswiki installed in /var/www/foswiki and we want to start a lighttpd server on port 80, and have our Foswiki content server under the URL http://server/dav (thus http://server/dav/Extensions/ConfiguringWebDAVContribWithFCGI.txt would be the URL to access this topic).

Lighttpd

A suitable lighttpd configuration file might be as follows:

# Configuration for lighttpd & factcgi based webdav server.
server.document-root = "/tmp"
server.modules = (
   "mod_cgi",
   "mod_fastcgi",
   "mod_accesslog",
   "mod_alias"
)
server.port = 80

# ipv6 support
$SERVER["socket"] == "[::]:80" { }
server.errorlog = "/var/www/foswiki/working/logs/lighttpd_error.log"
accesslog.filename = "/var/www/foswiki/working/logs/lighttpd_access.log"

# mimetype mapping
include_shell "/usr/share/lighttpd/create-mime.assign.pl"

$HTTP["url"] =~ "^/dav" {
  alias.url += ( "/dav" => "/var/www/foswiki/tools/webdav.fcgi" )
  fastcgi.server = (
    ".fcgi" => (
      (
        "socket"    => "/var/www/foswiki/working/tmp/webdav.sock",
        "bin-path"  => "/var/www/foswiki/tools/webdav.fcgi http://server:80/dav"
      ),
    )
  )
}

The alias.url remaps all /dav URLs to the webdav.fcgi server script.

The bin-path provides all the options to the webdav.fcgi script. A full list of available options can be found by running ./webdav.fcgi --help in the tools/ directory.

See http://redmine.lighttpd.net/projects/1/wiki/Docs_ModFastCGI for more information on configuring lighttpd and mod_fastcgi.

Once you have this configuration file you can run lighttpd as follows:

lighttpd -f <path to config file>

If you intend to use the lighttpd web server with Foswiki you are highly recommended to read about the FastCGIEngineContrib.

If you use a different filesystem - for example, the PlainPlusAttrs filesystem which can be used to export simple directory structures - then you may need to use the --root option to tell the script where the root of the filesystem is.

If you are having problems with WebDAV you can enable tracing using the --trace option. See WebDAVContrib#Debugging for more information.

Nginx

In contrast to most other web servers nginx is a proxying server which delegates the real work to backend worker processes, accessing them using a dedicated socket or IP address. In that sense it does not manage the life-cycle of a backend process the same way lighttpd or Apache do.

To use webdav.fcgi using nginx, we first have to start the backend process on its own. From the commandline, we can simply:

cd /var/www/foswiki/tools
./webdav.fcgi --listen 127.0.0.1:9001

This will start a daemon on port 9001, which will spawn 5 worker processes, managed by an FCGI::ProcManager implementation for WebDAVContrib.

(A full list of available options can be found by running ./webdav.fcgi --help in the tools/ directory.)

Of course this daemon will not survive a server restart, so you will need to install a system-wide init script into the operating system's start-up sequence. There's an appropriate example script (written for Debian Linux) in tools/foswiki-dav.init-script. You can copy this script to /etc/init.d/foswiki-dav. You will also need to create a file under /etc/defaults/foswiki-dav to hold the custom settings for your system:

# root directory where your foswiki is installed
FOSWIKI_ROOT=/var/www/foswiki

# script to be run, must be located in $FOSWIKI_ROOT/tools/wedav.fcgi
FOSWIKI_FCGI=webdav.fcgi

# port that the webdav.fcgi process will be listening on.
FOSWIKI_BIND=127.0.0.1:9001

# number of workers to be spawned
FOSWIKI_CHILDREN=5

Make sure the webdav.fcgi process is started properly using service foswiki-dav start and service foswiki-dav status.

Next, we have to configure nginx to contact the webdav.fcgi process on the configured port:

...
server {
  server_name ~^(www\.)?(?<domain>.+)$;

  set $foswiki_root /var/www/foswiki;

  ...

  location /dav {
     gzip off;

     # must match FOSWIKI_BIND in /etc/defaults/foswiki-dav
     fastcgi_pass   127.0.0.1:9001;

     fastcgi_split_path_info ^/dav/(.+?)(/.*)$;
     fastcgi_param  SCRIPT_FILENAME  $foswiki_root/tools/webdav.fcgi;
     fastcgi_param  PATH_INFO $fastcgi_path_info;

     include fastcgi_params;
  }

  ...
}

See http://foswiki.org/Support/FoswikiOnNginx for a full description on how to install Foswiki under nginx.

Apache

Installation with Apache mod_fcgid is quite straightforward; all that is required is to expose the tools/webdav.fcgi script through the Apache configuration.

ScriptAlias "/dav/" "/var/www/foswiki/tools/webdav.fcgi"

# FCGI must pass authorization header to script
FcgidPassHeader AUTHORIZATION
# Set options for server script. A full list of available options can be
# found by running =./webdav.fcgi --help= in the =tools/= directory.
FcgidInitialEnv WEBDAV_FCGI_OPTIONS "--apache --location /dav http://server:80/dav"

<Files /var/www/foswiki/tools/webdav.fcgi>
   SetHandler fcgid-script
   Options +ExecCGI
</Files>