nginx-dav-ext-module

nginx WebDAV PROPFIND,OPTIONS,LOCK,UNLOCK support.

Contents

• About
• Build
• Requirements
• Testing
• Locking
• Directives
  • dav_ext_methods
  • dav_ext_lock_zone
  • dav_ext_lock
• Example 1
• Example 2
• Example 3

About

The standard ngx_http_dav_module provides partial WebDAV implementation and only supports GET,HEAD,PUT,DELETE,MKCOL,COPY,MOVE methods.

For full WebDAV support in nginx you need to enable the standard ngx_http_dav_module as well as this module for the missing methods.

Build

Building nginx with the module:

# static module
$ ./configure --with-http_dav_module --add-module=/path/to/nginx-dav-ext-module

# dynamic module
$ ./configure --with-http_dav_module --add-dynamic-module=/path/to/nginx-dav-ext-module

Trying to compile nginx with this module but without ngx_http_dav_module will result in compilation error.

Requirements

• nginx version >= 1.13.4
• libxml2 + libxslt

The libxslt library is technically redundant and is only required since this combination is supported by nginx for the xslt module. Using builtin nginx mechanisms for linking against third-party libraries brings certain compatibility benefits. However this redundancy can be easily eliminated in the config file.

Testing

The module tests require standard nginx-tests and Perl HTTP::DAV library.

$ export PERL5LIB=/path/to/nginx-tests/lib
$ export TEST_NGINX_BINARY=/path/to/nginx
$ prove t

Locking

• Only the exclusive write locks are supported, which is the only type of locks described in the WebDAV specification.
• All currently held locks are kept in a list. Checking if an object is constrained by a lock requires O(n) operations. A huge number of simultaneously held locks may degrade performance. Thus it is not recommended to have a large lock timeout which would increase the number of locks.

Directives

dav_ext_methods

Syntax:	dav_ext_methods [PROPFIND] [OPTIONS] [LOCK] [UNLOCK]
Context:	http, server, location

Enables support for the specified WebDAV methods in the current scope.

dav_ext_lock_zone

Syntax:	dav_ext_lock_zone zone=NAME:SIZE [timeout=TIMEOUT]
Context:	http

Defines a shared zone for WebDAV locks with specified NAME and SIZE. Also, defines a lock expiration TIMEOUT. Default lock timeout value is 1 minute.

dav_ext_lock

Syntax:	dav_ext_lock zone=NAME
Context:	http, server, location

Enables WebDAV locking in the specified scope. Locks are stored in the shared zone specified by NAME. This zone must be defined with the dav_ext_lock_zone directive.

Note that even though this directive enables locking capabilities in the current scope, HTTP methods LOCK and UNLOCK should also be explicitly specified in the dav_ext_methods.

Example 1

Simple lockless example:

location / {
    root /data/www;

    dav_methods PUT DELETE MKCOL COPY MOVE;
    dav_ext_methods PROPFIND OPTIONS;
}

Example 2

WebDAV with locking:

http {
    dav_ext_lock_zone zone=foo:10m;

    ...

    server {
        ...

        location / {
            root /data/www;

            dav_methods PUT DELETE MKCOL COPY MOVE;
            dav_ext_methods PROPFIND OPTIONS LOCK UNLOCK;
            dav_ext_lock zone=foo;
        }
    }
}

Example 3

WebDAV with locking which works with MacOS client:

http {
    dav_ext_lock_zone zone=foo:10m;

    ...

    server {
        ...

        location / {
            root /data/www;

            # enable creating directories without trailing slash
            set $x $uri$request_method;
            if ($x ~ [^/]MKCOL$) {
                rewrite ^(.*)$ $1/;
            }

            dav_methods PUT DELETE MKCOL COPY MOVE;
            dav_ext_methods PROPFIND OPTIONS LOCK UNLOCK;
            dav_ext_lock zone=foo;
        }
    }
}