dav-ext: NGINX WebDAV PROPFIND,OPTIONS,LOCK,UNLOCK support

Installation

You can install this module in any RHEL-based distribution, including, but not limited to:

• RedHat Enterprise Linux 7, 8, 9
• CentOS 7, 8, 9
• AlmaLinux 8, 9
• Rocky Linux 8, 9
• Amazon Linux 2 and Amazon Linux 2023

yum -y install https://extras.getpagespeed.com/release-latest.rpm
yum -y install nginx-module-dav-ext

Enable the module by adding the following at the top of /etc/nginx/nginx.conf:

load_module modules/ngx_http_dav_ext_module.so;

This document describes nginx-module-dav-ext v3.0.0 released on Dec 17 2018.

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nginx-dav-ext-module

nginx WebDAV PROPFIND,OPTIONS,LOCK,UNLOCK support.

About

The standard ngxhhttpddavmmodule 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 ngxhhttpddavmmodule 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 ngxhhttpddavmmodule 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 nginxttests 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;
        }
    }
}

GitHub

You may find additional configuration tips and documentation for this module in the GitHub repository for nginx-module-dav-ext.