hurngchunlee / davrods

An Apache WebDAV interface to iRODS

Davrods - An Apache WebDAV interface to iRODS

Davrods provides access to iRODS servers using the WebDAV protocol. It is a bridge between the WebDAV protocol and the iRODS API, implemented as an Apache HTTPD module.

Davrods leverages the Apache server implementation of the WebDAV protocol, mod_dav, for compliance with the WebDAV Class 2 standard.

Notable features include:

• Supports WebDAV Class 2. Locks are local to the Apache server.
• Supports PAM and Native (a.k.a. STANDARD) iRODS authentication.
• Supports SSL encryption for the entire iRODS connection.
• Easy to configure using Apache configuration directives.
• Supports an anonymous access mode for password-less public access.
• Supports themeable directory listings for read-only web browser access.
• Supports iRODS server versions 4+ and is backwards compatible with 3.3.1.

Download

There are currently two supported Davrods versions:

• davrods-4.1_1.3.0, branch irods-4.1-libs
• davrods-4.2.1_1.3.0, branch master

The left side of the version number indicates the version of the iRODS client libraries that Davrods uses.

When installing Davrods on the same machine as an iRODS server, the version of Davrods must match the iRODS version. Otherwise, both Davrods versions listed above will work with either iRODS server version.

Installation

This section describes the installation steps for davrods-4.2.1_1.3.0.

To view instructions for davrods-4.1_1.3.0, switch to the irods-4.1-libs branch.

Using the binary distribution

Davrods depends on certain iRODS packages, which as of iRODS 4.2 are distributed at https://packages.irods.org/

After following the instructions for adding the iRODS repository to your package manager at the link above, Davrods can be installed as a binary package using the RPM on the releases page.

Download the Davrods package for your platform and install it using your package manager, for example:

yum install davrods-4.2.1_1.3.0-1.rpm

We currently distribute RPM packages for CentOS 7 only. If you require packaging for a different platform, please contact us by creating an issue.

See the Configuration section for instructions on how to configure Davrods once it has been installed.

Davrods and SELinux

If the machine on which you install Davrods is protected by SELinux, you may need to make changes to your policies to allow Davrods to run:

• Apache HTTPD must be allowed to connect to TCP port 1247

For example, the following command can be used to resolve this requirement:

setsebool -P httpd_can_network_connect true

Configuration

Davrods is configured in two locations: In a HTTPD vhost configuration file and in an iRODS environment file. The vhost config is the main configuration file, the iRODS environment file is used for iRODS client library configuration, similar to the configuration of icommands.

HTTPD vhost configuration

The Davrods RPM distribution installs two vhost template files:

1. /etc/httpd/conf.d/davrods-vhost.conf
2. /etc/httpd/conf.d/davrods-anonymous-vhost.conf

These files are provided completely commented out. To enable either configuration, simply remove the first column of # signs, and then tune the settings to your needs.

The normal vhost configuration (1) provides sane defaults for authenticated access.

The anonymous vhost configuration (2) allows password-less public access using the anonymous iRODS account.

You can enable both configurations simultaneously, as long as their ServerName values are unique (for example, you might use dav.example.com for authenticated access and public.dav.example.com for anonymous access).

The iRODS environment file

The binary distribution installs the irods_environment.json file in /etc/httpd/irods. In most iRODS setups, this file can be used as is.

Importantly, the first seven options (from irods_host up to and including irods_zone_name) are not read from this file. These settings are taken from their equivalent Davrods configuration directives in the vhost file instead.

The options in the provided environment file starting from irods_client_server_negotiation do affect the behaviour of Davrods. See the official documentation for help on these settings at: https://docs.irods.org/4.2.1/system_overview/configuration/#irodsirods_environmentjson

For instance, if you want Davrods to connect to iRODS 3.3.1, the irods_client_server_negotiation option must be set to "none".

Building from source

To build from source, the following build-time dependencies must be installed (package names may differ on your platform):

• cmake
• make
• gcc
• httpd-devel >= 2.4
• irods-devel >= 4.2.0
• openssl-devel
• irods-runtime >= 4.2.0
• rpmdevtools (if you are creating an RPM)

Additionally, the following runtime dependencies must be installed:

• irods-runtime >= 4.2.0
• openssl-libs
• httpd >= 2.4

Follow these instructions to build from source:

• First, browse to the directory where you have unpacked the Davrods source distribution.

• Check whether your umask is set to a sane value. If the output of umask is not 0022, run umask 0022 to fix it. This is important for avoiding conflicts in created packages later on.

• Create and generate a build directory.

mkdir build
cd build
cmake ..

• Compile the project

make

Now you can either build an RPM or install the project without a package manager. Packaging for Linux distributions other than CentOS-likes is not yet supported.

To create a package:

make package

That's it, you should now have an RPM in your build directory which you can install using yum.

To install without a package manager on CentOS:

Run the following as user root:

make install
chown apache:apache /var/lib/davrods
chmod 700 /var/lib/davrods

To install without a package manager on other distros:

Distributions other than CentOS (e.g. Ubuntu) have different HTTPD configuration layouts, which are not yet supported by the build system. For this reason you will need to install the files manually:

• Copy mod_davrods.so to your Apache module directory.
• Copy davrods.conf to your Apache module configuration/load directory.
• Copy davrods-vhost.conf and davrods-anonymous-vhost.conf to your Apache vhost configuration directory.
• Create an irods directory in a location where Apache HTTPD has read access.
• Copy irods_environment.json to the irods directory.
• Create directory /var/lib/davrods, and give apache exclusive access to it: chown apache:apache /var/lib/davrods; chmod 700 /var/lib/davrods

Bugs and ToDos

Please report any issues you encounter on the issues page.

Authors

• Chris Smeele

Contact information

For questions or support, contact Chris Smeele or Ton Smeele either directly or via the Utrecht University RDM page.

License

Copyright (c) 2016, 2017, Utrecht University.

Davrods is licensed under the GNU Lesser General Public License version 3 or higher (LGPLv3+). See the COPYING.LESSER file for details.

The lock_local.c file was adapted from the source of mod_dav_lock, a component of Apache HTTPD, and is used with permission granted by the Apache License. See the copyright and license notices in this file for details.