Pigeonhole Sieve Extdata Plugin
===============================

The extdata plugin adds the *vnd.dovecot.extdata* extension to the Sieve
language. It allows a Sieve script to lookup information from a datasource
external to the script. This makes use of Dovecot's dict mechanism in a
read-only manner, meaning that scripts cannot update dict data sources.

Getting the sources
-------------------

Currently, the sources of the extdata plugin are not released, but you can get
them from the their Mercurial repository. For Pigeonhole v0.2:

---%<-------------------------------------------------------------------------
hg clone  http://hg.rename-it.nl/pigeonhole-0.2-sieve-extdata/
---%<-------------------------------------------------------------------------

And for Pigeonhole v0.3:

---%<-------------------------------------------------------------------------
hg clone  http://hg.rename-it.nl/pigeonhole-0.3-sieve-extdata/
---%<-------------------------------------------------------------------------

And for Pigeonhole v0.4:

---%<-------------------------------------------------------------------------
hg clone  http://hg.rename-it.nl/pigeonhole-0.4-sieve-extdata/
---%<-------------------------------------------------------------------------

Compiling
---------

If you downloaded the sources of this plugin using Mercurial, you will need to
execute './autogen.sh' first to build the automake structure in your source
tree. This process requires autotools and libtool to be installed.

If you installed Dovecot from sources, the plugin's configure script should be
able to find the installed 'dovecot-config' automatically, along with the
Pigeonhole development headers:

---%<-------------------------------------------------------------------------
./configure
make
sudo make install
---%<-------------------------------------------------------------------------

If this doesn't work, you can use '--with-dovecot=<path>' configure option,
where the path points to a directory containing 'dovecot-config' file. This can
point to an installed file:

---%<-------------------------------------------------------------------------
./configure --with-dovecot=/usr/local/lib/dovecot
make
sudo make install
---%<-------------------------------------------------------------------------

The above example should also find the necessary Pigeonhole development headers
implicitly. You can also compile by pointing to compiled Dovecot and Pigeonhole
source trees:

---%<-------------------------------------------------------------------------
./configure --with-dovecot=../dovecot-2.0.0/
--with-pigeonhole=../dovecot-2.0-pigeonhole-0.2.0
make
sudo make install
---%<-------------------------------------------------------------------------

Configuration
-------------

This package builds and installs the sieve_extdata plugin for Pigeonhole Sieve.
The plugin is activated by adding it to the sieve_plugins setting

---%<-------------------------------------------------------------------------
sieve_plugins = sieve_extdata
---%<-------------------------------------------------------------------------

The following configuration settings are used:

sieve_extdata_dict_uri = :
  Specifies the uri of the dict that is used for extdata lookups.

Example:

---%<-------------------------------------------------------------------------
plugin {

  sieve = ~/.dovecot.sieve
  sieve_plugins = sieve_extdata

  sieve_extdata_dict_uri = file:/etc/dovecot/pigeonhole-sieve.dict
}
---%<-------------------------------------------------------------------------

Usage
-----

Sieve scripts can use the new 'vnd.dovecot.extdata' extension as follows:

---%<-------------------------------------------------------------------------
require ["variables", "vacation", "vnd.dovecot.extdata"];

vacation :days 30 :subject "${extdata.vacation_subject}"
"${extdata.vacation_message}";
keep;
---%<-------------------------------------------------------------------------

where "priv/vacation_subject" & "priv/vacation_message" would be looked up in
the Dovecot dict. See below for some example dicts:

Dict with flat file backend
---------------------------

To use a flat file backend for the above example, create a dict file with the
following format (for example /etc/dovecot/sieve-extdata-lookup.dict):

---%<-------------------------------------------------------------------------
priv/vacation_message
Sorry I am out of the office
---%<-------------------------------------------------------------------------

Dict with a SQL backend
-----------------------

To use a SQL backend for the above example, first set up a dict proxy. In
/etc/dovecot.conf:

---%<-------------------------------------------------------------------------
dict {
    sieve = mysql:/etc/dovecot/pigeonhole-sieve.dict
}
---%<-------------------------------------------------------------------------

And in /etc/dovecot/pigeonhole-sieve.dict:

---%<-------------------------------------------------------------------------
connect = host=localhost dbname=dovecot user=dovecot password=password

map {
  pattern = priv/vacation_message   # The dict value to lookup
  table = virtual_users             # The SQL table to perform the lookup in
  username_field = email            # The username field to search on in the
table
  value_field = vacation_msg        # The database value to return
}
---%<-------------------------------------------------------------------------

Finally configure extdata to use the proxy:

---%<-------------------------------------------------------------------------
sieve_extdata_dict_uri = proxy::sieve
---%<-------------------------------------------------------------------------

Read the (preliminary) specification
[http://hg.rename-it.nl/pigeonhole-0.2-sieve-extdata/raw-file/tip/doc/rfc/spec-bosch-sieve-external-data.txt]
for more information.

(This file was created from the wiki on 2018-07-09 04:42)
