[Dovecot] Allowing clients to test their Sieve scripts

[Ben Johnson]

On 6/14/2013 12:50 PM, Thomas Harold wrote:
> On 6/14/2013 12:40 PM, Frerich Raabe wrote:
>> Hi,
>>
>> One thing which came up repeatedly is that clients using the IMAP
>> server I run (using Dovecot 2.1) wonder whether they broke their Sieve
>> scripts, i.e. it often goes like "I don't know whether I just didn't
>> receive any mail, or whether my filters broke. Can you check the logs?".
>>
>> I then usually just run the sieve-test binary (part of the Pigeonhole
>> distribution) and send them the output. However, I was wondering - is
>> there maybe a way for them to try it themselves? Like, maybe a tiny
>> web server which just prints a form asking for a mail file and a sieve
>> script, and then it runs sieve-script and prints the output of that? I
>> wonder how other people do that.
>>
> 
> If you have Thunderbird, you may want to have them try out the Sieve
> plug-in available at http://sieve.mozdev.org/
> 
> It auto-compiles and displays errors in the edit window.
> 
> The other thing we do is use RoundCube webmail (which has a sieve
> plugin) and have our users edit their sieve scripts through that
> instead.  It's a form-based rules editor, so a bit harder for them to
> goof it up.
> 

One of the obvious limitations of using the Thunderbird plug-in, or the
web-based tool as cited, is that neither one has any way to know which
Sieve modules have been "require"d. Oftentimes fatal errors result from
referencing a module that hasn't been required.

It seems as though the only truly reliable method would be to validate
the scripts in consideration of your own environment. As you suggested,
a simple Web form (ideally, one that requires authentication) into which
users can paste scripts and email bodies would do the job. The form
inputs can then be passed to sieve-test. Needless to say, the form
inputs should be escaped very carefully to prevent arbitrary code from
being executed on your system.

Also, I second the Roundcube suggestion If your system supports
Roundcube, or if you already use it. The form-based rule editor is much
harder to screw-up, as Thomas noted.

Good luck!

-Ben