dovecot - Jan 2023 - sieve_extprograms plugin calling bash script

I receive an email a few times a week containing a URL for a live stream which
starts within a minute after receiving the email. I want to automate capturing
the whole stream.

I've been trying to write a sieve script which uses the sieve extprograms
plugin to call a bash script that parses the URL from the email and passes it to
a capture program. So far I've had no luck getting the bash script to call
_any_ external programs. I can't even write a file to /tmp/, so it's not
a filesystem permissions issue. The sieve script has no issues finding and
executing the bash script, it just does nothing other than return an exit code.

Does sieve put the extprogram script in some kind of sandbox where it has no
access to the system?

This may not be the best place to find answers to sieve plugin info. If so, can
someone point me in the right direction?

> On 27/01/2023 09:00 EET Tom <tom at grimps.net> wrote:
> 
>  
> I receive an email a few times a week containing a URL for a live stream
which starts within a minute after receiving the email. I want to automate
capturing the whole stream.
> 
> I've been trying to write a sieve script which uses the sieve
extprograms plugin to call a bash script that parses the URL from the email and
passes it to a capture program. So far I've had no luck getting the bash
script to call _any_ external programs. I can't even write a file to /tmp/,
so it's not a filesystem permissions issue. The sieve script has no issues
finding and executing the bash script, it just does nothing other than return an
exit code.
> 
> Does sieve put the extprogram script in some kind of sandbox where it has
no access to the system?
> 
> This may not be the best place to find answers to sieve plugin info. If so,
can someone point me in the right direction?
Can you provide doveconf -n and your sieve rules? And the script?

Also if you're on systemd, you will likely have PrivateTmp=yes in the unit,
so /tmp becomes /tmp/*systemd*dovecot*/tmp

Aki

Tom skrev den 2023-01-27 08:00:
> This may not be the best place to find answers to sieve plugin info.
> If so, can someone point me in the right direction?
https://doc.dovecot.org/configuration_manual/sieve/plugins/extprograms/

At the location /usr/lib/dovecot/sieve-execute, create the executable 
script vacationcheck.sh. In this example, the vacationcheck.sh script 
needs two parameters: the sender address and a time interval specified 
in seconds. The time interval is used to specify the minimum amount of 
time that needs to have passed since the sender was last seen. If the 
script returns exit code 0, then message is redirected in the Sieve 
script shown above.

+1