dovecot - May 2013 - Pigeonhole: extprograms - pipe

Hello!

I've tried to use extprograms pipe feature but stuck with "Broken
pipe"
errors in mail log:

May 17 15:18:57 backend1 dovecot: lmtp(20338, user at domain.tld): Debug:
3VMVFWFKllFyTwAArRg8UA: sieve: action pipe: running program: learn
May 17 15:18:57 backend1 dovecot: script: Error: write(response) failed:
Broken pipe
May 17 15:18:57 backend1 dovecot: lmtp(20338, user at domain.tld):
3VMVFWFKllFyTwAArRg8UA: sieve: execution of script
/data/mail/storage/domain/user at domain.tld/.dovecot.sieve;name=main script
failed, but implicit keep was successful (user logfile
/data/mail/storage/domain/buser at domain.tld/.dovecot.sieve.log should reveal
additional details)

/data/mail/storage/domain/buser at domain.tld/.dovecot.sieve.log:
error: msgid=<c7cd36f19be8164addf091a646b8b284 at domain.tld>: pipe
action:
failed to pipe message to program `learn': refer to server log for more
information. [2013-05-17 15:18:57] ham user at domain.tld 50796.


Sieve script contents:
require
["fileinto","copy","mailbox","vnd.dovecot.pipe"];

if anyof (header :is "Subject" "ham")
{
pipe :try "learn" ["ham"];
        fileinto "INBOX/ham";
        stop;
}

Sieve plugin config uncommented conents:
sieve_plugins = sieve_extprograms
*sieve_pipe_socket_dir = sieve-pipe*

  # Define the executed script as parameter to the sieve service
  executable = script /etc/dovecot/scripts/spam.sh

  # Use some unprivileged user for executing the program
  user = nobody

  # The unix socket located in the sieve_pipe_socket_dir (as defined in the
  # plugin {} section above)
  unix_listener sieve-pipe/learn {
    # LDA/LMTP must have access
     user = nobody
     mode = 0777
  }
}


spam.sh is message processing script which interacts with spamassassin.
I've tested pipe with spam.sh that redirects stdin to /dev/null and returns
0 but errors were logged anyway.
Note that spam.sh runs, getting the message from sieve and processing it to
spamassassin without a problem, but "broken pipe" is being logged.

At  7PM +0400 on 17/05/13 you (Anes Mukhametov) wrote:
> Hello!
> 
> I've tried to use extprograms pipe feature but stuck with "Broken
pipe"
> errors in mail log:
> 
> May 17 15:18:57 backend1 dovecot: lmtp(20338, user at domain.tld): Debug:
> 3VMVFWFKllFyTwAArRg8UA: sieve: action pipe: running program: learn
> May 17 15:18:57 backend1 dovecot: script: Error: write(response) failed:
> Broken pipe
I suspect that what's happening here is that your script isn't reading
the whole mail. However, that pipe that's broken is (I think) the socket
from the script service back to the master service, so I don't quite
understand how that could happen.
> May 17 15:18:57 backend1 dovecot: lmtp(20338, user at domain.tld):
> 3VMVFWFKllFyTwAArRg8UA: sieve: execution of script
> /data/mail/storage/domain/user at domain.tld/.dovecot.sieve;name=main
script
> failed, but implicit keep was successful (user logfile
> /data/mail/storage/domain/buser at domain.tld/.dovecot.sieve.log should
reveal
> additional details)
> 
> /data/mail/storage/domain/buser at domain.tld/.dovecot.sieve.log:
> error: msgid=<c7cd36f19be8164addf091a646b8b284 at domain.tld>: pipe
action:
> failed to pipe message to program `learn': refer to server log for more
> information. [2013-05-17 15:18:57] ham user at domain.tld 50796.
Mmm, recursively-referential error logs. Always fun...
> spam.sh is message processing script which interacts with spamassassin.
> I've tested pipe with spam.sh that redirects stdin to /dev/null and
returns
> 0 but errors were logged anyway.
Well, you shouldn't do that: redirecting stdin from /dev/null in a shell
script will close the incoming pipe, which means you won't read the mail
at all and sieve will get upset. What you need to do instead (if you've
got data to read and nothing to do with it) is 'cat >/dev/null',
which
will read it all and throw it away.
> Note that spam.sh runs, getting the message from sieve and processing it to
> spamassassin without a problem, but "broken pipe" is being
logged.
Hmm. Are you sure your real script is exitting with 0? spamc in learn
mode exits 5 or 6 depending on whether the mail was already learned or
not.

Ben