[Mailman-Users] running External Archiver on background/foreground

[Mark Sapiro]

Mohamed CHAARI wrote:

>Mark Sapiro wrote:
>> 
>> See
>> <http://mail.python.org/pipermail/mailman-users/2005-August/045994.html>.
>> 
>
>you mentioned, in the thread above (Aug 2005), that it would be better 
>to have a unique temporary file, to avoid conflict problems ...
>I've tried this, in mm_cfg.py, using unix timestamp
>
>PUBLIC_EXTERNAL_ARCHIVER = 'cat > /var/run/mailman/mail_tmp.$(date +%s); 
>/usr/local/bin/external_arch.pl %(listname)s &'
>
>but without success.
>is there a way to do it ? should I use Python functions to get unix 
>timestamp for current date ?


It looks to me as if you have inherited something from Jean-Philippe GIOLA and
it is now way more complicated than it needs to be.

Here are my observations on the above:

1) The name "mail_tmp.$(date +%s)" may still not be unique. What if two
messages arrive to be archived within the same second?

2)How does /usr/local/bin/external_arch.pl determine what file to read? And, if
it just picks one, it could be for the wrong list.

3)The reason the above doesn't work at all is mailman interpolates into the
PUBLIC_EXTERNAL_ARCHIVER string from a dictionary in order to replace
%(listname)s with the actual listname, but this interpolation sees the %s date
format and replaces it with the entire dictionary. You have to double the % to
avoid this. E.g.

'cat > /var/run/mailman/mail_tmp.$(date +%%s); /usr/local/bin/external_arch.pl
%(listname)s &'

4) The normal way to do this is to not bother with the tempfile stuff at all,
but rather to just pipe the message to the external archiver as in

PUBLIC_EXTERNAL_ARCHIVER = '/usr/local/bin/external_arch.pl %(listname)s'

Then external_arch.pl can just read it's standard input for the message. If you
do it this way, you can't run it in the background because it won't get
standard input from the pipe, but the only reason it might need to run in the
background is if it does something which locks the list.

I think Jean-Philippe GIOLA was doing these wierd contortions because he wanted
both the normal pipermail archive and an external archive, but the normal way
to do this is to just do normal archiving in Mailman and subscribe an address
to the list to do the external archiving.

-- 
Mark Sapiro <mark at msapiro.net>        The highway is for gamblers,
San Francisco Bay Area, California    better use your sense - B. Dylan