[Dovecot] Trouble implementing Antispam plug-in for Dovecot

[Ed W]

On 06/09/2012 18:56, Ben Johnson wrote:
>
> On 9/6/2012 6:10 AM, Charles Marcus wrote:
>> On 2012-09-05 6:20 PM, Ben Johnson <ben at indietorrent.org> wrote:
>>
>>> My configuration is Dovecot (1.2.9) + Sieve + SpamAssassin on Ubuntu
>> 10.04.
>>
>> 1.2.9 is really old... you really need to upgrade to a recent/stable
>> version.
> Thanks, Charles. I do see your point. One of the challenges we face in
> this regard is that we're using a Long-Term-Support version of Ubuntu
> (10.04) and 1.2.9 is the latest package in the OS's repository.
>
> That said, we could upgrade manually, but this is a production server on
> which downtime must be minimized, and we all know how unexpected issues
> arise during installation (even when the procedure is tested in a
> closely equivalent development environment).

I personally use (lightweight) virtualisation on any new machine, I 
really don't see any reason why NOT to.  I would typically also setup my 
mounts such that the operating system is separate from "the data".  This 
makes it easy to upgrade the OS/services, but without touching the data 
(test before/after on the same data for example)

So in my situation I would boot a fairly small (gentoo in my case) 
virtual environment that runs only dovecot + postfix, it mounts the mail 
spools separately - I say "boot", but because I'm using linux-vservers, 
it's really a fancy chroot, and so the instance will start in 2-3 
seconds (restarts are similarly near instant).  I would upgrade by 
cloning this installation, upgrading it, testing it to bits, and then to 
make it live basically you swap this "machine" for the live machine.  
There are various ways it could be made near seamless, but in my 
situation I can bear a couple of seconds whilst I literally restart the 
"machine"

Similarly I segregate all my services into a dozen or so "virtual 
machines", so DNS has it's own "machine" and so does logging, databases, 
almost every webservice gets its own virtual environment, etc. You could 
use a full blown vmware/kvm/etc if that floats your boat better, but the 
point remains it's so trivial to install, makes upgrades to trivial and 
massively decreases your downtime risk that it's very hard to find a 
reason NOT to do it...

I haven't tried too hard to keep my instances tiny, so each is probably 
around 400-600MB in my case.  However, if it were important this could 
easily be reduced to 10-100s MB each using various hardlink features.  
As you can see it's easy to snapshot a whole machine to manage 
upgrades/backups, etc


This is more about infrastructure, but I honestly can't get over how 
many people are sitting on their hands shackled by "I'm on Debian xxx 
and I can't install any software newer than 5 years old"... It's so easy 
to escape from that trap...!!

Good luck

Ed W