[imp] Taking best advantage of SQL backend for an IMAP server

[Kent Martin]

I was just having a bit of a think, which is always a bad sign, and have 
come up with what I think is a pretty good idea, bear with me here, a 
little preamble before I get to the point:

My setup - courier-imap with a mysql backend

Now, quite a while back, I little suggestion for getting pine to work 
with maildir style mail stores.

Essentially, it takes advantage of the "remote mailbox via ssh" feature 
of pine - this feature actually has nothing to do with ssh, it is simply 
a config option to gets pine to talk to stdio of a command and treat 
that as the IMAP session, enter the following script:

$ cat  /usr/bin/courier-imap-noerr

#!/bin/sh

umask 0077
cd $HOME && /usr/sbin/courier-imapd .maildir 2> /dev/null

So far so good - now we have an IMAP session on stdio
(incidentally, the pine config for this is 
ssh-path=/usr/bin/courier-imap-noerr)


So - to put this all in a horde/imp perspective, I should be able to do 
the following:

Have horde auth against the sql database (the password is stored in 
there as well obviously), then, rewrite the above script to be something 
like

$ cat /usr/bin/courier-imap-session
#!/bin/sh
umaske 0077
cd $1 && /usr/sbin/courier-imapd .maildir 2> /dev/null

now, as the mailstor dir is available in mysql as well, I should be able 
to somehow get IMP to invoke

/usr/bin/courier-imap-session $mailstore_dir

and talk to the stdio of that instead of an IMAP session

That'd cut down a fair bit of IMAP overhead and should be faster than 
imap-proxy :)

Has anybody tried something like this?

How much hacking of imp would need to take place, is there just some 
"server" driver I would need to write somewhere, or would I need to get 
a bit more intimate with the code than that?  There'd also be some 
trivial permissions issues to overcome in my case, and probably most 
cases, but that'd take all of 5 mins.  Obviously this is only a sensible 
option when the machine upon which your webserver runs has filesystem 
access to your mailstore.

Thoughts?

Cheers,

Kent.