dovecot - Mar 2007 - proxy host specified as fqdn in userdb

Abstract from http://wiki.dovecot.org/PasswordDatabase/ExtraFields/Proxy
>
> host=s: The destination server's *IP address*. This field is required. 
> Note that currently it's required to use an IP address since no DNS 
> resolving is done.
>
Hello Timo,
  Here goes one more item for the v2.0 wishlist:
  Will it become possible to do dovecot imap proxying based on a
"host"
userdb attribute that is an FQDN (instead of a numeric IP as it is now)?
  It would simplify things for large smtp clusters that already do LDAP 
mail routing, based on per user "mailHost" attribute containg mail 
server FQDNs (according to "IETF Internet Draft LDAP Schema for Intranet 
Mail Routing", http://www.sendmail.org/m4/laser.txt). It is 
kinda redundunt to keep an extra LDAP attribute for "host" that
contains
essentially the same information as "mailHost" attribute, but in
numeric
form.

   I know the proposed change is not that important for many people, so 
don't really bother unless it is trivial to implement.

apap

On Tue, 2007-03-27 at 00:56 +0300, Apostolos Papayanakis
wrote:
> Abstract from http://wiki.dovecot.org/PasswordDatabase/ExtraFields/Proxy
> 
> >
> > host=s: The destination server's *IP address*. This field is
required.
> > Note that currently it's required to use an IP address since no
DNS
> > resolving is done.
> >
> Hello Timo,
>   Here goes one more item for the v2.0 wishlist:
>   Will it become possible to do dovecot imap proxying based on a
"host"
> userdb attribute that is an FQDN (instead of a numeric IP as it is now)?
The problem with this is that it would require adding asynchronous DNS
library to Dovecot, or alternatively hoping that your DNS server is
never down (and hanging when it is). I don't really want to implement
the latter, and adding async DNS library just for proxying which is used
by very few people seems a bit bloaty.

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O/H Timo Sirainen ??????:
> On Tue, 2007-03-27 at 00:56 +0300, Apostolos Papayanakis wrote:
>   
>> Abstract from
http://wiki.dovecot.org/PasswordDatabase/ExtraFields/Proxy
>>
>>     
>>> host=s: The destination server's *IP address*. This field is
required.
>>> Note that currently it's required to use an IP address since no
DNS
>>> resolving is done.
>>>
>>>       
>> Hello Timo,
>>   Here goes one more item for the v2.0 wishlist:
>>   Will it become possible to do dovecot imap proxying based on a
"host"
>> userdb attribute that is an FQDN (instead of a numeric IP as it is
now)?
>>     
>
> The problem with this is that it would require adding asynchronous DNS
> library to Dovecot, or alternatively hoping that your DNS server is
> never down (and hanging when it is). I don't really want to implement
> the latter, and adding async DNS library just for proxying which is used
>
>
> by very few people seems a bit bloaty.
Thanks for the immediate answer! I had hoped that it would be ok for the 
proxy dovecot process to block on DNS, but it seems that this is not the 
case.
I will now happilly go ahead and create a "host" attribute containing 
the IP of the proxied servers as suggested.

apap

On Tue, Mar 27, 2007 at 01:03:54AM +0300, Timo Sirainen
wrote:
> On Tue, 2007-03-27 at 00:56 +0300, Apostolos Papayanakis wrote:
> > Abstract from
http://wiki.dovecot.org/PasswordDatabase/ExtraFields/Proxy
> > 
> > >
> > > host=s: The destination server's *IP address*. This field is
required.
> > > Note that currently it's required to use an IP address since
no DNS
> > > resolving is done.
> > >
> > Hello Timo,
> >   Here goes one more item for the v2.0 wishlist:
> >   Will it become possible to do dovecot imap proxying based on a
"host"
> > userdb attribute that is an FQDN (instead of a numeric IP as it is
now)?
> 
> The problem with this is that it would require adding asynchronous DNS
> library to Dovecot, or alternatively hoping that your DNS server is
> never down (and hanging when it is). I don't really want to implement
> the latter, and adding async DNS library just for proxying which is used
> by very few people seems a bit bloaty.
If we require SSL/TLS connections, are we not always "proxying"
connections?
if that is true, and most folks require SSL/TLS (is that not the case??),
then wouldn't most folks then be used by lots of people?

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