On 1.2.2013, at 0.35, Ben Morrow ben@morrow.me.uk wrote:
I am running Dovecot with system users (userdb passwd), but some of those users don't have shell accounts on the IMAP server so their shell on that machine is set to /usr/sbin/nologin. Currently I am using maildirs and this is not a problem, but I am in the process of switching to dbox which means I will need a cronjob running 'doveadm purge -A'.
During testing I found that those users with a 'nologin' shell are not included in the list returned by the userdb iterator, and that the iterator doesn't honour the first/last_valid_uid settings. This inconsistency seems undesirable, so the attached patch
- makes lookup perform the same checks as iteration,
Hmmh. You could also just have them aliased to other users, so this wouldn't be necessary..
- makes the 'nologin' check configurable,
- adds a new optional check that the user owns their home directory.
These settings are passwd-specific, so they would have to something like:
userdb { driver = passwd args = check-nologin=n check-home=y }
The last check was the one performed by qmail, and seems to me to be a more reliable 'is this a real user' check than a nologin shell.
It also performs disk I/O, slowing down the lookup.
If this patch is applied, the release notes for the next release should probably mention that system users with a 'nologin' shell will no longer be allowed to log in to IMAP until the 'auth_check_nologin' setting is changed from true to false.
The default will in any case be the same as it is now.
Also, there seem to be two first/last_valid_uid settings: first_valid_uid itself, which is honoured by the storage subsystem, and auth_first_valid_uid, which is honoured by the 'passwd' userdb. Is this intentional?
Nope, that's a bug. Fixed that in v2.2: http://hg.dovecot.org/dovecot-2.2/rev/18661d1d6ed0