userdb passwd-file default_fields uid not expanding %variable

[Tim Jones]

Hi all,

I'm trying to set up a very simple shared mail server, where each 'domain'
is a system user, i.e. 'example.com' is a real user with /home/example.com/,
a uid of 5001 (and gid 'example.com' of 5001).
Each domain\user has their own maildir inside their home, and a plain
passwd-file with the virtual mail users associated with that domain.

Version & config info:

> # dovecot -n
> # 2.2.13: /etc/dovecot/dovecot.conf
> # OS: Linux 3.2.0-4-amd64 x86_64 Debian 7.8
> auth_mechanisms = plain login
> auth_verbose = yes
> disable_plaintext_auth = no
> mail_location = mbox:~/mail:INBOX=/var/mail/%u
> namespace inbox {
>   inbox = yes
>   location =
>   mailbox Drafts {
>     special_use = \Drafts
>   }
>   mailbox Junk {
>     special_use = \Junk
>   }
>   mailbox Sent {
>     special_use = \Sent
>   }
>   mailbox "Sent Messages" {
>     special_use = \Sent
>   }
>   mailbox Trash {
>     special_use = \Trash
>   }
>   prefix =
> }
> passdb {
>   args = username_format=%n /home/%d/mail_users
>   driver = passwd-file
> }
> protocols = " imap lmtp pop3"
> ssl = no
> userdb {
>   args = username_format=%n /home/%d/mail_users
>   default_fields = uid=%d gid=%d home=/home/%d/mail/%n
> mail=maildir:/home/%d/mail/%n
>   driver = passwd-file
> }


Every time I try to authenticate via imap, I get the error

> <timestamp> <host> dovecot: auth: Fatal: passwd-file userdb: Invalid uid:
> %d
>

If I put fixed a uid and gid in the userdb default_fields line:

>   default_fields = uid=example.com gid=example.com home=/home/%d/mail/%n
> mail=maildir:/home/%d/mail/%n

authentication passes without a problem, but of course, only for users of
example.com.

Checking the wiki (http://wiki2.dovecot.org/UserDatabase#Userdb_settings)
clearly states that the default_fields values support %variables, so I'm
not sure if I'm missing some other config required for this to work.

Many thanks in advance,

[image: Fon] <http://www.fon.com/>Tim JonesSoftware Development+34 612345678
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