Home / server / Questions / 966426
Accepted
Skippy le Grand Gourou
Asked: 2019-05-09 09:27:26 +0800 CST

Dovecot migration from static to passwd-file userdb driver

  • 772

I have an email server set to use dovecot with virtual users :

passdb {
  driver = passwd-file
  args = username_format=%n /etc/vmail/%d/users
}

userdb {
  driver = static
  args = uid=109 gid=111 home=/home/vmail/%d/%n
}

Now I need to set storage quotas for some users. Apparently this isn't possible with the static driver, so I figured the simplest way to enable it would be to switch to passwd-file. However I struggle to actually get it working.

Using the same passdb as above and

userdb {
  driver = passwd-file
  args = username_format=%n /etc/vmail/%d/users
  default_fields = uid=vmail gid=vmail home=/home/vmail/%d/%n
}

93.184.216.34 I get the following errors :

dovecot: imap: Error: Authenticated user not found from userdb, auth lookup id=345505793 (client-pid=30121 client-id=1)

dovecot: auth: Error: passwd-file([email protected],93.184.216.34,): user not found from userdb

I tried many variations and read many pages of the dovecot wiki, including AuthDatabase/PasswdFile, but I can't seem to interpret the documentation correctly.

How do I transpose my static configuration into a passwd-file with minimal modifications ?

/etc/vmail/%d/users files are of the standard form

user:{SHA512}…

And here is the output of dovecot userdb for these settings :

userdb {
  args = username_format=%n /etc/vmail/%d/users
  auth_verbose = default
  default_fields = uid=vmail gid=vmail home=/home/vmail/%d/%n
  driver = passwd-file
  name = 
  override_fields = 
  result_failure = continue
  result_internalfail = continue
  result_success = return-ok
  skip = never
}
email-server

2 Answers

  1. Just to complement your answer, you only need two colons after the password field for the default_values in userdb to be picked up.

    /etc/dovecot/local.conf
-----------------------
passdb { 
  driver = passwd-file
  args = scheme=CRYPT username_format=%u /etc/dovecot/passwd
}

userdb {
    driver = passwd-file
    args = username_format=%u /etc/dovecot/passwd
    default_fields = uid=vmail gid=vmail home=/srv/vmail/%u
#    driver = static
#    args = uid=vmail gid=vmail home=/srv/vmail/%u
}

    /etc/dovecot/passwd
-------------------
[email protected]:{SHA512}longPasswordHash::

    Verification with doveadm gives also the home folder :

    $ doveadm user [email protected]
field   value
uid     5000
gid     5000
home    /srv/vmail/[email protected]
mail    maildir:/srv/vmail/[email protected]/Maildir
    • 2
  2. Best Answer

    I wrongly assumed that fields other than user and password were optional since default_fields would take care of them.

    Actually, the documentation states (emphasis mine)

    [The password file is] in the following format:

    user:password:uid:gid:(gecos):home:(shell):extra_fields

    For a password database it's enough to have only the user and password fields. For a user database, you need to set also uid, gid and preferably also home (see VirtualUsers). (gecos) and (shell) fields are unused by Dovecot.

    So those fields are actually mandatory. But since they are already set by default_fields, they can be empty :

    user:{SHA512}pwd:::

    I figured it by chance because the only working account was the one I was testing the quota on (using the per user userdb_quota_rule extra field)…

    The doveadm user [email protected] was also very useful for debugging this issue.

    • 1