running alternate dovecot instances on the same server

Chris Hoogendyk hoogendyk at bio.umass.edu
Sun May 1 00:00:53 UTC 2022


Aki,

Thankyou for your advice. I finally got around to this. I'm retired, working part time, and have 
more to do than fits the time. Anyway . . .

I did the configuration in /etc/dovecot/local.conf, which is included in the 
/etc/dovecot/dovecot.conf. However, the dovecot.conf includes the /etc/dovecot/conf.d/* before the 
local.conf. I  believe that means that the entries in the conf.d come first and have precedence. I 
was getting authorization failures. The section of my local.conf is as follows:

    #
    # master passwd added 4/30/2022 based on email from Aki Tuomi on Dovecot support list 3/21/2022,
    # modified based on example from
    https://doc.dovecot.org/configuration_manual/authentication/master_users/
    # also added userdb at bottom of this and removed lines from conf.d/auth-system.conf.ext to
    resolve precedence.
    #      CGH
    #
    auth_master_user_separator = *
    passdb {
       driver = passwd-file
       args = /etc/dovecot/passwd.masterusers
       master = yes
       result_success = continue
    }
    passdb {
       driver = pam
       args = session=yes %Ls
    }
    userdb {
       driver = passwd
    }

I had found entries in the /etc/dovecot/conf.d/auth-system.conf.ext that set drivers to pam for 
passdb and passwd for userdb. I commented those two lines out since I had them covered in my 
local.conf. That failed with the control process exiting with an error code. I quickly uncommented 
those two lines in auth-system.conf.ext and it started just fine (I have a lot of users dependent on 
this, although it is Saturday afternoon and a bit slow). Dovecot starts up alright with the above 
local.conf, but master user doesn't seem to work.

I'm testing with the following (master username and passwrd replaced):

    chrisho at marlin:/etc/dovecot$ telnet localhost 143
    Trying 127.0.0.1...
    Connected to localhost.
    Escape character is '^]'.
    * OK [CAPABILITY IMAP4rev1 LITERAL+ SASL-IR LOGIN-REFERRALS ID ENABLE IDLE STARTTLS AUTH=PLAIN]
    Dovecot ready.
    1 login chrisho*masteruser masterpassword
    1 NO [AUTHORIZATIONFAILED] Authorization failed
    2 exit
    Connection closed by foreign host.

What I'm seeing in the logs is:

    Apr 30 19:32:29 marlin auth[20859]: pam_unix(dovecot:auth): authentication failure; logname=
    uid=0 euid=0 tty=dovecot ruser=chrisho rhost=127.0.0.1
    Apr 30 19:32:29 marlin auth[20859]: pam_ldap: error trying to bind as user
    "uid=chrisho,ou=People,dc=bio,dc=nsm" (Invalid credentials)
    Apr 30 19:32:31 marlin auth[20859]: pam_unix(imap:auth): authentication failure; logname= uid=0
    euid=0 tty=dovecot ruser=chrisho rhost=127.0.0.1
    Apr 30 19:32:31 marlin auth[20859]: pam_ldap: error trying to bind as user
    "uid=chrisho,ou=People,dc=bio,dc=nsm" (Invalid credentials)

The output of doveconf -n is as follows:

    # 2.2.22 (fe789d2): /etc/dovecot/dovecot.conf
    # Pigeonhole version 0.4.13 (7b14904)
    # OS: Linux 4.4.0-223-generic x86_64 Ubuntu 16.04.7 LTS
    auth_master_user_separator = *
    default_process_limit = 200
    first_valid_gid = 98
    first_valid_uid = 1000
    login_access_sockets = tcpwrap
    mail_location = mbox:~/mail:INBOX=/var/mail/%u
    mail_max_userip_connections = 8
    mail_privileged_group = mail
    mbox_write_locks = dotlock fcntl
    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 {
       driver = pam
    }
    passdb {
       args = /etc/dovecot/passwd.masterusers
       driver = passwd-file
       master = yes
       result_success = continue
    }
    passdb {
       args = session=yes %Ls
       driver = pam
    }
    pop3_client_workarounds = outlook-no-nuls oe-ns-eoh
    pop3_reuse_xuidl = yes
    pop3_uidl_format = %08Xv%08Xu
    protocols = " imap pop3"
    service imap-login {
       inet_listener imap {
         address = localhost
         port = 143
       }
       inet_listener imaps {
         port = 993
         ssl = yes
       }
    }
    service pop3-login {
       inet_listener pop3 {
         port = 0
       }
       inet_listener pop3s {
         port = 995
         ssl = yes
       }
    }
    service tcpwrap {
       unix_listener login/tcpwrap {
         group = $default_login_user
         mode = 0600
         user = $default_login_user
       }
    }
    ssl = required
    ssl_ca = </etc/mail/tls/marlin/InCommonBundle.crt
    ssl_cert = </etc/mail/tls/marlin/sendmail.pem
    ssl_key = </etc/mail/tls/marlin/sendmail.pem
    ssl_protocols = !SSLv2 !SSLv3
    syslog_facility = local2
    userdb {
       driver = passwd
    }
    userdb {
       driver = passwd
    }

And, yes, Ubuntu 16.04 is EOL; however, we do have an Ubuntu Advantage account for this server. So 
we do get security patches and the hope is that we can do a release upgrade this summer.

Any further guidance would be much appreciated. If any further information is needed, I can provide it.


On 3/21/22 1:57 AM, Aki Tuomi wrote:
>> On 20/03/2022 22:36 Chris Hoogendyk <hoogendyk at bio.umass.edu> wrote:
>>
>>   
>> I'm posting to the list, but not on the list. I presume that means a reply-all to get to me as well
>> as the list?
>>
>> We have two servers (dovecot --version:  2.2.22 (fe789d2)) that handle email for two different
>> departments.
>>
>> We are transitioning mail service to the University central IT. They need to move accounts in an
>> automated fashion and therefore need a master password to our dovecot servers. However, we are
>> running with LDAP authentication, and I understand that a master password is not possible in that
>> configuration.
>>
> Hi!
>
> It is totally possible to use LDAP with master password, using configuration like this:
>
> # this must be first
> passdb {
>    driver = static
>    args = password=masterpass
> }
>
> # current passdb config
>
> # you probably already have this
> userdb {
>    driver = ldap
>    args = /path/to/ldap/userdb
> }
>
> If this does not work, please send your `doveconf -n` as well.
>
> Aki

-- 
---------------

Chris Hoogendyk

-
    O__  ---- Systems Administrator, Retired
   c/ /'_ --- Biology & Geosciences Departments
  (*) \(*) -- 315 Morrill Science Center III
~~~~~~~~~~ - University of Massachusetts, Amherst

<hoogendyk at bio.umass.edu>

---------------

Erdös 4



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