Can't change OpenDKIM socket in Debian stretch in /etc/default/opendkim

Question

I am trying to set up opendkim on Debian stretch but I fail at changing the socket. I want to change the socket to /var/spool/postfix/opendkim/opendkim.sock so I can use it with postfix.

I have added Socket local:/var/spool/postfix/opendkim/opendkim.sock to /etc/opendkim.conf

and also tried adding SOCKET="local:/var/spool/postfix/opendkim/opendkim.sock to /etc/default/opendkim (which I had to create).

No matter what I change or how often I restart opendkim, it always uses /var/run/opendkim/opendkim.sock as its socket.

➜  ~ netstat -a | fgrep LISTEN | grep open
unix  2      [ ACC ]     STREAM     LISTENING     5534128  /var/run/opendkim/opendkim.sock

➜  ~ sudo systemctl status opendkim.service

● opendkim.service - OpenDKIM DomainKeys Identified Mail (DKIM) Milter
   Loaded: loaded (/lib/systemd/system/opendkim.service; enabled; vendor preset: enabled)
   Active: active (running) since Sun 2017-04-30 12:41:54 CEST; 5min ago
     Docs: man:opendkim(8)
           man:opendkim.conf(5)
           man:opendkim-genkey(8)
           man:opendkim-genzone(8)
           man:opendkim-testadsp(8)
           man:opendkim-testkey
           http://www.opendkim.org/docs.html
  Process: 25246 ExecStart=/usr/sbin/opendkim -P /var/run/opendkim/opendkim.pid -p local:/var/run/opendkim/opendkim.sock (code=exited, status=0/SUCCESS)
 Main PID: 25248 (opendkim)
    Tasks: 7 (limit: 4915)
   CGroup: /system.slice/opendkim.service
           ├─25248 /usr/sbin/opendkim -P /var/run/opendkim/opendkim.pid -p local:/var/run/opendkim/opendkim.sock
           └─25249 /usr/sbin/opendkim -P /var/run/opendkim/opendkim.pid -p local:/var/run/opendkim/opendkim.sock

Apr 30 12:41:54 vServer systemd[1]: Starting OpenDKIM DomainKeys Identified Mail (DKIM) Milter...
Apr 30 12:41:54 vServer systemd[1]: Started OpenDKIM DomainKeys Identified Mail (DKIM) Milter.
Apr 30 12:41:54 vServer opendkim[25249]: OpenDKIM Filter v2.11.0 starting (args: -P /var/run/opendkim/opendkim.pid -p local:/var/run/opendkim/opendkim.sock)

What am I doing wrong? (I guess it's my mistake as I can't find anyone else with the same issue)

UPDATE:

Changing /etc/default/opendkim to SOCKET="inet:8891@localhost" and changing the postfix config to use this socket results in inet:localhost:8891: Connection refused

UPDATE2:

I have now replaced with the file bundled in the debian stretch package:

# Command-line options specified here will override the contents of                                                                                                         
# /etc/opendkim.conf. See opendkim(8) for a complete list of options.                                                                                                       
#DAEMON_OPTS=""                                                                                                                                                             
# Change to /var/spool/postfix/var/run/opendkim to use a Unix socket with                                                                                                   
# postfix in a chroot:                                                                                                                                                      
RUNDIR=/var/spool/postfix/var/run/opendkim                                                                                                                                  
#RUNDIR=/var/run/opendkim                                                                                                                                                   
#                                                                                                                                                                           
# Uncomment to specify an alternate socket                                                                                                                                  
# Note that setting this will override any Socket value in opendkim.conf                                                                                                    
# default:                                                                                                                                                                  
SOCKET=local:$RUNDIR/opendkim.sock                                                                                                                                          
# listen on all interfaces on port 54321:                                                                                                                                   
#SOCKET=inet:54321                                                                                                                                                          
# listen on loopback on port 12345:                                                                                                                                         
#SOCKET=inet:12345@localhost                                                                                                                                                
# listen on 192.0.2.1 on port 12345:                                                                                                                                        
#SOCKET=inet:[email protected]                                                                                                                                                
USER=opendkim                                                                                                                                                               
GROUP=opendkim                                                                                                                                                              
PIDFILE=$RUNDIR/$NAME.pid                                                                                                                                                   
EXTRAAFTER=   

The includes the following lines where the socket is decided:

if [ -f /etc/opendkim.conf ]; then                                                                                                                                          
    CONFIG_SOCKET=`awk '$1 == "Socket" { print $2 }' /etc/opendkim.conf`                                                                                                    
fi                                                                                                                                                                          

# This can be set via Socket option in config file, so it's not required                                                                                                    
if [ -n "$SOCKET" -a -z "$CONFIG_SOCKET" ]; then                                                                                                                            
    DAEMON_OPTS="-p $SOCKET $DAEMON_OPTS"                                                                                                                                   
fi

Solution 1

I finally found the solution.

The /etc/init.d/opendkim doesn't seem to do anything. But instead the servicefile /lib/systemd/system/opendkim.service is used which had the wrong socket hardcoded.

But the debian package also seems to include a bash that generates the correct systemd service.

So after running

/lib/opendkim/opendkim.service.generate
systemctl daemon-reload
service opendkim restart

and restarting opendkim the socket file appears in the expected place, which can be verified by calling:

tail /var/log/mail.log | grep OpenDKIM

Update: It seems there is an debian bugreport about this issue: #861169

Update 2021:

As this question is still read quite often, I want to make everyone aware of the recent NEWS entry:

[...]

We remind users that opendkim is best configured by editing /etc/opendkim.conf. The legacy defaults file at /etc/default/opendkim is still available, as is the script /lib/opendkim/opendkim.service.generate. However, these provide no additional value over the default configuration file /etc/opendkim.conf. Please take this opportunity to review your configuration setup.

Also beginning with Debian Bullseye the /etc/default/opendkim starts with:

# NOTE: This is a legacy configuration file. It is not used by the opendkim
# systemd service. Please use the corresponding configuration parameters in
# /etc/opendkim.conf instead.
#
# Previously, one would edit the default settings here, and then execute
# /lib/opendkim/opendkim.service.generate to generate systemd override files at
# /etc/systemd/system/opendkim.service.d/override.conf and
# /etc/tmpfiles.d/opendkim.conf. While this is still possible, it is now
# recommended to adjust the settings directly in /etc/opendkim.conf.

Solution 2

I don't have enough reputation to comment and wanted to acknowledge that after hours of searching for a solution to the OpenDKim-Postfix 'connection refused' error message, the /lib/systemd/system/opendkim.service edit provided by LocutusBE worked with Ubuntu 17.04:

warning: connect to Milter service inet:localhost:8891: Connection refused

edit /lib/systemd/system/opendkim.service

change:

ExecStart=/usr/sbin/opendkim -P /var/run/opendkim/opendkim.pid -p local:/var/run/opendkim/opendkim.sock

to:

ExecStart=/usr/sbin/opendkim -P /var/run/opendkim/opendkim.pid -p local:/var/run/opendkim/opendkim.sock -p inet:12301@localhost

systemctl daemon-reload

and

systemctl opendkim restart

Before attempting the edit I added the postfix user to the opendkim group and tried /lib/opendkim/opendkim.service.generate per Lukas Winkler's solution. The connection refused error persisted until the port number was added to /lib/systemd/system/opendkim.service.

To update /lib/systemd/system/opendkim.service, I used port 8891 for Ubuntu and commented out the original ExecStart line for testing purposes, then added a new line with port #:

/lib/systemd/system/opendkim.service (Service category):

    [Service]
    Type=forking
    PIDFile=/var/run/opendkim/opendkim.pid
    User=opendkim
    UMask=0007
    #ExecStart=/usr/sbin/opendkim -P /var/run/opendkim/opendkim.pid -p local:/var/run/opendkim/opendkim.sock
    ExecStart=/usr/sbin/opendkim -P /var/run/opendkim/opendkim.pid -p local:/var/run/opendkim/opendkim.sock -p inet:8891@localhost
    Restart=on-failure
    ExecReload=/bin/kill -USR1 $MAINPID

The matching port number was additionally specified in /etc/opendkim.conf:

Socket                  inet:8891@localhost

And /etc/postfix/main.cf:

smtpd_milters = inet:localhost:8891
non_smtpd_milters = $smtpd_milters
milter_default_action = accept

After restarting the systemctl daemon, opendkim, and postfix, outgoing mail was signed without issue and the mail log showed "DKIM-Signature field added".

systemctl daemon-reload
systemctl opendkim restart
systemctl postfix restart

There was no connection issue when configuring OpenDkim with Centos7 recently, so apparently in this instance it was Ubuntu-related. Thanks to Lukas Winkler for posting the question and those who shared their solutions.

Solution 3

I was stuck in that for hours until understanding what happens, using that conf:

> nocomment.sh /etc/default/opendkim 
RUNDIR=/var/spool/postfix/var/run/opendkim
SOCKET=local:$RUNDIR/$NAME.sock"
USER=opendkim
GROUP=opendkim
PIDFILE=$RUNDIR/$NAME.pid
EXTRAAFTER=

The problem is that logs don't show you that opendkim can't access to the sockets due to simple file access rights.

To correct that:

1. Add opendkim to postfix group (and not the contrary as I read somewhere)

2. chown postfix:root -R /var/spool/postfix/var/

3. verify that :

   $ ll /var/spool/postfix/var/run/opendkim/
   total 4
   -rw-rw---- 1 postfix root 6 avril 13 11:50 opendkim.pid
   srwxrwxr-x 1 postfix root 0 avril 13 11:50 opendkim.sock
   

I wrote some little reminder about OPENDKIM on DEBIAN BUSTER. Hope that may help

Solution 4

This worked for me:

edit /lib/systemd/system/opendkim.service

change:

ExecStart=/usr/sbin/opendkim -P /var/run/opendkim/opendkim.pid -p local:/var/run/opendkim/opendkim.sock

to:

ExecStart=/usr/sbin/opendkim -P /var/run/opendkim/opendkim.pid -p local:/var/run/opendkim/opendkim.sock -p inet:12301@localhost

systemctl daemon-reload

and

systemctl opendkim restart

Solution 5

In order to use inet socket you need to specify:

SOCKET="inet:12301@localhost" to /etc/default/opendkim

also, you need to change settings in Postfix consequently:

in /etc/postfix/main.cf add:

milter_protocol = 2
milter_default_action = accept
smtpd_milters = inet:localhost:12301
non_smtpd_milters = inet:localhost:12301

if you cannot set local to desired path, I would suggest you to:

• grab a log from mail, syslog or opendkim in /var/log and check

• check /etc/init.d/opendkim script and inspect if sock file is hard-set to a value

• try to go with default local:/var/run/opendkim/opendkim.sock - and specify smtpd_milters = local:/var/run/opendkim/opendkim.sock and non_smtpd_milters = local:/var/run/opendkim/opendkim.sock in /etc/postfix/main.cf

View more solutions

Comments

[Miloš Đakonović]

"so I can use it with postfix" Are you sure that you need this in order to make it work with Postfix?

[lw1.at]

@Miloshio I thought so as postfix runs in a chroot. (According to the tutorial I am following)

[lw1.at]

@Miloshio postfix claims connect to Milter service local:/var/run/opendkim/opendkim.sock: No such file or directory even thought it exists as it is chrooted to /var/spool/postfix/

[Miloš Đakonović]

It sounds like it is not chrooted. Please could you check again? Your paths should look like /var/spool/postfix/var/run... if it is

[Miloš Đakonović]

In any scenario, I would use inet instead of local. Maybe, if you are not debugging down service, try to implement: digitalocean.com/community/tutorials/…

[lw1.at]

I don't think that postfix is the issue. I have also tested /opendkim/opendkim.sock. But /var/spool/postfix/opendkim/opendkim.sock doesn't get created. And when I am using SOCKET="inet:8891@localhost" the it also doesn't work.

[lw1.at]

I have now changed the config to be exactly like yours (same port) but I still get warning: connect to Milter service inet:localhost:12301: Connection refused

[Miloš Đakonović]

did you try to restart both services after editing?

[lw1.at]

I did and now I also rebooted. When looking at mail.log I always see the following line OpenDKIM Filter v2.11.0 starting (args: -P /var/run/opendkim/opendkim.pid -p local:/var/run/opendkim/opendkim.sock)

[Miloš Đakonović]

You see that line even with SOCKET="inet:12301@localhost set to opendkim conf file?

[lw1.at]

thanks for the ideas. I found the solution (there's something odd with the debian package)

[lw1.at]

This is exactly the change which is done by the /lib/opendkim/opendkim.service.generate script.

[Ivan Mir]

Thanks a lot – this fixed it on Ubuntu 16.04.3 LTS that lacks opendkim.service.generate.

[Piyush Kumar]

opendkim ignores /etc/default/opendkim socket setting - for now we have to change /etc/opendkim.conf

[Eaten by a Grue]

🍺🍺🍺🍺🍺🍺🍺🍺

[Admin]

Very helpful!!!!