Logging appears to be broken

[Poldovico]

Upon starting the opendkim container, the message rsyslog: unrecognized service is printed to the log.
No logs are output other than those from the entrypoint script itself.
Per https://wiki.debian.org/Rsyslog, Debian Bookworm has deprecated the rsyslog service in favour of journald and no longer installs it by default, meaning presumably it is now missing in the Docker image.

opendkim-1  | Tables seem to exist.
opendkim-1  | rsyslog: unrecognized service
opendkim-1  | Creating /etc/opendkim.conf from template /usr/local/mailserver/templates/opendkim.conf
opendkim-1  | Creating /etc/default/opendkim from template /usr/local/mailserver/templates/default/opendkim
opendkim-1  | Starting OpenDKIM: opendkim.

A compose file for minimal reproduction follows:

name: dockerms
services:
  mysql:
    image: mysql:8.0
    volumes:
      - db_data:/var/lib/mysql
    restart: always
    environment:
      MYSQL_ROOT_PASSWORD: "roottestpwd"
      MYSQL_DATABASE: "mail"
      MYSQL_USER: "postfix"
      MYSQL_PASSWORD: "mysqltestpwd"
    networks:
      - test
  opendkim:
    image: technicalguru/mailserver-opendkim
    depends_on:
      - mysql
    restart: always
    volumes:
      - opendkim:/usr/local/mailserver/templates/
    environment:
      DKIM_DOMAIN: "example.com"
      DKIM_PORT: "41001"
      DKIM_DB_HOST: "mysql"
      DKIM_DB_NAME: "opendkimdb"
      DKIM_DB_USER: "opendkim"
      DKIM_DB_PASS: "dkimtestpwd"
      DKIM_SETUP_PASS: "roottestpwd"
    networks:
      - test
networks:
  test:
volumes:
  db_data:
  opendkim:

[Poldovico]

Looking again, I noticed rsyslog is installed in the Dockerfile, but it does not seem to be recognized as a service.

In my testing, I was able to restore logging by adding /usr/sbin/rsyslogd -n -iNONE & (copied from the systemd unit, though I do not understand its exact significance) right after service rsyslog start in the entrypoint script.
Upon restarting the container (docker compose restart opendkim), I got the following output:

opendkim-1  | Caught SIGTERM...
opendkim-1  | Stopping OpenDKIM: No /usr/sbin/opendkim found running; none killed.
opendkim-1  | opendkim.
opendkim-1  | rsyslog: unrecognized service
opendkim-1  | Tables seem to exist.
opendkim-1  | rsyslog: unrecognized service
opendkim-1  | rsyslogd: imklog: cannot open kernel log (/proc/kmsg): Operation not permitted.
opendkim-1  | rsyslogd: activation of module imklog failed [v8.2302.0 try https://www.rsyslog.com/e/2145 ]
opendkim-1  | Starting OpenDKIM: opendkim.
opendkim-1  | 2025-10-17T15:07:02.785028+00:00 ce86ae12bb64 opendkim[28]: OpenDKIM Filter v2.11.0 starting (args: -u opendkim -P /var/run/opendkim/opendkim.pid)
opendkim-1  | 2025-10-17T15:13:11.715320+00:00 ce86ae12bb64 opendkim[28]: OpenDKIM Filter v2.11.0 starting (args: -u opendkim -P /var/run/opendkim/opendkim.pid)

[technicalguru]

Yes, this is a known issue. I wasn't able to route log messages into stdout, as it shall be. I need to dig deeper in this issue. As upgrade to Debian 13 is up next, this might be resolved too. (Had to concentrate on multi-arch build first)