kazulog@sv1:~$ cat /etc/os-release | head -2
PRETTY_NAME="Ubuntu 26.04 LTS"
NAME="Ubuntu"
kazulog@sv1:~$ systemctl status rsyslog --no-pager | head -6 | cat
● rsyslog.service - System Logging Service
     Loaded: loaded (/usr/lib/systemd/system/rsyslog.service; enabled; preset: enabled)
     Active: active (running) since Sat 2026-09-12 08:23:00 JST; 5min ago
 Invocation: 13a9a0a695b14b73b2d9c064a636dacb
TriggeredBy: ● syslog.socket
       Docs: man:rsyslogd(8)
kazulog@sv1:~$ ls -l /etc/rsyslog.conf /etc/rsyslog.d/
-rw-r--r-- 1 root root 1213 Aug 22  2025 /etc/rsyslog.conf

/etc/rsyslog.d/:
total 12
-rw-r--r-- 1 root root  314 May 16  2023 20-ufw.conf
-rw-r--r-- 1 root root  255 Jul 24 01:34 21-cloudinit.conf
-rw-r--r-- 1 root root 1124 Aug 22  2025 50-default.conf
kazulog@sv1:~$ grep -n 'imudp\|imtcp\|imuxsock\|imklog\|IncludeConfig' /etc/rsyslog.conf
13:module(load="imuxsock") # provides support for local system logging
17:#module(load="imudp")
18:#input(type="imudp" port="514")
21:#module(load="imtcp")
22:#input(type="imtcp" port="514")
25:module(load="imklog" permitnonkernelfacility="on")
53:$IncludeConfig /etc/rsyslog.d/*.conf
kazulog@sv1:~$ cat /etc/rsyslog.conf
# /etc/rsyslog.conf configuration file for rsyslog
#
# For more information install rsyslog-doc and see
# /usr/share/doc/rsyslog-doc/html/configuration/index.html
#
# Default logging rules can be found in /etc/rsyslog.d/50-default.conf


#################
#### MODULES ####
#################

module(load="imuxsock") # provides support for local system logging
#module(load="immark")  # provides --MARK-- message capability

# provides UDP syslog reception
#module(load="imudp")
#input(type="imudp" port="514")

# provides TCP syslog reception
#module(load="imtcp")
#input(type="imtcp" port="514")

# provides kernel logging support and enable non-kernel klog messages
module(load="imklog" permitnonkernelfacility="on")

###########################
#### GLOBAL DIRECTIVES ####
###########################

# Filter duplicated messages
$RepeatedMsgReduction on

#
# Set the default permissions for all log files.
#
$FileOwner syslog
$FileGroup adm
$FileCreateMode 0640
$DirCreateMode 0755
$Umask 0022
$PrivDropToUser syslog
$PrivDropToGroup syslog

#
# Where to place spool and state files
#
$WorkDirectory /var/spool/rsyslog

#
# Include all config files in /etc/rsyslog.d/
#
$IncludeConfig /etc/rsyslog.d/*.conf