• Передача сообщений в syslog в shell скриптах
• Использование почтовых псевдонимов
• Сервис SNORT Копирование alert_unified2 в syslog

$ logger -t postfix -p mail.info 'Message from postfix'

$ logger -t kernel -p kern.emerg 'Kernel Panic'

• RSyslog — удобный способ сбора и обработки системных логов
• Настройка RSyslog на запись в базу данных MySQL

$ systemctl -a | grep syslog

$ less /etc/rsyslog.conf

$ man rsyslog.conf

root@server:~# cat /etc/rsyslog.d/30-cisco.conf

local0.* -/var/log/cisco.log

root@server:~# touch /var/log/cisco.log

debian# chown root:adm /var/log/cisco.log
ubuntu# chown syslog:adm /var/log/cisco.log

root@server:~# rsyslogd -N1

root@server:~# service rsyslog restart 

root@server:~# tail -f /var/log/cisco.log

root@server:~# cat /etc/rsyslog.conf

...
module(load="imudp")
input(type="imudp" port="514")
...

root@server:~# service rsyslog restart 

# cat /etc/rsyslog.d/my.conf

...
module(load="imfile")
input(type="imfile" File="/var/log/openvpn/openvpn_status_bmstu.log"
Tag="openvpn"
Severity="info"
Facility="local0")
...
*.*                                           @server.corp13.un

root@server:~# cat /etc/rsyslog.conf

...
module(load="omprog")

local0.* action(type="omprog" binary="/etc/script.sh")
...

root@server:~# service rsyslog restart 

• Мониторинг системы при помощи logwatch
• Использование почтовых псевдонимов

root@server:~# apt install logwatch

root@server:~# /etc/cron.daily/00logwatch

• How To Use Journalctl to View and Manipulate Systemd Logs

# journalctl -ra

# journalctl --no-pager

# journalctl -o json

# journalctl -o verbose

# journalctl -f

client3:~# journalctl -f | grep ansible-pull

# journalctl -ra -u postfix

# journalctl -ra -p err

# man systemd.journal-fields

# journalctl SYSLOG_FACILITY=2

# man journald.conf

# journalctl --disk-usage

# journalctl --vacuum-size=1G

• Receiving Syslog messages with a systemd

              0             kernel messages
              1             user-level messages
              2             mail system
              3             system daemons
              4             security/authorization messages
              5             messages generated internally by syslogd
              6             line printer subsystem
              7             network news subsystem
              8             UUCP subsystem
              9             clock daemon
             10             security/authorization messages
             11             FTP daemon
             12             NTP subsystem
             13             log audit
             14             log alert
             15             clock daemon (note 2)
             16             local use 0  (local0)
             17             local use 1  (local1)
             18             local use 2  (local2)
             19             local use 3  (local3)
             20             local use 4  (local4)
             21             local use 5  (local5)
             22             local use 6  (local6)
             23             local use 7  (local7)