Syslog

Per default VyOSs has minimal syslog logging enabled which is stored and rotated locally. Errors will be always logged to a local file, which includes local7 error messages, emergency messages will be sent to the console, too.

To configure syslog, you need to switch into configuration mode.

Logging to serial console

The below would log all messages to /dev/console.

set system syslog console facility all level all

Use the [tab] function to display all facilities and levels which can be configured.

[email protected]# set system syslog console facility <TAB>
Possible completions:
> all          All facilities excluding "mark"
> auth         Authentication and authorization
> authpriv     Non-system authorization
> cron         Cron daemon
> daemon       System daemons
> kern         Kernel
> lpr          Line printer spooler
> mail         Mail subsystem
> mark         Timestamp
> news         USENET subsystem
> protocols    depricated will be set to local7
> security     depricated will be set to auth
> syslog       Authentication and authorization
> user         Application processes
> uucp         UUCP subsystem
> local0       Local facility 0
> local1       Local facility 1
> local2       Local facility 2
> local3       Local facility 3
> local4       Local facility 4
> local5       Local facility 5
> local6       Local facility 6
> local7       Local facility 7

[email protected]# set system syslog console facility all level <TAB>
Possible completions:
 emerg        Emergency messages
 alert        Urgent messages
 crit         Critical messages
 err          Error messages
 warning      Warning messages
 notice       Messages for further investigation
 info         Informational messages
 debug        Debug messages
 all          Log everything

Logging to a custom file

Logging to a custom file, rotation size and the number of rotate files left on the system can be configured.

set system syslog file <FILENAME> facility <FACILITY>  level <LEVEL>
set system syslog file <FILENAME> archive file <NUMBER OF FILES>
set system syslog file FILENAME archive size <FILESIZE>

The very same setting can be applied to the global configuration, to modify the defaults for the global logging.

Logging to a remote host

Logging to a remote host leaves the local logging configuration intact, it can be configured in parallel. You can log ro multiple hosts at the same time, using either TCP or UDP. The default is sending the messages via UDP.

UDP

set system syslog host 10.1.1.1 facility all level all
<optional>
set system syslog host 10.1.1.1 facility all protocol udp

TCP

set system syslog host 10.1.1.2 facility all level all
set system syslog host 10.1.1.2 facility all protocol tcp

Logging to a local user account

If logging to a local useraccount is configured, all defined log messages are display on the console if the local user is logged in, if the user is not logged in, no messages are being displayed.

set system syslog user <LOCAL_USERNAME> facility <FACILITY> level <LEVEL>

Show logs

Display log files on the console

[email protected]:~$ show log
Possible completions:
  <Enter>       Execute the current command
  all           Show contents of all master log files
  authorization Show listing of authorization attempts
  cluster       Show log for Cluster
  conntrack-sync
                Show log for Conntrack-sync
  dhcp          Show log for Dynamic Host Control Protocol (DHCP)
  directory     Show listing of user-defined log files
  dns           Show log for Domain Name Service (DNS)
  file          Show contents of user-defined log file
  firewall      Show log for Firewall
  https         Show log for Https
  image         Show logs from an image
  lldp          Show log for Lldp
  nat           Show log for Network Address Translation (NAT)
  openvpn       Show log for Openvpn
  snmp          Show log for Simple Network Monitoring Protocol (SNMP)
  tail          Monitor last lines of messages file
  vpn           Show log for Virtual Private Network (VPN)
  vrrp          Show log for Virtual Router Redundancy Protocol (VRRP)
  webproxy      Show log for Webproxy

Show contents of a log file in an image

Log messages from a specified image can be displayed on the console:

$ show log image <image name>
$ show log image <image name> [all | authorization | directory | file <file name> | tail <lines>]

Details of allowed parameters:

all Display contents of all master log files of the specified image
authorization Display all authorization attempts of the specified image
directory Display list of all user-defined log files of the specified image
file <file name> Display contents of a specified user-defined log file of the specified image
tail Display last lines of the system log of the specified image
<lines> Number of lines to be displayed, default 10

When no options/parameters are used, the contents of the main syslog file are displayed.