mirror of
				https://github.com/vyos/vyos-documentation.git
				synced 2025-11-04 00:02:05 +01:00 
			
		
		
		
	
		
			
				
	
	
		
			227 lines
		
	
	
		
			11 KiB
		
	
	
	
		
			ReStructuredText
		
	
	
	
	
	
			
		
		
	
	
			227 lines
		
	
	
		
			11 KiB
		
	
	
	
		
			ReStructuredText
		
	
	
	
	
	
.. _syslog:
 | 
						|
 | 
						|
######
 | 
						|
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
 | 
						|
=======
 | 
						|
 | 
						|
Syslog supports logging to multiple targets, those targets could be a plain
 | 
						|
file on your VyOS installation itself, a serial console or a remote syslog
 | 
						|
server which is reached via :abbr:`IP (Internet Protocol)` UDP/TCP.
 | 
						|
 | 
						|
Console
 | 
						|
-------
 | 
						|
 | 
						|
.. cfgcmd:: set system syslog console facility <keyword> level <keyword>
 | 
						|
 | 
						|
Log syslog messages to ``/dev/console``, for an explanation on
 | 
						|
:ref:`syslog_facilities` keywords and :ref:`syslog_severity_level` keywords
 | 
						|
see tables below.
 | 
						|
 | 
						|
 | 
						|
Custom File
 | 
						|
-----------
 | 
						|
 | 
						|
.. cfgcmd:: set system syslog file <filename> facility <keyword> level <keyword>
 | 
						|
 | 
						|
Log syslog messages to file specified via `<filename>`, for en explanation on
 | 
						|
:ref:`syslog_facilities` keywords and :ref:`syslog_severity_level` keywords see
 | 
						|
tables below.
 | 
						|
 | 
						|
.. cfgcmd:: set system syslog file <filename> archive size <size>
 | 
						|
 | 
						|
Syslog will write `<size>` kilobytes into the file specified by `<filename>`.
 | 
						|
After this limit has been reached, the custom file is "rotated" by logrotate
 | 
						|
and a new custom file is created.
 | 
						|
 | 
						|
.. cfgcmd:: set system syslog file <filename> archive file <number>
 | 
						|
 | 
						|
Syslog uses logrotate to rotate logiles after a number of gives bytes. We keep
 | 
						|
as many as `<number>` rotated file before they are deleted on the system.
 | 
						|
 | 
						|
 | 
						|
Remote Host
 | 
						|
-----------
 | 
						|
 | 
						|
Logging to a remote host leaves the local logging configuration intact, it
 | 
						|
can be configured in parallel to a custom file or console logging. You can log
 | 
						|
to multiple hosts at the same time, using either TCP or UDP. The default is
 | 
						|
sending the messages via port 514/UDP.
 | 
						|
 | 
						|
 | 
						|
.. cfgcmd:: set system syslog host <address> facility <keyword> level <keyword>
 | 
						|
 | 
						|
Log syslog messages to remote host specified by `<address>`. The address can be
 | 
						|
specified by either FQDN or IP address. For en explanation on
 | 
						|
:ref:`syslog_facilities` keywords and :ref:`syslog_severity_level` keywords see
 | 
						|
tables below.
 | 
						|
 | 
						|
 | 
						|
.. cfgcmd:: set system syslog host <address> facility <keyword> protocol <udp|tcp>
 | 
						|
 | 
						|
Configure protocol used for communication to remote syslog host. This can be
 | 
						|
either UDP or TCP.
 | 
						|
 | 
						|
 | 
						|
Local User Account
 | 
						|
------------------
 | 
						|
 | 
						|
.. cfgcmd:: set system syslog user <username> facility <keyword> level <keyword>
 | 
						|
 | 
						|
If logging to a local user account 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. For en explanation on
 | 
						|
:ref:`syslog_facilities` keywords and :ref:`syslog_severity_level` keywords see
 | 
						|
tables below.
 | 
						|
 | 
						|
.. _syslog_facilities:
 | 
						|
 | 
						|
Facilities
 | 
						|
==========
 | 
						|
 | 
						|
List of facilities used by syslog. Most facilities names are self explanatory.
 | 
						|
Facilities local0 - local7 common usage is f.e. as network logs facilities for
 | 
						|
nodes and network equipment. Generally it depends on the situation how to
 | 
						|
classify logs and put them to facilities. See facilities more as a tool rather
 | 
						|
than a directive to follow.
 | 
						|
 | 
						|
Facilities can be adjusted to meet the needs of the user:
 | 
						|
 | 
						|
+----------+----------+----------------------------------------------------+
 | 
						|
| Facility | Keyword  | Description                                        |
 | 
						|
| Code     |          |                                                    |
 | 
						|
+==========+==========+====================================================+
 | 
						|
|          | all      | All facilities                                     |
 | 
						|
+----------+----------+----------------------------------------------------+
 | 
						|
| 0        | kern     | Kernel messages                                    |
 | 
						|
+----------+----------+----------------------------------------------------+
 | 
						|
| 1        | user     | User-level messages                                |
 | 
						|
+----------+----------+----------------------------------------------------+
 | 
						|
| 2        | mail     | Mail system                                        |
 | 
						|
+----------+----------+----------------------------------------------------+
 | 
						|
| 3        | daemon   | System daemons                                     |
 | 
						|
+----------+----------+----------------------------------------------------+
 | 
						|
| 4        | auth     | Security/authentication messages                   |
 | 
						|
+----------+----------+----------------------------------------------------+
 | 
						|
| 5        | syslog   | Messages generated internally by syslogd           |
 | 
						|
+----------+----------+----------------------------------------------------+
 | 
						|
| 6        | lpr      | Line printer subsystem                             |
 | 
						|
+----------+----------+----------------------------------------------------+
 | 
						|
| 7        | news     | Network news subsystem                             |
 | 
						|
+----------+----------+----------------------------------------------------+
 | 
						|
| 8        | uucp     | UUCP subsystem                                     |
 | 
						|
+----------+----------+----------------------------------------------------+
 | 
						|
| 9        | cron     | Clock daemon                                       |
 | 
						|
+----------+----------+----------------------------------------------------+
 | 
						|
| 10       | security | Security/authentication messages                   |
 | 
						|
+----------+----------+----------------------------------------------------+
 | 
						|
| 11       | ftp      | FTP daemon                                         |
 | 
						|
+----------+----------+----------------------------------------------------+
 | 
						|
| 12       | ntp      | NTP subsystem                                      |
 | 
						|
+----------+----------+----------------------------------------------------+
 | 
						|
| 13       | logaudit | Log audit                                          |
 | 
						|
+----------+----------+----------------------------------------------------+
 | 
						|
| 14       | logalert | Log alert                                          |
 | 
						|
+----------+----------+----------------------------------------------------+
 | 
						|
| 15       | clock    | clock daemon (note 2)                              |
 | 
						|
+----------+----------+----------------------------------------------------+
 | 
						|
| 16       | local0   | local use 0 (local0)                               |
 | 
						|
+----------+----------+----------------------------------------------------+
 | 
						|
| 17       | local1   | local use 1 (local1)                               |
 | 
						|
+----------+----------+----------------------------------------------------+
 | 
						|
| 18       | local2   | local use 2 (local2)                               |
 | 
						|
+----------+----------+----------------------------------------------------+
 | 
						|
| 19       | local3   | local use 3 (local3)                               |
 | 
						|
+----------+----------+----------------------------------------------------+
 | 
						|
| 20       | local4   | local use 4 (local4)                               |
 | 
						|
+----------+----------+----------------------------------------------------+
 | 
						|
| 21       | local5   | local use 5 (local5)                               |
 | 
						|
+----------+----------+----------------------------------------------------+
 | 
						|
| 22       | local6   |  use 6 (local6)                                    |
 | 
						|
+----------+----------+----------------------------------------------------+
 | 
						|
| 23       | local7   | local use 7 (local7)                               |
 | 
						|
+----------+----------+----------------------------------------------------+
 | 
						|
 | 
						|
.. _syslog_severity_level:
 | 
						|
 | 
						|
Severity Level
 | 
						|
==============
 | 
						|
 | 
						|
+-------+---------------+---------+-------------------------------------------+
 | 
						|
| Value | Severity      | Keyword | Description                               |
 | 
						|
+=======+===============+=========+===========================================+
 | 
						|
|       |               | all     | Log everything                            |
 | 
						|
+-------+---------------+---------+-------------------------------------------+
 | 
						|
| 0     | Emergency     | emerg   | System is unusable - a panic condition    |
 | 
						|
+-------+---------------+---------+-------------------------------------------+
 | 
						|
| 1     | Alert         | alert   | Action must be taken immediately - A      |
 | 
						|
|       |               |         | condition that should be corrected        |
 | 
						|
|       |               |         | immediately, such as a corrupted system   |
 | 
						|
|       |               |         | database.                                 |
 | 
						|
+-------+---------------+---------+-------------------------------------------+
 | 
						|
| 2     | Critical      | crit    | Critical conditions - e.g. hard drive     |
 | 
						|
|       |               |         | errors.                                   |
 | 
						|
+-------+---------------+---------+-------------------------------------------+
 | 
						|
| 3     | Error         | err     | Error conditions                          |
 | 
						|
+-------+---------------+---------+-------------------------------------------+
 | 
						|
| 4     | Warning       | warning | Warning conditions                        |
 | 
						|
+-------+---------------+---------+-------------------------------------------+
 | 
						|
| 5     | Notice        | notice  | Normal but significant conditions -       |
 | 
						|
|       |               |         | conditions that are not error conditions, |
 | 
						|
|       |               |         | but that may require special handling.    |
 | 
						|
+-------+---------------+---------+-------------------------------------------+
 | 
						|
| 6     | Informational | info    | Informational messages                    |
 | 
						|
+-------+---------------+---------+-------------------------------------------+
 | 
						|
| 7     | Debug         | debug   | Debug-level messages - Messages that      |
 | 
						|
|       |               |         | contain information normally of use only  |
 | 
						|
|       |               |         | when debugging a program.                 |
 | 
						|
+-------+---------------+---------+-------------------------------------------+
 | 
						|
 | 
						|
 | 
						|
Display Logs
 | 
						|
============
 | 
						|
 | 
						|
.. opcmd:: show log [all | authorization | cluster | conntrack-sync | ...]
 | 
						|
 | 
						|
Display log files of given category on the console. Use tab completion to get
 | 
						|
a list of available categories. Thos categories could be: all, authorization,
 | 
						|
cluster, conntrack-sync, dhcp, directory, dns, file, firewall, https, image
 | 
						|
lldp, nat, openvpn, snmp, tail, vpn, vrrp
 | 
						|
 | 
						|
If no option is specified, this defaults to `all`.
 | 
						|
 | 
						|
.. opcmd:: show log image <name> [all | authorization | directory | file <file name> | tail <lines>]
 | 
						|
 | 
						|
Log messages from a specified image can be displayed on the console. Details of
 | 
						|
allowed parameters:
 | 
						|
 | 
						|
.. list-table::
 | 
						|
   :widths: 25 75
 | 
						|
   :header-rows: 0
 | 
						|
 | 
						|
   * - 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.
 | 
						|
 | 
						|
.. hint:: Use ``show log | strip-private`` if you want to hide private data when sharing your logs.
 |