The pysros.syslog module provides functionality for obtaining and manipulating a syslog event.

Note

This module is available when executing on SR OS only. On a remote machine, the syslog function is not supported.

Important

The pysros.syslog module is designed to be used with the SR OS syslog functionality at high processing rates. It cannot be used with the pysros.management module, SR OS filesystem access, or the EHS, CRON, or pyexec execution pathways.

Two methods are available to modify the syslog message being sent:

  • The pysros.syslog.get_event() function retrieves the syslog event that is in the queue to be sent out and allows for its attributes to be modified. When the Python application terminates successfully, the newly modified attributes are reformatted using the default syslog format.

  • The pysros.syslog.Event.override_payload() method allows for an entirely new payload to be crafted based on the data from the original event but choosing a customer format and which data to include.

Note

The maximum length of a syslog message on SR OS is 1023 bytes. When modifying the payload to become larger than this maximum value, one of the following occurs:

pysros.syslog.get_event()

Obtain the syslog event queued to be sent out.

Returns:

The event object or None.

Return type:

pysros.syslog.Event or None

generate_pri(facility, severity)

Converts the event severity into a syslog severity and combines it with the facility to generate the syslog PRI value (See RFC 5424 for details) that can be used when formatting a new syslog payload.

Parameters:

  • facility (int) – Syslog facility value.

  • severity (str) – Event severity name.

Returns:

Syslog PRI value.

Return type:

str

Raises:
severity_to_name(severity)

Converts an event severity name into a syslog severity name.

Parameters:

severity (str) – Event severity name.

Returns:

Syslog severity name.

Return type:

str

Raises:

ValueError – for invalid severities, see pysros.syslog.Event.severity

get_system_name()

Retrieves the system name. This function is provided directly as part of the pysros.syslog module to provide enhanced performance for the syslog execution pathway.

Returns:

SR OS system name.

Return type:

str

class pysros.syslog.Event

The syslog Event class provides access to the header-fields of the messages, the individual fields of the event and the syslog-specific attributes.

Note

The header-fields can be modified unless stated otherwise.

Any changes are reflected in the actual syslog-packet being sent out.

If a change of message format is required, for example, the ordering or the value of the field needs to change, override_payload() should be used to override the complete message. In this case, the actual message first needs to be formatted using the format_msg() function before it is passed to the override_payload() function.

name

The name of the event.

Type:

str

appid

The name of the application that generated the event.

Type:

str

eventid

The event ID number of the application.

Type:

int

Raises:

ValueError – for negative values.

severity

The severity level of the event. Valid values are:

  • none

  • cleared

  • indeterminate

  • critical

  • major

  • minor

  • warning

Type:

str

sequence

The sequence number of the event in the syslog collector.

Type:

int

Raises:

ValueError – for negative values.

subject

The subject or affected object of the event.

Type:

str

router_name

The name of the SR OS router-instance (For example, Base) in which this event was triggered.

Type:

str

gentime

The time, in ISO 8601 format, that the event was generated.

Note

Changes to timestamp are reflected in this attribute.

Type:

str, read-only

timestamp

The time, in seconds, that the event was generated.

Type:

float

hostname

The hostname field of the syslog message. This can be an IP address, fully-qualified domain name (FQDN), or hostname.

Type:

str

log_prefix

The log-prefix inserted into the event message.

Type:

str

facility

The syslog facility code. A list of named values is provided in pysros.syslog.Facility.

Type:

int

Raises:

ValueError – for values outside of the valid range [0..31]

text

The event specific body formatted as a string. By default, this is generated from the eventparameters.

This attribute can be modified to provide new event text.

This message may include values from the eventparameters function.

Type:

str

eventparameters

The additional parameters specific to the event that caused the Python application to execute.

Note

The parameters returned cannot be modified to alter the generated event text. Instead, a new event text should be generated from the values and assigned to the text attribute.

Returns:

Event specific parameters. The parameters in this class are read-only.

Return type:

pysros.syslog.EventParams

format_msg()

Return a string representation of the SR OS formatted log message.

Returns:

SR OS formatted log message.

Return type:

str

format_syslog_msg()

Return a string representation of the SR OS formatted log message as it appears in the syslog packet. When any of the writable attributes on this event have been modified, the output of this function contains these changes.

Returns:

SR OS formatted syslog message.

Return type:

str

override_payload(payload)

Provide a custom syslog message as it appears in the packet. This includes header information (facility, timestamp, etc.) and body data (the actual message).

Attributes from this event can be used to construct a completely new message format. Any prior changes to the values of these attributes are used.

Parameters:

payload (str) – New syslog payload.

Raises:

ValueError – when payload is larger than the maximum of 1023 bytes.

drop()

Drop the syslog message from the send queue.

class pysros.syslog.EventParams

The additional parameters of the specific pysros.syslog.Event. This class is read-only. Specific additional parameters may be accessed using standard Python subscript syntax.

keys()

Obtain the additional parameter names.

Returns:

Additional parameter names for the event.

Return type:

tuple(str)

params[key]

Return the value of the parameter key. If the parameter does not exist, a KeyError is raised. key is of type str.

iter(params)

Return an iterator for the key value pairs of parameters.

Where an iterator is expected, this object can be passed and the iterator is used implicitly. This can be used to collect all pysros.syslog.Event.eventparameters into a standard Python dict.

Example use of the iterator for type conversion
>>> list(event.eventparameters)
[('key1', 'value1'), ('key2', 'value2'), ('key3', 'value3')]
>>> params = dict(event.eventparameters)
>>> type(params)
<class 'dict'>
>>> params
{'key1': 'value1', 'key2': 'value2', 'key3': 'value3'}
class pysros.syslog.Facility

Class similar to an Enum that defines constants that can be used as values for the pysros.syslog.Event.facility attribute.

Note

No instances of this class can be instantiated.

KERNEL = 0
USER = 1
MAIL = 2
SYSTEMD = 3
AUTH = 4
SYSLOGD = 5
PRINTER = 6
NETNEWS = 7
UUCP = 8
CRON = 9
AUTHPRIV = 10
FTP = 11
NTP = 12
LOGAUDIT = 13
LOGALERT = 14
CRON2 = 15
LOCAL0 = 16
LOCAL1 = 17
LOCAL2 = 18
LOCAL3 = 19
LOCAL4 = 20
LOCAL5 = 21
LOCAL6 = 22
LOCAL7 = 23