syslog-ng Premium Edition 7.0.17 - Administration Guide

class()

Description: The name of the Python class that implements the source, for example:

python(
    class("MyPythonSource")
);

If you want to store the Python code in an external Python file, the class() option must include the name of the Python file containing the class, without the path and the .py extension, for example:

python(
    class("MyPythonfilename.MyPythonSource")
);

For details, see Python code in external files

flags()

Description: Specifies the log parsing options of the source.

• assume-utf8: The assume-utf8 flag assumes that the incoming messages are UTF-8 encoded, but does not verify the encoding. If you explicitly want to validate the UTF-8 encoding of the incoming message, use the validate-utf8 flag.

• empty-lines: Use the empty-lines flag to keep the empty lines of the messages. By default, syslog-ng PE removes empty lines automatically.

• expect-hostname: If the expect-hostname flag is enabled, syslog-ng PE will assume that the log message contains a hostname and parse the message accordingly. This is the default behavior for TCP sources. Note that pipe sources use the no-hostname flag by default.

• kernel: The kernel flag makes the source default to the LOG_KERN | LOG_NOTICE priority if not specified otherwise.

• no-hostname: Enable the no-hostname flag if the log message does not include the hostname of the sender host. That way syslog-ng PE assumes that the first part of the message header is ${PROGRAM} instead of ${HOST}. For example:

  source s_dell {
      network(
          port(2000)
          flags(no-hostname)
      );
  };

• no-multi-line: The no-multi-line flag disables line-breaking in the messages: the entire message is converted to a single line. Note that this happens only if the underlying transport method actually supports multi-line messages. Currently the file() and pipe() drivers support multi-line messages.

• no-parse: By default, syslog-ng PE parses incoming messages as syslog messages. The no-parse flag completely disables syslog message parsing and processes the complete line as the message part of a syslog message. The syslog-ng PE application will generate a new syslog header (timestamp, host, and so on) automatically and put the entire incoming message into the MESSAGE part of the syslog message (available using the ${MESSAGE} macro). This flag is useful for parsing messages not complying to the syslog format.

  If you are using the flags(no-parse) option, then syslog message parsing is completely disabled, and the entire incoming message is treated as the ${MESSAGE} part of a syslog message. In this case, syslog-ng PE generates a new syslog header (timestamp, host, and so on) automatically. Note that since flags(no-parse) disables message parsing, it interferes with other flags, for example, disables flags(no-multi-line).

• dont-store-legacy-msghdr: By default, syslog-ng stores the original incoming header of the log message. This is useful if the original format of a non-syslog-compliant message must be retained (syslog-ng automatically corrects minor header errors, for example, adds a whitespace before msg in the following message: Jan 22 10:06:11 host program:msg). If you do not want to store the original header of the message, enable the dont-store-legacy-msghdr flag.

• sanitize-utf8: When using the sanitize-utf8 flag, syslog-ng PE converts non-UTF-8 input to an escaped form, which is valid UTF-8.

• store-raw-message: Save the original message as received from the client in the ${RAWMSG} macro. You can forward this raw message in its original form to another syslog-ng node using the syslog-ng() destination, or to a SIEM system, ensuring that the SIEM can process it. Available only in 7.0.9 and later.

• syslog-protocol: The syslog-protocol flag specifies that incoming messages are expected to be formatted according to the new IETF syslog protocol standard (RFC5424), but without the frame header. Note that this flag is not needed for the syslog driver, which handles only messages that have a frame header.

• validate-utf8: The validate-utf8 flag enables encoding-verification for messages formatted according to the new IETF syslog standard (for details, see IETF-syslog messages). If theBOM1character is missing, but the message is otherwise UTF-8 compliant, syslog-ng automatically adds the BOM character to the message.

The flags and the hostname-related options (for example, use-dns) set in the configuration file influence the behavior of the LogMessage.parse() method of the Python source. They have no effect if you set the message or the hostname directly, without using LogMessage.parse().

loaders()

Description: The syslog-ng PE application imports Python modules specified in this option, before importing the code of the Python class. This option has effect only when the Python class is provided in an external Python file. This option has no effect when the Python class is provided within the syslog-ng PE configuration file (in a python{} block). You can use the loaders() option to modify the import mechanism that imports Python class. For example, that way you can use hy in your Python class.

python(class(usermodule.HyParser) loaders(hy))

options()

Description: This option allows you to pass custom values from the configuration file to the Python code. Enclose both the option names and their values in double-quotes. The Python code will receive these values during initialization as the options dictionary. For example, you can use this to set the IP address of the server from the configuration file, so it is not hard-coded in the Python object.

python(
    class("MyPythonClass")
    options(
        "host" "127.0.0.1"
        "port" "1883"
        "otheroption" "value")
);

For example, you can refer to the value of the host field in the Python code as options["host"]. Note that the Python code receives the values as strings, so you might have to cast them to the type required, for example: int(options["port"])

Limitations

• The snmptrap() source has only the options listed in snmptrap() source options. Other options commonly available in other source drivers are not supported.

• In addition to traps, the log of snmptrapd may contain other messages (for example, daemon start/stop information, debug logs) as well. Currently syslog-ng PE discards these messages.

• Because of a bug, snmptrapd does not escape String values in the VarBindList if it can resolve an OID to a symbolic name. As a result, syslog-ng PE cannot process traps that contain the = in the value of the string. To overcome this problem, disable resolving OIDs in snmptrapd.

• The colon (:) character is commonly used in SNMP traps. However, this character cannot be used in the name of syslog-ng PE macros (name-value pairs). Therefore, the syslog-ng PE application automatically replaces all consecutive : characters with a single underscore (_) character. For example, you can reference the value of the NET-SNMP-EXAMPLES-MIB::netSnmpExampleString key using the ${NET-SNMP-EXAMPLES-MIB_netSnmpExampleString} macro.

  Note that this affects only name-value pairs (macros). The generated message always contains the original name of the key.

Prerequisites

• Configure snmptrapd to log into a file.

• If you use SMIv1 traps, include the following format string in the configuration file of snmptrapd:

  format1 %.4y-%.2m-%.2l %.2h:%.2j:%.2k %B [%b]: %N\n\t%W Trap (%q) Uptime: %#T\n%v\n

• If you use SMIv2 traps, use the default format. The snmptrap() source of syslog-ng PE expects this default format:

  format2 %.4y-%.2m-%.2l %.2h:%.2j:%.2k %B [%b]:\n%v\n

• Beacause of an snmptrapd bug, if you specify the filename in the configuration file with logOption, you must also specify another output as a command line argument (-Lf, -Ls). Otherwise, snmptrapd will not apply the the trap format.

To use the snmptrap() driver, the scl.conf file must be included in your syslog-ng PE configuration:

@include "scl.conf"

filename()

Description: The log file of snmptrapd. The syslog-ng PE application reads the traps from this file.

In addition to traps, the log of snmptrapd may contain other messages (for example, daemon start/stop information, debug logs) as well. Currently syslog-ng PE discards these messages.

prefix()

Description: Insert a prefix before the name part of the parsed name-value pairs to help further processing. For example:

• To insert the my-parsed-data. prefix, use the prefix(my-parsed-data.) option.

• To refer to a particular data that has a prefix, use the prefix in the name of the macro, for example, ${my-parsed-data.name} .

• If you forward the parsed messages using the IETF-syslog protocol, you can insert all the parsed data into the SDATA part of the message using the prefix(.SDATA.my-parsed-data.) option.

Default value: .snmp. option.

set-message-macro()

Description: The snmptrap() source automatically parses the traps into name-value pairs, so you can handle the content of the trap as a structured message. Consequently, you might not even need the ${MESSAGE} part of the log message. If set-message-macro() is set to no, syslog-ng PE leaves the ${MESSAGE} part empty. If set-message-macro() is set to yes, syslog-ng PE generates a regular log message from the trap.

Declaration

sun-streams(<name_of_the_streams_device> door(<filename_of_the_door>));