The Python destination allows you to write your own destination in Python. The python() destination has the following options. The class() option is mandatory. For details on writing destinations in Python, see python: writing custom Python destinations.
class()
| Type: | string |
| Default: | N/A |
Description: The name of the Python class that implements the destination, for example:
python(
class("MyPythonDestination")
);
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.MyPythonDestination")
);
For details, see Python code in external files
disk-buffer()
Description: This option enables putting outgoing messages into the disk-buffer file of the destination to avoid message loss in case of a system failure on the destination side. It has the following options:
| disk-buf-size() | |
| Type: | number [bytes] |
| Default: | |
| Description: This is a required option. The maximum size of the disk-buffer file in bytes. The minimum value is 1048576 bytes. If you set a smaller value, the minimum value will be used automatically. It replaces the old log-disk-fifo-size() option. | |
| mem-buf-length() | |
| Type: | number [messages] |
| Default: | 10000 |
| Description: Use this option if the option reliable() is set to no. This option contains the number of messages stored in overflow queue. It replaces the old log-fifo-size() option. It inherits the value of the global log-fifo-size() option if provided. If it is not provided, the default value is 10000 messages. Note that this option will be ignored if the option reliable() is set to yes. | |
| mem-buf-size() | |
| Type: | number [bytes] |
| Default: | 163840000 |
| Description: Use this option if the option reliable() is set to yes. This option contains the size of the messages in bytes that is used in the memory part of the disk-buffer file. It replaces the old log-fifo-size() option. It does not inherit the value of the global log-fifo-size() option, even if it is provided. Note that this option will be ignored if the option reliable() is set to no. | |
| quot-size() | |
| Type: | number [messages] |
| Default: | 1000 |
|
Description: The number of messages stored in the output buffer of the destination. Note that if you change the value of this option and the disk-buffer file already exists, the change will take effect when the disk-buffer file becomes empty. | |
| reliable() | |||
| Type: | yes|no | ||
| Default: | no | ||
|
Description: If set to yes, syslog-ng PE cannot lose logs in case of reload/restart, unreachable destination or syslog-ng PE crash. This solution provides a slower, but reliable disk-buffer option. It is created and initialized at startup and gradually grows as new messages arrive. If set to no, the normal disk-buffer option will be used. This provides a faster, but less reliable disk-buffer option.
| |||
| truncate-size-ratio() | |||
| Type: | number (for percentage) between 0 and 1 | ||
| Default: | 0.1 (10%) | ||
|
Description: Limits the truncation of the disk-buffer file. Truncating the disk-buffer file can slow down disk I/O operations, but it saves disk space. As a result, syslog-ng PE only truncates the file if the possible disk gain is more than truncate-size-ratio() times disk-buf-size().
| |||
Example: Examples for using disk-buffer()
In the following case, reliable disk-buffer() is used.
destination d_demo {
network("127.0.0.1"
port(3333)
disk-buffer(
mem-buf-size(10000)
disk-buf-size(2000000)
reliable(yes)
dir("/tmp/disk-buffer")
)
);
};
In the following case normal disk-buffer() is used.
destination d_demo {
network("127.0.0.1"
port(3333)
disk-buffer(
mem-buf-length(10000)
disk-buf-size(2000000)
reliable(no)
dir("/tmp/disk-buffer")
)
);
};frac-digits()
| Type: | number |
| Default: | 0 |
Description: The syslog-ng PE application can store fractions of a second in the timestamps according to the ISO8601 format. The frac-digits() parameter specifies the number of digits stored. The digits storing the fractions are padded by zeros if the original timestamp of the message specifies only seconds. Fractions can always be stored for the time the message was received.
NOTE: The syslog-ng PE application can add the fractions to non-ISO8601 timestamps as well.
NOTE: As syslog-ng PE is precise up to the microsecond, when the frac-digits() option is set to a value higher than 6, syslog-ng PE will truncate the fraction seconds in the timestamps after 6 digits.
log-fifo-size()
| Type: | number |
| Default: | Use global setting. |
Description: The number of messages that the output queue can store.
on-error()
| Accepted values: |
drop-message|drop-property|fallback-to-string| silently-drop-message|silently-drop-property|silently-fallback-to-string |
| Default: | Use the global setting (which defaults to drop-message) |
Description: Controls what happens when type-casting fails and syslog-ng PE cannot convert some data to the specified type. By default, syslog-ng PE drops the entire message and logs the error. Currently the value-pairs() option uses the settings of on-error().
-
drop-message: Drop the entire message and log an error message to the internal() source. This is the default behavior of syslog-ng PE.
-
drop-property: Omit the affected property (macro, template, or message-field) from the log message and log an error message to the internal() source.
-
fallback-to-string: Convert the property to string and log an error message to the internal() source.
-
silently-drop-message: Drop the entire message silently, without logging the error.
-
silently-drop-property: Omit the affected property (macro, template, or message-field) silently, without logging the error.
-
silently-fallback-to-string: Convert the property to string silently, without logging the error.
options()
| Type: | string |
| Default: | N/A |
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"])
persist-name()
| Type: | string |
| Default: |
None |
Description:If you receive the following error message during syslog-ng PE startup, set the persist-name() option of the duplicate drivers:
Error checking the uniqueness of the persist names, please override it with persist-name option. Shutting down.
This error occurs if you use identical drivers in multiple sources, for example, if you configure two file sources to read from the same file. In this case, set the persist-name() of the drivers to a custom string, for example, persist-name("example-persist-name1").
NOTE: Starting with
log {
source { python(class(PyNetworkSource) options("port" "8080") persist-name("<unique-string>); };
source { python(class(PyNetworkSource) options("port" "8081")); };
};
Alternatively, you can include the following line in the Python package: @staticmethod generate_persist_name. For example:
from syslogng import LogSource
class PyNetworSource(LogSource):
@staticmethod
def generate_persist_name(options):
return options["port"]
def run(self):
pass
def request_exit(self):
passthrottle()
| Type: | number |
| Default: | 0 |
Description: Sets the maximum number of messages sent to the destination per second. Use this output-rate-limiting functionality only when using the disk-buffer option as well to avoid the risk of losing messages. Specifying 0 or a lower value sets the output limit to unlimited.
value-pairs()
| Type: | parameter list of the value-pairs() option |
| Default: | scope("selected-macros" "nv-pairs") |
Description: The value-pairs() option creates structured name-value pairs from the data and metadata of the log message. For details on using value-pairs(), see Structuring macros, metadata, and other value-pairs.
NOTE: Empty keys are not logged.
You can use this option to limit which name-value pairs are passed to the Python code for each message. Note that if you use the value-pairs() option, the Python code receives the specified value-pairs as a Python dict. Otherwise, it receives the message object. In the following example, only the text of the log message is passed to Python.
destination d_python_to_file {
python(
class("pythonexample.TextDestination")
value-pairs(key(MESSAGE))
);
};