out_syslog: add preset configurations (#898)

Signed-off-by: Takahiro Yamashita <[email protected]>

Signed-off-by: Takahiro Yamashita <[email protected]>

Author: nokute78

pipeline/outputs/syslog.md

@@ -16,11 +16,17 @@ As of Fluent Bit v1.5.3 the configuration is very strict. You must be aware of t
 | syslog\_format | The Syslog protocol format to use. Available options are `rfc3164` and `rfc5424`. | rfc5424 |
 | syslog\_maxsize | The maximum size allowed per message. The value must be an integer representing the number of bytes allowed. If no value is provided, the default size is set depending of the protocol version specified by `syslog_format`.<br><br>`rfc3164` sets max size to 1024 bytes.<br><br>`rfc5424` sets the size to 2048 bytes. |  |
 | syslog\_severity\_key | The key name from the original record that contains the Syslog severity number. This configuration is optional. |  |
+| syslog\_severity\_preset | The preset severity number. It will be overwritten if `syslog_severity_key` is set and a key of a record is matched. This configuration is optional. | 6 |
 | syslog\_facility\_key | The key name from the original record that contains the Syslog facility number. This configuration is optional. |  |
+| syslog\_facility\_preset | The preset facility number. It will be overwritten if `syslog_facility_key` is set and a key of a record is matched. This configuration is optional. | 1 |
 | syslog\_hostname\_key | The key name from the original record that contains the hostname that generated the message. This configuration is optional. |  |
+| syslog\_hostname\_preset | The preset hostname. It will be overwritten if `syslog_hostname_key` is set and a key of a record is matched. This configuration is optional. | |
 | syslog\_appname\_key | The key name from the original record that contains the application name that generated the message. This configuration is optional. |  |
+| syslog\_appname\_preset | The preset application name. It will be overwritten if `syslog_appname_key` is set and a key of a record is matched. This configuration is optional. | |
 | syslog\_procid\_key | The key name from the original record that contains the Process ID that generated the message. This configuration is optional. |  |
+| syslog\_procid\_preset | The preset process ID. It will be overwritten if `syslog_procid_key` is set and a key of a record is matched. This configuration is optional. | |
 | syslog\_msgid\_key | The key name from the original record that contains the Message ID associated to the message. This configuration is optional. |  |
+| syslog\_msgid\_preset | The preset message ID. It will be overwritten if `syslog_msgid_key` is set and a key of a record is matched. This configuration is optional. | |
 | syslog\_sd\_key | The key name from the original record that contains the Structured Data \(SD\)  content. This configuration is optional. |  |
 | syslog\_message\_key | The key name from the original record that contains the message to deliver. Note that this property is **mandatory**, otherwise the message will be empty. |  |