Setting message fields to specific values
To set a field of the message to a specific value, you have to:
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define the string to include in the message, and
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select the field where it should be included.
You can set the value of available macros, for example HOST, MESSAGE, PROGRAM, or any user-defined macros created using parsers (for details, see parser: Parse and segment structured messages and db-parser: Process message content with a pattern database (patterndb)). Hard macros cannot be modified. For details on the hard and soft macros, see Hard vs. soft macros). Note that the rewrite operation completely replaces any previous value of that field. Use the following syntax:
Declaration:
rewrite <name_of_the_rule> {
set("<string to include>", value(<field name>));
};Example: Setting message fields to a particular value
The following example sets the HOST field of the message to myhost.
rewrite r_rewrite_set{
set("myhost", value("HOST"));
};
The following example appends the "suffix" string to the MESSAGE field:
rewrite r_rewrite_set{
set("$MESSAGE suffix", value("MESSAGE"));
};
For details on rewriting SDATA fields, see Creating custom SDATA fields.
You can also use the following options in rewrite rules that use the set() operator.
rewrite <name_of_the_rule> {
set("<string to include>", value(<field name>), on-error("fallback-to-string");
};
frac-digits()
| Type: | number |
| Default: | 0 |
Description: The syslog-ng 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 that syslog-ng can add the fractions to non-ISO8601 timestamps as well.
local-time-zone()
| Type: | name of the timezone, or the timezone offset |
| Default: | The local timezone. |
Description: Sets the timezone used when expanding filename and tablename templates.
The timezone can be specified by using the name, for example, time-zone("Europe/Budapest")), or as the timezone offset in +/-HH:MM format, for example, +01:00). On Linux and UNIX platforms, the valid timezone names are listed under the /usr/share/zoneinfo directory.
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 OSE cannot convert some data to the specified type. By default, syslog-ng OSE drops the entire message and logs the error. Currently the value-pairs() option uses the settings of on-error().
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drop-message: Drop the entire message and log an error message to the internal() source. This is the default behavior of syslog-ng OSE.
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drop-property: Omit the affected property (macro, template, or message-field) from the log message and log an error message to the internal() source.
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fallback-to-string: Convert the property to string and log an error message to the internal() source.
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silently-drop-message: Drop the entire message silently, without logging the error.
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silently-drop-property: Omit the affected property (macro, template, or message-field) silently, without logging the error.
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silently-fallback-to-string: Convert the property to string silently, without logging the error.
send-time-zone()
| Accepted values: | name of the timezone, or the timezone offset |
| Default: | local timezone |
Description: Specifies the time zone associated with the messages sent by syslog-ng, if not specified otherwise in the message or in the destination driver. For details, see Timezones and daylight saving.
The timezone can be specified by using the name, for example, time-zone("Europe/Budapest")), or as the timezone offset in +/-HH:MM format, for example, +01:00). On Linux and UNIX platforms, the valid timezone names are listed under the /usr/share/zoneinfo directory.
time-zone()
| Type: | name of the timezone, or the timezone offset |
| Default: | unspecified |
Description: Convert timestamps to the timezone specified by this option. If this option is not set, then the original timezone information in the message is used. Converting the timezone changes the values of all date-related macros derived from the timestamp, for example, HOUR. For the complete list of such macros, see Date-related macros.
The timezone can be specified by using the name, for example, time-zone("Europe/Budapest")), or as the timezone offset in +/-HH:MM format, for example, +01:00). On Linux and UNIX platforms, the valid timezone names are listed under the /usr/share/zoneinfo directory.
ts-format()
| Type: | rfc3164, bsd, rfc3339, iso |
| Default: | rfc3164 |
Description: Override the global timestamp format (set in the global ts-format() parameter) for the specific destination. For details, see ts-format().
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NOTE:
This option applies only to file and file-like destinations. Destinations that use specific protocols (for example, network(), or syslog()) ignore this option. For protocol-like destinations, use a template locally in the destination, or use the proto-template option. |
