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regexp
The regexp parser plugin parses logs by given regexp pattern. The regexp must have at least one named capture (?<NAME>PATTERN). If the regexp has a capture named time, this is configurable via time_key parameter, it is used as the time of the event. You can specify the time format using the time_format parameter.
<parse>
@type regexp
expression /.../
</parse>

Parameters

See Parse Section Configurations for common parameters.

expression

type
default
version
regexp
required parameter
1.2.0
Specifies the regular expression for matching logs. Regular expression also supports i and m suffix.

i (ignorecase)

Ignores case in matching.
expression /.../i

m (multiline)

Build regular expression as a multiline mode. . matches the newline. See Ruby's Regexp.
expression /.../m

both

Specifies both i and m.
expression /.../im
expression is the string type before 1.2.0.

ignorecase

type
default
version
bool
false
0.14.2
Ignores case in matching. Use i option with expression.
Deprecated since 1.2.0. Use expression /pattern/i instead.

multiline

type
default
version
bool
false
0.14.2
Builds regular expression in multiline mode. . matches the newline. See Ruby's Regexp. Use m option with expression.
Deprecated since 1.2.0. Use expression /pattern/m instead.

Example

With this configuration:
<parse>
@type regexp
expression /^\[(?<logtime>[^\]]*)\] (?<name>[^ ]*) (?<title>[^ ]*) (?<id>\d*)$/
time_key logtime
time_format %Y-%m-%d %H:%M:%S %z
types id:integer
</parse>
This incoming event:
[2013-02-28 12:00:00 +0900] alice engineer 1
is parsed as:
time:
1362020400 (2013-02-28 12:00:00 +0900)
record:
{
"name" : "alice",
"title": "engineer",
"id" : 1
}

FAQ

How to debug my regexp pattern?

fluentd-ui's in_tail editor helps your regexp testing. Another way, Fluentular is a great website to test your regexp for Fluentd configuration.
NOTE: You may hit Application Error at Fluentular due to heroku's free plan limitation. Retry a few hours later or use fluentd-ui instead.
If this article is incorrect or outdated, or omits critical information, please let us know. Fluentd is an open-source project under Cloud Native Computing Foundation (CNCF). All components are available under the Apache 2 License.
Last modified 11mo ago
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Parameters
expression
ignorecase
multiline
Example
FAQ
How to debug my regexp pattern?