Parser

The Parser Filter plugin allows to parse field in event records.

Configuration Parameters

The plugin supports the following configuration parameters:

Key	Description	Default
Key_Name	Specify field name in record to parse.
Parser	Specify the parser name to interpret the field. Multiple Parser entries are allowed (one per line).
Preserve_Key	Keep original Key_Name field in the parsed result. If false, the field will be removed.	False
Reserve_Data	Keep all other original fields in the parsed result. If false, all other original fields will be removed.	False
Unescape_Key	If the key is a escaped string (e.g: stringify JSON), unescape the string before to apply the parser.	False

Getting Started

Configuration File

This is an example to parser a record {"data":"100 0.5 true This is example"}.

The plugin needs parser file which defines how to parse field.

[PARSER]
    Name dummy_test
    Format regex
    Regex ^(?<INT>[^ ]+) (?<FLOAT>[^ ]+) (?<BOOL>[^ ]+) (?<STRING>.+)$

The path of parser file should be written in configuration file at [SERVICE] section.

[SERVICE]
    Parsers_File /path/to/parsers.conf

[INPUT]
    Name dummy
    Tag  dummy.data
    Dummy {"data":"100 0.5 true This is example"}

[FILTER]
    Name parser
    Match dummy.*
    Key_Name data
    Parser dummy_test

[OUTPUT]
    Name stdout
    Match *

The output is

$ fluent-bit -c dummy.conf
Fluent Bit v1.x.x
* Copyright (C) 2019-2020 The Fluent Bit Authors
* Copyright (C) 2015-2018 Treasure Data
* Fluent Bit is a CNCF sub-project under the umbrella of Fluentd
* https://fluentbit.io

[2017/07/06 22:33:12] [ info] [engine] started
[0] dummy.data: [1499347993.001371317, {"INT"=>"100", "FLOAT"=>"0.5", "BOOL"=>"true", "STRING"=>"This is example"}]
[1] dummy.data: [1499347994.001303118, {"INT"=>"100", "FLOAT"=>"0.5", "BOOL"=>"true", "STRING"=>"This is example"}]
[2] dummy.data: [1499347995.001296133, {"INT"=>"100", "FLOAT"=>"0.5", "BOOL"=>"true", "STRING"=>"This is example"}]
[3] dummy.data: [1499347996.001320284, {"INT"=>"100", "FLOAT"=>"0.5", "BOOL"=>"true", "STRING"=>"This is example"}]

You can see the record {"data":"100 0.5 true This is example"} are parsed.

Preserve original fields

By default, the parser plugin only keeps the parsed fields in its output.

If you enable Reserve_Data, all other fields are preserved:

[PARSER]
    Name dummy_test
    Format regex
    Regex ^(?<INT>[^ ]+) (?<FLOAT>[^ ]+) (?<BOOL>[^ ]+) (?<STRING>.+)$

[SERVICE]
    Parsers_File /path/to/parsers.conf

[INPUT]
    Name dummy
    Tag  dummy.data
    Dummy {"data":"100 0.5 true This is example", "key1":"value1", "key2":"value2"}

[FILTER]
    Name parser
    Match dummy.*
    Key_Name data
    Parser dummy_test
    Reserve_Data On

This will produce the output:

$ fluent-bit -c dummy.conf
Fluent-Bit v0.12.0
Copyright (C) Treasure Data

[2017/07/06 22:33:12] [ info] [engine] started
[0] dummy.data: [1499347993.001371317, {"INT"=>"100", "FLOAT"=>"0.5", "BOOL"=>"true", "STRING"=>"This is example"}, "key1":"value1", "key2":"value2"]
[1] dummy.data: [1499347994.001303118, {"INT"=>"100", "FLOAT"=>"0.5", "BOOL"=>"true", "STRING"=>"This is example"}, "key1":"value1", "key2":"value2"]
[2] dummy.data: [1499347995.001296133, {"INT"=>"100", "FLOAT"=>"0.5", "BOOL"=>"true", "STRING"=>"This is example"}, "key1":"value1", "key2":"value2"]
[3] dummy.data: [1499347996.001320284, {"INT"=>"100", "FLOAT"=>"0.5", "BOOL"=>"true", "STRING"=>"This is example"}, "key1":"value1", "key2":"value2"]

If you enable Reserved_Data and Preserve_Key, the original key field will be preserved as well:

[PARSER]
    Name dummy_test
    Format regex
    Regex ^(?<INT>[^ ]+) (?<FLOAT>[^ ]+) (?<BOOL>[^ ]+) (?<STRING>.+)$

[SERVICE]
    Parsers_File /path/to/parsers.conf

[INPUT]
    Name dummy
    Tag  dummy.data
    Dummy {"data":"100 0.5 true This is example", "key1":"value1", "key2":"value2"}

[FILTER]
    Name parser
    Match dummy.*
    Key_Name data
    Parser dummy_test
    Reserve_Data On
    Preserve_Key On

This will produce the output:

$ fluent-bit -c dummy.conf
Fluent-Bit v0.12.0
Copyright (C) Treasure Data

[2017/07/06 22:33:12] [ info] [engine] started
[0] dummy.data: [1499347993.001371317, {"data":"100 0.5 true This is example", "INT"=>"100", "FLOAT"=>"0.5", "BOOL"=>"true", "STRING"=>"This is example"}]
[1] dummy.data: [1499347994.001303118, {"data":"100 0.5 true This is example", "INT"=>"100", "FLOAT"=>"0.5", "BOOL"=>"true", "STRING"=>"This is example"}]
[2] dummy.data: [1499347995.001296133, {"data":"100 0.5 true This is example", "INT"=>"100", "FLOAT"=>"0.5", "BOOL"=>"true", "STRING"=>"This is example"}]
[3] dummy.data: [1499347996.001320284, {"data":"100 0.5 true This is example", "INT"=>"100", "FLOAT"=>"0.5", "BOOL"=>"true", "STRING"=>"This is example"}]

Time Resolution and Fractional Seconds

Some timestamps might have fractional seconds, like 2017-05-17T15:44:31.187512963Z. The %L format option for Time_Format is provided as a way to indicate that content must be interpreted as fractional seconds. To parse the previous example, you could specify Time_Format %Y-%m-%dT%H:%M:%S.%LZ.

The option %L is only valid when used after seconds (%S) or seconds since the Epoch (%s), e.g: %S.%L or %s.%L.

Support for %L was added in Fluent Bit 0.12.