Handle properly the 4 combinations for Reserve_Data and Preserve_Key:

• Off/Off: keep only parsed fields
• Off/On: parsed fields + original key
• On/Off: all fields except target key
• On/On: keep all fields

Testing

• Example configuration file for the change

[SERVICE]
    Parsers_File ./parser.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 Off
    Preserve_Key On

[OUTPUT]
    Name stdout
    Match *

Parsers

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

• Debug log output from testing the change

Backporting

• Backport to latest stable release.

Fluent Bit is licensed under Apache 2.0, by submitting this pull request I understand that this code will be released under the terms of that license.