Record Modifier

The Record Modifier Filter plugin allows to append fields or to exclude specific fields.

Configuration Parameters

The plugin supports the following configuration parameters: Remove_key and Allowlist_key are exclusive.

Key	Description
Record	Append fields. This parameter needs key and value pair.
Remove_key	If the key is matched, that field is removed.
Allowlist_key	If the key is not matched, that field is removed.
Whitelist_key	An alias of Allowlist_key for backwards compatibility.

Getting Started

In order to start filtering records, you can run the filter from the command line or through the configuration file.

This is a sample in_mem record to filter.

{"Mem.total"=>1016024, "Mem.used"=>716672, "Mem.free"=>299352, "Swap.total"=>2064380, "Swap.used"=>32656, "Swap.free"=>2031724}

Append fields

The following configuration file is to append product name and hostname (via environment variable) to record.

[INPUT]
    Name mem
    Tag  mem.local

[OUTPUT]
    Name  stdout
    Match *

[FILTER]
    Name record_modifier
    Match *
    Record hostname ${HOSTNAME}
    Record product Awesome_Tool

You can also run the filter from command line.

$ fluent-bit -i mem -o stdout -F record_modifier -p 'Record=hostname ${HOSTNAME}' -p 'Record=product Awesome_Tool' -m '*'

The output will be

[0] mem.local: [1492436882.000000000, {"Mem.total"=>1016024, "Mem.used"=>716672, "Mem.free"=>299352, "Swap.total"=>2064380, "Swap.used"=>32656, "Swap.free"=>2031724, "hostname"=>"localhost.localdomain", "product"=>"Awesome_Tool"}]

Remove fields with Remove_key

The following configuration file is to remove 'Swap.*' fields.

[INPUT]
    Name mem
    Tag  mem.local

[OUTPUT]
    Name  stdout
    Match *

[FILTER]
    Name record_modifier
    Match *
    Remove_key Swap.total
    Remove_key Swap.used
    Remove_key Swap.free

You can also run the filter from command line.

$ fluent-bit -i mem -o stdout -F  record_modifier -p 'Remove_key=Swap.total' -p 'Remove_key=Swap.free' -p 'Remove_key=Swap.used' -m '*'

The output will be

[0] mem.local: [1492436998.000000000, {"Mem.total"=>1016024, "Mem.used"=>716672, "Mem.free"=>295332}]

Remove fields with Allowlist_key

The following configuration file is to remain 'Mem.*' fields.

[INPUT]
    Name mem
    Tag  mem.local

[OUTPUT]
    Name  stdout
    Match *

[FILTER]
    Name record_modifier
    Match *
    Allowlist_key Mem.total
    Allowlist_key Mem.used
    Allowlist_key Mem.free

You can also run the filter from command line.

$ fluent-bit -i mem -o stdout -F  record_modifier -p 'Allowlist_key=Mem.total' -p 'Allowlist_key=Mem.free' -p 'Allowlist_key=Mem.used' -m '*'

The output will be

[0] mem.local: [1492436998.000000000, {"Mem.total"=>1016024, "Mem.used"=>716672, "Mem.free"=>295332}]