Type Converter

The Type Converter Filter plugin allows to convert data type and append new key value pair.

This plugin is useful in combination with plugins which expect incoming string value. e.g. filter_grep, filter_modify

Configuration Parameters

The plugin supports the following configuration parameters. It needs four parameters.

<config_parameter> <src_key_name> <dst_key_name> <dst_data_type>

dst_data_type allows int, uint, float and string.

e.g. int_key id id_str string



This parameter is for integer source.


This parameter is for unsigned integer source.


This parameter is for float source.


This parameter is for string source.

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}

The plugin outputs uint values and filter_type_converter converts them into string type.

Convert uint to string

    Name mem

    Name type_converter
    Match *
    uint_key Mem.total Mem.total_str string
    uint_key Mem.used  Mem.used_str  string
    uint_key Mem.free  Mem.free_str  string

    Name stdout
    Match *

You can also run the filter from command line.

$ fluent-bit -i mem -o stdout -F type_converter -p 'uint_key=Mem.total Mem.total_str string' -p 'uint_key=Mem.used Mem.used_str string' -p 'uint_key=Mem.free Mem.free_str string' -m '*'

The output will be

[0] mem.0: [1639915154.160159749, {"Mem.total"=>8146052, "Mem.used"=>4513564, "Mem.free"=>3632488, "Swap.total"=>1918356, "Swap.used"=>0, "Swap.free"=>1918356, "Mem.total_str"=>"8146052", "Mem.used_str"=>"4513564", "Mem.free_str"=>"3632488"}]

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