Type Converter

The Type Converter filter plugin converts data types and appends new key-value pairs.

You can use this filter in combination with plugins which expect incoming string value. For example, Grep and 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. For example, int_key id id_str string.

Key	Description
int_key	This parameter is for an integer source.
uint_key	This parameter is for an unsigned integer source.
float_key	This parameter is for a float source.
str_key	This parameter is for a string source.

Get started

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

fluent-bit.yaml

pipeline:
    inputs:
        - name: mem
    
    filters:
        - name: type_converter
          match: '*'
          uint_key:
            - Mem.total Mem.total_str string
            - Mem.used  Mem.used_str  string
            - Mem.free  Mem.free_str  string
    
    outputs:
        - name: stdout
          match: '*'

fluent-bit.conf

[INPUT]
    Name mem

[FILTER]
    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

[OUTPUT]
    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"}]