File

The file output plugin allows to write the data received through the input plugin to file.

Configuration Parameters

The plugin supports the following configuration parameters:

Key	Description	Default
Path	Directory path to store files. If not set, Fluent Bit will write the files on it's own positioned directory. note: this option was added on Fluent Bit v1.4.6
File	Set file name to store the records. If not set, the file name will be the tag associated with the records.
Format	The format of the file content. See also Format section. Default: out_file.
Mkdir	Recursively create output directory if it does not exist. Permissions set to 0755.
Workers	The number of workers to perform flush operations for this output.	1

Format

out_file format

Output time, tag and json records. There is no configuration parameters for out_file.

tag: [time, {"key1":"value1", "key2":"value2", "key3":"value3"}]

plain format

Output the records as JSON (without additional tag and timestamp attributes). There is no configuration parameters for plain format.

{"key1":"value1", "key2":"value2", "key3":"value3"}

csv format

Output the records as csv. Csv supports an additional configuration parameter.

Key	Description
Delimiter	The character to separate each data. Accepted values are "\t" (or "tab"), "space" or "comma". Other values are ignored and will use default silently. Default: ','

time[delimiter]"value1"[delimiter]"value2"[delimiter]"value3"

ltsv format

Output the records as LTSV. LTSV supports an additional configuration parameter.

Key	Description
Delimiter	The character to separate each pair. Default: '\t'(TAB)
Label_Delimiter	The character to separate label and the value. Default: ':'

field1[label_delimiter]value1[delimiter]field2[label_delimiter]value2\n

template format

Output the records using a custom format template.

Key	Description
Template	The format string. Default: '{time} {message}'

This accepts a formatting template and fills placeholders using corresponding values in a record.

For example, if you set up the configuration as below:

[INPUT]
  Name mem

[OUTPUT]
  Name file
  Match *
  Format template
  Template {time} used={Mem.used} free={Mem.free} total={Mem.total}

You will get the following output:

1564462620.000254 used=1045448 free=31760160 total=32805608

Getting Started

You can run the plugin from the command line or through the configuration file:

Command Line

From the command line you can let Fluent Bit count up a data with the following options:

$ fluent-bit -i cpu -o file -p path=output.txt

Configuration File

In your main configuration file append the following Input & Output sections:

[INPUT]
    Name cpu
    Tag  cpu

[OUTPUT]
    Name file
    Match *
    Path output_dir