Some of Fluentd's plugins support the <parse> section to specify how to parse raw data.

Parse section overview

Parse section can be in <source>, <match> or <filter> sections. It's enabled for plugins which support parser plugin features.

<source>
  @type tail
  # parameters for input plugin
  <parse>
    # parse section parameters
  </parse>
</source>

parser plugin type

<parse> section requires @type parameter to specify the type of parser plugin. Fluentd core bundles a lot of useful parser plugins. 3rd party plugins are also available when installed.

<parse>
  @type apache2
</parse>

For more details, see plugins documentation.

Parameters

@type

@type key is to specify the type of parser plugin.

<parse>
  @type regexp
  # ...
</parse>

These parsers are built-in by default.

• ​regexp​

• ​apache2​

• ​apache_error​

• ​nginx​

• ​syslog​

• ​csv​

• ​tsv​

• ​ltsv​

• ​json​

• ​multiline​

• ​none​

Parse parameters

These parameters default value will be overwritten by individual parser plugins.

• types (hash) (optional): Specify types for converting field into

  other type. See below "The detail of types parameter" section.

  • Default: nil

  • string-based hash: field1:type, field2:type, field3:type:option, field4:type:option

  • JSON format: {"field1":"type", "field2":"type", "field3":"type:option", "field4":"type:option"}

  • example: types user_id:integer,paid:bool,paid_usd_amount:float

• time_key (string) (optional): Specify time field for event time. If the event doesn't have this field, current time is used.

  • Default: nil

  • Note that json, ltsv and regexp override the default value of this parameter and set it to time by default.

• null_value_pattern (string) (optional): Specify null value pattern.

  • Default: nil

• null_empty_string (bool) (optional): If true, empty string field is replaced with nil.

  • Default: false

• estimate_current_event (bool) (optional): If true, use Fluent::EventTime.now(current time) as a timestamp when time_key is specified.

  • Default: false

• keep_time_key (bool) (optional): If true, keep time field in the record.

  • Default: false

• timeout (time) (optional): Specify timeout for parse processing. This is mainly for detecting wrong regexp pattern.

  • Default: nil

The detail of types parameter

The list of supported types are shown below:

• string

Convert field into String type. This uses to_s method for conversion.

• bool

Convert "true", "yes" or "1" string into true. Otherwise, false.

• integer ("int" would NOT work!)

Convert field into Integer type. This uses to_i method for conversion. For example, "1000" string is converted into 1000.

• float

Convert field into Float type. This uses to_f method for conversion. For example, "7.45" string is converted into 7.45.

• time

Convert field into Fluent::EventTime type. This uses Fluentd's time parser for conversion. For time type, the third field specifies a time format you would in time_format.

date:time:%d/%b/%Y:%H:%M:%S %z # for string with time format
date:time:unixtime             # for integer time
date:time:float                # for float time

See time_type and time_format parameters in Time parameters section.

• array

Convert string field into Array type. For the "array" type, the third field specifies the delimiter (the default is ","). For example, if a field called "item_ids" contains the value "3,4,5", types item_ids:array parses it as ["3", "4", "5"]. Alternatively, if the value is "Adam|Alice|Bob", types item_ids:array:| parses it as ["Adam", "Alice", "Bob"].

Time parameters

• time_type (enum) (optional): parse/format value according to this type

  • Default: string

  • Available values: float, unixtime, string

    • float: seconds from Epoch + nano seconds (e.g. 1510544836.154709804)

    • unixtime: seconds from Epoch (e.g. 1510544815)

    • string: use format specified by time_format, local time or time zone

• time_format (string) (optional): process value using specified format. This is available only when time_type is string

  • Default: nil

  • Available time format:

    • For more details about formatting, see Time#strftime​

    • For more details about parsing, see Time.strptime​

    • %iso8601 (only for parsing)

    • Use %N to parse/format subsecond, because strptime does not support %3N, %6N, %9N, and %L

• localtime (bool) (optional): if true, use local time. Otherwise, UTC is used. This is exclusive with utc.

  • Default: true

• utc (bool) (optional): if true, use UTC. Otherwise, local time is used. This is exclusive with localtime.

  • Default: false

• timezone (string) (optional): use specified timezone. one can parse/format the time value in the specified timezone.

  • Default: nil

  • Available time zone format:

    1. [+-]HH:MM (e.g. "+09:00") (recommended)

    2. [+-]HHMM (e.g. "+0900")

    3. [+-]HH (e.g. "+09")

    4. Region/Zone (e.g. "Asia/Tokyo")

    5. Region/Zone/Zone (e.g. "America/Argentina/Buenos_Aires")

If this article is incorrect or outdated, or omits critical information, please let us know. Fluentd is a open source project under Cloud Native Computing Foundation (CNCF). All components are available under the Apache 2 License.