Plugin Helper: Parser

The parser plugin helper manages the lifecycle of the parser plugin.

Here is an example:

require 'fluent/plugin/input'

module Fluent::Plugin
  class ExampleInput < Input
    Fluent::Plugin.register_input('example', self)

    # 1. Load parser helper
    helpers :parser

    # Omit `shutdown` and other plugin APIs

    def configure(conf)
      super

      # 2. Create parser plugin instance
      @parser = parser_create
    end

    def start
      super

      # Use parser helper in combination usually with other plugin helpers
      timer_execute(:example_timer, 10) do
        read_raw_data do |text|
          # 3. Call `@parser.parse(text)` to parse raw data
          @parser.parse(text) do |time, record|
            router.emit(tag, time, record)
          end
        end
      end
    end
  end
end

For more details, see the following articles:

• Parser Plugin Overview
• Writing Parser Plugins
• Parser Plugin

Methods

parser_create(usage: "", type: nil, conf: nil, default_type: nil)

This method creates a parser plugin instance with the given parameters.

• usage: unique name required for multiple parsers

• type: parser type

• conf: parser plugin configuration

• default_type: default parser type

Examples

# Create parser plugin instance using <parse> section in fluent.conf during configure phase
@parser = parser_create
@parser.parse(text) do |time, record|
  # ...
end

# Create JSON parser
@json_parser = parser_create(usage: 'parser_in_example_json', type: 'json')
@json_parser.parse(json) do |time, record|
  # ...
end

# Create MessagePack parser
@msgpack_parser = parser_create(usage: 'parser_in_example_msgpack', type: 'msgpack')
@msgpack_parser.parse(msgpack_binary) do |time, record|
  # ...
end

Plugins using parser

• filter_parser
• in_exec
• in_http
• in_syslog
• in_tail
• in_tcp
• in_udp
• out_exec_filter

If this article is incorrect or outdated, or omits critical information, please let us know.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