Versions | v1.0 (td-agent3)

Socket Plugin Helper API

socket helper creates various types of socket instances.

Here is the code example with socket helper:

require 'fluent/plugin/output'

module Fluent::Plugin
  class ExampleOutput < Output
    Fluent::Plugin.register_output('example', self)

    # 1. load socket helper
    helpers :socket

    config_param :host, :string
    config_param :port, :integer

    # omit configure, shutdown and other plugin API

    def try_write(chunk)
      # 2. create socket
      socket = socket_create(:tcp, @host, @port)
      chunk.each do |time, record|
        # 3. write data to socket
        socket.write(record.to_json)
      end
    ensure
      # 4. close socket
      socket.close if socket
    end
  end
end

socket helper doesn’t manage life cycle of the socket. User must close the socket when it is no longer needed.

Table of Contents

Methods

socket_create(proto, host, port, **kwargs, &block)

This method creates socket instance with given protocol type

If block is given, it will be invoked with the socket instance as a parameter, and socket will be automatically closed when the block terminates.

  • proto: protocol type. :tcp, :udp, :tls
  • host: host name or IP address
  • port: port number
  • kwargs: extra options. for more details, see below methods.
  • block: customize created socket

Code example:

# TCP
socket = socket_create(:tcp, "example.com", 12340)
socket.write(data)
socket.close

# UDP
socket = socket_create(:udp, "example.com", 12341)
socket.write(data)
socket.close

# TLS
socket = socket_create(:tls, "example.com", 12342, insecure: true)
socket.write(data)
socket.close

# close socket automatically
socket_create(:udp, "example.com", 12341) do |sock|
  sock.write(data)
end

socket_create_tcp(host, port, **kwargs, &block)

This method creates socket instance for TCP

If block is given, it will be invoked with the socket instance as a parameter, and socket will be automatically closed when the block terminates.

  • host: hostname or IP address
  • port: port number
  • kwargs: extra options
    • resolve_name: if true, resolve hostname
    • nonblock: if true, use non-blocking I/O
    • linger_timeout: the timeout time in seconds used to set SO_LINGER
    • recv_timeout: the timeout time in seconds used to set SO_RECVTIMEO
    • send_timeout: the timeout time in seconds used to set SO_SNDTIMEO

socket_create_udp(host, port, **kwargs, &block)

This method creates socket instance for UDP

If block is given, it will be invoked with the socket instance as a parameter, and socket will be automatically closed when the block terminates.

  • host: host name or IP address
  • port: port number
  • kwargs: extra options
    • resolve_name: if true, resolve hostname
    • connect: if true, connect to host
    • nonblock: if true, use non-blocking I/O
    • linger_timeout: the timeout time in seconds used to set SO_LINGER
    • recv_timeout: the timeout time in seconds used to set SO_RECVTIMEO
    • send_timeout: the timeout time in seconds used to set SO_SNDTIMEO

socket_create_tls(host, port, **kwargs, &block)

This method creates socket instance for TLS

If block is given, it will be invoked with the socket instance as a parameter, and socket will be automatically closed when the block terminates.

  • host: host name or IP address
  • port: port number
  • kwargs: extra options
    • version: set TLS version :'TLSv1_1' or :'TLSv1_2'. Default: :'TLSv1_2'
    • ciphers: set the list of available cpher suites. Default: "ALL:!aNULL:!eNULL:!SSLv2"
    • insecure: if true, set TLS verify mode NONE
    • verify_fqdn: if true, check the server certificate is valid for the hostname
    • fqdn: set FQDN
    • enable_system_cert_store: if true, enable system default cert store
    • allow_self_signed_cert: if true, allow self signed certificate
    • cert_paths: files contain PEM-encoded certificates

socket used plugins

Last updated: 2018-09-23 04:03:45 +0000

Versions | v1.0 (td-agent3)

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.