udp

The udp_server and udp_client connectors allow UDP based datagram clients and servers to be integrated with tremor.

udp_server

The udp_server binds to the host and port given in url and listens on incoming UDP packets. Incoming UDP packets are being received into a local buffer of buf_size bytes, which determines the maximum packet size. Each UDP packet will be deserialized by the preprocessors and the codec.

This connector can only be used to receive events, thus pipelines can only be connected to the out and err ports.

Events coming from the udp_server connector do not have any metadata associated with them. The tremor::origin::scheme() function can be used and checked for equality with "udp-server" to determine if an event is coming from the udp_server connector.

Configuration

Option	Description	Type	Required	Default value
url	The host and port to bind to and listen on for incoming packets.	string	yes
buf_size	UDP receive buffer size. This should be greater than or equal to the expected maximum packet size.	positive integer	no	8192
socket_options	See UDP socket options.	record	no	See UDP socket options defaults

Example:

config.troy

define connector `udp-in` from udp_server
with
  codec = "string",
  preprocessors = [
    "separate"
  ]
  config = {
    "url": "localhost:4242",
    "buf_size": 4096,
    "socket_options": {
      "SO_REUSEPORT": true
    }
  }
end;

udp_client

The UDP client will open a UDP socket to write data to the given host and port configured in url. It will write the event payload, processed by the configured codec and postprocessors, out to the socket.

Configuration

Option	Description	Type	Required	Default value
url	The host and port to connect to.	string	yes
bind	The host and port to bind to prior to connecting	string	no	"0.0.0.0:0" if the connect url resolves to an IPv4 address, "[::]:0" if it resolves to IPv6.
socket_options	See UDP socket options.	record	no	See UDP socket options defaults

The udp client, by default binds to 0.0.0.0:0 allowing to send to all interfaces of the system running tremor and picking a random port. This can be overwritten adding "bind": "<ip>:<port>" to the config.

:::warn If you are hardening an installation it might make sense to limit the interfaces a udp client can send to by specifying the "bind" config. :::

Example:

config.troy

define connector `udp-out` from udp_client
with
  codec = "yaml",
  postprocessors = ["base64"],
  config = {
    "url": "localhost:4242",
    "bind": "127.0.0.1:65535",
    "socket_options: {
      "SO_REUSEPORT": true
    }
  }
end;