Whippet - a request/response cli tool for MQTT v5

Whippet is a simple command line tool for sending requests and receiving responses over MQTT v5.

Typically, you'll use whippet to request something over MQTT and get a response back. Whippet will take care of generating and matching up MQTT correlation IDs as well as setting the response topic for the request.

Whippets secondary use case is a library for performing MQTT request/response operations. This is why a lot of the logic is in the whippet package.

Whippet has a wrapper around the paho MQTT client. Its use is optional, naturally. You can just provide your own paho client.

Usage

$ echo "ping" | whippet -server tcp://localhost:1883 -topic "my/topic" -qos 1
pong

The message to be sent is read from stdin and the response is written to stdout. Any error messages are written to stderr.

Options

Application Help Guide

Below are the command-line options available for the application:

• -clientID string
  Specifies a clientID for the connection.
  Default: $hostname-$random

• -help
  Prints this help message.

• -password string
  Password to match username.

• -qos int
  The Quality of Service (QoS) level to send the messages at.
  Default: 1

• -response-topic string
  Topic the other party should respond to. Defaults to the publish topic.

• -retained
  Specifies if the messages are sent with the retained flag.

• -server string
  The full URL of the MQTT server to connect to.
  Default: localhost:1883

• -timeout duration
  Timeout for the operation.
  Default: 10s

• -topic string
  Topic to publish the messages on.

• -username string
  A username to authenticate to the MQTT server.

Development

This is quite a simple tool and I made it to scratch my itch. If you need anything in it, feel free to open an issue or a PR.

The one thing I'll likely add is support for client TLS certs.

Note that the tests fire up a Mochi MQTT broker on port 1883. This is why we have a dependency on github.com/mochi-co/mqtt.