mqtt-test-client

README

MQTT Connectivity Testing Tool

This application is an MQTT Testing Tool for testing MQTT connections and sending/receiving messages from topics.

The tool is created for the purpose of testing connectivity to our MQTT broker with certificate-key pair that we provided. And it was created since not everyone has any (easy) way of testing connectivity with MQTT protocol.

Tool itself is very low-effort console application. It does unstructured logging to console for debugging purposes.

Features

• Connect to an MQTT broker using TLS with client certificate authentication
• Subscribe to one or multiple MQTT topics
• Display received messages in the console
• Gracefully reconnects and resubscribes to topics upon connection loss
• Listens for a TCP connections so one can connect to it and try publishing.

Dependencies

For MQTT connections the tool uses eclipse/paho.mqtt.golang which is under license: Eclipse Public License - v 2.0 (EPL-2.0)

Installation

You can download the pre-compiled binaries from the GitHub releases page or compile the tool yourself using the provided Makefile.

After downloading the binary, you may need to give it "execute" permissions. If you're on a Unix-like system (such as Linux or MacOS), you can do this by navigating to the directory containing the downloaded file and running:

chmod +x <your-binary-file>

To compile from source, ensure you have a working Go environment and make installed, and then run make from the project root:

make

Or by default with Go tools from the project root:

go mod download

go build -o mqtt-test-client main.go

Usage

./mqtt-test-client --mqtt-broker-addr=<broker URL> \
    --mqtt-broker-client-id=<client ID> \
    --mqtt-broker-device-cert=<path to certificate> \
    --mqtt-broker-device-key=<path to private key> \
    --mqtt-broker-root-ca=<path to root CA> \
    --mqtt-topics-to-sub=<comma-separated list of topics>

Flags:

• -mqtt-broker-addr: URL of the MQTT broker, for example: "tcps://foo-ats.iot.eu-north-1.amazonaws.com:8883/mqtt"
• -mqtt-broker-client-id: Client ID used for connecting to the broker (default is "mqtt-test-client")
• -mqtt-broker-device-cert: Filepath to the certificate file
• -mqtt-broker-device-key: Filepath to the private key for the certificate
• -mqtt-broker-root-ca: Filepath to the root CA file, for example "AmazonRootCA1.pem"
• -mqtt-topics-to-sub: Comma-separated list of topics to subscribe to

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To test publish one can connect to a running applications port 9596 with a tool like netcat or telnet for example with netcat:

$ nc localhost 9596

after connection is made, type the message as | for example. Newline (enter) will send the message.

my/test/topic|{"foo": "bar", "quz": 22.13}

the tool will split the sent line as topic + message and send it to a broker.

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NOTE Application is set to exit on CTLR+C It listens for interrupt, kill, and some other signals. If the TCP connection is still open in other console the application will wait on connection to be closed before exiting. So if you have made publish attempts with netcat, telnet, etc.. be sure to close the connection before exiting the running tool.

License

This project is licensed under the MIT License - see the LICENSE file for details