mqtt-client

A simple command-line MQTT WebSocket client written in Go. This tool allows you to publish messages (including periodic timestamps) and subscribe to topics on an MQTT broker over WebSockets.

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Features

• Connect to any MQTT broker supporting WebSockets
• Publish custom messages or periodic timestamps
• Subscribe to topics and print received messages
• Configurable broker address, port, and topic

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Download & Installation

1. Download the latest release:
   • Go to the Releases page of this repository.
   • Download the appropriate binary for your operating system (e.g., mqtt-client-darwin-amd64, mqtt-client-linux-amd64, etc.).
2. (Optional) Rename and move the binary:

   mv mqtt-client-* mqtt-client
   chmod +x mqtt-client
   sudo mv mqtt-client /usr/local/bin/

3. Verify installation:

   mqtt-client --help

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📥 Quick Download by Operating System

Download the appropriate binary for your operating system and architecture using wget:

# For Linux
wget https://github.com/atakanaydinbas/mqtt-client/releases/download/v1.0.0/mqtt-client-linux-<arch>

# For macOS (darwin)
wget https://github.com/atakanaydinbas/mqtt-client/releases/download/v1.0.0/mqtt-client-darwin-<arch>

After downloading, make it executable and move it to your PATH:

chmod +x mqtt-client-<os>-<arch>
sudo mv mqtt-client-<os>-<arch> /usr/local/bin/mqtt-client

Note:
Replace <os> with linux or darwin depending on your operating system.
Replace <arch> with amd64 for most modern PCs (x86_64) or arm64 for ARM-based devices (such as Apple Silicon Macs or Raspberry Pi).
For example, use mqtt-client-linux-amd64 for Linux on x86_64, or mqtt-client-darwin-arm64 for macOS on Apple Silicon.

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Building from Source

If you cannot download the binary from the Releases section, you can build the CLI tool from source. Make sure you have Go 1.21+ installed.

1. Clone the repository:

   git clone https://github.com/atakanaydinbas/mqtt-client.git
   cd mqtt-client

2. Build the CLI:

   go build -o mqtt-client

3. (Optional) Move the binary to your PATH:

   chmod +x mqtt-client
   sudo mv mqtt-client /usr/local/bin/

4. Verify installation:

   mqtt-client --help

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Usage

All commands support the following global flags:

• --broker, -b : MQTT broker address (default: localhost)
• --port, -p : MQTT WebSocket port (default: 9001)
• --topic, -t : MQTT topic (default: test/topic)
• --username : Username for broker authentication (optional)
• --password : Password for broker authentication (optional)
• --tls : Enable TLS (wss://) connection (optional)
• --ca-cert : Path to CA certificate file (optional, for self-signed brokers)
• --client-cert : Path to client certificate file (optional, for mTLS)
• --client-key : Path to client private key file (optional, for mTLS)
• --insecure : Skip server certificate verification (not recommended)

TLS Usage

• For most public brokers, just use --tls (no certs needed).
• For self-signed/private brokers, use --tls --ca-cert <path>.
• Only use --client-cert and --client-key if the broker requires client authentication (mTLS).
• Use --insecure to skip server verification (for development only).

Examples:

# Connect to a public broker with TLS (no certs needed)
mqtt-client publish --tls -b test.mosquitto.org -p 8081 -t my/topic

# Connect to a broker with a self-signed certificate
mqtt-client subscribe --tls --ca-cert /path/to/ca.pem -b mybroker.local -p 8081 -t my/topic

# Connect with mutual TLS (client certs)
mqtt-client publish --tls --ca-cert /path/to/ca.pem --client-cert /path/to/client.crt --client-key /path/to/client.key -b mybroker.local -p 8081 -t my/topic

Publish

Publish a message to a topic, or (by default) publish the current timestamp every 10 seconds.

mqtt-client publish [message] [flags]

• [message] (optional): Message to publish (overrides timestamp loop)
• --message, -m : Message to publish (overrides timestamp loop)

Examples:

mqtt-client publish "Hello, MQTT!" -b test.mosquitto.org -p 8081 -t my/topic
mqtt-client publish --message "Quick message"
mqtt-client publish  # Publishes timestamp every 10 seconds

Subscribe

Subscribe to a topic and print all received messages.

mqtt-client subscribe [flags]

Example:

mqtt-client subscribe -b test.mosquitto.org -p 8081 -t my/topic

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Architecture

flowchart TD
    A["User (CLI)"] -->|"publish/subscribe commands"| B["mqtt-client (cobra CLI)"]
    B -->|"Uses"| C["pkg/mqtt (Client)"]
    C -->|"Connects via WebSocket"| D["MQTT Broker"]

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Dependencies

• Go 1.21+
• github.com/eclipse/paho.mqtt.golang
• github.com/spf13/cobra

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License

This project is hosted at atakanaydinbas/mqtt-client.

License: This project is licensed under the MIT License.