Installing a MQTT and access it from external ip

here are the steps to install Mosquitto and Mosquitto clients on Ubuntu and configure the MQTT broker to be accessible externally without requiring a username and password:

Step 1: Update Your Package List

First, update your package list to make sure you have the latest information on the newest versions of packages and their dependencies.

bashCopy codesudo apt update

Step 2: Install Mosquitto and Mosquitto Clients

Install the Mosquitto broker and client tools using the following commands:

bashCopy codesudo apt install mosquitto mosquitto-clients

Step 3: Enable and Start the Mosquitto Service

Enable Mosquitto to start on boot and then start the service:

bashCopy codesudo systemctl enable mosquitto
sudo systemctl start mosquitto

Step 4: Configure Mosquitto to Allow External Access

Edit the Mosquitto configuration file to allow connections from external devices. Open the configuration file with a text editor:

bashCopy codesudo nano /etc/mosquitto/mosquitto.conf

Add the following lines to the configuration file to allow anonymous connections and listen on all network interfaces:

confCopy codeallow_anonymous true
listener 1883 0.0.0.0

Save the file and exit the text editor (Ctrl+O, Enter, Ctrl+X).

Step 5: Restart the Mosquitto Service

Restart the Mosquitto service to apply the changes:

bashCopy codesudo systemctl restart mosquitto

Step 6: Configure Firewall (If Applicable)

If you have a firewall enabled, you need to allow traffic on port 1883 to ensure the MQTT broker can be accessed externally. Use the following command to allow traffic on port 1883:

bashCopy codesudo ufw allow 1883

Step 7: Test the MQTT Broker

You can use Mosquitto clients to test the MQTT broker. Open a terminal and use the following commands to publish and subscribe to topics.

Subscribe to a Topic:

bashCopy codemosquitto_sub -h <your-server-ip> -t test/topic

Publish a Message to the Topic:

Open another terminal and use the following command:

bashCopy codemosquitto_pub -h <your-server-ip> -t test/topic -m "Hello, MQTT"

Replace <your-server-ip> with the IP address of your Ubuntu server running Mosquitto.