Expose MQTT port 1883 and test message flow using MQTT CLI

Using Loadbalancer

Exposing port 1883 using Load Balancer

1. Open values.yaml and search for port 1883 under hivemq.ports.port

   ports:
       - name: "mqtt"
         port: 1883
         expose: true
         patch:
           - '[{"op":"add","path":"/spec/selector/hivemq.com~1node-offline","value":"false"},{"op":"add","path":"/metadata/annotations","value":{"service.spec.externalTrafficPolicy":"Local"}}]'
           # If you want Kubernetes to expose the MQTT port to external traffic
           # - '[{"op":"add","path":"/spec/type","value":"LoadBalancer"}]'

2. Uncomment and expose the loadbalancer

   ports:
       - name: "mqtt"
         port: 1883
         expose: true
         patch:
           - '[{"op":"add","path":"/spec/selector/hivemq.com~1node-offline","value":"false"},{"op":"add","path":"/metadata/annotations","value":{"service.spec.externalTrafficPolicy":"Local"}}]'
           # If you want Kubernetes to expose the MQTT port to external traffic
           - '[{"op":"add","path":"/spec/type","value":"LoadBalancer"}]'

3. Save the file and apply the changes

   helm upgrade hivemq --install hivemq/hivemq-operator --values values.yaml

4. Check if the service for port 1883 has an external IP address now (in our case its hivemq-hivemq-mqtt) and notice the external port IP.

   kubectl get services

Connect To Your HiveMQ Cluster using MQTT CLI

• Once your HiveMQ cluster is up and running, you are ready to connect clients to the cluster with the MQTT-CLI. To obtain the exposed ENDPOINT of the created load balancer on which clients connect to your cluster, enter:

kubectl get hivemq-clusters

• Output similar to the following displays: (20.79.151.169 in our case)

$ kubectl get hivemq-clusters
NAME     SIZE   IMAGE            VERSION     STATUS    ENDPOINT       MESSAGE
hivemq   3      hivemq/hivemq4   k8s-4.24.0   Running   20.79.151.169   Live updates completed successfully

• Create a subscriber

mqtt sub -i SUB -h 20.79.151.169 -p 1883 -T -t '#'

• Create a publisher and publish the message. This should send a message to the subscriber. Test: Hello

mqtt publish --topic Test --message Hello --host 20.79.151.169 --port 1883

You have now successfully connected a new MQTT client to a HiveMQ cluster hosted on Azure.

Using Port Forwarding

Exposing port 1883 using Port Forwarding

• Run the following command to get the services and look for the MQTT service (hivemq-hivemq-mqtt in our case)

  kubectl get services

• Run the port forwarding as follows

  kubectl port-forward hivemq-hivemq-mqtt 1883:1883

• After running this command, you can access your service on localhost:1883

Connect To Your HiveMQ Cluster using the MQTT CLI

• Create a subscriber

mqtt sub -i SUB -h localhost -p 1883 -T -t '#'

• Create a publisher and publish the message. This should send a message to the subscriber. Test: Hello

mqtt publish --topic Test --message Hello --host localhost --port 1883

You have now successfully connected a new MQTT client to a HiveMQ cluster hosted on Azure.