VerneMq Kubernetes StatefulSet + LoadBalancer

README.md

Deploy VerneMq inside Kubernetes

Allow the default service account to read pods data, by adding a role binding:

TODO: Now the yaml works only for the dev1 namespace, how can I make it more generic?

kubectl apply -f ./add-read-pods-binding.yaml

Deploy the VerneMQ StatefulSet:

kubectl apply -f ./vernemq.yaml

TODO: Mount volumes...

Check cluster running this command inside one of the pod:

vmq-admin cluster show

More info: https://hub.docker.com/r/erlio/docker-vernemq/

Testing

Sample node.js testing app:

npm install mqtt

import * as mqtt from "mqtt"
const client = mqtt.connect('mqtt://YOUR-LOADBALANCER-IP')

client.on('connect', function () {
  console.log("Connected...")
  client.subscribe('presence', (err) => {
    if (err) {
      console.error("Failed to subscribe");
      return;
    }

    client.publish('presence', 'Hello mqtt');
  });

});

client.on("error", function(err) {
  console.error(err);
});

client.on('message', function (topic, message) {
  // message is Buffer
  console.log(topic, message.toString())
  client.end()
});

add-read-pods-binding.yaml

kind: ClusterRole
apiVersion: rbac.authorization.k8s.io/v1
metadata:
  # ClusterRoles not bound to namespace?
  # namespace: default
  name: pod-reader
rules:
  - apiGroups: [""] # "" indicates the core API group
    resources: ["pods"]
    verbs: ["get", "watch", "list"]
...
---
apiVersion: rbac.authorization.k8s.io/v1beta1
kind: ClusterRoleBinding
metadata:
  name: pod-reader-pod
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: pod-reader
subjects:
  - kind: ServiceAccount
    name: default
    namespace: dev1 # TODO: Here I should use the current namespace or all namespace, change this if your namespace is different

vernemq.yaml

kind: Service
apiVersion: v1
metadata:
  name: vernemq-public
spec:
  selector:
    app: vernemq
  ports:
  - name: mqtt
    protocol: TCP
    port: 1883
    targetPort: 1883
  - name: websocket
    protocol: TCP
    port: 8080
    targetPort: 8080
  type: LoadBalancer
  
---

apiVersion: v1
kind: Service
metadata:
  name: vernemq
spec:
  ports:
    - port: 1883
      name: mqtt
    - port: 8883
      name: mqttssl
  clusterIP: None
  selector:
    app: vernemq

---

apiVersion: apps/v1
kind: StatefulSet
metadata:
  name: vernemq-set
  labels:
    app: vernemq
spec:
  serviceName: vernemq
  replicas: 2
  selector:
    matchLabels:
      app: vernemq
  template:
    metadata:
      labels:
        app: vernemq
    spec:
      containers:
      - name: docker-vernemq
        image: erlio/docker-vernemq:1.4.1
        ports:
        - containerPort: 1883
          name: mqtt
        - containerPort: 8080
          name: websocket
        env:
        - name: DOCKER_VERNEMQ_ALLOW_ANONYMOUS
          value: "on"
        - name: DOCKER_VERNEMQ_DISCOVERY_KUBERNETES
          value: "1"
        - name: DOCKER_VERNEMQ_KUBERNETES_APP_LABEL
          value: "vernemq"
        - name: DOCKER_VERNEMQ_KUBERNETES_NAMESPACE
          valueFrom:
            fieldRef:
              fieldPath: metadata.namespace
        - name: MY_POD_NAME
          valueFrom:
            fieldRef:
              fieldPath: metadata.name