Demo Nginx service health endpoint for MetlalLB in K8s.

metallb-health.yaml

apiVersion: v1
kind: Namespace
metadata:
  name: metallb-health

---
apiVersion: v1
kind: ConfigMap
metadata:
  name: nginx-conf
  namespace: metallb-health
data:
  nginx.conf.template: |
    server {
      listen 80 default_server;
      listen [::]:80 default_server;

      server_name _;
      
      location = /health {
        access_log off;
        add_header 'Content-Type' 'text/plain';
        add_header 'Hostname' '${HOSTNAME}';
        return 200 'OK';
      }
    }

---
apiVersion: apps/v1
kind: DaemonSet
metadata:
  name: metallb-health
  namespace: metallb-health
spec:
  selector:
    matchLabels:
      app: metallb-health
  template:
    metadata:
      labels:
        app: metallb-health
    spec:
      containers:
      - name: metallb-health
        image: nginx:1.23-alpine
        ports:
        - name: http
          containerPort: 80
        volumeMounts:
        - mountPath: /etc/nginx/templates
          readOnly: true
          name: nginx-conf
        env:
          - name: HOSTNAME
            valueFrom:
              fieldRef:
                fieldPath: spec.nodeName
        resources:
          requests:
            memory: "64Mi"
            cpu: "250m"
          limits:
            memory: "128Mi"
            cpu: "500m"
      volumes:
      - name: nginx-conf
        configMap:
          name: nginx-conf
          items:
            - key: nginx.conf.template
              path: nginx.conf.template

---
apiVersion: v1
kind: Service
metadata:
  name: metallb-health
  namespace: metallb-health
  annotations:
    metallb.universe.tf/address-pool: ipaddresspool
    metallb.universe.tf/allow-shared-ip: "metallb-ipaddresspool"
spec:
  ports:
  - port: 8082
    protocol: TCP
    targetPort: 80
  selector:
    app: metallb-health
  type: LoadBalancer