Kubernetes nginx refresh ip address when upstream service IP changes

Best way is to use an DNS sidecar on your nginx pod as below:

apiVersion: v1kind: ConfigMapmetadata:  namespace: issue-795  name: nginx-configdata:  nginx.conf: |-    user  nginx;    worker_processes  1;    events {      worker_connections  4096;  ## Default: 1024    }    http {      server { # php/fastcgi        listen 80;        resolver 127.0.0.1:53 ipv6=off valid=10s;        set $upstream http://backend:8080;        location / {              proxy_pass $upstream;              proxy_http_version 1.1;         }      }    }---apiVersion: extensions/v1beta1kind: Deploymentmetadata:  namespace: issue-795  name: proxyspec:  replicas: 1  template:    metadata:      labels:        app: proxy    spec:      containers:      - name: nginx        image: nginx        ports:        - containerPort: 80        volumeMounts:        - name: nginx-config          mountPath: /etc/nginx/nginx.conf          subPath: nginx.conf      - name: dnsmasq        image: "janeczku/go-dnsmasq:release-1.0.7"        args:          - --listen          - "127.0.0.1:53"          - --default-resolver          - --append-search-domains      volumes:      - name: nginx-config        configMap:          name: nginx-config---apiVersion: v1kind: Servicemetadata:  namespace: issue-795  name: backendspec:  ports:  - port: 80    targetPort: 8080  clusterIP: None  selector:    app: backend---apiVersion: apps/v1kind: StatefulSetmetadata:  name: backend  namespace: issue-795spec:  serviceName: "backend"  replicas: 2  selector:    matchLabels:      app: backend  template:    metadata:      labels:        app: backend    spec:      containers:      - name: echoserver        image: gcr.io/google_containers/echoserver:1.4        imagePullPolicy: Always        ports:        - containerPort: 8080

I would recommand the use of Ingress resource on Kubernetes with the Nginx Ingress Controller.

Its whole purpose is to have a proxy inside your Kubernetes cluster that redirects the traffic to ClusterIP Services.

So you only have one external ELB that redirects all the traffic into your Kubernetes cluster. The Ingress Controller then redirects the traffic to different services.

For more advanced ingress controllers, you can look at Kong Ingress Controller.