A bit inexperienced at this, so looking for some help on how I can do this! Sorry if it is unclear of what I'm looking to do.

Objective

I have an Angular front-end that is location based. I am hoping to be able to use the users public IP by taking it and using a geolocation service to give me the city/region that they are from.

Update #1

From one of the answers below, I now am getting an IP address in SpringBoot, but unfortunately it is the IP address of the DigitalOcean droplet.

Current Setup

I am using a Spring Security Custom Filter to perform this action. This sits behind the Angular application.

I was hoping that I would be able to use the HttpServletRequest request.getRemoteAddr() to get the IP address, but I have found that once the SpringBoot application is deployed on Kubernetes, which sits behind an NGINX proxy, the getRemoteAddr() gives me the Digital Ocean droplet IP.

Due to this, I was hoping I would be able to pass this client IP address forward as the X-Forwarded-For header, or even a custom X-Client-IP header. How would I go about this if I'm performing these actions as part of a Spring Security Filter? Is it even possible?

Nginx Config

location / {
    proxy_set_header    Host               $host;
    proxy_set_header    X-Client-IP        $proxy_add_x_forwarded_for;
    proxy_set_header    X-Real-IP          $remote_addr;
    proxy_set_header    X-Forwarded-For    $proxy_add_x_forwarded_for;
    proxy_set_header    X-Forwarded-Host   $host;
    proxy_set_header    X-Forwarded-Server $host;
    proxy_set_header    X-Forwarded-Port   $server_port;
    proxy_set_header    X-Forwarded-Proto  $scheme;

    rewrite .* /index.html break;
  }

Spring Boot Filter

private static String getClientIpAddr(HttpServletRequest request) {
        String ip = request.getHeader("X-Forwarded-For");

        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("Proxy-Client-IP");
        }
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("WL-Proxy-Client-IP");
        }
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("HTTP_CLIENT_IP");
        }
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("HTTP_X_FORWARDED_FOR");
        }
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("X-Real-IP");
        }
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("X-Client-IP");
        }
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getRemoteAddr();
        }

        return ip;
    }

All of these return null apart from request.getRemoteAddr() (which returns the loadbalancer IP).

Kubernetes Setup

kind: Deployment
apiVersion: apps/v1
metadata:
  name: example-webapp-frontend-deployment
spec:
  revisionHistoryLimit: 3
  minReadySeconds: 30
  replicas: 1
  strategy:
    type: RollingUpdate
    rollingUpdate:
      maxSurge: 1
      maxUnavailable: 0
  selector:
    matchLabels:
      app: example-webapp-frontend
  template:
    metadata:
      labels:
        app: example-webapp-frontend
    spec:
      restartPolicy: Always
      containers:
        - name: example-webapp-frontend
          image: docker-example/example-webapp-frontend:latest
          imagePullPolicy: Always
          ports:
            - containerPort: 80
      imagePullSecrets:
        - name: docker-creds

---

apiVersion: v1
kind: Service
metadata:
  name: example-webapp-frontend-service
spec:
  selector:
    app: example-webapp-frontend
  ports:
    - protocol: TCP
      targetPort: 80
      port: 80

---

kind: Deployment
apiVersion: apps/v1
metadata:
  name: example-webapp-bff-deployment
spec:
  revisionHistoryLimit: 3
  minReadySeconds: 30
  replicas: 1
  strategy:
    type: RollingUpdate
    rollingUpdate:
      maxSurge: 1
      maxUnavailable: 0
  selector:
    matchLabels:
      app: example-webapp-bff
  template:
    metadata:
      labels:
        app: example-webapp-bff
    spec:
      restartPolicy: Always
      containers:
        - name: example-webapp-bff
          image: docker-example/example-webapp-bff:latest
          imagePullPolicy: Always
          ports:
            - containerPort: 9874
      imagePullSecrets:
        - name: docker-creds

---

apiVersion: v1
kind: Service
metadata:
  name: example-webapp-bff-service
spec:
  selector:
    app: example-webapp-bff
  ports:
    - protocol: TCP
      targetPort: 9874
      port: 9874

---

    apiVersion: extensions/v1beta1
    kind: Ingress
    metadata:
      annotations:
        kubernetes.io/ingress.class: "nginx"
        nginx.ingress.kubernetes.io/proxy-read-timeout: "12h"
        nginx.ingress.kubernetes.io/ssl-redirect: "true"
        nginx.ingress.kubernetes.io/force-ssl-redirect: "true"
      name: webapp-ingress
      namespace: default
    spec:
      tls:
        - hosts:
            - example.com
          secretName: example-tls
      rules:
        - host: example.com
          http:
            paths:
              - path: /
                backend:
                  serviceName: webapp-frontend-service
                  servicePort: 80
        - host: example.com
          http:
            paths:
              - path: /api/
                backend:
                  serviceName: webapp-bff-service
                  servicePort: 9874

Spring Boot Config

server.forward-headers-strategy=NATIVE
server.tomcat.remote-ip-header=x-forwarded-for
server.tomcat.internal-proxies="\
              10\\.\\d{1,3}\\.\\d{1,3}\\.\\d{1,3}|\
              192\\.168\\.\\d{1,3}\\.\\d{1,3}|\
              169\\.254\\.\\d{1,3}\\.\\d{1,3}|\
              127\\.\\d{1,3}\\.\\d{1,3}\\.\\d{1,3}|\
              172\\.1[6-9]{1}\\.\\d{1,3}\\.\\d{1,3}|\
              172\\.2[0-9]{1}\\.\\d{1,3}\\.\\d{1,3}|\
              172\\.3[0-1]{1}\\.\\d{1,3}\\.\\d{1,3}\
              172\\.3[0-1]{1}\\.\\d{1,3}\\.\\d{1,3}\
              <digital-ocean-droplet-IP>\
              <digital-ocean-droplet-IP>\
              <digital-ocean-loadbalancer-IP>"

Digital Ocean Kubernetes Config

I have a cluster that has a single pool of two nodes. I have a Digital Ocean load balancer that sits in front of it. Currently running version 1.17.5.,

Anyone able to provide suggestions? Thanks in advance.