Google Cloud TCP Load Balancer forward ip

Question

I use Google Cloud TCP load balancer forwarding requests to a Kubernetes NGINX service. As expected the logs on the NGINX show the Load Balancer IP. How can I retrieve the actual IP

Answer 1

Use $http_x_forwarded_for variable to log the original ip of user.

Answer 2

The forwarded headers from the Load Balancer are

X-Forwarded-For
X-Forwarded-Proto

Thus on nginx "$http_x_forwarded_for" shall be used

location / {
  ...
  proxy_set_header  X-Forwarded-For  $proxy_add_x_forwarded_for;
  ...
}

If you are using Kubernetes and services you need to set the extrernal traffic policy to local

kind: Service
apiVersion: v1
metadata:
  name: proxy-service
spec:
  selector:
    app: the-application
  type: LoadBalancer
  externalTrafficPolicy: Local
  ports:
  - protocol: TCP
    port: 443
    targetPort: 443
    name: https