How do i get hostname in the kubernetes pod - go

Question

I have 3 ingress pointing to the same service. In my kubernetes pod, how can i find the hostname and from which subdomain request is coming . my backend code in golang server.
when the request comes to any pod, i want to know from which subdomain(x,y,x) request has come to pod. Currently in the golang code it's giving hostname as pod ip address
kind: Ingress
metadata:
annotations:
ingress.kubernetes.io/browser-xss-filter: 'true'
ingress.kubernetes.io/force-hsts: 'true'
ingress.kubernetes.io/hsts-include-subdomains: 'true'
ingress.kubernetes.io/hsts-max-age: '315360000'
name: test
namespace: test
spec:
rules:
- host: http://x.test.com
http:
paths:
- backend:
serviceName: test-service
servicePort: 8080
path: /
- host: http://y.test.com
http:
paths:
- backend:
serviceName: test-service
servicePort: 8080
path: /
- host: http://z.test.com
http:
paths:
- backend:
serviceName: test-service
servicePort: 8080
path: /
func Subdomain( r *http.Request) {
host := r.URL.Host
host = strings.TrimSpace(host)
//Figure out if a subdomain exists in the host given.
host_parts := strings.Split(host, ".")
if len(host_parts) > 2 {
//The subdomain exists, we store it as the first element
//in a new array
subdomain := []string{host_parts[0]}
}
}

Answer 1

Try to use the X-Forwarded-Host header added by the ingress controller