K8S Ingress showing how to block access based on the client's User-Agent

ingress-ua-blocking.yaml

---
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: web-app-ingress
  annotations:
    nginx.ingress.kubernetes.io/configuration-snippet: |
      if ($http_user_agent = "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_3) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/80.0.3987.132 Safari/537.36" ) {
          # use more_set_headers here instead of add_header for kubernetes(openresty).
          more_set_headers "Content-Type: application/json";      
          return 426 '{"error":"please upgrade your client"}';
      }
  labels:
    k8s-app: web-app
spec:
  rules:
  - host: "mysite.com"
    http: &http_rule
      paths:
      - path: /the/path/you/want/to/block/traffic/based/on/user-agent
        backend:
          serviceName: web-app-svc
          servicePort: 8080
  tls: 
    - hosts:
        - "mysite.com"
      secretName: letsencrypt-prod