Add SameSite=None support and conditionally omit SameSite=None for backwards compatibility

docs/examples/affinity/cookie/ingress-samesite.yaml

@@ -0,0 +1,40 @@
+apiVersion: networking.k8s.io/v1beta1
+kind: Ingress
+metadata:
+  name: cookie-samesite-none
+  annotations:
+    nginx.ingress.kubernetes.io/affinity: "cookie"
+    nginx.ingress.kubernetes.io/session-cookie-name: "SSNONE"
+    nginx.ingress.kubernetes.io/session-cookie-expires: "172800"
+    nginx.ingress.kubernetes.io/session-cookie-max-age: "172800"
+    nginx.ingress.kubernetes.io/session-cookie-samesite: "None"
+    nginx.ingress.kubernetes.io/session-cookie-conditional-samesite-none: "true" # omits SameSite=None for older browsers which reject cookies with SameSite=None
+spec:
+  rules:
+  - host: stickyingress-samesite-none.example.com
+    http:
+      paths:
+      - backend:
+          serviceName: http-svc
+          servicePort: 80
+        path: /
+---
+apiVersion: networking.k8s.io/v1beta1
+kind: Ingress
+metadata:
+  name: cookie-samesite-strict
+  annotations:
+    nginx.ingress.kubernetes.io/affinity: "cookie"
+    nginx.ingress.kubernetes.io/session-cookie-name: "STRICTCOOKIENAME"
+    nginx.ingress.kubernetes.io/session-cookie-expires: "172800"
+    nginx.ingress.kubernetes.io/session-cookie-max-age: "172800"
+    nginx.ingress.kubernetes.io/session-cookie-samesite: "Strict"
+spec:
+  rules:
+  - host: stickyingress-samesite-strict.example.com
+    http:
+      paths:
+      - backend:
+          serviceName: http-svc
+          servicePort: 80
+        path: /