Dual-stack docs for Kubernetes 1.20

Signed-off-by: Bridget Kromhout <bridget@kromhout.org>
Co-authored-by: Tim Bannister <tim@scalefactory.com>
Co-authored-by: Lachlan Evenson <lachlan.evenson@microsoft.com>

content/en/examples/service/networking/dual-stack-default-svc.yaml

@@ -2,10 +2,11 @@ apiVersion: v1
 kind: Service
 metadata:
   name: my-service
+  labels:
+    app: MyApp
 spec:
   selector:
     app: MyApp
   ports:
     - protocol: TCP
       port: 80
-      targetPort: 9376

content/en/examples/service/networking/dual-stack-ipfamilies-ipv6.yaml

@@ -2,11 +2,13 @@ apiVersion: v1
 kind: Service
 metadata:
   name: my-service
+  labels:
+    app: MyApp
 spec:
-  ipFamily: IPv4
+  ipFamilies:
+  - IPv6
   selector:
     app: MyApp
   ports:
     - protocol: TCP
       port: 80
-      targetPort: 9376

content/en/examples/service/networking/dual-stack-prefer-ipv6-lb-svc.yaml

@@ -5,11 +5,12 @@ metadata:
   labels:
     app: MyApp
 spec:
-  ipFamily: IPv6
+  ipFamilyPolicy: PreferDualStack
+  ipFamilies:
+  - IPv6
   type: LoadBalancer
   selector:
     app: MyApp
   ports:
     - protocol: TCP
       port: 80
-      targetPort: 9376

content/en/examples/service/networking/dual-stack-preferred-ipfamilies-svc.yaml

@@ -0,0 +1,16 @@
+apiVersion: v1
+kind: Service
+metadata:
+  name: my-service
+  labels:
+    app: MyApp
+spec:
+  ipFamilyPolicy: PreferDualStack
+  ipFamilies:
+  - IPv6
+  - IPv4
+  selector:
+    app: MyApp
+  ports:
+    - protocol: TCP
+      port: 80

content/en/examples/service/networking/dual-stack-preferred-svc.yaml

@@ -0,0 +1,13 @@
+apiVersion: v1
+kind: Service
+metadata:
+  name: my-service
+  labels:
+    app: MyApp
+spec:
+  ipFamilyPolicy: PreferDualStack
+  selector:
+    app: MyApp
+  ports:
+    - protocol: TCP
+      port: 80