feat: add dual-stack support

Makefile

@@ -262,6 +262,7 @@ create-management-cluster: $(KUSTOMIZE) $(ENVSUBST) ## Create a management clust
 	# apply CNI ClusterResourceSets
 	kubectl create configmap calico-addon --from-file=templates/addons/calico.yaml
 	kubectl create configmap calico-ipv6-addon --from-file=templates/addons/calico-ipv6.yaml
+	kubectl create configmap calico-dual-stack-addon --from-file=templates/addons/calico-dual-stack.yaml
 	kubectl create configmap calico-windows-addon --from-file=templates/addons/windows/calico
 	kubectl create configmap flannel-windows-addon --from-file=templates/addons/windows/flannel
 
@@ -455,6 +456,7 @@ generate-addons: fetch-calico-manifests ## Generate metric-server, calico calico
 	$(KUSTOMIZE) build $(ADDONS_DIR)/metrics-server > $(ADDONS_DIR)/metrics-server/metrics-server.yaml
 	$(KUSTOMIZE) build $(ADDONS_DIR)/calico > $(ADDONS_DIR)/calico.yaml
 	$(KUSTOMIZE) build $(ADDONS_DIR)/calico-ipv6 > $(ADDONS_DIR)/calico-ipv6.yaml
+	$(KUSTOMIZE) build $(ADDONS_DIR)/calico-dual-stack > $(ADDONS_DIR)/calico-dual-stack.yaml
 
 # When updating this, make sure to also update the Windows image version in templates/addons/windows/calico.
 CALICO_VERSION := v3.22.1

docs/book/src/topics/dual-stack.md

@@ -0,0 +1,69 @@
+# Dual-stack clusters
+
+## Overview
+
+CAPZ enables you to create [dual-stack](https://kubernetes.io/docs/concepts/services-networking/dual-stack/) Kubernetes cluster on Microsoft Azure.
+
+- Dual-stack support is available for Kubernetes version 1.21.0 and later on Azure.
+
+To deploy a cluster using dual-stack, use the [dual-stack flavor template](../../../../templates/cluster-template-dual-stack.yaml).
+
+Things to try out after the cluster created:
+
+- Nodes have 2 internal IPs, one from each IP family.
+
+```bash
+kubectl get node <node name> -o go-template --template='{{range .status.addresses}}{{printf "%s: %s \n" .type .address}}{{end}}'
+Hostname: capi-dual-stack-md-0-j96nr 
+InternalIP: 10.1.0.4 
+InternalIP: 2001:1234:5678:9abd::4 
+```
+
+- Nodes have 2 `PodCIDRs`, one from each IP family.
+
+```bash
+kubectl get node <node name> -o go-template --template='{{range .spec.podCIDRs}}{{printf "%s\n" .}}{{end}}'
+10.244.2.0/24
+2001:1234:5678:9a42::/64
+```
+
+- Pods have 2 `PodIP`, one from each IP family.
+
+```bash
+kubectl get pods <pod name> -o go-template --template='{{range .status.podIPs}}{{printf "%s \n" .ip}}{{end}}' 
+10.244.2.37 
+2001:1234:5678:9a42::25 
+```
+
+- Able to reach other pods in cluster using IPv4 and IPv6.
+
+```bash
+# inside the nginx-pod
+/ # ifconfig eth0
+eth0      Link encap:Ethernet  HWaddr 8A:B2:32:92:4F:87
+          inet addr:10.244.2.2  Bcast:0.0.0.0  Mask:255.255.255.255
+          inet6 addr: 2001:1234:5678:9a42::2/128 Scope:Global
+          inet6 addr: fe80::88b2:32ff:fe92:4f87/64 Scope:Link
+          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
+          RX packets:9 errors:0 dropped:0 overruns:0 frame:0
+          TX packets:10 errors:0 dropped:1 overruns:0 carrier:0
+          collisions:0 txqueuelen:0
+          RX bytes:906 (906.0 B)  TX bytes:840 (840.0 B)
+
+/ # ping -c 2 10.244.1.2
+PING 10.244.1.2 (10.244.1.2): 56 data bytes
+64 bytes from 10.244.1.2: seq=0 ttl=62 time=1.366 ms
+64 bytes from 10.244.1.2: seq=1 ttl=62 time=1.396 ms
+
+--- 10.244.1.2 ping statistics ---
+2 packets transmitted, 2 packets received, 0% packet loss
+round-trip min/avg/max = 1.366/1.381/1.396 ms
+/ # ping -c 2 2001:1234:5678:9a41::2
+PING 2001:1234:5678:9a41::2 (2001:1234:5678:9a41::2): 56 data bytes
+64 bytes from 2001:1234:5678:9a41::2: seq=0 ttl=62 time=1.264 ms
+64 bytes from 2001:1234:5678:9a41::2: seq=1 ttl=62 time=1.233 ms
+
+--- 2001:1234:5678:9a41::2 ping statistics ---
+2 packets transmitted, 2 packets received, 0% packet loss
+round-trip min/avg/max = 1.233/1.248/1.264 ms
+```