CORS-4220: pass dualstack cluster and service cidrs as comma-separated lists

kube-controller-manager expects the dualstack cluster and service CIDRs
to be passed as comma-separated list arguments [0].

This ensures the dualstack cluster and service cidrs are indeed passed
as comma-separated lists.

References

[0] https://kubernetes.io/docs/concepts/services-networking/dual-stack/#configure-ipv4-ipv6-dual-stack

Author: tthvo

bindata/bootkube/config/bootstrap-config-overrides.yaml

@@ -14,16 +14,16 @@ extendedArguments:
   authorization-kubeconfig:
   - "/etc/kubernetes/secrets/kubeconfig"
   {{if .ClusterCIDR }}
-  cluster-cidr: {{range .ClusterCIDR}}
-  - {{.}}{{end}}
+  cluster-cidr:
+  - {{range $i, $cidr := .ClusterCIDR}}{{if $i}},{{end}}{{$cidr}}{{end}}
   {{end}}
   {{if .ServiceClusterIPRange }}
-  service-cluster-ip-range: {{range .ServiceClusterIPRange}}
-  - {{.}}{{end}}
+  service-cluster-ip-range:
+  - {{range $i, $ipRange := .ServiceClusterIPRange}}{{if $i}},{{end}}{{$ipRange}}{{end}}
   {{end}}
   pv-recycler-pod-template-filepath-nfs: # bootstrap KCM doesn't need recycler templates
   - ""
   pv-recycler-pod-template-filepath-hostpath:
   - ""
   feature-gates: {{range .FeatureGates}}
-    - {{.}}{{end}}
+    - {{.}}{{end}}

pkg/operator/configobservation/network/observe_network.go

@@ -36,7 +36,8 @@ func ObserveClusterCIDRs(genericListers configobserver.Listers, recorder events.
 	}
 
 	if len(clusterCIDRs) > 0 {
-		if err := unstructured.SetNestedStringSlice(observedConfig, clusterCIDRs, clusterCIDRsPath...); err != nil {
+		clusterIPRange := strings.Join(clusterCIDRs, ",")
+		if err := unstructured.SetNestedStringSlice(observedConfig, []string{clusterIPRange}, clusterCIDRsPath...); err != nil {
 			errs = append(errs, err)
 		}
 	}

pkg/operator/configobservation/network/observe_networking_test.go

@@ -25,6 +25,22 @@ func TestObserveClusterCIDRs(t *testing.T) {
 		expectedError   bool
 	}
 	tests := []Test{
+		{
+			"single cluster network",
+			&configv1.Network{
+				ObjectMeta: metav1.ObjectMeta{Name: "cluster"},
+				Status: configv1.NetworkStatus{ClusterNetwork: []configv1.ClusterNetworkEntry{
+					{CIDR: "podCIDR"},
+				}},
+			},
+			map[string]interface{}{},
+			map[string]interface{}{
+				"extendedArguments": map[string]interface{}{
+					"cluster-cidr": []interface{}{"podCIDR"},
+				},
+			},
+			false,
+		},
 		{
 			"clusterNetworks",
 			&configv1.Network{
@@ -37,7 +53,7 @@ func TestObserveClusterCIDRs(t *testing.T) {
 			map[string]interface{}{
 				"extendedArguments": map[string]interface{}{
 					"cluster-cidr": []interface{}{
-						"podCIDR1", "podCIDR2",
+						"podCIDR1,podCIDR2",
 					},
 				},
 			},