Merge pull request #16905 from danwinship/clusternetwork-3.6-vs-3.7-s…

…tage

Automatic merge from submit-queue.

Fix defaulting of legacy ClusterNetwork fields

Backport of #16897

pkg/network/master/master.go

@@ -54,13 +54,16 @@ func Start(networkConfig osconfigapi.MasterNetworkConfig, networkClient networkc
 
 	var err error
 	var clusterNetworkEntries []networkapi.ClusterNetworkEntry
-	for _, cidr := range networkConfig.ClusterNetworks {
-		clusterNetworkEntries = append(clusterNetworkEntries, networkapi.ClusterNetworkEntry{CIDR: cidr.CIDR, HostSubnetLength: cidr.HostSubnetLength})
+	for _, entry := range networkConfig.ClusterNetworks {
+		clusterNetworkEntries = append(clusterNetworkEntries, networkapi.ClusterNetworkEntry{CIDR: entry.CIDR, HostSubnetLength: entry.HostSubnetLength})
 	}
 	master.networkInfo, err = common.ParseNetworkInfo(clusterNetworkEntries, networkConfig.ServiceNetworkCIDR)
 	if err != nil {
 		return err
 	}
+	if len(clusterNetworkEntries) == 0 {
+		panic("No ClusterNetworks set in networkConfig; should have been defaulted in if not configured")
+	}
 
 	configCN := &networkapi.ClusterNetwork{
 		TypeMeta:   metav1.TypeMeta{Kind: "ClusterNetwork"},
@@ -69,6 +72,10 @@ func Start(networkConfig osconfigapi.MasterNetworkConfig, networkClient networkc
 		ClusterNetworks: clusterNetworkEntries,
 		ServiceNetwork:  networkConfig.ServiceNetworkCIDR,
 		PluginName:      networkConfig.NetworkPluginName,
+
+		// Need to set these for backward compat
+		Network:          clusterNetworkEntries[0].CIDR,
+		HostSubnetLength: clusterNetworkEntries[0].HostSubnetLength,
 	}
 	osapivalidation.SetDefaultClusterNetwork(*configCN)