"Key" backwards compatibility for overlay templates

internal/pkg/overlay/overlay.go

@@ -39,6 +39,7 @@ type TemplateStruct struct {
 	SystemOverlay  string
 	NetDevs        map[string]*node.NetDevs
 	Tags           map[string]string
+	Keys           map[string]string
 	AllNodes       []node.NodeInfo
 	NFSMounts      []string
 }
@@ -208,6 +209,10 @@ func BuildOverlay(nodeInfo node.NodeInfo, overlayName string) error {
 		tstruct.NetDevs[devname].IpCIDR = netaddr.String()
 
 	}
+	// Backwards compatibility for templates using "Keys"
+	for keyname, key := range nodeInfo.Tags {
+		tstruct.Keys[keyname] = key.Get()
+	}
 	for keyname, key := range nodeInfo.Tags {
 		tstruct.Tags[keyname] = key.Get()
 	}