[occm] validate flavor name, fallback on flavor id (kubernetes#1364)

The node.kubernetes.io/instance-type label accepts alphanumeric
characters, '-', '_', and '.' only. If the flavor name contains
invalid characters, the flavor id is used instead.

Signed-off-by: Sean Schneeweiss <sean.schneeweiss@daimler.com>

pkg/cloudprovider/providers/openstack/openstack_instances.go

@@ -29,6 +29,7 @@ import (
 
 	"k8s.io/api/core/v1"
 	"k8s.io/apimachinery/pkg/types"
+	"k8s.io/apimachinery/pkg/util/validation"
 	cloudprovider "k8s.io/cloud-provider"
 	"k8s.io/cloud-provider-openstack/pkg/metrics"
 	"k8s.io/cloud-provider-openstack/pkg/util/errors"
@@ -280,21 +281,38 @@ func srvInstanceType(client *gophercloud.ServiceClient, srv *servers.Server) (st
 	keys := []string{"original_name", "id"}
 	for _, key := range keys {
 		val, found := srv.Flavor[key]
-		if found {
-			flavor, ok := val.(string)
-			if ok {
-				if key == "id" {
-					mc := metrics.NewMetricContext("flavor", "get")
-					f, err := flavors.Get(client, flavor).Extract()
-					if mc.ObserveRequest(err) == nil {
-						return f.Name, nil
-					}
-				}
-				return flavor, nil
+		if !found {
+			continue
+		}
+
+		flavor, ok := val.(string)
+		if !ok {
+			continue
+		}
+
+		if key == "original_name" && isValidLabelValue(flavor) {
+			return flavor, nil
+		}
+
+		// get flavor name by id
+		mc := metrics.NewMetricContext("flavor", "get")
+		f, err := flavors.Get(client, flavor).Extract()
+		if mc.ObserveRequest(err) == nil {
+			if isValidLabelValue(f.Name) {
+				return f.Name, nil
 			}
+			// fallback on flavor id
+			return f.ID, nil
 		}
 	}
-	return "", fmt.Errorf("flavor name/id not found")
+	return "", fmt.Errorf("flavor original_name/id not found")
+}
+
+func isValidLabelValue(v string) bool {
+	if errs := validation.IsValidLabelValue(v); len(errs) != 0 {
+		return false
+	}
+	return true
 }
 
 // If Instances.InstanceID or cloudprovider.GetInstanceProviderID is changed, the regexp should be changed too.