Poll and notice changes to cluster UID

controllers/gce/utils/utils.go

@@ -20,6 +20,7 @@ import (
 	"fmt"
 	"strconv"
 	"strings"
+	"sync"
 
 	"github.com/golang/glog"
 	compute "google.golang.org/api/compute/v1"
@@ -82,7 +83,42 @@ const (
 
 // Namer handles centralized naming for the cluster.
 type Namer struct {
-	ClusterName string
+	clusterName string
+	nameLock    sync.Mutex
+}
+
+// NewNamer creates a new namer.
+func NewNamer(clusterName string) *Namer {
+	namer := &Namer{}
+	namer.SetClusterName(clusterName)
+	return namer
+}
+
+// NameComponents is a struct representing the components of a a GCE resource
+// name constructed by the namer. The format of such a name is:
+// k8s-resource-<metadata, eg port>--uid
+type NameComponents struct {
+	ClusterName, Resource, Metadata string
+}
+
+// SetClusterName sets the UID/name of this cluster.
+func (n *Namer) SetClusterName(name string) {
+	n.nameLock.Lock()
+	defer n.nameLock.Unlock()
+	if strings.Contains(name, clusterNameDelimiter) {
+		tokens := strings.Split(name, clusterNameDelimiter)
+		glog.Warningf("Given name %v contains %v, taking last token in: %+v", name, clusterNameDelimiter, tokens)
+		name = tokens[len(tokens)-1]
+	}
+	glog.Infof("Changing cluster name from %v to %v", n.clusterName, name)
+	n.clusterName = name
+}
+
+// GetClusterName returns the UID/name of this cluster.
+func (n *Namer) GetClusterName() string {
+	n.nameLock.Lock()
+	defer n.nameLock.Unlock()
+	return n.clusterName
 }
 
 // Truncate truncates the given key to a GCE length limit.
@@ -96,10 +132,28 @@ func (n *Namer) Truncate(key string) string {
 }
 
 func (n *Namer) decorateName(name string) string {
-	if n.ClusterName == "" {
+	clusterName := n.GetClusterName()
+	if clusterName == "" {
 		return name
 	}
-	return n.Truncate(fmt.Sprintf("%v%v%v", name, clusterNameDelimiter, n.ClusterName))
+	return n.Truncate(fmt.Sprintf("%v%v%v", name, clusterNameDelimiter, clusterName))
+}
+
+// ParseName parses the name of a resource generated by the namer.
+func (n *Namer) ParseName(name string) *NameComponents {
+	l := strings.Split(name, clusterNameDelimiter)
+	var uid, resource string
+	if len(l) >= 2 {
+		uid = l[len(l)-1]
+	}
+	c := strings.Split(name, "-")
+	if len(c) >= 2 {
+		resource = c[1]
+	}
+	return &NameComponents{
+		ClusterName: uid,
+		Resource:    resource,
+	}
 }
 
 // NameBelongsToCluster checks if a given name is tagged with this cluster's UID.
@@ -109,8 +163,9 @@ func (n *Namer) NameBelongsToCluster(name string) bool {
 		return false
 	}
 	parts := strings.Split(name, clusterNameDelimiter)
+	clusterName := n.GetClusterName()
 	if len(parts) == 1 {
-		if n.ClusterName == "" {
+		if clusterName == "" {
 			return true
 		}
 		return false
@@ -119,7 +174,7 @@ func (n *Namer) NameBelongsToCluster(name string) bool {
 		glog.Warningf("Too many parts to name %v, ignoring", name)
 		return false
 	}
-	return parts[1] == n.ClusterName
+	return parts[1] == clusterName
 }
 
 // BeName constructs the name for a backend.
@@ -152,11 +207,12 @@ func (n *Namer) IGName() string {
 
 // FrSuffix constructs the glbc specific suffix for the FirewallRule.
 func (n *Namer) FrSuffix() string {
+	clusterName := n.GetClusterName()
 	// The entire cluster only needs a single firewall rule.
-	if n.ClusterName == "" {
+	if clusterName == "" {
 		return globalFirewallSuffix
 	}
-	return n.Truncate(fmt.Sprintf("%v%v%v", globalFirewallSuffix, clusterNameDelimiter, n.ClusterName))
+	return n.Truncate(fmt.Sprintf("%v%v%v", globalFirewallSuffix, clusterNameDelimiter, clusterName))
 }
 
 // FrName constructs the full firewall rule name, this is the name assigned by
@@ -174,10 +230,11 @@ func (n *Namer) LBName(key string) string {
 	// namespace conflicts in the Ubernetes context.
 	parts := strings.Split(key, clusterNameDelimiter)
 	scrubbedName := strings.Replace(key, "/", "-", -1)
-	if n.ClusterName == "" || parts[len(parts)-1] == n.ClusterName {
+	clusterName := n.GetClusterName()
+	if clusterName == "" || parts[len(parts)-1] == clusterName {
 		return scrubbedName
 	}
-	return n.Truncate(fmt.Sprintf("%v%v%v", scrubbedName, clusterNameDelimiter, n.ClusterName))
+	return n.Truncate(fmt.Sprintf("%v%v%v", scrubbedName, clusterNameDelimiter, clusterName))
 }
 
 // GCEURLMap is a nested map of hostname->path regex->backend