Fix ipam reclaim

prog/kube-peers/annotations.go

@@ -73,8 +73,10 @@ const (
 	retryPeriod  = time.Second * 2
 	jitterFactor = 1.0
 
+	// Prefix all our annotation keys with this string so they don't clash with anyone else's
+	KubePeersPrefix = "kube-peers.weave.works/"
 	// KubePeersAnnotationKey is the default annotation key
-	KubePeersAnnotationKey = "kube-peers.weave.works/peers"
+	KubePeersAnnotationKey = KubePeersPrefix + "peers"
 )
 
 func (cml *configMapAnnotations) Init() error {
@@ -130,46 +132,59 @@ func (cml *configMapAnnotations) UpdatePeerList(list peerList) error {
 	return cml.UpdateAnnotation(KubePeersAnnotationKey, string(recordBytes))
 }
 
-func (cml *configMapAnnotations) UpdateAnnotation(key, value string) error {
+// Clean up a string so it meets the Kubernetes requiremements for Annotation keys:
+// name part must consist of alphanumeric characters, '-', '_' or '.', and must
+// start and end with an alphanumeric character (e.g. 'MyName', or 'my.name', or '123-abc')
+func cleanKey(key string) string {
+	buf := []byte(key)
+	for i, c := range buf {
+		if (c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z') || (c >= '0' && c <= '9') || c == '-' || c == '_' || c == '.' || c == '/' {
+			continue
+		}
+		buf[i] = '_'
+	}
+	return string(buf)
+}
+
+func (cml *configMapAnnotations) GetAnnotation(key string) (string, bool) {
+	value, ok := cml.cm.Annotations[cleanKey(key)]
+	return value, ok
+}
+
+func (cml *configMapAnnotations) UpdateAnnotation(key, value string) (err error) {
 	if cml.cm == nil {
 		return errors.New("endpoint not initialized, call Init first")
 	}
-	cm := cml.cm
-	cm.Annotations[key] = value
-	cm, err := cml.Client.ConfigMaps(cml.Namespace).Update(cml.cm)
-	if err == nil {
-		cml.cm = cm
-	}
+	// speculatively change the state, then replace with whatever comes back
+	// from Update(), which will be the latest on the server whatever happened
+	cml.cm.Annotations[cleanKey(key)] = value
+	cml.cm, err = cml.Client.ConfigMaps(cml.Namespace).Update(cml.cm)
 	return err
 }
 
-func (cml *configMapAnnotations) RemoveAnnotation(key string) error {
+func (cml *configMapAnnotations) RemoveAnnotation(key string) (err error) {
 	if cml.cm == nil {
 		return errors.New("endpoint not initialized, call Init first")
 	}
-	cm := cml.cm
-	delete(cm.Annotations, key)
-	cm, err := cml.Client.ConfigMaps(cml.Namespace).Update(cml.cm)
-	if err == nil {
-		cml.cm = cm
-	}
+	// speculatively change the state, then replace with whatever comes back
+	// from Update(), which will be the latest on the server whatever happened
+	delete(cml.cm.Annotations, cleanKey(key))
+	cml.cm, err = cml.Client.ConfigMaps(cml.Namespace).Update(cml.cm)
 	return err
 }
 
-func (cml *configMapAnnotations) RemoveAnnotationsWithValue(valueToRemove string) error {
+func (cml *configMapAnnotations) RemoveAnnotationsWithValue(valueToRemove string) (err error) {
 	if cml.cm == nil {
 		return errors.New("endpoint not initialized, call Init first")
 	}
-	cm := cml.cm
-	for key, value := range cm.Annotations {
+	// speculatively change the state, then replace with whatever comes back
+	// from Update(), which will be the latest on the server whatever happened
+	for key, value := range cml.cm.Annotations {
 		if value == valueToRemove {
-			delete(cm.Annotations, key)
+			delete(cml.cm.Annotations, key) // don't need to clean this key as it came from the map
 		}
 	}
-	cm, err := cml.Client.ConfigMaps(cml.Namespace).Update(cml.cm)
-	if err == nil {
-		cml.cm = cm
-	}
+	cml.cm, err = cml.Client.ConfigMaps(cml.Namespace).Update(cml.cm)
 	return err
 }
 

prog/kube-peers/main.go

@@ -98,6 +98,9 @@ func checkIamInPeerList(cml *configMapAnnotations, c *kubernetes.Clientset, peer
 // Kubernetes, remove it from Weave IPAM
 func reclaimRemovedPeers(weave *weaveapi.Client, cml *configMapAnnotations, nodes []nodeInfo, myPeerName string) error {
 	for {
+		if err := cml.Init(); err != nil {
+			return err
+		}
 		// 1. Compare peers stored in the peerList against all peers reported by k8s now.
 		storedPeerList, err := cml.GetPeerList()
 		if err != nil {
@@ -119,7 +122,7 @@ func reclaimRemovedPeers(weave *weaveapi.Client, cml *configMapAnnotations, node
 			common.Log.Debugln("[kube-peers] Preparing to remove disappeared peer", peer)
 			okToRemove := false
 			// 3. Check if there is an existing annotation with key X
-			if existingAnnotation, found := cml.cm.Annotations[peer.PeerName]; found {
+			if existingAnnotation, found := cml.GetAnnotation(KubePeersPrefix + peer.PeerName); found {
 				common.Log.Debugln("[kube-peers] Existing annotation", existingAnnotation)
 				// 4.   If annotation already contains my identity, ok;
 				if existingAnnotation == myPeerName {
@@ -128,14 +131,16 @@ func reclaimRemovedPeers(weave *weaveapi.Client, cml *configMapAnnotations, node
 			} else {
 				// 5.   If non-existent, write an annotation with key X and contents "my identity"
 				common.Log.Debugln("[kube-peers] Noting I plan to remove ", peer.PeerName)
-				if err := cml.UpdateAnnotation(peer.PeerName, myPeerName); err == nil {
+				if err := cml.UpdateAnnotation(KubePeersPrefix+peer.PeerName, myPeerName); err == nil {
 					okToRemove = true
+				} else {
+					common.Log.Debugln("[kube-peers] error from UpdateAnnotation: ", err)
 				}
 			}
 			if okToRemove {
 				// 6.   If step 4 or 5 succeeded, rmpeer X
 				result, err := weave.RmPeer(peer.PeerName)
-				common.Log.Infoln("[kube-peers] rmpeer of", peer.PeerName, ":", result)
+				common.Log.Infof("[kube-peers] rmpeer of %s: %s", peer.PeerName, result)
 				if err != nil {
 					return err
 				}
@@ -146,15 +151,12 @@ func reclaimRemovedPeers(weave *weaveapi.Client, cml *configMapAnnotations, node
 					}
 					// 7a.    Remove X from peerList
 					storedPeerList.remove(peer.PeerName)
-					common.Log.Infoln("[kube-peers] Removing peer ", peer.PeerName, ". Expecting to remove linked annotation next.")
 					if err := cml.UpdatePeerList(*storedPeerList); err != nil {
 						return err
 					}
-					common.Log.Infoln("[kube-peers] Removing annotation ", peer.PeerName)
 					// 7b.    Remove annotation with key X
-					return cml.RemoveAnnotation(peer.PeerName)
+					return cml.RemoveAnnotation(KubePeersPrefix + peer.PeerName)
 				})
-				common.Log.Debugln("[kube-peers] Finished removal of ", peer.PeerName)
 			}
 			// 8.   If step 5 failed due to optimistic lock conflict, stop: someone else is handling X