From 06f3793f0525b6571dd1282d6ceb69189fb347ee Mon Sep 17 00:00:00 2001
From: Bryan Boreham <bjboreham@gmail.com>
Date: Fri, 12 Feb 2016 10:19:07 +0000
Subject: [PATCH] Remove persisted IPAM ring data on peerName change

---
 ipam/allocator.go | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/ipam/allocator.go b/ipam/allocator.go
index 7d4d4096..4d758f36 100644
--- a/ipam/allocator.go
+++ b/ipam/allocator.go
@@ -768,15 +768,31 @@ func (alloc *Allocator) reportFreeSpace() {
 // Persisting the Ring
 const (
 	ringIdent = "ring"
+	nameIdent = "peername"
 )
 
 func (alloc *Allocator) persistRing() {
+	// It would be better if these two Save operations happened in the same transaction
+	if err := alloc.db.Save(nameIdent, alloc.ourName); err != nil {
+		common.Log.Errorf("Error persisting ring data: %s", err)
+		return
+	}
 	if err := alloc.db.Save(ringIdent, alloc.ring); err != nil {
 		common.Log.Errorf("Error persisting ring data: %s", err)
 	}
 }
 
 func (alloc *Allocator) loadPersistedRing() {
+	var checkPeerName mesh.PeerName
+	if err := alloc.db.Load(nameIdent, &checkPeerName); err != nil {
+		common.Log.Errorf("Error loading persisted peer name: %s", err)
+		return
+	}
+	if checkPeerName != alloc.ourName {
+		alloc.infof("Deleting persisted data for peername %s", checkPeerName)
+		alloc.persistRing()
+		return
+	}
 	if err := alloc.db.Load(ringIdent, &alloc.ring); err != nil {
 		common.Log.Errorf("Error loading persisted ring data: %s", err)
 	}