From 5f6a257e0ca0b17a8cddc200a05d11f6d0186872 Mon Sep 17 00:00:00 2001
From: Chanwit Kaewkasi <chanwit@gmail.com>
Date: Mon, 5 Jan 2015 23:54:20 +0700
Subject: [PATCH] report error when two Docker's IDs are duplicated

Signed-off-by: Chanwit Kaewkasi <chanwit@gmail.com>
---
 cluster/cluster.go | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/cluster/cluster.go b/cluster/cluster.go
index 204f1e1d93..28471f1885 100644
--- a/cluster/cluster.go
+++ b/cluster/cluster.go
@@ -48,7 +48,11 @@ func (c *Cluster) AddNode(n *Node) error {
 	c.Lock()
 	defer c.Unlock()
 
-	if _, exists := c.nodes[n.ID]; exists {
+	if old, exists := c.nodes[n.ID]; exists {
+		if old.IP != n.IP {
+			log.Errorf("ID duplicated: %s", n.ID)
+			log.Errorf("IP [%s] and [%s] share the same ID", old.IP, n.IP)
+		}
 		return ErrNodeAlreadyRegistered
 	}