From ec28539e43b681f17b3dfa1aaaf0838f97ee4dc5 Mon Sep 17 00:00:00 2001
From: Conor Landry <conor.landry@shopify.com>
Date: Tue, 13 Nov 2018 13:20:15 -0500
Subject: [PATCH] bugfix: do not merge catch-all canary backends with itself

---
 internal/ingress/controller/controller.go | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/internal/ingress/controller/controller.go b/internal/ingress/controller/controller.go
index 62143ac55..3247e3ece 100644
--- a/internal/ingress/controller/controller.go
+++ b/internal/ingress/controller/controller.go
@@ -1008,13 +1008,15 @@ func mergeAlternativeBackends(ing *extensions.Ingress, upstreams map[string]*ing
 
 		ups := upstreams[upsName]
 
-		defLoc := servers[defServerName].Locations[0]
+		for _, defLoc := range servers[defServerName].Locations {
+			if !upstreams[defLoc.Backend].NoServer {
+				glog.Infof("matching backend %v found for alternative backend %v",
+					upstreams[defLoc.Backend].Name, ups.Name)
 
-		glog.Infof("matching backend %v found for alternative backend %v",
-			upstreams[defLoc.Backend].Name, ups.Name)
-
-		upstreams[defLoc.Backend].AlternativeBackends =
-			append(upstreams[defLoc.Backend].AlternativeBackends, ups.Name)
+				upstreams[defLoc.Backend].AlternativeBackends =
+					append(upstreams[defLoc.Backend].AlternativeBackends, ups.Name)
+			}
+		}
 	}
 
 	for _, rule := range ing.Spec.Rules {