Ignore server for container with empty IP address.

provider/rancher/config.go

@@ -166,6 +166,11 @@ func getServers(service rancherData) map[string]types.Server {
 	var servers map[string]types.Server
 
 	for index, ip := range service.Containers {
+		if len(ip) == 0 {
+			log.Warnf("Unable to find the IP address for a container in the service %q: this container is ignored.", service.Name)
+			continue
+		}
+
 		if servers == nil {
 			servers = make(map[string]types.Server)
 		}

provider/rancher/config_test.go

@@ -832,6 +832,18 @@ func TestGetServers(t *testing.T) {
 			},
 			expected: nil,
 		},
+		{
+			desc: "should return nil when no server IPs",
+			service: rancherData{
+				Labels: map[string]string{
+					label.TraefikWeight: "7",
+				},
+				Containers: []string{""},
+				Health:     "healthy",
+				State:      "active",
+			},
+			expected: nil,
+		},
 		{
 			desc: "should use default weight when invalid weight value",
 			service: rancherData{