From 8fea5f8dc5c2dfb59653ef19d3512e0a22e6934a Mon Sep 17 00:00:00 2001
From: Ryan Uber <ru@ryanuber.com>
Date: Mon, 24 Aug 2015 16:56:41 -0700
Subject: [PATCH] consul/state: track highest index when querying services

---
 consul/state/state_store.go      | 23 ++++++++++++++++++++---
 consul/state/state_store_test.go | 16 ++++++++++++++--
 consul/structs/structs.go        |  2 ++
 3 files changed, 36 insertions(+), 5 deletions(-)

diff --git a/consul/state/state_store.go b/consul/state/state_store.go
index 90b6f799d..4ef13fc90 100644
--- a/consul/state/state_store.go
+++ b/consul/state/state_store.go
@@ -157,13 +157,14 @@ func (s *StateStore) NodeServices(nodeID string) (*structs.NodeServices, error)
 	defer tx.Abort()
 
 	// Query the node
-	node, err := tx.First("nodes", "id", nodeID)
+	n, err := tx.First("nodes", "id", nodeID)
 	if err != nil {
 		return nil, fmt.Errorf("node lookup failed: %s", err)
 	}
-	if node == nil {
+	if n == nil {
 		return nil, nil
 	}
+	node := n.(*structs.Node)
 
 	// Read all of the services
 	services, err := tx.Get("services", "node", nodeID)
@@ -173,13 +174,25 @@ func (s *StateStore) NodeServices(nodeID string) (*structs.NodeServices, error)
 
 	// Initialize the node services struct
 	ns := &structs.NodeServices{
-		Node:     *node.(*structs.Node),
+		Node:     *node,
 		Services: make(map[string]*structs.NodeService),
 	}
+	ns.CreateIndex = node.CreateIndex
+	ns.CreateIndex = node.CreateIndex
 
 	// Add all of the services to the map
 	for service := services.Next(); service != nil; service = services.Next() {
 		sn := service.(*structs.ServiceNode)
+
+		// Track the highest index
+		if sn.CreateIndex > ns.CreateIndex {
+			ns.CreateIndex = sn.CreateIndex
+		}
+		if sn.ModifyIndex > ns.ModifyIndex {
+			ns.ModifyIndex = sn.ModifyIndex
+		}
+
+		// Create the NodeService
 		svc := &structs.NodeService{
 			ID:      sn.ServiceID,
 			Service: sn.ServiceName,
@@ -187,6 +200,10 @@ func (s *StateStore) NodeServices(nodeID string) (*structs.NodeServices, error)
 			Address: sn.ServiceAddress,
 			Port:    sn.ServicePort,
 		}
+		svc.CreateIndex = sn.CreateIndex
+		svc.ModifyIndex = sn.ModifyIndex
+
+		// Add the service to the result
 		ns.Services[svc.ID] = svc
 	}
 
diff --git a/consul/state/state_store_test.go b/consul/state/state_store_test.go
index 94c8a4636..c133a87db 100644
--- a/consul/state/state_store_test.go
+++ b/consul/state/state_store_test.go
@@ -142,10 +142,22 @@ func TestStateStore_EnsureService_NodeServices(t *testing.T) {
 	if out == nil || len(out.Services) != 2 {
 		t.Fatalf("bad services: %#v", out)
 	}
-	if svc := out.Services["service1"]; !reflect.DeepEqual(ns1, svc) {
+
+	// Results match the inserted services and have the proper indexes set
+	expect1 := *ns1
+	expect1.CreateIndex, expect1.ModifyIndex = 10, 10
+	if svc := out.Services["service1"]; !reflect.DeepEqual(&expect1, svc) {
 		t.Fatalf("bad: %#v", svc)
 	}
-	if svc := out.Services["service2"]; !reflect.DeepEqual(&ns2, svc) {
+
+	expect2 := ns2
+	expect2.CreateIndex, expect2.ModifyIndex = 20, 20
+	if svc := out.Services["service2"]; !reflect.DeepEqual(&expect2, svc) {
 		t.Fatalf("bad: %#v %#v", ns2, svc)
 	}
+
+	// Lastly, ensure that the highest index was preserved.
+	if out.CreateIndex != 20 || out.ModifyIndex != 20 {
+		t.Fatalf("bad index: %d, %d", out.CreateIndex, out.ModifyIndex)
+	}
 }
diff --git a/consul/structs/structs.go b/consul/structs/structs.go
index 213e3af62..586aff168 100644
--- a/consul/structs/structs.go
+++ b/consul/structs/structs.go
@@ -269,6 +269,8 @@ type NodeService struct {
 type NodeServices struct {
 	Node     Node
 	Services map[string]*NodeService
+
+	Index
 }
 
 // HealthCheck represents a single check on a given node