From 283c5d1be1d950a2c35970a1833b2db2a48e9731 Mon Sep 17 00:00:00 2001
From: Armon Dadgar <armon.dadgar@gmail.com>
Date: Thu, 3 Apr 2014 11:23:55 -0700
Subject: [PATCH 1/8] consul: Replace single tag with list of tags

---
 consul/structs/structs.go | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/consul/structs/structs.go b/consul/structs/structs.go
index 638749cfc0..5c11801a7f 100644
--- a/consul/structs/structs.go
+++ b/consul/structs/structs.go
@@ -105,7 +105,7 @@ type ServiceNode struct {
 	Address     string
 	ServiceID   string
 	ServiceName string
-	ServiceTag  string
+	ServiceTags []string
 	ServicePort int
 }
 type ServiceNodes []ServiceNode
@@ -114,7 +114,7 @@ type ServiceNodes []ServiceNode
 type NodeService struct {
 	ID      string
 	Service string
-	Tag     string
+	Tags    []string
 	Port    int
 }
 type NodeServices struct {

From 13bff3a09bf9ef88295feecd9ab67188be787a88 Mon Sep 17 00:00:00 2001
From: Armon Dadgar <armon.dadgar@gmail.com>
Date: Thu, 3 Apr 2014 12:03:02 -0700
Subject: [PATCH 2/8] consul: Change state store to support multiple tags

---
 consul/state_store.go | 44 +++++++++++++++++++++++++++++++------------
 1 file changed, 32 insertions(+), 12 deletions(-)

diff --git a/consul/state_store.go b/consul/state_store.go
index 4b08c04640..8962b0e0b0 100644
--- a/consul/state_store.go
+++ b/consul/state_store.go
@@ -145,7 +145,7 @@ func (s *StateStore) initialize() error {
 			},
 			"service": &MDBIndex{
 				AllowBlank: true,
-				Fields:     []string{"ServiceName", "ServiceTag"},
+				Fields:     []string{"ServiceName"},
 			},
 		},
 		Decoder: func(buf []byte) interface{} {
@@ -318,7 +318,7 @@ func (s *StateStore) EnsureService(index uint64, node string, ns *structs.NodeSe
 		Node:        node,
 		ServiceID:   ns.ID,
 		ServiceName: ns.Service,
-		ServiceTag:  ns.Tag,
+		ServiceTags: ns.Tags,
 		ServicePort: ns.Port,
 	}
 
@@ -382,7 +382,7 @@ func (s *StateStore) parseNodeServices(tables MDBTables, tx *MDBTxn, name string
 		srv := &structs.NodeService{
 			ID:      service.ServiceID,
 			Service: service.ServiceName,
-			Tag:     service.ServiceTag,
+			Tags:    service.ServiceTags,
 			Port:    service.ServicePort,
 		}
 		ns.Services[srv.ID] = srv
@@ -456,8 +456,6 @@ func (s *StateStore) DeleteNode(index uint64, node string) error {
 
 // Services is used to return all the services with a list of associated tags
 func (s *StateStore) Services() (uint64, map[string][]string) {
-	// TODO: Optimize to not table scan.. We can do a distinct
-	// type of query to avoid this
 	services := make(map[string][]string)
 	idx, res, err := s.serviceTable.Get("id")
 	if err != nil {
@@ -466,12 +464,17 @@ func (s *StateStore) Services() (uint64, map[string][]string) {
 	}
 	for _, r := range res {
 		srv := r.(*structs.ServiceNode)
-
-		tags := services[srv.ServiceName]
-		if !strContains(tags, srv.ServiceTag) {
-			tags = append(tags, srv.ServiceTag)
+		tags, ok := services[srv.ServiceName]
+		if !ok {
 			services[srv.ServiceName] = tags
 		}
+
+		for _, tag := range srv.ServiceTags {
+			if !strContains(tags, tag) {
+				tags = append(tags, tag)
+				services[srv.ServiceName] = tags
+			}
+		}
 	}
 	return idx, services
 }
@@ -508,10 +511,26 @@ func (s *StateStore) ServiceTagNodes(service, tag string) (uint64, structs.Servi
 		panic(fmt.Errorf("Failed to get last index: %v", err))
 	}
 
-	res, err := s.serviceTable.GetTxn(tx, "service", service, tag)
+	res, err := s.serviceTable.GetTxn(tx, "service", service)
+	res = serviceTagFilter(res, tag)
 	return idx, s.parseServiceNodes(tx, s.nodeTable, res, err)
 }
 
+// serviceTagFilter is used to filter a list of *structs.ServiceNode which do
+// not have the specified tag
+func serviceTagFilter(l []interface{}, tag string) []interface{} {
+	n := len(l)
+	for i := 0; i < n; i++ {
+		srv := l[i].(*structs.ServiceNode)
+		if !strContains(srv.ServiceTags, tag) {
+			l[i], l[n-1] = l[n-1], nil
+			i--
+			n--
+		}
+	}
+	return l[:n]
+}
+
 // parseServiceNodes parses results ServiceNodes and ServiceTagNodes
 func (s *StateStore) parseServiceNodes(tx *MDBTxn, table *MDBTable, res []interface{}, err error) structs.ServiceNodes {
 	nodes := make(structs.ServiceNodes, len(res))
@@ -668,7 +687,8 @@ func (s *StateStore) CheckServiceTagNodes(service, tag string) (uint64, structs.
 		panic(fmt.Errorf("Failed to get last index: %v", err))
 	}
 
-	res, err := s.serviceTable.GetTxn(tx, "service", service, tag)
+	res, err := s.serviceTable.GetTxn(tx, "service", service)
+	res = serviceTagFilter(res, tag)
 	return idx, s.parseCheckServiceNodes(tx, res, err)
 }
 
@@ -704,7 +724,7 @@ func (s *StateStore) parseCheckServiceNodes(tx *MDBTxn, res []interface{}, err e
 		nodes[i].Service = structs.NodeService{
 			ID:      srv.ServiceID,
 			Service: srv.ServiceName,
-			Tag:     srv.ServiceTag,
+			Tags:    srv.ServiceTags,
 			Port:    srv.ServicePort,
 		}
 		nodes[i].Checks = checks

From 4a1faf435c1e0795b95a842017afb3101041ddb5 Mon Sep 17 00:00:00 2001
From: Armon Dadgar <armon.dadgar@gmail.com>
Date: Thu, 3 Apr 2014 12:03:10 -0700
Subject: [PATCH 3/8] consul: Updating all the tests

---
 consul/catalog_endpoint_test.go | 24 ++++-----
 consul/fsm_test.go              | 16 +++---
 consul/health_endpoint_test.go  |  8 +--
 consul/state_store_test.go      | 96 ++++++++++++++++-----------------
 4 files changed, 72 insertions(+), 72 deletions(-)

diff --git a/consul/catalog_endpoint_test.go b/consul/catalog_endpoint_test.go
index 9ebd079d1f..1184d6ddb5 100644
--- a/consul/catalog_endpoint_test.go
+++ b/consul/catalog_endpoint_test.go
@@ -23,7 +23,7 @@ func TestCatalogRegister(t *testing.T) {
 		Address:    "127.0.0.1",
 		Service: &structs.NodeService{
 			Service: "db",
-			Tag:     "master",
+			Tags:    []string{"master"},
 			Port:    8000,
 		},
 	}
@@ -79,7 +79,7 @@ func TestCatalogRegister_ForwardLeader(t *testing.T) {
 		Address:    "127.0.0.1",
 		Service: &structs.NodeService{
 			Service: "db",
-			Tag:     "master",
+			Tags:    []string{"master"},
 			Port:    8000,
 		},
 	}
@@ -116,7 +116,7 @@ func TestCatalogRegister_ForwardDC(t *testing.T) {
 		Address:    "127.0.0.1",
 		Service: &structs.NodeService{
 			Service: "db",
-			Tag:     "master",
+			Tags:    []string{"master"},
 			Port:    8000,
 		},
 	}
@@ -277,7 +277,7 @@ func TestCatalogListServices(t *testing.T) {
 
 	// Just add a node
 	s1.fsm.State().EnsureNode(1, structs.Node{"foo", "127.0.0.1"})
-	s1.fsm.State().EnsureService(2, "foo", &structs.NodeService{"db", "db", "primary", 5000})
+	s1.fsm.State().EnsureService(2, "foo", &structs.NodeService{"db", "db", []string{"primary"}, 5000})
 
 	if err := client.Call("Catalog.ListServices", &args, &out); err != nil {
 		t.Fatalf("err: %v", err)
@@ -287,7 +287,7 @@ func TestCatalogListServices(t *testing.T) {
 		t.Fatalf("bad: %v", out)
 	}
 	// Consul service should auto-register
-	if len(out.Services["consul"]) != 1 {
+	if _, ok := out.Services["consul"]; !ok {
 		t.Fatalf("bad: %v", out)
 	}
 	if len(out.Services["db"]) != 1 {
@@ -327,7 +327,7 @@ func TestCatalogListServices_Blocking(t *testing.T) {
 	go func() {
 		time.Sleep(100 * time.Millisecond)
 		s1.fsm.State().EnsureNode(1, structs.Node{"foo", "127.0.0.1"})
-		s1.fsm.State().EnsureService(2, "foo", &structs.NodeService{"db", "db", "primary", 5000})
+		s1.fsm.State().EnsureService(2, "foo", &structs.NodeService{"db", "db", []string{"primary"}, 5000})
 	}()
 
 	// Re-run the query
@@ -418,7 +418,7 @@ func TestCatalogListServiceNodes(t *testing.T) {
 
 	// Just add a node
 	s1.fsm.State().EnsureNode(1, structs.Node{"foo", "127.0.0.1"})
-	s1.fsm.State().EnsureService(2, "foo", &structs.NodeService{"db", "db", "primary", 5000})
+	s1.fsm.State().EnsureService(2, "foo", &structs.NodeService{"db", "db", []string{"primary"}, 5000})
 
 	if err := client.Call("Catalog.ServiceNodes", &args, &out); err != nil {
 		t.Fatalf("err: %v", err)
@@ -462,8 +462,8 @@ func TestCatalogNodeServices(t *testing.T) {
 
 	// Just add a node
 	s1.fsm.State().EnsureNode(1, structs.Node{"foo", "127.0.0.1"})
-	s1.fsm.State().EnsureService(2, "foo", &structs.NodeService{"db", "db", "primary", 5000})
-	s1.fsm.State().EnsureService(3, "foo", &structs.NodeService{"web", "web", "", 80})
+	s1.fsm.State().EnsureService(2, "foo", &structs.NodeService{"db", "db", []string{"primary"}, 5000})
+	s1.fsm.State().EnsureService(3, "foo", &structs.NodeService{"web", "web", nil, 80})
 
 	if err := client.Call("Catalog.NodeServices", &args, &out); err != nil {
 		t.Fatalf("err: %v", err)
@@ -476,10 +476,10 @@ func TestCatalogNodeServices(t *testing.T) {
 		t.Fatalf("bad: %v", out)
 	}
 	services := out.NodeServices.Services
-	if services["db"].Tag != "primary" || services["db"].Port != 5000 {
+	if !strContains(services["db"].Tags, "primary") || services["db"].Port != 5000 {
 		t.Fatalf("bad: %v", out)
 	}
-	if services["web"].Tag != "" || services["web"].Port != 80 {
+	if services["web"].Tags != nil || services["web"].Port != 80 {
 		t.Fatalf("bad: %v", out)
 	}
 }
@@ -498,7 +498,7 @@ func TestCatalogRegister_FailedCase1(t *testing.T) {
 		Address:    "127.0.0.2",
 		Service: &structs.NodeService{
 			Service: "web",
-			Tag:     "",
+			Tags:    nil,
 			Port:    8000,
 		},
 	}
diff --git a/consul/fsm_test.go b/consul/fsm_test.go
index 24f7c7cbbf..ac8453bec2 100644
--- a/consul/fsm_test.go
+++ b/consul/fsm_test.go
@@ -85,7 +85,7 @@ func TestFSM_RegisterNode_Service(t *testing.T) {
 		Service: &structs.NodeService{
 			ID:      "db",
 			Service: "db",
-			Tag:     "master",
+			Tags:    []string{"master"},
 			Port:    8000,
 		},
 		Check: &structs.HealthCheck{
@@ -138,7 +138,7 @@ func TestFSM_DeregisterService(t *testing.T) {
 		Service: &structs.NodeService{
 			ID:      "db",
 			Service: "db",
-			Tag:     "master",
+			Tags:    []string{"master"},
 			Port:    8000,
 		},
 	}
@@ -248,7 +248,7 @@ func TestFSM_DeregisterNode(t *testing.T) {
 		Service: &structs.NodeService{
 			ID:      "db",
 			Service: "db",
-			Tag:     "master",
+			Tags:    []string{"master"},
 			Port:    8000,
 		},
 		Check: &structs.HealthCheck{
@@ -311,10 +311,10 @@ func TestFSM_SnapshotRestore(t *testing.T) {
 	// Add some state
 	fsm.state.EnsureNode(1, structs.Node{"foo", "127.0.0.1"})
 	fsm.state.EnsureNode(2, structs.Node{"baz", "127.0.0.2"})
-	fsm.state.EnsureService(3, "foo", &structs.NodeService{"web", "web", "", 80})
-	fsm.state.EnsureService(4, "foo", &structs.NodeService{"db", "db", "primary", 5000})
-	fsm.state.EnsureService(5, "baz", &structs.NodeService{"web", "web", "", 80})
-	fsm.state.EnsureService(6, "baz", &structs.NodeService{"db", "db", "secondary", 5000})
+	fsm.state.EnsureService(3, "foo", &structs.NodeService{"web", "web", nil, 80})
+	fsm.state.EnsureService(4, "foo", &structs.NodeService{"db", "db", []string{"primary"}, 5000})
+	fsm.state.EnsureService(5, "baz", &structs.NodeService{"web", "web", nil, 80})
+	fsm.state.EnsureService(6, "baz", &structs.NodeService{"db", "db", []string{"secondary"}, 5000})
 	fsm.state.EnsureCheck(7, &structs.HealthCheck{
 		Node:      "foo",
 		CheckID:   "web",
@@ -363,7 +363,7 @@ func TestFSM_SnapshotRestore(t *testing.T) {
 	if len(fooSrv.Services) != 2 {
 		t.Fatalf("Bad: %v", fooSrv)
 	}
-	if fooSrv.Services["db"].Tag != "primary" {
+	if !strContains(fooSrv.Services["db"].Tags, "primary") {
 		t.Fatalf("Bad: %v", fooSrv)
 	}
 	if fooSrv.Services["db"].Port != 5000 {
diff --git a/consul/health_endpoint_test.go b/consul/health_endpoint_test.go
index 000b57ee47..465f358467 100644
--- a/consul/health_endpoint_test.go
+++ b/consul/health_endpoint_test.go
@@ -160,7 +160,7 @@ func TestHealth_ServiceNodes(t *testing.T) {
 		Service: &structs.NodeService{
 			ID:      "db",
 			Service: "db",
-			Tag:     "master",
+			Tags:    []string{"master"},
 		},
 		Check: &structs.HealthCheck{
 			Name:      "db connect",
@@ -180,7 +180,7 @@ func TestHealth_ServiceNodes(t *testing.T) {
 		Service: &structs.NodeService{
 			ID:      "db",
 			Service: "db",
-			Tag:     "slave",
+			Tags:    []string{"slave"},
 		},
 		Check: &structs.HealthCheck{
 			Name:      "db connect",
@@ -213,10 +213,10 @@ func TestHealth_ServiceNodes(t *testing.T) {
 	if nodes[1].Node.Node != "bar" {
 		t.Fatalf("Bad: %v", nodes[1])
 	}
-	if nodes[0].Service.Tag != "master" {
+	if !strContains(nodes[0].Service.Tags, "master") {
 		t.Fatalf("Bad: %v", nodes[0])
 	}
-	if nodes[1].Service.Tag != "slave" {
+	if !strContains(nodes[1].Service.Tags, "slave") {
 		t.Fatalf("Bad: %v", nodes[1])
 	}
 	if nodes[0].Checks[0].Status != structs.HealthPassing {
diff --git a/consul/state_store_test.go b/consul/state_store_test.go
index 5e5bf3e8e1..dbdb2bcc23 100644
--- a/consul/state_store_test.go
+++ b/consul/state_store_test.go
@@ -96,15 +96,15 @@ func TestEnsureService(t *testing.T) {
 		t.Fatalf("err: %v", err)
 	}
 
-	if err := store.EnsureService(11, "foo", &structs.NodeService{"api", "api", "", 5000}); err != nil {
+	if err := store.EnsureService(11, "foo", &structs.NodeService{"api", "api", nil, 5000}); err != nil {
 		t.Fatalf("err: %v", err)
 	}
 
-	if err := store.EnsureService(12, "foo", &structs.NodeService{"api", "api", "", 5001}); err != nil {
+	if err := store.EnsureService(12, "foo", &structs.NodeService{"api", "api", nil, 5001}); err != nil {
 		t.Fatalf("err: %v", err)
 	}
 
-	if err := store.EnsureService(13, "foo", &structs.NodeService{"db", "db", "master", 8000}); err != nil {
+	if err := store.EnsureService(13, "foo", &structs.NodeService{"db", "db", []string{"master"}, 8000}); err != nil {
 		t.Fatalf("err: %v", err)
 	}
 
@@ -117,7 +117,7 @@ func TestEnsureService(t *testing.T) {
 	if !ok {
 		t.Fatalf("missing api: %#v", services)
 	}
-	if entry.Tag != "" || entry.Port != 5001 {
+	if entry.Tags != nil || entry.Port != 5001 {
 		t.Fatalf("Bad entry: %#v", entry)
 	}
 
@@ -125,7 +125,7 @@ func TestEnsureService(t *testing.T) {
 	if !ok {
 		t.Fatalf("missing db: %#v", services)
 	}
-	if entry.Tag != "master" || entry.Port != 8000 {
+	if !strContains(entry.Tags, "master") || entry.Port != 8000 {
 		t.Fatalf("Bad entry: %#v", entry)
 	}
 }
@@ -141,15 +141,15 @@ func TestEnsureService_DuplicateNode(t *testing.T) {
 		t.Fatalf("err: %v", err)
 	}
 
-	if err := store.EnsureService(11, "foo", &structs.NodeService{"api1", "api", "", 5000}); err != nil {
+	if err := store.EnsureService(11, "foo", &structs.NodeService{"api1", "api", nil, 5000}); err != nil {
 		t.Fatalf("err: %v", err)
 	}
 
-	if err := store.EnsureService(12, "foo", &structs.NodeService{"api2", "api", "", 5001}); err != nil {
+	if err := store.EnsureService(12, "foo", &structs.NodeService{"api2", "api", nil, 5001}); err != nil {
 		t.Fatalf("err: %v", err)
 	}
 
-	if err := store.EnsureService(13, "foo", &structs.NodeService{"api3", "api", "", 5002}); err != nil {
+	if err := store.EnsureService(13, "foo", &structs.NodeService{"api3", "api", nil, 5002}); err != nil {
 		t.Fatalf("err: %v", err)
 	}
 
@@ -162,7 +162,7 @@ func TestEnsureService_DuplicateNode(t *testing.T) {
 	if !ok {
 		t.Fatalf("missing api: %#v", services)
 	}
-	if entry.Tag != "" || entry.Port != 5000 {
+	if entry.Tags != nil || entry.Port != 5000 {
 		t.Fatalf("Bad entry: %#v", entry)
 	}
 
@@ -170,7 +170,7 @@ func TestEnsureService_DuplicateNode(t *testing.T) {
 	if !ok {
 		t.Fatalf("missing api: %#v", services)
 	}
-	if entry.Tag != "" || entry.Port != 5001 {
+	if entry.Tags != nil || entry.Port != 5001 {
 		t.Fatalf("Bad entry: %#v", entry)
 	}
 
@@ -178,7 +178,7 @@ func TestEnsureService_DuplicateNode(t *testing.T) {
 	if !ok {
 		t.Fatalf("missing api: %#v", services)
 	}
-	if entry.Tag != "" || entry.Port != 5002 {
+	if entry.Tags != nil || entry.Port != 5002 {
 		t.Fatalf("Bad entry: %#v", entry)
 	}
 }
@@ -194,7 +194,7 @@ func TestDeleteNodeService(t *testing.T) {
 		t.Fatalf("err: %v", err)
 	}
 
-	if err := store.EnsureService(12, "foo", &structs.NodeService{"api", "api", "", 5000}); err != nil {
+	if err := store.EnsureService(12, "foo", &structs.NodeService{"api", "api", nil, 5000}); err != nil {
 		t.Fatalf("err: %v", err)
 	}
 
@@ -242,11 +242,11 @@ func TestDeleteNodeService_One(t *testing.T) {
 		t.Fatalf("err: %v", err)
 	}
 
-	if err := store.EnsureService(12, "foo", &structs.NodeService{"api", "api", "", 5000}); err != nil {
+	if err := store.EnsureService(12, "foo", &structs.NodeService{"api", "api", nil, 5000}); err != nil {
 		t.Fatalf("err: %v", err)
 	}
 
-	if err := store.EnsureService(13, "foo", &structs.NodeService{"api2", "api", "", 5001}); err != nil {
+	if err := store.EnsureService(13, "foo", &structs.NodeService{"api2", "api", nil, 5001}); err != nil {
 		t.Fatalf("err: %v", err)
 	}
 
@@ -279,7 +279,7 @@ func TestDeleteNode(t *testing.T) {
 		t.Fatalf("err: %v")
 	}
 
-	if err := store.EnsureService(21, "foo", &structs.NodeService{"api", "api", "", 5000}); err != nil {
+	if err := store.EnsureService(21, "foo", &structs.NodeService{"api", "api", nil, 5000}); err != nil {
 		t.Fatalf("err: %v")
 	}
 
@@ -338,15 +338,15 @@ func TestGetServices(t *testing.T) {
 		t.Fatalf("err: %v")
 	}
 
-	if err := store.EnsureService(32, "foo", &structs.NodeService{"api", "api", "", 5000}); err != nil {
+	if err := store.EnsureService(32, "foo", &structs.NodeService{"api", "api", nil, 5000}); err != nil {
 		t.Fatalf("err: %v")
 	}
 
-	if err := store.EnsureService(33, "foo", &structs.NodeService{"db", "db", "master", 8000}); err != nil {
+	if err := store.EnsureService(33, "foo", &structs.NodeService{"db", "db", []string{"master"}, 8000}); err != nil {
 		t.Fatalf("err: %v")
 	}
 
-	if err := store.EnsureService(34, "bar", &structs.NodeService{"db", "db", "slave", 8000}); err != nil {
+	if err := store.EnsureService(34, "bar", &structs.NodeService{"db", "db", []string{"slave"}, 8000}); err != nil {
 		t.Fatalf("err: %v")
 	}
 
@@ -359,7 +359,7 @@ func TestGetServices(t *testing.T) {
 	if !ok {
 		t.Fatalf("missing api: %#v", services)
 	}
-	if len(tags) != 1 || tags[0] != "" {
+	if len(tags) != 0 {
 		t.Fatalf("Bad entry: %#v", tags)
 	}
 
@@ -388,23 +388,23 @@ func TestServiceNodes(t *testing.T) {
 		t.Fatalf("err: %v")
 	}
 
-	if err := store.EnsureService(12, "foo", &structs.NodeService{"api", "api", "", 5000}); err != nil {
+	if err := store.EnsureService(12, "foo", &structs.NodeService{"api", "api", nil, 5000}); err != nil {
 		t.Fatalf("err: %v")
 	}
 
-	if err := store.EnsureService(13, "bar", &structs.NodeService{"api", "api", "", 5000}); err != nil {
+	if err := store.EnsureService(13, "bar", &structs.NodeService{"api", "api", nil, 5000}); err != nil {
 		t.Fatalf("err: %v")
 	}
 
-	if err := store.EnsureService(14, "foo", &structs.NodeService{"db", "db", "master", 8000}); err != nil {
+	if err := store.EnsureService(14, "foo", &structs.NodeService{"db", "db", []string{"master"}, 8000}); err != nil {
 		t.Fatalf("err: %v")
 	}
 
-	if err := store.EnsureService(15, "bar", &structs.NodeService{"db", "db", "slave", 8000}); err != nil {
+	if err := store.EnsureService(15, "bar", &structs.NodeService{"db", "db", []string{"slave"}, 8000}); err != nil {
 		t.Fatalf("err: %v")
 	}
 
-	if err := store.EnsureService(16, "bar", &structs.NodeService{"db2", "db", "slave", 8001}); err != nil {
+	if err := store.EnsureService(16, "bar", &structs.NodeService{"db2", "db", []string{"slave"}, 8001}); err != nil {
 		t.Fatalf("err: %v")
 	}
 
@@ -424,7 +424,7 @@ func TestServiceNodes(t *testing.T) {
 	if nodes[0].ServiceID != "db" {
 		t.Fatalf("bad: %v", nodes)
 	}
-	if nodes[0].ServiceTag != "master" {
+	if !strContains(nodes[0].ServiceTags, "master") {
 		t.Fatalf("bad: %v", nodes)
 	}
 	if nodes[0].ServicePort != 8000 {
@@ -440,7 +440,7 @@ func TestServiceNodes(t *testing.T) {
 	if nodes[1].ServiceID != "db" {
 		t.Fatalf("bad: %v", nodes)
 	}
-	if nodes[1].ServiceTag != "slave" {
+	if !strContains(nodes[1].ServiceTags, "slave") {
 		t.Fatalf("bad: %v", nodes)
 	}
 	if nodes[1].ServicePort != 8000 {
@@ -456,7 +456,7 @@ func TestServiceNodes(t *testing.T) {
 	if nodes[2].ServiceID != "db2" {
 		t.Fatalf("bad: %v", nodes)
 	}
-	if nodes[2].ServiceTag != "slave" {
+	if !strContains(nodes[2].ServiceTags, "slave") {
 		t.Fatalf("bad: %v", nodes)
 	}
 	if nodes[2].ServicePort != 8001 {
@@ -479,15 +479,15 @@ func TestServiceTagNodes(t *testing.T) {
 		t.Fatalf("err: %v")
 	}
 
-	if err := store.EnsureService(17, "foo", &structs.NodeService{"db", "db", "master", 8000}); err != nil {
+	if err := store.EnsureService(17, "foo", &structs.NodeService{"db", "db", []string{"master"}, 8000}); err != nil {
 		t.Fatalf("err: %v")
 	}
 
-	if err := store.EnsureService(18, "foo", &structs.NodeService{"db2", "db", "slave", 8001}); err != nil {
+	if err := store.EnsureService(18, "foo", &structs.NodeService{"db2", "db", []string{"slave"}, 8001}); err != nil {
 		t.Fatalf("err: %v")
 	}
 
-	if err := store.EnsureService(19, "bar", &structs.NodeService{"db", "db", "slave", 8000}); err != nil {
+	if err := store.EnsureService(19, "bar", &structs.NodeService{"db", "db", []string{"slave"}, 8000}); err != nil {
 		t.Fatalf("err: %v")
 	}
 
@@ -504,7 +504,7 @@ func TestServiceTagNodes(t *testing.T) {
 	if nodes[0].Address != "127.0.0.1" {
 		t.Fatalf("bad: %v", nodes)
 	}
-	if nodes[0].ServiceTag != "master" {
+	if !strContains(nodes[0].ServiceTags, "master") {
 		t.Fatalf("bad: %v", nodes)
 	}
 	if nodes[0].ServicePort != 8000 {
@@ -527,15 +527,15 @@ func TestStoreSnapshot(t *testing.T) {
 		t.Fatalf("err: %v")
 	}
 
-	if err := store.EnsureService(10, "foo", &structs.NodeService{"db", "db", "master", 8000}); err != nil {
+	if err := store.EnsureService(10, "foo", &structs.NodeService{"db", "db", []string{"master"}, 8000}); err != nil {
 		t.Fatalf("err: %v")
 	}
 
-	if err := store.EnsureService(11, "foo", &structs.NodeService{"db2", "db", "slave", 8001}); err != nil {
+	if err := store.EnsureService(11, "foo", &structs.NodeService{"db2", "db", []string{"slave"}, 8001}); err != nil {
 		t.Fatalf("err: %v")
 	}
 
-	if err := store.EnsureService(12, "bar", &structs.NodeService{"db", "db", "slave", 8000}); err != nil {
+	if err := store.EnsureService(12, "bar", &structs.NodeService{"db", "db", []string{"slave"}, 8000}); err != nil {
 		t.Fatalf("err: %v")
 	}
 
@@ -580,15 +580,15 @@ func TestStoreSnapshot(t *testing.T) {
 
 	// Ensure we get the service entries
 	services := snap.NodeServices("foo")
-	if services.Services["db"].Tag != "master" {
+	if !strContains(services.Services["db"].Tags, "master") {
 		t.Fatalf("bad: %v", services)
 	}
-	if services.Services["db2"].Tag != "slave" {
+	if !strContains(services.Services["db2"].Tags, "slave") {
 		t.Fatalf("bad: %v", services)
 	}
 
 	services = snap.NodeServices("bar")
-	if services.Services["db"].Tag != "slave" {
+	if !strContains(services.Services["db"].Tags, "slave") {
 		t.Fatalf("bad: %v", services)
 	}
 
@@ -624,10 +624,10 @@ func TestStoreSnapshot(t *testing.T) {
 	}
 
 	// Make some changes!
-	if err := store.EnsureService(14, "foo", &structs.NodeService{"db", "db", "slave", 8000}); err != nil {
+	if err := store.EnsureService(14, "foo", &structs.NodeService{"db", "db", []string{"slave"}, 8000}); err != nil {
 		t.Fatalf("err: %v", err)
 	}
-	if err := store.EnsureService(15, "bar", &structs.NodeService{"db", "db", "master", 8000}); err != nil {
+	if err := store.EnsureService(15, "bar", &structs.NodeService{"db", "db", []string{"master"}, 8000}); err != nil {
 		t.Fatalf("err: %v", err)
 	}
 	if err := store.EnsureNode(16, structs.Node{"baz", "127.0.0.3"}); err != nil {
@@ -656,15 +656,15 @@ func TestStoreSnapshot(t *testing.T) {
 
 	// Ensure old service entries
 	services = snap.NodeServices("foo")
-	if services.Services["db"].Tag != "master" {
+	if !strContains(services.Services["db"].Tags, "master") {
 		t.Fatalf("bad: %v", services)
 	}
-	if services.Services["db2"].Tag != "slave" {
+	if !strContains(services.Services["db2"].Tags, "slave") {
 		t.Fatalf("bad: %v", services)
 	}
 
 	services = snap.NodeServices("bar")
-	if services.Services["db"].Tag != "slave" {
+	if !strContains(services.Services["db"].Tags, "slave") {
 		t.Fatalf("bad: %v", services)
 	}
 
@@ -709,7 +709,7 @@ func TestEnsureCheck(t *testing.T) {
 	if err := store.EnsureNode(1, structs.Node{"foo", "127.0.0.1"}); err != nil {
 		t.Fatalf("err: %v", err)
 	}
-	if err := store.EnsureService(2, "foo", &structs.NodeService{"db1", "db", "master", 8000}); err != nil {
+	if err := store.EnsureService(2, "foo", &structs.NodeService{"db1", "db", []string{"master"}, 8000}); err != nil {
 		t.Fatalf("err: %v")
 	}
 	check := &structs.HealthCheck{
@@ -791,7 +791,7 @@ func TestDeleteNodeCheck(t *testing.T) {
 	if err := store.EnsureNode(1, structs.Node{"foo", "127.0.0.1"}); err != nil {
 		t.Fatalf("err: %v", err)
 	}
-	if err := store.EnsureService(2, "foo", &structs.NodeService{"db1", "db", "master", 8000}); err != nil {
+	if err := store.EnsureService(2, "foo", &structs.NodeService{"db1", "db", []string{"master"}, 8000}); err != nil {
 		t.Fatalf("err: %v")
 	}
 	check := &structs.HealthCheck{
@@ -841,7 +841,7 @@ func TestCheckServiceNodes(t *testing.T) {
 	if err := store.EnsureNode(1, structs.Node{"foo", "127.0.0.1"}); err != nil {
 		t.Fatalf("err: %v", err)
 	}
-	if err := store.EnsureService(2, "foo", &structs.NodeService{"db1", "db", "master", 8000}); err != nil {
+	if err := store.EnsureService(2, "foo", &structs.NodeService{"db1", "db", []string{"master"}, 8000}); err != nil {
 		t.Fatalf("err: %v")
 	}
 	check := &structs.HealthCheck{
@@ -922,7 +922,7 @@ func BenchmarkCheckServiceNodes(t *testing.B) {
 	if err := store.EnsureNode(1, structs.Node{"foo", "127.0.0.1"}); err != nil {
 		t.Fatalf("err: %v", err)
 	}
-	if err := store.EnsureService(2, "foo", &structs.NodeService{"db1", "db", "master", 8000}); err != nil {
+	if err := store.EnsureService(2, "foo", &structs.NodeService{"db1", "db", []string{"master"}, 8000}); err != nil {
 		t.Fatalf("err: %v")
 	}
 	check := &structs.HealthCheck{
@@ -964,7 +964,7 @@ func TestSS_Register_Deregister_Query(t *testing.T) {
 	srv := &structs.NodeService{
 		"statsite-box-stats",
 		"statsite-box-stats",
-		"",
+		nil,
 		0}
 	if err := store.EnsureService(2, "foo", srv); err != nil {
 		t.Fatalf("err: %v")
@@ -973,7 +973,7 @@ func TestSS_Register_Deregister_Query(t *testing.T) {
 	srv = &structs.NodeService{
 		"statsite-share-stats",
 		"statsite-share-stats",
-		"",
+		nil,
 		0}
 	if err := store.EnsureService(3, "foo", srv); err != nil {
 		t.Fatalf("err: %v")

From 7f399a0eccb3a7ac54ec2cbf6e616616eb823dc4 Mon Sep 17 00:00:00 2001
From: Armon Dadgar <armon.dadgar@gmail.com>
Date: Thu, 3 Apr 2014 12:07:17 -0700
Subject: [PATCH 4/8] consul: Adding test for multiple tags with lookup

---
 consul/state_store_test.go | 76 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 76 insertions(+)

diff --git a/consul/state_store_test.go b/consul/state_store_test.go
index dbdb2bcc23..dd46adf6ae 100644
--- a/consul/state_store_test.go
+++ b/consul/state_store_test.go
@@ -512,6 +512,82 @@ func TestServiceTagNodes(t *testing.T) {
 	}
 }
 
+func TestServiceTagNodes_MultipleTags(t *testing.T) {
+	store, err := testStateStore()
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+	defer store.Close()
+
+	if err := store.EnsureNode(15, structs.Node{"foo", "127.0.0.1"}); err != nil {
+		t.Fatalf("err: %v")
+	}
+
+	if err := store.EnsureNode(16, structs.Node{"bar", "127.0.0.2"}); err != nil {
+		t.Fatalf("err: %v")
+	}
+
+	if err := store.EnsureService(17, "foo", &structs.NodeService{"db", "db", []string{"master", "v2"}, 8000}); err != nil {
+		t.Fatalf("err: %v")
+	}
+
+	if err := store.EnsureService(18, "foo", &structs.NodeService{"db2", "db", []string{"slave", "v2", "dev"}, 8001}); err != nil {
+		t.Fatalf("err: %v")
+	}
+
+	if err := store.EnsureService(19, "bar", &structs.NodeService{"db", "db", []string{"slave", "v2"}, 8000}); err != nil {
+		t.Fatalf("err: %v")
+	}
+
+	idx, nodes := store.ServiceTagNodes("db", "master")
+	if idx != 19 {
+		t.Fatalf("bad: %v", idx)
+	}
+	if len(nodes) != 1 {
+		t.Fatalf("bad: %v", nodes)
+	}
+	if nodes[0].Node != "foo" {
+		t.Fatalf("bad: %v", nodes)
+	}
+	if nodes[0].Address != "127.0.0.1" {
+		t.Fatalf("bad: %v", nodes)
+	}
+	if !strContains(nodes[0].ServiceTags, "master") {
+		t.Fatalf("bad: %v", nodes)
+	}
+	if nodes[0].ServicePort != 8000 {
+		t.Fatalf("bad: %v", nodes)
+	}
+
+	idx, nodes = store.ServiceTagNodes("db", "v2")
+	if idx != 19 {
+		t.Fatalf("bad: %v", idx)
+	}
+	if len(nodes) != 3 {
+		t.Fatalf("bad: %v", nodes)
+	}
+
+	idx, nodes = store.ServiceTagNodes("db", "dev")
+	if idx != 19 {
+		t.Fatalf("bad: %v", idx)
+	}
+	if len(nodes) != 1 {
+		t.Fatalf("bad: %v", nodes)
+	}
+	if nodes[0].Node != "foo" {
+		t.Fatalf("bad: %v", nodes)
+	}
+	if nodes[0].Address != "127.0.0.1" {
+		t.Fatalf("bad: %v", nodes)
+	}
+	if !strContains(nodes[0].ServiceTags, "dev") {
+		t.Fatalf("bad: %v", nodes)
+	}
+	if nodes[0].ServicePort != 8001 {
+		t.Fatalf("bad: %v", nodes)
+	}
+}
+
 func TestStoreSnapshot(t *testing.T) {
 	store, err := testStateStore()
 	if err != nil {

From 8db2e3bd5844cd7dcc7b0c80a3eb1168f6e78575 Mon Sep 17 00:00:00 2001
From: Armon Dadgar <armon.dadgar@gmail.com>
Date: Thu, 3 Apr 2014 12:12:23 -0700
Subject: [PATCH 5/8] agent: Support multiple tags per service registration

---
 command/agent/agent_endpoint_test.go   |  4 ++--
 command/agent/agent_test.go            |  2 +-
 command/agent/catalog_endpoint_test.go |  4 ++--
 command/agent/config_test.go           |  4 ++--
 command/agent/dns_test.go              | 18 +++++++++---------
 command/agent/local_test.go            |  8 ++++----
 command/agent/structs.go               |  4 ++--
 command/agent/util.go                  | 10 ++++++++++
 8 files changed, 32 insertions(+), 22 deletions(-)

diff --git a/command/agent/agent_endpoint_test.go b/command/agent/agent_endpoint_test.go
index 14a07ea2cb..088e42ee5a 100644
--- a/command/agent/agent_endpoint_test.go
+++ b/command/agent/agent_endpoint_test.go
@@ -19,7 +19,7 @@ func TestHTTPAgentServices(t *testing.T) {
 	srv1 := &structs.NodeService{
 		ID:      "mysql",
 		Service: "mysql",
-		Tag:     "master",
+		Tags:    []string{"master"},
 		Port:    5000,
 	}
 	srv.agent.state.AddService(srv1)
@@ -394,7 +394,7 @@ func TestHTTPAgentRegisterService(t *testing.T) {
 	}
 	args := &ServiceDefinition{
 		Name: "test",
-		Tag:  "master",
+		Tags: []string{"master"},
 		Port: 8000,
 		Check: CheckType{
 			TTL: 15 * time.Second,
diff --git a/command/agent/agent_test.go b/command/agent/agent_test.go
index 8dde02690b..7d59d420e2 100644
--- a/command/agent/agent_test.go
+++ b/command/agent/agent_test.go
@@ -108,7 +108,7 @@ func TestAgent_AddService(t *testing.T) {
 	srv := &structs.NodeService{
 		ID:      "redis",
 		Service: "redis",
-		Tag:     "foo",
+		Tags:    []string{"foo"},
 		Port:    8000,
 	}
 	chk := &CheckType{TTL: time.Minute}
diff --git a/command/agent/catalog_endpoint_test.go b/command/agent/catalog_endpoint_test.go
index 03928aaf93..573ddf8863 100644
--- a/command/agent/catalog_endpoint_test.go
+++ b/command/agent/catalog_endpoint_test.go
@@ -249,7 +249,7 @@ func TestCatalogServiceNodes(t *testing.T) {
 		Address:    "127.0.0.1",
 		Service: &structs.NodeService{
 			Service: "api",
-			Tag:     "a",
+			Tags:    []string{"a"},
 		},
 	}
 	var out struct{}
@@ -293,7 +293,7 @@ func TestCatalogNodeServices(t *testing.T) {
 		Address:    "127.0.0.1",
 		Service: &structs.NodeService{
 			Service: "api",
-			Tag:     "a",
+			Tags:    []string{"a"},
 		},
 	}
 	var out struct{}
diff --git a/command/agent/config_test.go b/command/agent/config_test.go
index 878e61a0e7..d6d3f6eaa2 100644
--- a/command/agent/config_test.go
+++ b/command/agent/config_test.go
@@ -197,7 +197,7 @@ func TestDecodeConfig(t *testing.T) {
 
 func TestDecodeConfig_Service(t *testing.T) {
 	// Basics
-	input := `{"service": {"id": "red1", "name": "redis", "tag": "master", "port":8000, "check": {"script": "/bin/check_redis", "interval": "10s", "ttl": "15s" }}}`
+	input := `{"service": {"id": "red1", "name": "redis", "tags": ["master"], "port":8000, "check": {"script": "/bin/check_redis", "interval": "10s", "ttl": "15s" }}}`
 	config, err := DecodeConfig(bytes.NewReader([]byte(input)))
 	if err != nil {
 		t.Fatalf("err: %s", err)
@@ -216,7 +216,7 @@ func TestDecodeConfig_Service(t *testing.T) {
 		t.Fatalf("bad: %v", serv)
 	}
 
-	if serv.Tag != "master" {
+	if !strContains(serv.Tags, "master") {
 		t.Fatalf("bad: %v", serv)
 	}
 
diff --git a/command/agent/dns_test.go b/command/agent/dns_test.go
index 68592923d1..e065ea4a46 100644
--- a/command/agent/dns_test.go
+++ b/command/agent/dns_test.go
@@ -219,7 +219,7 @@ func TestDNS_ServiceLookup(t *testing.T) {
 		Address:    "127.0.0.1",
 		Service: &structs.NodeService{
 			Service: "db",
-			Tag:     "master",
+			Tags:    []string{"master"},
 			Port:    12345,
 		},
 	}
@@ -279,7 +279,7 @@ func TestDNS_ServiceLookup_Dedup(t *testing.T) {
 		Address:    "127.0.0.1",
 		Service: &structs.NodeService{
 			Service: "db",
-			Tag:     "master",
+			Tags:    []string{"master"},
 			Port:    12345,
 		},
 	}
@@ -295,7 +295,7 @@ func TestDNS_ServiceLookup_Dedup(t *testing.T) {
 		Service: &structs.NodeService{
 			ID:      "db2",
 			Service: "db",
-			Tag:     "slave",
+			Tags:    []string{"slave"},
 			Port:    12345,
 		},
 	}
@@ -310,7 +310,7 @@ func TestDNS_ServiceLookup_Dedup(t *testing.T) {
 		Service: &structs.NodeService{
 			ID:      "db3",
 			Service: "db",
-			Tag:     "slave",
+			Tags:    []string{"slave"},
 			Port:    12346,
 		},
 	}
@@ -355,7 +355,7 @@ func TestDNS_ServiceLookup_Dedup_SRV(t *testing.T) {
 		Address:    "127.0.0.1",
 		Service: &structs.NodeService{
 			Service: "db",
-			Tag:     "master",
+			Tags:    []string{"master"},
 			Port:    12345,
 		},
 	}
@@ -371,7 +371,7 @@ func TestDNS_ServiceLookup_Dedup_SRV(t *testing.T) {
 		Service: &structs.NodeService{
 			ID:      "db2",
 			Service: "db",
-			Tag:     "slave",
+			Tags:    []string{"slave"},
 			Port:    12345,
 		},
 	}
@@ -386,7 +386,7 @@ func TestDNS_ServiceLookup_Dedup_SRV(t *testing.T) {
 		Service: &structs.NodeService{
 			ID:      "db3",
 			Service: "db",
-			Tag:     "slave",
+			Tags:    []string{"slave"},
 			Port:    12346,
 		},
 	}
@@ -482,7 +482,7 @@ func TestDNS_ServiceLookup_FilterCritical(t *testing.T) {
 		Address:    "127.0.0.1",
 		Service: &structs.NodeService{
 			Service: "db",
-			Tag:     "master",
+			Tags:    []string{"master"},
 			Port:    12345,
 		},
 		Check: &structs.HealthCheck{
@@ -502,7 +502,7 @@ func TestDNS_ServiceLookup_FilterCritical(t *testing.T) {
 		Address:    "127.0.0.2",
 		Service: &structs.NodeService{
 			Service: "db",
-			Tag:     "master",
+			Tags:    []string{"master"},
 			Port:    12345,
 		},
 		Check: &structs.HealthCheck{
diff --git a/command/agent/local_test.go b/command/agent/local_test.go
index be6bdbbebb..a84c1a2929 100644
--- a/command/agent/local_test.go
+++ b/command/agent/local_test.go
@@ -29,7 +29,7 @@ func TestAgentAntiEntropy_Services(t *testing.T) {
 	srv1 := &structs.NodeService{
 		ID:      "mysql",
 		Service: "mysql",
-		Tag:     "master",
+		Tags:    []string{"master"},
 		Port:    5000,
 	}
 	agent.state.AddService(srv1)
@@ -42,7 +42,7 @@ func TestAgentAntiEntropy_Services(t *testing.T) {
 	srv2 := &structs.NodeService{
 		ID:      "redis",
 		Service: "redis",
-		Tag:     "",
+		Tags:    nil,
 		Port:    8000,
 	}
 	agent.state.AddService(srv2)
@@ -59,7 +59,7 @@ func TestAgentAntiEntropy_Services(t *testing.T) {
 	srv3 := &structs.NodeService{
 		ID:      "web",
 		Service: "web",
-		Tag:     "",
+		Tags:    nil,
 		Port:    80,
 	}
 	agent.state.AddService(srv3)
@@ -68,7 +68,7 @@ func TestAgentAntiEntropy_Services(t *testing.T) {
 	srv4 := &structs.NodeService{
 		ID:      "lb",
 		Service: "lb",
-		Tag:     "",
+		Tags:    nil,
 		Port:    443,
 	}
 	args.Service = srv4
diff --git a/command/agent/structs.go b/command/agent/structs.go
index 876ce4f8d8..2370c3936a 100644
--- a/command/agent/structs.go
+++ b/command/agent/structs.go
@@ -8,7 +8,7 @@ import (
 type ServiceDefinition struct {
 	ID    string
 	Name  string
-	Tag   string
+	Tags  []string
 	Port  int
 	Check CheckType
 }
@@ -17,7 +17,7 @@ func (s *ServiceDefinition) NodeService() *structs.NodeService {
 	ns := &structs.NodeService{
 		ID:      s.ID,
 		Service: s.Name,
-		Tag:     s.Tag,
+		Tags:    s.Tags,
 		Port:    s.Port,
 	}
 	if ns.ID == "" && ns.Service != "" {
diff --git a/command/agent/util.go b/command/agent/util.go
index f6ce7747e9..8f6103a804 100644
--- a/command/agent/util.go
+++ b/command/agent/util.go
@@ -29,3 +29,13 @@ func aeScale(interval time.Duration, n int) time.Duration {
 func randomStagger(intv time.Duration) time.Duration {
 	return time.Duration(uint64(rand.Int63()) % uint64(intv))
 }
+
+// strContains checks if a list contains a string
+func strContains(l []string, s string) bool {
+	for _, v := range l {
+		if v == s {
+			return true
+		}
+	}
+	return false
+}

From 6e26f463a534ea9300fd8e9bccd9e01d6566b7ca Mon Sep 17 00:00:00 2001
From: Armon Dadgar <armon.dadgar@gmail.com>
Date: Thu, 3 Apr 2014 14:18:57 -0700
Subject: [PATCH 6/8] website: Updating the tags documentation

---
 website/source/docs/agent/http.html.markdown  | 22 +++++++++----------
 .../source/docs/agent/services.html.markdown  |  8 +++----
 2 files changed, 15 insertions(+), 15 deletions(-)

diff --git a/website/source/docs/agent/http.html.markdown b/website/source/docs/agent/http.html.markdown
index b938e7ec94..6150a5946b 100644
--- a/website/source/docs/agent/http.html.markdown
+++ b/website/source/docs/agent/http.html.markdown
@@ -169,7 +169,7 @@ This endpoint is hit with a GET and returns a JSON body like this:
         "redis":{
             "ID":"redis",
             "Service":"redis",
-            "Tag":"",
+            "Tags":[],
             "Port":8000
         }
     }
@@ -301,7 +301,7 @@ body must look like:
     {
         "ID": "redis1",
 	    "Name": "redis",
-	    "Tag": "master",
+	    "Tags": ["master", "v1"],
 	    "Port": 8000,
         "Check": {
             "Script": "/usr/local/bin/check_redis.py",
@@ -312,7 +312,7 @@ body must look like:
 
 The `Name` field is mandatory,  If an `ID` is not provided, it is set to `Name`.
 You cannot have duplicate `ID` entries per agent, so it may be necessary to provide an ID.
-`Tag`, `Port` and `Check` are optional. If `Check` is provided, only one of `Script` and `Interval`
+`Tags`, `Port` and `Check` are optional. If `Check` is provided, only one of `Script` and `Interval`
 or `TTL` should be provided. There is more information about checks [here](/docs/agent/checks.html).
 
 The created check will be named "service:\<ServiceId\>".
@@ -361,7 +361,7 @@ body must look like:
         "Service": {
             "ID": "redis1",
             "Service": "redis",
-            "Tag": "master",
+            "Tags": ["master", "v1"],
             "Port": 8000,
         },
         "Check": {
@@ -381,7 +381,7 @@ the node with the catalog.
 
 If the `Service` key is provided, then the service will also be registered. If
 `ID` is not provided, it will be defaulted to `Service`. It is mandated that the
-ID be node-unique. Both `Tag` and `Port` can be omitted.
+ID be node-unique. Both `Tags` and `Port` can be omitted.
 
 If the `Check` key is provided, then a health check will also be registered. It
 is important to remember that this register API is very low level. This manipulates
@@ -480,8 +480,8 @@ however the dc can be provided using the "?dc=" query parameter.
 It returns a JSON body like this:
 
     {
-        "consul":[""],
-        "redis":[""],
+        "consul":[],
+        "redis":[],
         "postgresql":["master","slave"]
     }
 
@@ -508,7 +508,7 @@ It returns a JSON body like this:
             "Address":"10.1.10.12",
             "ServiceID":"redis",
             "ServiceName":"redis",
-            "ServiceTag":"",
+            "ServiceTags":[],
             "ServicePort":8000
         }
     ]
@@ -533,13 +533,13 @@ It returns a JSON body like this:
             "consul":{
                 "ID":"consul",
                 "Service":"consul",
-                "Tag":"",
+                "Tags":[],
                 "Port":8300
             },
             "redis":{
                 "ID":"redis",
                 "Service":"redis",
-                "Tag":"",
+                "Tags":["v1"],
                 "Port":8000
             }
         }
@@ -655,7 +655,7 @@ It returns a JSON body like this:
             "Service":{
                 "ID":"redis",
                 "Service":"redis",
-                "Tag":"",
+                "Tags":[],
                 "Port":8000
             },
             "Checks":[
diff --git a/website/source/docs/agent/services.html.markdown b/website/source/docs/agent/services.html.markdown
index 19d8cbed09..22f958588c 100644
--- a/website/source/docs/agent/services.html.markdown
+++ b/website/source/docs/agent/services.html.markdown
@@ -20,7 +20,7 @@ A service definition that is a script looks like:
     {
         "service": {
             "name": "redis",
-            "tag": "master",
+            "tags": ["master"],
             "port": 8000,
             "check": {
                 "script": "/usr/local/bin/check_redis.py",
@@ -30,12 +30,12 @@ A service definition that is a script looks like:
     }
 
 A service definition must include a `name`, and may optionally provide
-an `id`, `tag`, `port`, and `check`.  The `id` is set to the `name` if not
+an `id`, `tags`, `port`, and `check`.  The `id` is set to the `name` if not
 provided. It is required that all services have a unique ID, so if names
 might conflict, then unique ID's should be provided.
 
-The `tag` is an opaque value to Consul, but can be used to distinguish
-between "master" or "slave" nodes, or any other service level labels.
+The `tags` is a list of opaque value to Consul, but can be used to distinguish
+between "master" or "slave" nodes, different versions, or any other service level labels.
 The `port` can be used as well to make a service oriented architecture
 simpler to configure. This way the address and port of a service can
 be discovered.

From 30307f877b6816214f355531b6f57976370d190b Mon Sep 17 00:00:00 2001
From: Armon Dadgar <armon.dadgar@gmail.com>
Date: Thu, 3 Apr 2014 14:22:43 -0700
Subject: [PATCH 7/8] agent: Add backwards compatibility hack for old 'tag'
 definitions

---
 command/agent/config.go | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/command/agent/config.go b/command/agent/config.go
index ad8a8b8754..a2e83740b9 100644
--- a/command/agent/config.go
+++ b/command/agent/config.go
@@ -186,6 +186,14 @@ func DecodeServiceDefinition(raw interface{}) (*ServiceDefinition, error) {
 	if !ok {
 		goto AFTER_FIX
 	}
+
+	// If no 'tags', handle the deprecated 'tag' value.
+	if _, ok := rawMap["tags"]; !ok {
+		if tag, ok := rawMap["tag"]; ok {
+			rawMap["tags"] = []interface{}{tag}
+		}
+	}
+
 	sub, ok = rawMap["check"]
 	if !ok {
 		goto AFTER_FIX

From 7c31a313db4baeb65eca62f9a7a4e138ea944caf Mon Sep 17 00:00:00 2001
From: Armon Dadgar <armon.dadgar@gmail.com>
Date: Thu, 3 Apr 2014 14:40:05 -0700
Subject: [PATCH 8/8] website: Correct some empty lists to null

---
 website/source/docs/agent/http.html.markdown | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/website/source/docs/agent/http.html.markdown b/website/source/docs/agent/http.html.markdown
index 6150a5946b..e9e95a00cb 100644
--- a/website/source/docs/agent/http.html.markdown
+++ b/website/source/docs/agent/http.html.markdown
@@ -169,7 +169,7 @@ This endpoint is hit with a GET and returns a JSON body like this:
         "redis":{
             "ID":"redis",
             "Service":"redis",
-            "Tags":[],
+            "Tags":null,
             "Port":8000
         }
     }
@@ -508,7 +508,7 @@ It returns a JSON body like this:
             "Address":"10.1.10.12",
             "ServiceID":"redis",
             "ServiceName":"redis",
-            "ServiceTags":[],
+            "ServiceTags":null,
             "ServicePort":8000
         }
     ]
@@ -533,7 +533,7 @@ It returns a JSON body like this:
             "consul":{
                 "ID":"consul",
                 "Service":"consul",
-                "Tags":[],
+                "Tags":null,
                 "Port":8300
             },
             "redis":{
@@ -655,7 +655,7 @@ It returns a JSON body like this:
             "Service":{
                 "ID":"redis",
                 "Service":"redis",
-                "Tags":[],
+                "Tags":null,
                 "Port":8000
             },
             "Checks":[