consul: Health endpoints support blocking queries

consul/health_endpoint.go

@@ -12,35 +12,41 @@ type Health struct {
 
 // ChecksInState is used to get all the checks in a given state
 func (h *Health) ChecksInState(args *structs.ChecksInStateRequest,
-	reply *structs.HealthChecks) error {
+	reply *structs.IndexedHealthChecks) error {
 	if done, err := h.srv.forward("Health.ChecksInState", args.Datacenter, args, reply); done {
 		return err
 	}
 
 	// Get the state specific checks
 	state := h.srv.fsm.State()
-	_, checks := state.ChecksInState(args.State)
+	return h.srv.blockingRPC(&args.BlockingQuery,
-	*reply = checks
+		state.QueryTables("ChecksInState"),
-	return nil
+		func() (uint64, error) {
+			reply.Index, reply.HealthChecks = state.ChecksInState(args.State)
+			return reply.Index, nil
+		})
 }
 
 // NodeChecks is used to get all the checks for a node
 func (h *Health) NodeChecks(args *structs.NodeSpecificRequest,
-	reply *structs.HealthChecks) error {
+	reply *structs.IndexedHealthChecks) error {
 	if done, err := h.srv.forward("Health.NodeChecks", args.Datacenter, args, reply); done {
 		return err
 	}
 
 	// Get the node checks
 	state := h.srv.fsm.State()
-	_, checks := state.NodeChecks(args.Node)
+	return h.srv.blockingRPC(&args.BlockingQuery,
-	*reply = checks
+		state.QueryTables("NodeChecks"),
-	return nil
+		func() (uint64, error) {
+			reply.Index, reply.HealthChecks = state.NodeChecks(args.Node)
+			return reply.Index, nil
+		})
 }
 
 // ServiceChecks is used to get all the checks for a service
 func (h *Health) ServiceChecks(args *structs.ServiceSpecificRequest,
-	reply *structs.HealthChecks) error {
+	reply *structs.IndexedHealthChecks) error {
 	// Reject if tag filtering is on
 	if args.TagFilter {
 		return fmt.Errorf("Tag filtering is not supported")
@@ -53,13 +59,16 @@ func (h *Health) ServiceChecks(args *structs.ServiceSpecificRequest,
 
 	// Get the service checks
 	state := h.srv.fsm.State()
-	_, checks := state.ServiceChecks(args.ServiceName)
+	return h.srv.blockingRPC(&args.BlockingQuery,
-	*reply = checks
+		state.QueryTables("ServiceChecks"),
-	return nil
+		func() (uint64, error) {
+			reply.Index, reply.HealthChecks = state.ServiceChecks(args.ServiceName)
+			return reply.Index, nil
+		})
 }
 
 // ServiceNodes returns all the nodes registered as part of a service including health info
-func (h *Health) ServiceNodes(args *structs.ServiceSpecificRequest, reply *structs.CheckServiceNodes) error {
+func (h *Health) ServiceNodes(args *structs.ServiceSpecificRequest, reply *structs.IndexedCheckServiceNodes) error {
 	if done, err := h.srv.forward("Health.ServiceNodes", args.Datacenter, args, reply); done {
 		return err
 	}
@@ -71,13 +80,14 @@ func (h *Health) ServiceNodes(args *structs.ServiceSpecificRequest, reply *struc
 
 	// Get the nodes
 	state := h.srv.fsm.State()
-	var nodes structs.CheckServiceNodes
+	return h.srv.blockingRPC(&args.BlockingQuery,
+		state.QueryTables("CheckServiceNodes"),
+		func() (uint64, error) {
 			if args.TagFilter {
-		_, nodes = state.CheckServiceTagNodes(args.ServiceName, args.ServiceTag)
+				reply.Index, reply.Nodes = state.CheckServiceTagNodes(args.ServiceName, args.ServiceTag)
 			} else {
-		_, nodes = state.CheckServiceNodes(args.ServiceName)
+				reply.Index, reply.Nodes = state.CheckServiceNodes(args.ServiceName)
 			}
-
+			return reply.Index, nil
-	*reply = nodes
+		})
-	return nil
 }

consul/health_endpoint_test.go

@@ -31,15 +31,16 @@ func TestHealth_ChecksInState(t *testing.T) {
 		t.Fatalf("err: %v", err)
 	}
 
-	var checks structs.HealthChecks
+	var out2 structs.IndexedHealthChecks
 	inState := structs.ChecksInStateRequest{
 		Datacenter: "dc1",
 		State:      structs.HealthPassing,
 	}
-	if err := client.Call("Health.ChecksInState", &inState, &checks); err != nil {
+	if err := client.Call("Health.ChecksInState", &inState, &out2); err != nil {
 		t.Fatalf("err: %v", err)
 	}
 
+	checks := out2.HealthChecks
 	if len(checks) != 2 {
 		t.Fatalf("Bad: %v", checks)
 	}
@@ -77,15 +78,16 @@ func TestHealth_NodeChecks(t *testing.T) {
 		t.Fatalf("err: %v", err)
 	}
 
-	var checks structs.HealthChecks
+	var out2 structs.IndexedHealthChecks
 	node := structs.NodeSpecificRequest{
 		Datacenter: "dc1",
 		Node:       "foo",
 	}
-	if err := client.Call("Health.NodeChecks", &node, &checks); err != nil {
+	if err := client.Call("Health.NodeChecks", &node, &out2); err != nil {
 		t.Fatalf("err: %v", err)
 	}
 
+	checks := out2.HealthChecks
 	if len(checks) != 1 {
 		t.Fatalf("Bad: %v", checks)
 	}
@@ -123,15 +125,16 @@ func TestHealth_ServiceChecks(t *testing.T) {
 		t.Fatalf("err: %v", err)
 	}
 
-	var checks structs.HealthChecks
+	var out2 structs.IndexedHealthChecks
 	node := structs.ServiceSpecificRequest{
 		Datacenter:  "dc1",
 		ServiceName: "db",
 	}
-	if err := client.Call("Health.ServiceChecks", &node, &checks); err != nil {
+	if err := client.Call("Health.ServiceChecks", &node, &out2); err != nil {
 		t.Fatalf("err: %v", err)
 	}
 
+	checks := out2.HealthChecks
 	if len(checks) != 1 {
 		t.Fatalf("Bad: %v", checks)
 	}
@@ -189,17 +192,18 @@ func TestHealth_ServiceNodes(t *testing.T) {
 		t.Fatalf("err: %v", err)
 	}
 
-	var nodes structs.CheckServiceNodes
+	var out2 structs.IndexedCheckServiceNodes
 	req := structs.ServiceSpecificRequest{
 		Datacenter:  "dc1",
 		ServiceName: "db",
 		ServiceTag:  "master",
 		TagFilter:   false,
 	}
-	if err := client.Call("Health.ServiceNodes", &req, &nodes); err != nil {
+	if err := client.Call("Health.ServiceNodes", &req, &out2); err != nil {
 		t.Fatalf("err: %v", err)
 	}
 
+	nodes := out2.Nodes
 	if len(nodes) != 2 {
 		t.Fatalf("Bad: %v", nodes)
 	}

consul/state_store.go

@@ -199,6 +199,10 @@ func (s *StateStore) initialize() error {
 		"Services":          MDBTables{s.serviceTable},
 		"ServiceNodes":      MDBTables{s.nodeTable, s.serviceTable},
 		"NodeServices":      MDBTables{s.nodeTable, s.serviceTable},
+		"ChecksInState":     MDBTables{s.checkTable},
+		"NodeChecks":        MDBTables{s.checkTable},
+		"ServiceChecks":     MDBTables{s.checkTable},
+		"CheckServiceNodes": MDBTables{s.nodeTable, s.serviceTable, s.checkTable},
 	}
 	return nil
 }
@@ -598,7 +602,7 @@ func parseHealthChecks(idx uint64, res []interface{}, err error) (uint64, struct
 // CheckServiceNodes returns the nodes associated with a given service, along
 // with any associated check
 func (s *StateStore) CheckServiceNodes(service string) (uint64, structs.CheckServiceNodes) {
-	tables := MDBTables{s.nodeTable, s.serviceTable, s.checkTable}
+	tables := s.queryTables["CheckServiceNodes"]
 	tx, err := tables.StartTxn(true)
 	if err != nil {
 		panic(fmt.Errorf("Failed to start txn: %v", err))
@@ -617,7 +621,7 @@ func (s *StateStore) CheckServiceNodes(service string) (uint64, structs.CheckSer
 // CheckServiceNodes returns the nodes associated with a given service, along
 // with any associated checks
 func (s *StateStore) CheckServiceTagNodes(service, tag string) (uint64, structs.CheckServiceNodes) {
-	tables := MDBTables{s.nodeTable, s.serviceTable, s.checkTable}
+	tables := s.queryTables["CheckServiceNodes"]
 	tx, err := tables.StartTxn(true)
 	if err != nil {
 		panic(fmt.Errorf("Failed to start txn: %v", err))

consul/structs/structs.go

@@ -167,6 +167,11 @@ type IndexedHealthChecks struct {
 	HealthChecks HealthChecks
 }
 
+type IndexedCheckServiceNodes struct {
+	Index uint64
+	Nodes CheckServiceNodes
+}
+
 // Decode is used to decode a MsgPack encoded object
 func Decode(buf []byte, out interface{}) error {
 	var handle codec.MsgpackHandle