Merge pull request #2702 from hashicorp/f-dns-nodeid

DNS lookup by Consul node ID

consul/state/catalog.go

@@ -9,6 +9,13 @@ import (
 	"github.com/hashicorp/go-memdb"
 )
 
+const (
+	// minUUIDLookupLen is used as a minimum length of a node name required before
+	// we test to see if the name is actually a UUID and perform an ID-based node
+	// lookup.
+	minUUIDLookupLen = 8
+)
+
 // Nodes is used to pull the full list of nodes for use during snapshots.
 func (s *StateSnapshot) Nodes() (memdb.ResultIterator, error) {
 	iter, err := s.tx.Get("nodes", "id")
@@ -151,7 +158,7 @@ func (s *StateStore) ensureNodeTxn(tx *memdb.Txn, idx uint64, node *structs.Node
 	// Check for an existing node
 	existing, err := tx.First("nodes", "id", node.Node)
 	if err != nil {
-		return fmt.Errorf("node lookup failed: %s", err)
+		return fmt.Errorf("node name lookup failed: %s", err)
 	}
 
 	// Get the indexes
@@ -174,7 +181,7 @@ func (s *StateStore) ensureNodeTxn(tx *memdb.Txn, idx uint64, node *structs.Node
 	return nil
 }
 
-// GetNode is used to retrieve a node registration by node ID.
+// GetNode is used to retrieve a node registration by node name ID.
 func (s *StateStore) GetNode(id string) (uint64, *structs.Node, error) {
 	tx := s.db.Txn(false)
 	defer tx.Abort()
@@ -193,6 +200,25 @@ func (s *StateStore) GetNode(id string) (uint64, *structs.Node, error) {
 	return idx, nil, nil
 }
 
+// GetNodeID is used to retrieve a node registration by node ID.
+func (s *StateStore) GetNodeID(id types.NodeID) (uint64, *structs.Node, error) {
+	tx := s.db.Txn(false)
+	defer tx.Abort()
+
+	// Get the table index.
+	idx := maxIndexTxn(tx, "nodes")
+
+	// Retrieve the node from the state store
+	node, err := tx.First("nodes", "uuid", string(id))
+	if err != nil {
+		return 0, nil, fmt.Errorf("node lookup failed: %s", err)
+	}
+	if node != nil {
+		return idx, node.(*structs.Node), nil
+	}
+	return idx, nil, nil
+}
+
 // Nodes is used to return all of the known nodes.
 func (s *StateStore) Nodes(ws memdb.WatchSet) (uint64, structs.Nodes, error) {
 	tx := s.db.Txn(false)
@@ -655,23 +681,56 @@ func (s *StateStore) NodeService(nodeName string, serviceID string) (uint64, *st
 }
 
 // NodeServices is used to query service registrations by node ID.
-func (s *StateStore) NodeServices(ws memdb.WatchSet, nodeName string) (uint64, *structs.NodeServices, error) {
+func (s *StateStore) NodeServices(ws memdb.WatchSet, nodeNameOrID string) (uint64, *structs.NodeServices, error) {
 	tx := s.db.Txn(false)
 	defer tx.Abort()
 
 	// Get the table index.
 	idx := maxIndexTxn(tx, "nodes", "services")
 
-	// Query the node
-	watchCh, n, err := tx.FirstWatch("nodes", "id", nodeName)
+	// Query the node by node name
+	watchCh, n, err := tx.FirstWatch("nodes", "id", nodeNameOrID)
 	if err != nil {
 		return 0, nil, fmt.Errorf("node lookup failed: %s", err)
 	}
-	ws.Add(watchCh)
-	if n == nil {
-		return 0, nil, nil
+
+	if n != nil {
+		ws.Add(watchCh)
+	} else {
+		if len(nodeNameOrID) < minUUIDLookupLen {
+			ws.Add(watchCh)
+			return 0, nil, nil
+		}
+
+		// Attempt to lookup the node by its node ID
+		iter, err := tx.Get("nodes", "uuid_prefix", nodeNameOrID)
+		if err != nil {
+			ws.Add(watchCh)
+			// TODO(sean@): We could/should log an error re: the uuid_prefix lookup
+			// failing once a logger has been introduced to the catalog.
+			return 0, nil, nil
+		}
+
+		n = iter.Next()
+		if n == nil {
+			// No nodes matched, even with the Node ID: add a watch on the node name.
+			ws.Add(watchCh)
+			return 0, nil, nil
+		}
+
+		idWatchCh := iter.WatchCh()
+		if iter.Next() != nil {
+			// More than one match present: Watch on the node name channel and return
+			// an empty result (node lookups can not be ambiguous).
+			ws.Add(watchCh)
+			return 0, nil, nil
+		}
+
+		ws.Add(idWatchCh)
 	}
+
 	node := n.(*structs.Node)
+	nodeName := node.Node
 
 	// Read all of the services
 	services, err := tx.Get("services", "node", nodeName)

consul/state/catalog_test.go

@@ -10,14 +10,23 @@ import (
 	"github.com/hashicorp/consul/lib"
 	"github.com/hashicorp/consul/types"
 	"github.com/hashicorp/go-memdb"
+	uuid "github.com/hashicorp/go-uuid"
 )
 
+func makeRandomNodeID(t *testing.T) types.NodeID {
+	id, err := uuid.GenerateUUID()
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+	return types.NodeID(id)
+}
+
 func TestStateStore_EnsureRegistration(t *testing.T) {
 	s := testStateStore(t)
 
 	// Start with just a node.
 	req := &structs.RegisterRequest{
-		ID:      types.NodeID("40e4a748-2192-161a-0510-9bf59fe950b5"),
+		ID:      makeRandomNodeID(t),
 		Node:    "node1",
 		Address: "1.2.3.4",
 		TaggedAddresses: map[string]string{
@@ -27,6 +36,7 @@ func TestStateStore_EnsureRegistration(t *testing.T) {
 			"somekey": "somevalue",
 		},
 	}
+	nodeID := req.ID
 	if err := s.EnsureRegistration(1, req); err != nil {
 		t.Fatalf("err: %s", err)
 	}
@@ -37,14 +47,21 @@ func TestStateStore_EnsureRegistration(t *testing.T) {
 		if err != nil {
 			t.Fatalf("err: %s", err)
 		}
-		if out.ID != types.NodeID("40e4a748-2192-161a-0510-9bf59fe950b5") ||
+		if out.ID != nodeID ||
 			out.Node != "node1" || out.Address != "1.2.3.4" ||
 			len(out.TaggedAddresses) != 1 ||
 			out.TaggedAddresses["hello"] != "world" ||
 			out.Meta["somekey"] != "somevalue" ||
 			out.CreateIndex != 1 || out.ModifyIndex != 1 {
 			t.Fatalf("bad node returned: %#v", out)
 		}
+		_, out2, err := s.GetNodeID(nodeID)
+		if err != nil {
+			t.Fatalf("err: %s", err)
+		}
+		if !reflect.DeepEqual(out, out2) {
+			t.Fatalf("bad node returned: %#v -- %#v", out, out2)
+		}
 	}
 	verifyNode()
 
@@ -183,27 +200,39 @@ func TestStateStore_EnsureRegistration_Restore(t *testing.T) {
 
 	// Start with just a node.
 	req := &structs.RegisterRequest{
+		ID:      makeRandomNodeID(t),
 		Node:    "node1",
 		Address: "1.2.3.4",
 	}
+	nodeID := string(req.ID)
+	nodeName := string(req.Node)
 	restore := s.Restore()
 	if err := restore.Registration(1, req); err != nil {
 		t.Fatalf("err: %s", err)
 	}
 	restore.Commit()
 
 	// Retrieve the node and verify its contents.
-	verifyNode := func() {
-		_, out, err := s.GetNode("node1")
+	verifyNode := func(nodeLookup string) {
+		_, out, err := s.GetNode(nodeLookup)
 		if err != nil {
 			t.Fatalf("err: %s", err)
 		}
-		if out.Node != "node1" || out.Address != "1.2.3.4" ||
+		if out == nil {
+			_, out, err = s.GetNodeID(types.NodeID(nodeLookup))
+			if err != nil {
+				t.Fatalf("err: %s", err)
+			}
+		}
+
+		if out == nil || out.Address != "1.2.3.4" ||
+			!(out.Node == nodeLookup || string(out.ID) == nodeLookup) ||
 			out.CreateIndex != 1 || out.ModifyIndex != 1 {
 			t.Fatalf("bad node returned: %#v", out)
 		}
 	}
-	verifyNode()
+	verifyNode(nodeID)
+	verifyNode(nodeName)
 
 	// Add in a service definition.
 	req.Service = &structs.NodeService{
@@ -219,8 +248,8 @@ func TestStateStore_EnsureRegistration_Restore(t *testing.T) {
 	restore.Commit()
 
 	// Verify that the service got registered.
-	verifyService := func() {
-		idx, out, err := s.NodeServices(nil, "node1")
+	verifyService := func(nodeLookup string) {
+		idx, out, err := s.NodeServices(nil, nodeLookup)
 		if err != nil {
 			t.Fatalf("err: %s", err)
 		}
@@ -240,7 +269,7 @@ func TestStateStore_EnsureRegistration_Restore(t *testing.T) {
 
 	// Add in a top-level check.
 	req.Check = &structs.HealthCheck{
-		Node:    "node1",
+		Node:    nodeName,
 		CheckID: "check1",
 		Name:    "check",
 	}
@@ -252,7 +281,7 @@ func TestStateStore_EnsureRegistration_Restore(t *testing.T) {
 
 	// Verify that the check got registered.
 	verifyCheck := func() {
-		idx, out, err := s.NodeChecks(nil, "node1")
+		idx, out, err := s.NodeChecks(nil, nodeName)
 		if err != nil {
 			t.Fatalf("err: %s", err)
 		}
@@ -263,19 +292,21 @@ func TestStateStore_EnsureRegistration_Restore(t *testing.T) {
 			t.Fatalf("bad: %#v", out)
 		}
 		c := out[0]
-		if c.Node != "node1" || c.CheckID != "check1" || c.Name != "check" ||
+		if c.Node != nodeName || c.CheckID != "check1" || c.Name != "check" ||
 			c.CreateIndex != 3 || c.ModifyIndex != 3 {
 			t.Fatalf("bad check returned: %#v", c)
 		}
 	}
-	verifyNode()
-	verifyService()
+	verifyNode(nodeID)
+	verifyNode(nodeName)
+	verifyService(nodeID)
+	verifyService(nodeName)
 	verifyCheck()
 
 	// Add in another check via the slice.
 	req.Checks = structs.HealthChecks{
 		&structs.HealthCheck{
-			Node:    "node1",
+			Node:    nodeName,
 			CheckID: "check2",
 			Name:    "check",
 		},
@@ -287,10 +318,12 @@ func TestStateStore_EnsureRegistration_Restore(t *testing.T) {
 	restore.Commit()
 
 	// Verify that the additional check got registered.
-	verifyNode()
-	verifyService()
+	verifyNode(nodeID)
+	verifyNode(nodeName)
+	verifyService(nodeID)
+	verifyService(nodeName)
 	func() {
-		idx, out, err := s.NodeChecks(nil, "node1")
+		idx, out, err := s.NodeChecks(nil, nodeName)
 		if err != nil {
 			t.Fatalf("err: %s", err)
 		}
@@ -301,13 +334,13 @@ func TestStateStore_EnsureRegistration_Restore(t *testing.T) {
 			t.Fatalf("bad: %#v", out)
 		}
 		c1 := out[0]
-		if c1.Node != "node1" || c1.CheckID != "check1" || c1.Name != "check" ||
+		if c1.Node != nodeName || c1.CheckID != "check1" || c1.Name != "check" ||
 			c1.CreateIndex != 3 || c1.ModifyIndex != 4 {
 			t.Fatalf("bad check returned: %#v", c1)
 		}
 
 		c2 := out[1]
-		if c2.Node != "node1" || c2.CheckID != "check2" || c2.Name != "check" ||
+		if c2.Node != nodeName || c2.CheckID != "check2" || c2.Name != "check" ||
 			c2.CreateIndex != 4 || c2.ModifyIndex != 4 {
 			t.Fatalf("bad check returned: %#v", c2)
 		}

consul/state/prepared_query.go

@@ -14,6 +14,11 @@ var validUUID = regexp.MustCompile(`(?i)^[\da-f]{8}-[\da-f]{4}-[\da-f]{4}-[\da-f
 
 // isUUID returns true if the given string is a valid UUID.
 func isUUID(str string) bool {
+	const uuidLen = 36
+	if len(str) != uuidLen {
+		return false
+	}
+
 	return validUUID.MatchString(str)
 }
 

consul/state/schema.go

@@ -78,6 +78,14 @@ func nodesTableSchema() *memdb.TableSchema {
 					Lowercase: true,
 				},
 			},
+			"uuid": &memdb.IndexSchema{
+				Name:         "uuid",
+				AllowMissing: true,
+				Unique:       true,
+				Indexer: &memdb.UUIDFieldIndex{
+					Field: "ID",
+				},
+			},
 			"meta": &memdb.IndexSchema{
 				Name:         "meta",
 				AllowMissing: true,