feat(GraphQL): Zero HTTP endpoints are now available at GraphQL admin…

… (GRAPHQL-1118) (#6649)

This PR makes Zero HTTP endpoints available in GraphQL admin. It also adds a flag `--disable_admin_http` in Zero which can be used to disable the administrative HTTP endpoints in Zero. The following are considered as the administrative endpoints for Zero:
* `/state`
* `/removeNode`
* `/moveTablet`
* `/assign`
* `/enterpriseLicense`

RFC: https://discuss.dgraph.io/t/moving-zero-http-endpoints-to-alpha-graphql-admin/10725
(cherry picked from commit 07be3c9)

# Conflicts:
#	dgraph/cmd/zero/run.go
#	protos/pb/pb.pb.go

dgraph/cmd/zero/http.go

@@ -65,7 +65,7 @@ func (st *state) assign(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	num := &pb.Num{Val: uint64(val)}
+	num := &pb.Num{Val: val}
 	ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
 	defer cancel()
 
@@ -87,7 +87,7 @@ func (st *state) assign(w http.ResponseWriter, r *http.Request) {
 		ids, err = st.zero.AssignIds(ctx, num)
 	default:
 		x.SetStatus(w, x.Error,
-			fmt.Sprintf("Invalid what: [%s]. Must be one of uids or timestamps", what))
+			fmt.Sprintf("Invalid what: [%s]. Must be one of: [uids, timestamps, nsids]", what))
 		return
 	}
 	if err != nil {
@@ -124,7 +124,10 @@ func (st *state) removeNode(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	if err := st.zero.removeNode(context.Background(), nodeId, uint32(groupId)); err != nil {
+	if _, err := st.zero.RemoveNode(
+		context.Background(),
+		&pb.RemoveNodeRequest{NodeId: nodeId, GroupId: uint32(groupId)},
+	); err != nil {
 		x.SetStatus(w, x.Error, err.Error())
 		return
 	}
@@ -154,8 +157,6 @@ func (st *state) moveTablet(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	tablet := r.URL.Query().Get("tablet")
-
 	namespace := r.URL.Query().Get("namespace")
 	namespace = strings.TrimSpace(namespace)
 	ns := x.GalaxyNamespace
@@ -168,7 +169,7 @@ func (st *state) moveTablet(w http.ResponseWriter, r *http.Request) {
 		}
 	}
 
-	tablet = x.NamespaceAttr(ns, tablet)
+	tablet := r.URL.Query().Get("tablet")
 	if len(tablet) == 0 {
 		w.WriteHeader(http.StatusBadRequest)
 		x.SetStatus(w, x.ErrorInvalidRequest, "tablet is a mandatory query parameter")
@@ -178,50 +179,28 @@ func (st *state) moveTablet(w http.ResponseWriter, r *http.Request) {
 	groupId, ok := intFromQueryParam(w, r, "group")
 	if !ok {
 		w.WriteHeader(http.StatusBadRequest)
-		x.SetStatus(w, x.ErrorInvalidRequest, fmt.Sprintf(
-			"Query parameter 'group' should contain a valid integer."))
-		return
-	}
-	dstGroup := uint32(groupId)
-	knownGroups := st.zero.KnownGroups()
-	var isKnown bool
-	for _, grp := range knownGroups {
-		if grp == dstGroup {
-			isKnown = true
-			break
-		}
-	}
-	if !isKnown {
-		w.WriteHeader(http.StatusBadRequest)
-		x.SetStatus(w, x.ErrorInvalidRequest, fmt.Sprintf("Group: [%d] is not a known group.",
-			dstGroup))
-		return
-	}
-
-	tab := st.zero.ServingTablet(tablet)
-	if tab == nil {
-		w.WriteHeader(http.StatusBadRequest)
-		x.SetStatus(w, x.ErrorInvalidRequest, fmt.Sprintf("No tablet found for: %s", tablet))
-		return
-	}
-
-	srcGroup := tab.GroupId
-	if srcGroup == dstGroup {
-		w.WriteHeader(http.StatusInternalServerError)
 		x.SetStatus(w, x.ErrorInvalidRequest,
-			fmt.Sprintf("Tablet: [%s] is already being served by group: [%d]", tablet, srcGroup))
+			"Query parameter 'group' should contain a valid integer.")
 		return
 	}
+	dstGroup := uint32(groupId)
 
-	if err := st.zero.movePredicate(tablet, srcGroup, dstGroup); err != nil {
-		glog.Errorf("While moving predicate %s from %d -> %d. Error: %v",
-			tablet, srcGroup, dstGroup, err)
-		w.WriteHeader(http.StatusInternalServerError)
-		x.SetStatus(w, x.Error, err.Error())
+	var resp *pb.Status
+	var err error
+	if resp, err = st.zero.MoveTablet(
+		context.Background(),
+		&pb.MoveTabletRequest{Namespace: ns, Tablet: tablet, DstGroup: dstGroup},
+	); err != nil {
+		if resp.GetMsg() == x.ErrorInvalidRequest {
+			w.WriteHeader(http.StatusBadRequest)
+			x.SetStatus(w, x.ErrorInvalidRequest, err.Error())
+		} else {
+			w.WriteHeader(http.StatusInternalServerError)
+			x.SetStatus(w, x.Error, err.Error())
+		}
 		return
 	}
-	_, err := fmt.Fprintf(w, "Predicate: [%s] moved from group [%d] to [%d]",
-		tablet, srcGroup, dstGroup)
+	_, err = fmt.Fprint(w, resp.GetMsg())
 	if err != nil {
 		glog.Warningf("Error while writing response: %+v", err)
 	}

dgraph/cmd/zero/license_ee.go

@@ -13,7 +13,6 @@
 package zero
 
 import (
-	"bytes"
 	"context"
 	"io/ioutil"
 	"math"
@@ -139,7 +138,7 @@ func (st *state) applyEnterpriseLicense(w http.ResponseWriter, r *http.Request)
 
 	ctx, cancel := context.WithTimeout(context.Background(), time.Minute)
 	defer cancel()
-	if err := st.zero.applyLicense(ctx, bytes.NewReader(b)); err != nil {
+	if _, err := st.zero.ApplyLicense(ctx, &pb.ApplyLicenseRequest{License: b}); err != nil {
 		w.WriteHeader(http.StatusBadRequest)
 		x.SetStatus(w, x.ErrorInvalidRequest, err.Error())
 		return
@@ -157,7 +156,7 @@ func (s *Server) applyLicenseFile(path string) {
 	}
 	ctx, cancel := context.WithTimeout(context.Background(), time.Minute)
 	defer cancel()
-	if err = s.applyLicense(ctx, bytes.NewReader(content)); err != nil {
+	if _, err = s.ApplyLicense(ctx, &pb.ApplyLicenseRequest{License: content}); err != nil {
 		glog.Infof("Unable to apply license at %v due to error %v", path, err)
 	}
 }

dgraph/cmd/zero/run.go

@@ -101,6 +101,8 @@ instances to achieve high-availability.
 	flag.StringP("wal", "w", "zw", "Directory storing WAL.")
 	flag.Duration("rebalance_interval", 8*time.Minute, "Interval for trying a predicate move.")
 	flag.String("enterprise_license", "", "Path to the enterprise license file.")
+	flag.Bool("disable_admin_http", false,
+		"Turn on/off the administrative endpoints exposed over Zero's HTTP port.")
 
 	flag.String("limit", worker.ZeroLimitsDefaults, z.NewSuperFlagHelp(worker.ZeroLimitsDefaults).
 		Head("Limit options").
@@ -325,11 +327,14 @@ func run() {
 	http.Handle("/", audit.AuditRequestHttp(baseMux))
 
 	baseMux.HandleFunc("/health", st.pingResponse)
-	baseMux.HandleFunc("/state", st.getState)
-	baseMux.HandleFunc("/removeNode", st.removeNode)
-	baseMux.HandleFunc("/moveTablet", st.moveTablet)
-	baseMux.HandleFunc("/assign", st.assign)
-	baseMux.HandleFunc("/enterpriseLicense", st.applyEnterpriseLicense)
+	// the following endpoints are disabled only if the flag is explicitly set to true
+	if !Zero.Conf.GetBool("disable_admin_http") {
+		baseMux.HandleFunc("/state", st.getState)
+		baseMux.HandleFunc("/removeNode", st.removeNode)
+		baseMux.HandleFunc("/moveTablet", st.moveTablet)
+		baseMux.HandleFunc("/assign", st.assign)
+		baseMux.HandleFunc("/enterpriseLicense", st.applyEnterpriseLicense)
+	}
 	baseMux.HandleFunc("/debug/jemalloc", x.JemallocHandler)
 	zpages.Handle(baseMux, "/debug/z")
 

dgraph/cmd/zero/tablet.go

@@ -72,6 +72,52 @@ func (s *Server) rebalanceTablets() {
 	}
 }
 
+// MoveTablet can be used to move a tablet to a specific group.
+// It takes in tablet and destination group as argument.
+// It returns a *pb.Status to be used by the `/moveTablet` HTTP handler in Zero.
+func (s *Server) MoveTablet(ctx context.Context, req *pb.MoveTabletRequest) (*pb.Status, error) {
+	if !s.Node.AmLeader() {
+		return &pb.Status{Code: 1, Msg: x.Error}, errNotLeader
+	}
+
+	knownGroups := s.KnownGroups()
+	var isKnown bool
+	for _, grp := range knownGroups {
+		if grp == req.DstGroup {
+			isKnown = true
+			break
+		}
+	}
+	if !isKnown {
+		return &pb.Status{Code: 1, Msg: x.ErrorInvalidRequest},
+			fmt.Errorf("Group: [%d] is not a known group.", req.DstGroup)
+	}
+
+	tablet := x.NamespaceAttr(req.Namespace, req.Tablet)
+	tab := s.ServingTablet(tablet)
+	if tab == nil {
+		return &pb.Status{Code: 1, Msg: x.ErrorInvalidRequest},
+			fmt.Errorf("namespace: %d. No tablet found for: %s", req.Namespace, req.Tablet)
+	}
+
+	srcGroup := tab.GroupId
+	if srcGroup == req.DstGroup {
+		return &pb.Status{Code: 1, Msg: x.ErrorInvalidRequest},
+			fmt.Errorf("namespace: %d. Tablet: [%s] is already being served by group: [%d]",
+				req.Namespace, req.Tablet, srcGroup)
+	}
+
+	if err := s.movePredicate(tablet, srcGroup, req.DstGroup); err != nil {
+		glog.Errorf("namespace: %d. While moving predicate %s from %d -> %d. Error: %v",
+			req.Namespace, req.Tablet, srcGroup, req.DstGroup, err)
+		return &pb.Status{Code: 1, Msg: x.Error}, err
+	}
+
+	return &pb.Status{Code: 0, Msg: fmt.Sprintf("namespace: %d. "+
+		"Predicate: [%s] moved from group [%d] to [%d]", req.Namespace, req.Tablet, srcGroup,
+		req.DstGroup)}, nil
+}
+
 // movePredicate is the main entry point for move predicate logic. This Zero must remain the leader
 // for the entire duration of predicate move. If this Zero stops being the leader, the final
 // proposal of reassigning the tablet to the destination would fail automatically.

dgraph/cmd/zero/zero.go

@@ -17,9 +17,9 @@
 package zero
 
 import (
+	"bytes"
 	"context"
 	"crypto/tls"
-	"io"
 	"math"
 	"strings"
 	"sync"
@@ -405,26 +405,32 @@ func (s *Server) createProposals(dst *pb.Group) ([]*pb.ZeroProposal, error) {
 	return res, nil
 }
 
-// removeNode removes the given node from the given group.
+// RemoveNode removes the given node from the given group.
 // It's the user's responsibility to ensure that node doesn't come back again
 // before calling the api.
-func (s *Server) removeNode(ctx context.Context, nodeId uint64, groupId uint32) error {
-	if groupId == 0 {
-		return s.Node.ProposePeerRemoval(ctx, nodeId)
+func (s *Server) RemoveNode(ctx context.Context, req *pb.RemoveNodeRequest) (*pb.Status, error) {
+	if req.GroupId == 0 {
+		return nil, s.Node.ProposePeerRemoval(ctx, req.NodeId)
 	}
 	zp := &pb.ZeroProposal{}
-	zp.Member = &pb.Member{Id: nodeId, GroupId: groupId, AmDead: true}
-	if _, ok := s.state.Groups[groupId]; !ok {
-		return errors.Errorf("No group with groupId %d found", groupId)
+	zp.Member = &pb.Member{Id: req.NodeId, GroupId: req.GroupId, AmDead: true}
+	if _, ok := s.state.Groups[req.GroupId]; !ok {
+		return nil, errors.Errorf("No group with groupId %d found", req.GroupId)
 	}
-	if _, ok := s.state.Groups[groupId].Members[nodeId]; !ok {
-		return errors.Errorf("No node with nodeId %d found in group %d", nodeId, groupId)
+	if _, ok := s.state.Groups[req.GroupId].Members[req.NodeId]; !ok {
+		return nil, errors.Errorf("No node with nodeId %d found in group %d", req.NodeId,
+			req.GroupId)
 	}
-	if len(s.state.Groups[groupId].Members) == 1 && len(s.state.Groups[groupId].Tablets) > 0 {
-		return errors.Errorf("Move all tablets from group %d before removing the last node", groupId)
+	if len(s.state.Groups[req.GroupId].Members) == 1 && len(s.state.Groups[req.GroupId].
+		Tablets) > 0 {
+		return nil, errors.Errorf("Move all tablets from group %d before removing the last node",
+			req.GroupId)
+	}
+	if err := s.Node.proposeAndWait(ctx, zp); err != nil {
+		return nil, err
 	}
 
-	return s.Node.proposeAndWait(ctx, zp)
+	return &pb.Status{}, nil
 }
 
 // Connect is used by Alpha nodes to connect the very first time with group zero.
@@ -805,19 +811,21 @@ func (s *Server) latestMembershipState(ctx context.Context) (*pb.MembershipState
 	return ms, nil
 }
 
-func (s *Server) applyLicense(ctx context.Context, signedData io.Reader) error {
+func (s *Server) ApplyLicense(ctx context.Context, req *pb.ApplyLicenseRequest) (*pb.Status,
+	error) {
 	var l license
+	signedData := bytes.NewReader(req.License)
 	if err := verifySignature(signedData, strings.NewReader(publicKey), &l); err != nil {
-		return errors.Wrapf(err, "while extracting enterprise details from the license")
+		return nil, errors.Wrapf(err, "while extracting enterprise details from the license")
 	}
 
 	numNodes := len(s.state.GetZeros())
 	for _, group := range s.state.GetGroups() {
 		numNodes += len(group.GetMembers())
 	}
 	if uint64(numNodes) > l.MaxNodes {
-		return errors.Errorf("Your license only allows [%v] (Alpha + Zero) nodes. You have: [%v].",
-			l.MaxNodes, numNodes)
+		return nil, errors.Errorf("Your license only allows [%v] (Alpha + Zero) nodes. "+
+			"You have: [%v].", l.MaxNodes, numNodes)
 	}
 
 	proposal := &pb.ZeroProposal{
@@ -830,8 +838,8 @@ func (s *Server) applyLicense(ctx context.Context, signedData io.Reader) error {
 
 	err := s.Node.proposeAndWait(ctx, proposal)
 	if err != nil {
-		return errors.Wrapf(err, "while proposing enterprise license state to cluster")
+		return nil, errors.Wrapf(err, "while proposing enterprise license state to cluster")
 	}
 	glog.Infof("Enterprise license proposed to the cluster %+v", proposal)
-	return nil
+	return &pb.Status{}, nil
 }

dgraph/cmd/zero/zero_test.go

@@ -30,8 +30,8 @@ func TestRemoveNode(t *testing.T) {
 			Groups: map[uint32]*pb.Group{1: {Members: map[uint64]*pb.Member{}}},
 		},
 	}
-	err := server.removeNode(context.TODO(), 3, 1)
+	_, err := server.RemoveNode(context.TODO(), &pb.RemoveNodeRequest{NodeId: 3, GroupId: 1})
 	require.Error(t, err)
-	err = server.removeNode(context.TODO(), 1, 2)
+	_, err = server.RemoveNode(context.TODO(), &pb.RemoveNodeRequest{NodeId: 1, GroupId: 2})
 	require.Error(t, err)
 }

ee/acl/acl_test.go

@@ -2736,6 +2736,70 @@ func TestGuardianOnlyAccessForAdminEndpoints(t *testing.T) {
 			guardianErr:        "The path \"\" does not exist or it is inaccessible.",
 			guardianData:       `{"restore": {"code": "Failure"}}`,
 		},
+		{
+			name: "removeNode has guardian auth",
+			query: `
+					mutation {
+					  removeNode(input: {nodeId: 1, groupId: 2147483640}) {
+						response {
+							code
+						}
+					  }
+					}`,
+			queryName:          "removeNode",
+			testGuardianAccess: true,
+			guardianErr:        "No group with groupId 2147483640 found",
+			guardianData:       `{"removeNode": null}`,
+		},
+		{
+			name: "moveTablet has guardian auth",
+			query: `
+					mutation {
+					  moveTablet(input: {tablet: "non_existent_pred", groupId: 2147483640}) {
+						response {
+							code
+							message
+						}
+					  }
+					}`,
+			queryName:          "moveTablet",
+			testGuardianAccess: true,
+			guardianErr:        "Group: [2147483640] is not a known group.",
+			guardianData:       `{"moveTablet": null}`,
+		},
+		{
+			name: "assign has guardian auth",
+			query: `
+					mutation {
+					  assign(input: {what: UID, num: 0}) {
+						response {
+							startId
+							endId
+							readOnly
+						}
+					  }
+					}`,
+			queryName:          "assign",
+			testGuardianAccess: true,
+			guardianErr:        "Nothing to be leased",
+			guardianData:       `{"assign": null}`,
+		},
+		{
+			name: "enterpriseLicense has guardian auth",
+			query: `
+					mutation {
+					  enterpriseLicense(input: {license: ""}) {
+						response {
+							code
+						}
+					  }
+					}`,
+			queryName:          "enterpriseLicense",
+			testGuardianAccess: true,
+			guardianErr: "while extracting enterprise details from the license: while decoding" +
+				" license file: EOF",
+			guardianData: `{"enterpriseLicense": null}`,
+		},
 		{
 			name: "getGQLSchema has guardian auth",
 			query: `