Golang store.UpdateNode函數代碼示例

func (rm *roleManager) reconcileRole(node *api.Node) {
	if node.Role == node.Spec.DesiredRole {
		// Nothing to do.
		delete(rm.pending, node.ID)
		return
	}

	// Promotion can proceed right away.
	if node.Spec.DesiredRole == api.NodeRoleManager && node.Role == api.NodeRoleWorker {
		err := rm.store.Update(func(tx store.Tx) error {
			updatedNode := store.GetNode(tx, node.ID)
			if updatedNode == nil || updatedNode.Spec.DesiredRole != node.Spec.DesiredRole || updatedNode.Role != node.Role {
				return nil
			}
			updatedNode.Role = api.NodeRoleManager
			return store.UpdateNode(tx, updatedNode)
		})
		if err != nil {
			log.L.WithError(err).Errorf("failed to promote node %s", node.ID)
		} else {
			delete(rm.pending, node.ID)
		}
	} else if node.Spec.DesiredRole == api.NodeRoleWorker && node.Role == api.NodeRoleManager {
		// Check for node in memberlist
		member := rm.raft.GetMemberByNodeID(node.ID)
		if member != nil {
			// Quorum safeguard
			if !rm.raft.CanRemoveMember(member.RaftID) {
				// TODO(aaronl): Retry later
				log.L.Debugf("can't demote node %s at this time: removing member from raft would result in a loss of quorum", node.ID)
				return
			}

			rmCtx, rmCancel := context.WithTimeout(rm.ctx, 5*time.Second)
			defer rmCancel()

			if err := rm.raft.RemoveMember(rmCtx, member.RaftID); err != nil {
				// TODO(aaronl): Retry later
				log.L.WithError(err).Debugf("can't demote node %s at this time", node.ID)
				return
			}
		}

		err := rm.store.Update(func(tx store.Tx) error {
			updatedNode := store.GetNode(tx, node.ID)
			if updatedNode == nil || updatedNode.Spec.DesiredRole != node.Spec.DesiredRole || updatedNode.Role != node.Role {
				return nil
			}
			updatedNode.Role = api.NodeRoleWorker

			return store.UpdateNode(tx, updatedNode)
		})
		if err != nil {
			log.L.WithError(err).Errorf("failed to demote node %s", node.ID)
		} else {
			delete(rm.pending, node.ID)
		}
	}
}

func (a *Allocator) allocateNode(ctx context.Context, nc *networkContext, node *api.Node) error {
	if err := nc.nwkAllocator.AllocateNode(node); err != nil {
		return err
	}

	if err := a.store.Update(func(tx store.Tx) error {
		for {
			err := store.UpdateNode(tx, node)
			if err != nil && err != store.ErrSequenceConflict {
				return fmt.Errorf("failed updating state in store transaction for node %s: %v", node.ID, err)
			}

			if err == store.ErrSequenceConflict {
				storeNode := store.GetNode(tx, node.ID)
				storeNode.Attachment = node.Attachment.Copy()
				node = storeNode
				continue
			}

			break
		}
		return nil
	}); err != nil {
		if err := nc.nwkAllocator.DeallocateNode(node); err != nil {
			log.G(ctx).WithError(err).Errorf("failed rolling back allocation of node %s: %v", node.ID, err)
		}

		return err
	}

	return nil
}

// UpdateNode updates a Node referenced by NodeID with the given NodeSpec.
// - Returns `NotFound` if the Node is not found.
// - Returns `InvalidArgument` if the NodeSpec is malformed.
// - Returns an error if the update fails.
func (s *Server) UpdateNode(ctx context.Context, request *api.UpdateNodeRequest) (*api.UpdateNodeResponse, error) {
	if request.NodeID == "" || request.NodeVersion == nil {
		return nil, grpc.Errorf(codes.InvalidArgument, errInvalidArgument.Error())
	}
	if err := validateNodeSpec(request.Spec); err != nil {
		return nil, err
	}

	var (
		node   *api.Node
		demote bool
	)
	err := s.store.Update(func(tx store.Tx) error {
		node = store.GetNode(tx, request.NodeID)
		if node == nil {
			return nil
		}

		// Demotion sanity checks.
		if node.Spec.Role == api.NodeRoleManager && request.Spec.Role == api.NodeRoleWorker {
			demote = true
			managers, err := store.FindNodes(tx, store.ByRole(api.NodeRoleManager))
			if err != nil {
				return grpc.Errorf(codes.Internal, "internal store error: %v", err)
			}
			if len(managers) == 1 && managers[0].ID == node.ID {
				return grpc.Errorf(codes.FailedPrecondition, "attempting to demote the last manager of the swarm")
			}
		}

		node.Meta.Version = *request.NodeVersion
		node.Spec = *request.Spec.Copy()
		return store.UpdateNode(tx, node)
	})
	if err != nil {
		return nil, err
	}
	if node == nil {
		return nil, grpc.Errorf(codes.NotFound, "node %s not found", request.NodeID)
	}

	if demote && s.raft != nil {
		memberlist := s.raft.GetMemberlist()
		for raftID, member := range memberlist {
			if member.NodeID == request.NodeID {
				if err := s.raft.RemoveMember(ctx, raftID); err != nil {
					return nil, err
				}
				break
			}
		}
	}

	return &api.UpdateNodeResponse{
		Node: node,
	}, nil
}

// UpdateNode updates a Node referenced by NodeID with the given NodeSpec.
// - Returns `NotFound` if the Node is not found.
// - Returns `InvalidArgument` if the NodeSpec is malformed.
// - Returns an error if the update fails.
func (s *Server) UpdateNode(ctx context.Context, request *api.UpdateNodeRequest) (*api.UpdateNodeResponse, error) {
	if request.NodeID == "" || request.NodeVersion == nil {
		return nil, grpc.Errorf(codes.InvalidArgument, errInvalidArgument.Error())
	}
	if err := validateNodeSpec(request.Spec); err != nil {
		return nil, err
	}

	var (
		node   *api.Node
		member *membership.Member
	)

	err := s.store.Update(func(tx store.Tx) error {
		node = store.GetNode(tx, request.NodeID)
		if node == nil {
			return grpc.Errorf(codes.NotFound, "node %s not found", request.NodeID)
		}

		// Demotion sanity checks.
		if node.Spec.DesiredRole == api.NodeRoleManager && request.Spec.DesiredRole == api.NodeRoleWorker {
			// Check for manager entries in Store.
			managers, err := store.FindNodes(tx, store.ByRole(api.NodeRoleManager))
			if err != nil {
				return grpc.Errorf(codes.Internal, "internal store error: %v", err)
			}
			if len(managers) == 1 && managers[0].ID == node.ID {
				return grpc.Errorf(codes.FailedPrecondition, "attempting to demote the last manager of the swarm")
			}

			// Check for node in memberlist
			if member = s.raft.GetMemberByNodeID(request.NodeID); member == nil {
				return grpc.Errorf(codes.NotFound, "can't find manager in raft memberlist")
			}

			// Quorum safeguard
			if !s.raft.CanRemoveMember(member.RaftID) {
				return grpc.Errorf(codes.FailedPrecondition, "can't remove member from the raft: this would result in a loss of quorum")
			}
		}

		node.Meta.Version = *request.NodeVersion
		node.Spec = *request.Spec.Copy()
		return store.UpdateNode(tx, node)
	})
	if err != nil {
		return nil, err
	}

	return &api.UpdateNodeResponse{
		Node: node,
	}, nil
}

func (a *Allocator) commitAllocatedNode(ctx context.Context, batch *store.Batch, node *api.Node) error {
	if err := batch.Update(func(tx store.Tx) error {
		err := store.UpdateNode(tx, node)

		if err == store.ErrSequenceConflict {
			storeNode := store.GetNode(tx, node.ID)
			storeNode.Attachment = node.Attachment.Copy()
			err = store.UpdateNode(tx, storeNode)
		}

		return errors.Wrapf(err, "failed updating state in store transaction for node %s", node.ID)
	}); err != nil {
		if err := a.netCtx.nwkAllocator.DeallocateNode(node); err != nil {
			log.G(ctx).WithError(err).Errorf("failed rolling back allocation of node %s", node.ID)
		}

		return err
	}

	return nil
}

func (d *Dispatcher) markNodesUnknown(ctx context.Context) error {
	log := log.G(ctx).WithField("method", "(*Dispatcher).markNodesUnknown")
	var nodes []*api.Node
	var err error
	d.store.View(func(tx store.ReadTx) {
		nodes, err = store.FindNodes(tx, store.All)
	})
	if err != nil {
		return fmt.Errorf("failed to get list of nodes: %v", err)
	}
	_, err = d.store.Batch(func(batch *store.Batch) error {
		for _, n := range nodes {
			err := batch.Update(func(tx store.Tx) error {
				// check if node is still here
				node := store.GetNode(tx, n.ID)
				if node == nil {
					return nil
				}
				// do not try to resurrect down nodes
				if node.Status.State == api.NodeStatus_DOWN {
					return nil
				}
				node.Status = api.NodeStatus{
					State:   api.NodeStatus_UNKNOWN,
					Message: `Node moved to "unknown" state due to leadership change in cluster`,
				}
				nodeID := node.ID

				expireFunc := func() {
					log := log.WithField("node", nodeID)
					nodeStatus := api.NodeStatus{State: api.NodeStatus_DOWN, Message: `heartbeat failure for node in "unknown" state`}
					log.Debugf("heartbeat expiration for unknown node")
					if err := d.nodeRemove(nodeID, nodeStatus); err != nil {
						log.WithError(err).Errorf(`failed deregistering node after heartbeat expiration for node in "unknown" state`)
					}
				}
				if err := d.nodes.AddUnknown(node, expireFunc); err != nil {
					return fmt.Errorf(`adding node in "unknown" state to node store failed: %v`, err)
				}
				if err := store.UpdateNode(tx, node); err != nil {
					return fmt.Errorf("update failed %v", err)
				}
				return nil
			})
			if err != nil {
				log.WithField("node", n.ID).WithError(err).Errorf(`failed to move node to "unknown" state`)
			}
		}
		return nil
	})
	return err
}

// register is used for registration of node with particular dispatcher.
func (d *Dispatcher) register(ctx context.Context, nodeID string, description *api.NodeDescription) (string, error) {
	// prevent register until we're ready to accept it
	if err := d.isRunningLocked(); err != nil {
		return "", err
	}

	if err := d.nodes.CheckRateLimit(nodeID); err != nil {
		return "", err
	}

	// create or update node in store
	// TODO(stevvooe): Validate node specification.
	var node *api.Node
	err := d.store.Update(func(tx store.Tx) error {
		node = store.GetNode(tx, nodeID)
		if node == nil {
			return ErrNodeNotFound
		}

		node.Description = description
		node.Status = api.NodeStatus{
			State: api.NodeStatus_READY,
		}
		return store.UpdateNode(tx, node)

	})
	if err != nil {
		return "", err
	}

	expireFunc := func() {
		nodeStatus := api.NodeStatus{State: api.NodeStatus_DOWN, Message: "heartbeat failure"}
		log.G(ctx).Debugf("heartbeat expiration")
		if err := d.nodeRemove(nodeID, nodeStatus); err != nil {
			log.G(ctx).WithError(err).Errorf("failed deregistering node after heartbeat expiration")
		}
	}

	rn := d.nodes.Add(node, expireFunc)

	// NOTE(stevvooe): We need be a little careful with re-registration. The
	// current implementation just matches the node id and then gives away the
	// sessionID. If we ever want to use sessionID as a secret, which we may
	// want to, this is giving away the keys to the kitchen.
	//
	// The right behavior is going to be informed by identity. Basically, each
	// time a node registers, we invalidate the session and issue a new
	// session, once identity is proven. This will cause misbehaved agents to
	// be kicked when multiple connections are made.
	return rn.SessionID, nil
}

// issueRenewCertificate receives a nodeID and a CSR and modifies the node's certificate entry with the new CSR
// and changes the state to RENEW, so it can be picked up and signed by the signing reconciliation loop
func (s *Server) issueRenewCertificate(ctx context.Context, nodeID string, csr []byte) (*api.IssueNodeCertificateResponse, error) {
	var (
		cert api.Certificate
		node *api.Node
	)
	err := s.store.Update(func(tx store.Tx) error {

		// Attempt to retrieve the node with nodeID
		node = store.GetNode(tx, nodeID)
		if node == nil {
			log.G(ctx).WithFields(logrus.Fields{
				"node.id": nodeID,
				"method":  "issueRenewCertificate",
			}).Warnf("node does not exist")
			// If this node doesn't exist, we shouldn't be renewing a certificate for it
			return grpc.Errorf(codes.NotFound, "node %s not found when attempting to renew certificate", nodeID)
		}

		// Create a new Certificate entry for this node with the new CSR and a RENEW state
		cert = api.Certificate{
			CSR:  csr,
			CN:   node.ID,
			Role: node.Spec.Role,
			Status: api.IssuanceStatus{
				State: api.IssuanceStateRenew,
			},
		}

		node.Certificate = cert
		return store.UpdateNode(tx, node)
	})
	if err != nil {
		return nil, err
	}

	log.G(ctx).WithFields(logrus.Fields{
		"cert.cn":   cert.CN,
		"cert.role": cert.Role,
		"method":    "issueRenewCertificate",
	}).Debugf("node certificate updated")

	return &api.IssueNodeCertificateResponse{
		NodeID:         nodeID,
		NodeMembership: node.Spec.Membership,
	}, nil
}

func TestForceRotationIsNoop(t *testing.T) {
	tc := testutils.NewTestCA(t)
	defer tc.Stop()

	// Get a new Certificate issued
	csr, _, err := ca.GenerateNewCSR()
	assert.NoError(t, err)

	issueRequest := &api.IssueNodeCertificateRequest{CSR: csr, Token: tc.WorkerToken}
	issueResponse, err := tc.NodeCAClients[0].IssueNodeCertificate(context.Background(), issueRequest)
	assert.NoError(t, err)
	assert.NotNil(t, issueResponse.NodeID)
	assert.Equal(t, api.NodeMembershipAccepted, issueResponse.NodeMembership)

	// Check that the Certificate is successfully issued
	statusRequest := &api.NodeCertificateStatusRequest{NodeID: issueResponse.NodeID}
	statusResponse, err := tc.NodeCAClients[0].NodeCertificateStatus(context.Background(), statusRequest)
	require.NoError(t, err)
	assert.Equal(t, api.IssuanceStateIssued, statusResponse.Status.State)
	assert.NotNil(t, statusResponse.Certificate.Certificate)
	assert.Equal(t, api.NodeRoleWorker, statusResponse.Certificate.Role)

	// Update the certificate status to IssuanceStateRotate which should be a server-side noop
	err = tc.MemoryStore.Update(func(tx store.Tx) error {
		// Attempt to retrieve the node with nodeID
		node := store.GetNode(tx, issueResponse.NodeID)
		assert.NotNil(t, node)

		node.Certificate.Status.State = api.IssuanceStateRotate
		return store.UpdateNode(tx, node)
	})
	assert.NoError(t, err)

	// Wait a bit and check that the certificate hasn't changed/been reissued
	time.Sleep(250 * time.Millisecond)

	statusNewResponse, err := tc.NodeCAClients[0].NodeCertificateStatus(context.Background(), statusRequest)
	require.NoError(t, err)
	assert.Equal(t, statusResponse.Certificate.Certificate, statusNewResponse.Certificate.Certificate)
	assert.Equal(t, api.IssuanceStateRotate, statusNewResponse.Certificate.Status.State)
	assert.Equal(t, api.NodeRoleWorker, statusNewResponse.Certificate.Role)
}

func (d *Dispatcher) nodeRemove(id string, status api.NodeStatus) error {
	if err := d.isRunningLocked(); err != nil {
		return err
	}
	// TODO(aaronl): Is it worth batching node removals?
	err := d.store.Update(func(tx store.Tx) error {
		node := store.GetNode(tx, id)
		if node == nil {
			return errors.New("node not found")
		}
		node.Status = status
		return store.UpdateNode(tx, node)
	})
	if err != nil {
		return fmt.Errorf("failed to update node %s status to down: %v", id, err)
	}

	if rn := d.nodes.Delete(id); rn == nil {
		return fmt.Errorf("node %s is not found in local storage", id)
	}

	return nil
}

func (d *Dispatcher) markNodesUnknown(ctx context.Context) error {
	log := log.G(ctx).WithField("method", "(*Dispatcher).markNodesUnknown")
	var nodes []*api.Node
	var err error
	d.store.View(func(tx store.ReadTx) {
		nodes, err = store.FindNodes(tx, store.All)
	})
	if err != nil {
		return errors.Wrap(err, "failed to get list of nodes")
	}
	_, err = d.store.Batch(func(batch *store.Batch) error {
		for _, n := range nodes {
			err := batch.Update(func(tx store.Tx) error {
				// check if node is still here
				node := store.GetNode(tx, n.ID)
				if node == nil {
					return nil
				}
				// do not try to resurrect down nodes
				if node.Status.State == api.NodeStatus_DOWN {
					nodeCopy := node
					expireFunc := func() {
						if err := d.moveTasksToOrphaned(nodeCopy.ID); err != nil {
							log.WithError(err).Error(`failed to move all tasks to "ORPHANED" state`)
						}

						d.downNodes.Delete(nodeCopy.ID)
					}

					d.downNodes.Add(nodeCopy, expireFunc)
					return nil
				}

				node.Status.State = api.NodeStatus_UNKNOWN
				node.Status.Message = `Node moved to "unknown" state due to leadership change in cluster`

				nodeID := node.ID

				expireFunc := func() {
					log := log.WithField("node", nodeID)
					log.Debugf("heartbeat expiration for unknown node")
					if err := d.markNodeNotReady(nodeID, api.NodeStatus_DOWN, `heartbeat failure for node in "unknown" state`); err != nil {
						log.WithError(err).Errorf(`failed deregistering node after heartbeat expiration for node in "unknown" state`)
					}
				}
				if err := d.nodes.AddUnknown(node, expireFunc); err != nil {
					return errors.Wrap(err, `adding node in "unknown" state to node store failed`)
				}
				if err := store.UpdateNode(tx, node); err != nil {
					return errors.Wrap(err, "update failed")
				}
				return nil
			})
			if err != nil {
				log.WithField("node", n.ID).WithError(err).Errorf(`failed to move node to "unknown" state`)
			}
		}
		return nil
	})
	return err
}

func TestIsStateDirty(t *testing.T) {
	ctx := context.Background()

	temp, err := ioutil.TempFile("", "test-socket")
	assert.NoError(t, err)
	assert.NoError(t, temp.Close())
	assert.NoError(t, os.Remove(temp.Name()))

	defer os.RemoveAll(temp.Name())

	stateDir, err := ioutil.TempDir("", "test-raft")
	assert.NoError(t, err)
	defer os.RemoveAll(stateDir)

	tc := testutils.NewTestCA(t, func(p ca.CertPaths) *ca.KeyReadWriter {
		return ca.NewKeyReadWriter(p, []byte("kek"), nil)
	})
	defer tc.Stop()

	managerSecurityConfig, err := tc.NewNodeConfig(ca.ManagerRole)
	assert.NoError(t, err)

	m, err := New(&Config{
		RemoteAPI:        &RemoteAddrs{ListenAddr: "127.0.0.1:0"},
		ControlAPI:       temp.Name(),
		StateDir:         stateDir,
		SecurityConfig:   managerSecurityConfig,
		AutoLockManagers: true,
		UnlockKey:        []byte("kek"),
	})
	assert.NoError(t, err)
	assert.NotNil(t, m)

	go m.Run(ctx)
	defer m.Stop(ctx, false)

	// State should never be dirty just after creating the manager
	isDirty, err := m.IsStateDirty()
	assert.NoError(t, err)
	assert.False(t, isDirty)

	// Wait for cluster and node to be created.
	watch, cancel := state.Watch(m.raftNode.MemoryStore().WatchQueue())
	defer cancel()
	<-watch
	<-watch

	// Updating the node should not cause the state to become dirty
	assert.NoError(t, m.raftNode.MemoryStore().Update(func(tx store.Tx) error {
		node := store.GetNode(tx, m.config.SecurityConfig.ClientTLSCreds.NodeID())
		require.NotNil(t, node)
		node.Spec.Availability = api.NodeAvailabilityPause
		return store.UpdateNode(tx, node)
	}))
	isDirty, err = m.IsStateDirty()
	assert.NoError(t, err)
	assert.False(t, isDirty)

	// Adding a service should cause the state to become dirty
	assert.NoError(t, m.raftNode.MemoryStore().Update(func(tx store.Tx) error {
		return store.CreateService(tx, &api.Service{ID: "foo"})
	}))
	isDirty, err = m.IsStateDirty()
	assert.NoError(t, err)
	assert.True(t, isDirty)
}

func (d *Dispatcher) processUpdates(ctx context.Context) {
	var (
		taskUpdates map[string]*api.TaskStatus
		nodeUpdates map[string]nodeUpdate
	)
	d.taskUpdatesLock.Lock()
	if len(d.taskUpdates) != 0 {
		taskUpdates = d.taskUpdates
		d.taskUpdates = make(map[string]*api.TaskStatus)
	}
	d.taskUpdatesLock.Unlock()

	d.nodeUpdatesLock.Lock()
	if len(d.nodeUpdates) != 0 {
		nodeUpdates = d.nodeUpdates
		d.nodeUpdates = make(map[string]nodeUpdate)
	}
	d.nodeUpdatesLock.Unlock()

	if len(taskUpdates) == 0 && len(nodeUpdates) == 0 {
		return
	}

	log := log.G(ctx).WithFields(logrus.Fields{
		"method": "(*Dispatcher).processUpdates",
	})

	_, err := d.store.Batch(func(batch *store.Batch) error {
		for taskID, status := range taskUpdates {
			err := batch.Update(func(tx store.Tx) error {
				logger := log.WithField("task.id", taskID)
				task := store.GetTask(tx, taskID)
				if task == nil {
					logger.Errorf("task unavailable")
					return nil
				}

				logger = logger.WithField("state.transition", fmt.Sprintf("%v->%v", task.Status.State, status.State))

				if task.Status == *status {
					logger.Debug("task status identical, ignoring")
					return nil
				}

				if task.Status.State > status.State {
					logger.Debug("task status invalid transition")
					return nil
				}

				task.Status = *status
				if err := store.UpdateTask(tx, task); err != nil {
					logger.WithError(err).Error("failed to update task status")
					return nil
				}
				logger.Debug("task status updated")
				return nil
			})
			if err != nil {
				log.WithError(err).Error("dispatcher task update transaction failed")
			}
		}

		for nodeID, nodeUpdate := range nodeUpdates {
			err := batch.Update(func(tx store.Tx) error {
				logger := log.WithField("node.id", nodeID)
				node := store.GetNode(tx, nodeID)
				if node == nil {
					logger.Errorf("node unavailable")
					return nil
				}

				if nodeUpdate.status != nil {
					node.Status.State = nodeUpdate.status.State
					node.Status.Message = nodeUpdate.status.Message
					if nodeUpdate.status.Addr != "" {
						node.Status.Addr = nodeUpdate.status.Addr
					}
				}
				if nodeUpdate.description != nil {
					node.Description = nodeUpdate.description
				}

				if err := store.UpdateNode(tx, node); err != nil {
					logger.WithError(err).Error("failed to update node status")
					return nil
				}
				logger.Debug("node status updated")
				return nil
			})
			if err != nil {
				log.WithError(err).Error("dispatcher node update transaction failed")
			}
		}

		return nil
	})
	if err != nil {
		log.WithError(err).Error("dispatcher batch failed")
	}

//.........這裏部分代碼省略.........

//.........這裏部分代碼省略.........
			NodeID: "id1",
		},
		{
			ID:           "id2",
			DesiredState: api.TaskStateRunning,
			Spec: api.TaskSpec{
				Placement: &api.Placement{
					Constraints: []string{"node.role == worker"},
				},
			},
			Status: api.TaskStatus{
				State: api.TaskStateRunning,
			},
			NodeID: "id1",
		},
		{
			ID:           "id3",
			DesiredState: api.TaskStateNew,
			Status: api.TaskStatus{
				State: api.TaskStateNew,
			},
			NodeID: "id2",
		},
		{
			ID:           "id4",
			DesiredState: api.TaskStateReady,
			Spec: api.TaskSpec{
				Resources: &api.ResourceRequirements{
					Reservations: &api.Resources{
						MemoryBytes: 9e8,
					},
				},
			},
			Status: api.TaskStatus{
				State: api.TaskStatePending,
			},
			NodeID: "id2",
		},
	}

	s := store.NewMemoryStore(nil)
	assert.NotNil(t, s)
	defer s.Close()

	err := s.Update(func(tx store.Tx) error {
		// Prepoulate nodes
		for _, n := range nodes {
			assert.NoError(t, store.CreateNode(tx, n))
		}

		// Prepopulate tasks
		for _, task := range tasks {
			assert.NoError(t, store.CreateTask(tx, task))
		}
		return nil
	})
	assert.NoError(t, err)

	watch, cancel := state.Watch(s.WatchQueue(), state.EventUpdateTask{})
	defer cancel()

	constraintEnforcer := New(s)
	defer constraintEnforcer.Stop()

	go constraintEnforcer.Run()

	// id0 should be killed immediately
	shutdown1 := testutils.WatchShutdownTask(t, watch)
	assert.Equal(t, "id0", shutdown1.ID)

	// Change node id1 to a manager
	err = s.Update(func(tx store.Tx) error {
		node := store.GetNode(tx, "id1")
		if node == nil {
			t.Fatal("could not get node id1")
		}
		node.Role = api.NodeRoleManager
		assert.NoError(t, store.UpdateNode(tx, node))
		return nil
	})
	assert.NoError(t, err)

	shutdown2 := testutils.WatchShutdownTask(t, watch)
	assert.Equal(t, "id2", shutdown2.ID)

	// Change resources on node id2
	err = s.Update(func(tx store.Tx) error {
		node := store.GetNode(tx, "id2")
		if node == nil {
			t.Fatal("could not get node id2")
		}
		node.Description.Resources.MemoryBytes = 5e8
		assert.NoError(t, store.UpdateNode(tx, node))
		return nil
	})
	assert.NoError(t, err)

	shutdown3 := testutils.WatchShutdownTask(t, watch)
	assert.Equal(t, "id4", shutdown3.ID)
}

// signNodeCert does the bulk of the work for signing a certificate
func (s *Server) signNodeCert(ctx context.Context, node *api.Node) {
	rootCA := s.securityConfig.RootCA()
	externalCA := s.securityConfig.externalCA

	node = node.Copy()
	nodeID := node.ID
	// Convert the role from proto format
	role, err := ParseRole(node.Certificate.Role)
	if err != nil {
		log.G(ctx).WithFields(logrus.Fields{
			"node.id": node.ID,
			"method":  "(*Server).signNodeCert",
		}).WithError(err).Errorf("failed to parse role")
		return
	}

	// Attempt to sign the CSR
	var (
		rawCSR = node.Certificate.CSR
		cn     = node.Certificate.CN
		ou     = role
		org    = s.securityConfig.ClientTLSCreds.Organization()
	)

	// Try using the external CA first.
	cert, err := externalCA.Sign(PrepareCSR(rawCSR, cn, ou, org))
	if err == ErrNoExternalCAURLs {
		// No external CA servers configured. Try using the local CA.
		cert, err = rootCA.ParseValidateAndSignCSR(rawCSR, cn, ou, org)
	}

	if err != nil {
		log.G(ctx).WithFields(logrus.Fields{
			"node.id": node.ID,
			"method":  "(*Server).signNodeCert",
		}).WithError(err).Errorf("failed to sign CSR")
		// If this error is due the lack of signer, maybe some other
		// manager in the future will pick it up. Return without
		// changing the state of the certificate.
		if err == ErrNoValidSigner {
			return
		}
		// If the current state is already Failed, no need to change it
		if node.Certificate.Status.State == api.IssuanceStateFailed {
			return
		}
		// We failed to sign this CSR, change the state to FAILED
		err = s.store.Update(func(tx store.Tx) error {
			node := store.GetNode(tx, nodeID)
			if node == nil {
				return fmt.Errorf("node %s not found", nodeID)
			}

			node.Certificate.Status = api.IssuanceStatus{
				State: api.IssuanceStateFailed,
				Err:   err.Error(),
			}

			return store.UpdateNode(tx, node)
		})
		if err != nil {
			log.G(ctx).WithFields(logrus.Fields{
				"node.id": nodeID,
				"method":  "(*Server).signNodeCert",
			}).WithError(err).Errorf("transaction failed when setting state to FAILED")
		}
		return
	}

	// We were able to successfully sign the new CSR. Let's try to update the nodeStore
	for {
		err = s.store.Update(func(tx store.Tx) error {
			node.Certificate.Certificate = cert
			node.Certificate.Status = api.IssuanceStatus{
				State: api.IssuanceStateIssued,
			}

			err := store.UpdateNode(tx, node)
			if err != nil {
				node = store.GetNode(tx, nodeID)
				if node == nil {
					err = fmt.Errorf("node %s does not exist", nodeID)
				}
			}
			return err
		})
		if err == nil {
			log.G(ctx).WithFields(logrus.Fields{
				"node.id":   node.ID,
				"node.role": node.Certificate.Role,
				"method":    "(*Server).signNodeCert",
			}).Debugf("certificate issued")
			break
		}
		if err == store.ErrSequenceConflict {
			continue
		}

		log.G(ctx).WithFields(logrus.Fields{
//.........這裏部分代碼省略.........