replace ephemeral deletion logic (#2008)

* replace ephemeral deletion logic this commit replaces the way we remove ephemeral nodes, currently they are deleted in a loop and we look at last seen time. This time is now only set when a node disconnects and there was a bug (#2006) where nodes that had never disconnected was deleted since they did not have a last seen. The new logic will start an expiry timer when the node disconnects and delete the node from the database when the timer is up. If the node reconnects within the expiry, the timer is cancelled. Fixes #2006 Signed-off-by: Kristoffer Dalby <kristoffer@tailscale.com> * use uint64 as authekyid and ptr helper in tests Signed-off-by: Kristoffer Dalby <kristoffer@tailscale.com> * add test db helper Signed-off-by: Kristoffer Dalby <kristoffer@tailscale.com> * add list ephemeral node func Signed-off-by: Kristoffer Dalby <kristoffer@tailscale.com> * schedule ephemeral nodes for removal on startup Signed-off-by: Kristoffer Dalby <kristoffer@tailscale.com> * fix gorm query for postgres Signed-off-by: Kristoffer Dalby <kristoffer@tailscale.com> * add godoc Signed-off-by: Kristoffer Dalby <kristoffer@tailscale.com> --------- Signed-off-by: Kristoffer Dalby <kristoffer@tailscale.com>
2024-12-25 21:55:52 -05:00 · 2024-07-18 10:01:59 +02:00 · 2024-07-18 10:01:59 +02:00 · 7e62031444
commit 7e62031444
parent 58bd38a609
13 changed files with 417 additions and 206 deletions
--- a/.github/workflows/test-integration.yaml
+++ b/.github/workflows/test-integration.yaml
@ -42,6 +42,7 @@ jobs:
          - TestPingAllByIPPublicDERP
          - TestAuthKeyLogoutAndRelogin
          - TestEphemeral
+          - TestEphemeral2006DeletedTooQuickly
          - TestPingAllByHostname
          - TestTaildrop
          - TestResolveMagicDNS
--- a/hscontrol/app.go
+++ b/hscontrol/app.go
@ -91,6 +91,7 @@ type Headscale struct {
 	db              *db.HSDatabase
 	ipAlloc         *db.IPAllocator
 	noisePrivateKey *key.MachinePrivate
+	ephemeralGC     *db.EphemeralGarbageCollector

 	DERPMap    *tailcfg.DERPMap
 	DERPServer *derpServer.DERPServer
@ -153,6 +154,12 @@ func NewHeadscale(cfg *types.Config) (*Headscale, error) {
 		return nil, err
 	}

+	app.ephemeralGC = db.NewEphemeralGarbageCollector(func(ni types.NodeID) {
+		if err := app.db.DeleteEphemeralNode(ni); err != nil {
+			log.Err(err).Uint64("node.id", ni.Uint64()).Msgf("failed to delete ephemeral node")
+		}
+	})
+
 	if cfg.OIDC.Issuer != "" {
 		err = app.initOIDC()
 		if err != nil {
@ -217,47 +224,6 @@ func (h *Headscale) redirect(w http.ResponseWriter, req *http.Request) {
 	http.Redirect(w, req, target, http.StatusFound)
 }

-// deleteExpireEphemeralNodes deletes ephemeral node records that have not been
-// seen for longer than h.cfg.EphemeralNodeInactivityTimeout.
-func (h *Headscale) deleteExpireEphemeralNodes(ctx context.Context, every time.Duration) {
-	ticker := time.NewTicker(every)
-
-	for {
-		select {
-		case <-ctx.Done():
-			ticker.Stop()
-			return
-		case <-ticker.C:
-			var removed []types.NodeID
-			var changed []types.NodeID
-			if err := h.db.Write(func(tx *gorm.DB) error {
-				removed, changed = db.DeleteExpiredEphemeralNodes(tx, h.cfg.EphemeralNodeInactivityTimeout)
-
-				return nil
-			}); err != nil {
-				log.Error().Err(err).Msg("database error while expiring ephemeral nodes")
-				continue
-			}
-
-			if removed != nil {
-				ctx := types.NotifyCtx(context.Background(), "expire-ephemeral", "na")
-				h.nodeNotifier.NotifyAll(ctx, types.StateUpdate{
-					Type:    types.StatePeerRemoved,
-					Removed: removed,
-				})
-			}
-
-			if changed != nil {
-				ctx := types.NotifyCtx(context.Background(), "expire-ephemeral", "na")
-				h.nodeNotifier.NotifyAll(ctx, types.StateUpdate{
-					Type:        types.StatePeerChanged,
-					ChangeNodes: changed,
-				})
-			}
-		}
-	}
-}
-
 // expireExpiredNodes expires nodes that have an explicit expiry set
 // after that expiry time has passed.
 func (h *Headscale) expireExpiredNodes(ctx context.Context, every time.Duration) {
@ -557,9 +523,18 @@ func (h *Headscale) Serve() error {
 		return errEmptyInitialDERPMap
 	}

-	expireEphemeralCtx, expireEphemeralCancel := context.WithCancel(context.Background())
-	defer expireEphemeralCancel()
-	go h.deleteExpireEphemeralNodes(expireEphemeralCtx, updateInterval)
+	// Start ephemeral node garbage collector and schedule all nodes
+	// that are already in the database and ephemeral. If they are still
+	// around between restarts, they will reconnect and the GC will
+	// be cancelled.
+	go h.ephemeralGC.Start()
+	ephmNodes, err := h.db.ListEphemeralNodes()
+	if err != nil {
+		return fmt.Errorf("failed to list ephemeral nodes: %w", err)
+	}
+	for _, node := range ephmNodes {
+		h.ephemeralGC.Schedule(node.ID, h.cfg.EphemeralNodeInactivityTimeout)
+	}

 	expireNodeCtx, expireNodeCancel := context.WithCancel(context.Background())
 	defer expireNodeCancel()
@ -809,7 +784,7 @@ func (h *Headscale) Serve() error {
 					Msg("Received signal to stop, shutting down gracefully")

 				expireNodeCancel()
-				expireEphemeralCancel()
+				h.ephemeralGC.Close()

 				trace("waiting for netmap stream to close")
 				h.pollNetMapStreamWG.Wait()
--- a/hscontrol/auth.go
+++ b/hscontrol/auth.go
@ -16,6 +16,7 @@ import (
 	"gorm.io/gorm"
 	"tailscale.com/tailcfg"
 	"tailscale.com/types/key"
+	"tailscale.com/types/ptr"
 )

 func logAuthFunc(
@ -314,9 +315,8 @@ func (h *Headscale) handleAuthKey(
 			Msg("node was already registered before, refreshing with new auth key")

 		node.NodeKey = nodeKey
-		pakID := uint(pak.ID)
-		if pakID != 0 {
-			node.AuthKeyID = &pakID
+		if pak.ID != 0 {
+			node.AuthKeyID = ptr.To(pak.ID)
 		}

 		node.Expiry = &registerRequest.Expiry
@ -394,7 +394,7 @@ func (h *Headscale) handleAuthKey(

 		pakID := uint(pak.ID)
 		if pakID != 0 {
-			nodeToRegister.AuthKeyID = &pakID
+			nodeToRegister.AuthKeyID = ptr.To(pak.ID)
 		}
 		node, err = h.db.RegisterNode(
 			nodeToRegister,
--- a/hscontrol/db/node.go
+++ b/hscontrol/db/node.go
@ -12,6 +12,7 @@ import (
 	"github.com/patrickmn/go-cache"
 	"github.com/puzpuzpuz/xsync/v3"
 	"github.com/rs/zerolog/log"
+	"github.com/sasha-s/go-deadlock"
 	"gorm.io/gorm"
 	"tailscale.com/tailcfg"
 	"tailscale.com/types/key"
@ -78,6 +79,17 @@ func ListNodes(tx *gorm.DB) (types.Nodes, error) {
 	return nodes, nil
 }

+func (hsdb *HSDatabase) ListEphemeralNodes() (types.Nodes, error) {
+	return Read(hsdb.DB, func(rx *gorm.DB) (types.Nodes, error) {
+		nodes := types.Nodes{}
+		if err := rx.Joins("AuthKey").Where(`"AuthKey"."ephemeral" = true`).Find(&nodes).Error; err != nil {
+			return nil, err
+		}
+
+		return nodes, nil
+	})
+}
+
 func listNodesByGivenName(tx *gorm.DB, givenName string) (types.Nodes, error) {
 	nodes := types.Nodes{}
 	if err := tx.
@ -286,6 +298,20 @@ func DeleteNode(tx *gorm.DB,
 	return changed, nil
 }

+// DeleteEphemeralNode deletes a Node from the database, note that this method
+// will remove it straight, and not notify any changes or consider any routes.
+// It is intended for Ephemeral nodes.
+func (hsdb *HSDatabase) DeleteEphemeralNode(
+	nodeID types.NodeID,
+) error {
+	return hsdb.Write(func(tx *gorm.DB) error {
+		if err := tx.Unscoped().Delete(&types.Node{}, nodeID).Error; err != nil {
+			return err
+		}
+		return nil
+	})
+}
+
 // SetLastSeen sets a node's last seen field indicating that we
 // have recently communicating with this node.
 func SetLastSeen(tx *gorm.DB, nodeID types.NodeID, lastSeen time.Time) error {
@ -660,51 +686,6 @@ func GenerateGivenName(
 	return givenName, nil
 }

-func DeleteExpiredEphemeralNodes(tx *gorm.DB,
-	inactivityThreshold time.Duration,
-) ([]types.NodeID, []types.NodeID) {
-	users, err := ListUsers(tx)
-	if err != nil {
-		return nil, nil
-	}
-
-	var expired []types.NodeID
-	var changedNodes []types.NodeID
-	for _, user := range users {
-		nodes, err := ListNodesByUser(tx, user.Name)
-		if err != nil {
-			return nil, nil
-		}
-
-		for idx, node := range nodes {
-			if node.IsEphemeral() && node.LastSeen != nil &&
-				time.Now().
-					After(node.LastSeen.Add(inactivityThreshold)) {
-				expired = append(expired, node.ID)
-
-				log.Info().
-					Str("node", node.Hostname).
-					Msg("Ephemeral client removed from database")
-
-					// empty isConnected map as ephemeral nodes are not routes
-				changed, err := DeleteNode(tx, nodes[idx], nil)
-				if err != nil {
-					log.Error().
-						Err(err).
-						Str("node", node.Hostname).
-						Msg("🤮 Cannot delete ephemeral node from the database")
-				}
-
-				changedNodes = append(changedNodes, changed...)
-			}
-		}
-
-		// TODO(kradalby): needs to be moved out of transaction
-	}
-
-	return expired, changedNodes
-}
-
 func ExpireExpiredNodes(tx *gorm.DB,
 	lastCheck time.Time,
 ) (time.Time, types.StateUpdate, bool) {
@ -737,3 +718,78 @@ func ExpireExpiredNodes(tx *gorm.DB,

 	return started, types.StateUpdate{}, false
 }
+
+// EphemeralGarbageCollector is a garbage collector that will delete nodes after
+// a certain amount of time.
+// It is used to delete ephemeral nodes that have disconnected and should be
+// cleaned up.
+type EphemeralGarbageCollector struct {
+	mu deadlock.Mutex
+
+	deleteFunc  func(types.NodeID)
+	toBeDeleted map[types.NodeID]*time.Timer
+
+	deleteCh chan types.NodeID
+	cancelCh chan struct{}
+}
+
+// NewEphemeralGarbageCollector creates a new EphemeralGarbageCollector, it takes
+// a deleteFunc that will be called when a node is scheduled for deletion.
+func NewEphemeralGarbageCollector(deleteFunc func(types.NodeID)) *EphemeralGarbageCollector {
+	return &EphemeralGarbageCollector{
+		toBeDeleted: make(map[types.NodeID]*time.Timer),
+		deleteCh:    make(chan types.NodeID, 10),
+		cancelCh:    make(chan struct{}),
+		deleteFunc:  deleteFunc,
+	}
+}
+
+// Close stops the garbage collector.
+func (e *EphemeralGarbageCollector) Close() {
+	e.cancelCh <- struct{}{}
+}
+
+// Schedule schedules a node for deletion after the expiry duration.
+func (e *EphemeralGarbageCollector) Schedule(nodeID types.NodeID, expiry time.Duration) {
+	e.mu.Lock()
+	defer e.mu.Unlock()
+
+	timer := time.NewTimer(expiry)
+	e.toBeDeleted[nodeID] = timer
+
+	go func() {
+		select {
+		case _, ok := <-timer.C:
+			if ok {
+				e.deleteCh <- nodeID
+			}
+		}
+	}()
+}
+
+// Cancel cancels the deletion of a node.
+func (e *EphemeralGarbageCollector) Cancel(nodeID types.NodeID) {
+	e.mu.Lock()
+	defer e.mu.Unlock()
+
+	if timer, ok := e.toBeDeleted[nodeID]; ok {
+		timer.Stop()
+		delete(e.toBeDeleted, nodeID)
+	}
+}
+
+// Start starts the garbage collector.
+func (e *EphemeralGarbageCollector) Start() {
+	for {
+		select {
+		case <-e.cancelCh:
+			return
+		case nodeID := <-e.deleteCh:
+			e.mu.Lock()
+			delete(e.toBeDeleted, nodeID)
+			e.mu.Unlock()
+
+			go e.deleteFunc(nodeID)
+		}
+	}
+}
--- a/hscontrol/db/node_test.go
+++ b/hscontrol/db/node_test.go
@ -1,17 +1,23 @@
 package db

 import (
+	"crypto/rand"
 	"fmt"
+	"math/big"
 	"net/netip"
 	"regexp"
 	"strconv"
+	"sync"
 	"testing"
 	"time"

+	"github.com/google/go-cmp/cmp"
 	"github.com/puzpuzpuz/xsync/v3"
+	"github.com/stretchr/testify/assert"
 	"gopkg.in/check.v1"
 	"tailscale.com/tailcfg"
 	"tailscale.com/types/key"
+	"tailscale.com/types/ptr"

 	"github.com/juanfont/headscale/hscontrol/policy"
 	"github.com/juanfont/headscale/hscontrol/types"
@ -30,7 +36,6 @@ func (s *Suite) TestGetNode(c *check.C) {

 	nodeKey := key.NewNode()
 	machineKey := key.NewMachine()
-	pakID := uint(pak.ID)

 	node := &types.Node{
 		ID:             0,
@ -39,7 +44,7 @@ func (s *Suite) TestGetNode(c *check.C) {
 		Hostname:       "testnode",
 		UserID:         user.ID,
 		RegisterMethod: util.RegisterMethodAuthKey,
-		AuthKeyID:      &pakID,
+		AuthKeyID:      ptr.To(pak.ID),
 	}
 	trx := db.DB.Save(node)
 	c.Assert(trx.Error, check.IsNil)
@ -61,7 +66,6 @@ func (s *Suite) TestGetNodeByID(c *check.C) {
 	nodeKey := key.NewNode()
 	machineKey := key.NewMachine()

-	pakID := uint(pak.ID)
 	node := types.Node{
 		ID:             0,
 		MachineKey:     machineKey.Public(),
@ -69,7 +73,7 @@ func (s *Suite) TestGetNodeByID(c *check.C) {
 		Hostname:       "testnode",
 		UserID:         user.ID,
 		RegisterMethod: util.RegisterMethodAuthKey,
-		AuthKeyID:      &pakID,
+		AuthKeyID:      ptr.To(pak.ID),
 	}
 	trx := db.DB.Save(&node)
 	c.Assert(trx.Error, check.IsNil)
@ -93,7 +97,6 @@ func (s *Suite) TestGetNodeByAnyNodeKey(c *check.C) {

 	machineKey := key.NewMachine()

-	pakID := uint(pak.ID)
 	node := types.Node{
 		ID:             0,
 		MachineKey:     machineKey.Public(),
@ -101,7 +104,7 @@ func (s *Suite) TestGetNodeByAnyNodeKey(c *check.C) {
 		Hostname:       "testnode",
 		UserID:         user.ID,
 		RegisterMethod: util.RegisterMethodAuthKey,
-		AuthKeyID:      &pakID,
+		AuthKeyID:      ptr.To(pak.ID),
 	}
 	trx := db.DB.Save(&node)
 	c.Assert(trx.Error, check.IsNil)
@ -145,7 +148,6 @@ func (s *Suite) TestListPeers(c *check.C) {
 	_, err = db.GetNodeByID(0)
 	c.Assert(err, check.NotNil)

-	pakID := uint(pak.ID)
 	for index := 0; index <= 10; index++ {
 		nodeKey := key.NewNode()
 		machineKey := key.NewMachine()
@ -157,7 +159,7 @@ func (s *Suite) TestListPeers(c *check.C) {
 			Hostname:       "testnode" + strconv.Itoa(index),
 			UserID:         user.ID,
 			RegisterMethod: util.RegisterMethodAuthKey,
-			AuthKeyID:      &pakID,
+			AuthKeyID:      ptr.To(pak.ID),
 		}
 		trx := db.DB.Save(&node)
 		c.Assert(trx.Error, check.IsNil)
@ -197,7 +199,6 @@ func (s *Suite) TestGetACLFilteredPeers(c *check.C) {
 	for index := 0; index <= 10; index++ {
 		nodeKey := key.NewNode()
 		machineKey := key.NewMachine()
-		pakID := uint(stor[index%2].key.ID)

 		v4 := netip.MustParseAddr(fmt.Sprintf("100.64.0.%v", strconv.Itoa(index+1)))
 		node := types.Node{
@ -208,7 +209,7 @@ func (s *Suite) TestGetACLFilteredPeers(c *check.C) {
 			Hostname:       "testnode" + strconv.Itoa(index),
 			UserID:         stor[index%2].user.ID,
 			RegisterMethod: util.RegisterMethodAuthKey,
-			AuthKeyID:      &pakID,
+			AuthKeyID:      ptr.To(stor[index%2].key.ID),
 		}
 		trx := db.DB.Save(&node)
 		c.Assert(trx.Error, check.IsNil)
@ -283,7 +284,6 @@ func (s *Suite) TestExpireNode(c *check.C) {

 	nodeKey := key.NewNode()
 	machineKey := key.NewMachine()
-	pakID := uint(pak.ID)

 	node := &types.Node{
 		ID:             0,
@ -292,7 +292,7 @@ func (s *Suite) TestExpireNode(c *check.C) {
 		Hostname:       "testnode",
 		UserID:         user.ID,
 		RegisterMethod: util.RegisterMethodAuthKey,
-		AuthKeyID:      &pakID,
+		AuthKeyID:      ptr.To(pak.ID),
 		Expiry:         &time.Time{},
 	}
 	db.DB.Save(node)
@ -328,7 +328,6 @@ func (s *Suite) TestGenerateGivenName(c *check.C) {

 	machineKey2 := key.NewMachine()

-	pakID := uint(pak.ID)
 	node := &types.Node{
 		ID:             0,
 		MachineKey:     machineKey.Public(),
@ -337,7 +336,7 @@ func (s *Suite) TestGenerateGivenName(c *check.C) {
 		GivenName:      "hostname-1",
 		UserID:         user1.ID,
 		RegisterMethod: util.RegisterMethodAuthKey,
-		AuthKeyID:      &pakID,
+		AuthKeyID:      ptr.To(pak.ID),
 	}

 	trx := db.DB.Save(node)
@ -372,7 +371,6 @@ func (s *Suite) TestSetTags(c *check.C) {
 	nodeKey := key.NewNode()
 	machineKey := key.NewMachine()

-	pakID := uint(pak.ID)
 	node := &types.Node{
 		ID:             0,
 		MachineKey:     machineKey.Public(),
@ -380,7 +378,7 @@ func (s *Suite) TestSetTags(c *check.C) {
 		Hostname:       "testnode",
 		UserID:         user.ID,
 		RegisterMethod: util.RegisterMethodAuthKey,
-		AuthKeyID:      &pakID,
+		AuthKeyID:      ptr.To(pak.ID),
 	}

 	trx := db.DB.Save(node)
@ -566,7 +564,6 @@ func (s *Suite) TestAutoApproveRoutes(c *check.C) {
 	route2 := netip.MustParsePrefix("10.11.0.0/24")

 	v4 := netip.MustParseAddr("100.64.0.1")
-	pakID := uint(pak.ID)
 	node := types.Node{
 		ID:             0,
 		MachineKey:     machineKey.Public(),
@ -574,7 +571,7 @@ func (s *Suite) TestAutoApproveRoutes(c *check.C) {
 		Hostname:       "test",
 		UserID:         user.ID,
 		RegisterMethod: util.RegisterMethodAuthKey,
-		AuthKeyID:      &pakID,
+		AuthKeyID:      ptr.To(pak.ID),
 		Hostinfo: &tailcfg.Hostinfo{
 			RequestTags: []string{"tag:exit"},
 			RoutableIPs: []netip.Prefix{defaultRouteV4, defaultRouteV6, route1, route2},
@ -600,3 +597,121 @@ func (s *Suite) TestAutoApproveRoutes(c *check.C) {
 	c.Assert(err, check.IsNil)
 	c.Assert(enabledRoutes, check.HasLen, 4)
 }
+
+func TestEphemeralGarbageCollectorOrder(t *testing.T) {
+	want := []types.NodeID{1, 3}
+	got := []types.NodeID{}
+
+	e := NewEphemeralGarbageCollector(func(ni types.NodeID) {
+		got = append(got, ni)
+	})
+	go e.Start()
+
+	e.Schedule(1, 1*time.Second)
+	e.Schedule(2, 2*time.Second)
+	e.Schedule(3, 3*time.Second)
+	e.Schedule(4, 4*time.Second)
+	e.Cancel(2)
+	e.Cancel(4)
+
+	time.Sleep(6 * time.Second)
+
+	e.Close()
+
+	if diff := cmp.Diff(want, got); diff != "" {
+		t.Errorf("wrong nodes deleted, unexpected result (-want +got):\n%s", diff)
+	}
+}
+
+func TestEphemeralGarbageCollectorLoads(t *testing.T) {
+	var got []types.NodeID
+	var mu sync.Mutex
+
+	want := 1000
+
+	e := NewEphemeralGarbageCollector(func(ni types.NodeID) {
+		defer mu.Unlock()
+		mu.Lock()
+
+		time.Sleep(time.Duration(generateRandomNumber(t, 3)) * time.Millisecond)
+		got = append(got, ni)
+	})
+	go e.Start()
+
+	for i := 0; i < want; i++ {
+		go e.Schedule(types.NodeID(i), 1*time.Second)
+	}
+
+	time.Sleep(10 * time.Second)
+
+	e.Close()
+	if len(got) != want {
+		t.Errorf("expected %d, got %d", want, len(got))
+	}
+}
+
+func generateRandomNumber(t *testing.T, max int64) int64 {
+	t.Helper()
+	maxB := big.NewInt(max)
+	n, err := rand.Int(rand.Reader, maxB)
+	if err != nil {
+		t.Fatalf("getting random number: %s", err)
+	}
+	return n.Int64() + 1
+}
+
+func TestListEphemeralNodes(t *testing.T) {
+	db, err := newTestDB()
+	if err != nil {
+		t.Fatalf("creating db: %s", err)
+	}
+
+	user, err := db.CreateUser("test")
+	assert.NoError(t, err)
+
+	pak, err := db.CreatePreAuthKey(user.Name, false, false, nil, nil)
+	assert.NoError(t, err)
+
+	pakEph, err := db.CreatePreAuthKey(user.Name, false, true, nil, nil)
+	assert.NoError(t, err)
+
+	node := types.Node{
+		ID:             0,
+		MachineKey:     key.NewMachine().Public(),
+		NodeKey:        key.NewNode().Public(),
+		Hostname:       "test",
+		UserID:         user.ID,
+		RegisterMethod: util.RegisterMethodAuthKey,
+		AuthKeyID:      ptr.To(pak.ID),
+	}
+
+	nodeEph := types.Node{
+		ID:             0,
+		MachineKey:     key.NewMachine().Public(),
+		NodeKey:        key.NewNode().Public(),
+		Hostname:       "ephemeral",
+		UserID:         user.ID,
+		RegisterMethod: util.RegisterMethodAuthKey,
+		AuthKeyID:      ptr.To(pakEph.ID),
+	}
+
+	err = db.DB.Save(&node).Error
+	assert.NoError(t, err)
+
+	err = db.DB.Save(&nodeEph).Error
+	assert.NoError(t, err)
+
+	nodes, err := db.ListNodes()
+	assert.NoError(t, err)
+
+	ephemeralNodes, err := db.ListEphemeralNodes()
+	assert.NoError(t, err)
+
+	assert.Len(t, nodes, 2)
+	assert.Len(t, ephemeralNodes, 1)
+
+	assert.Equal(t, nodeEph.ID, ephemeralNodes[0].ID)
+	assert.Equal(t, nodeEph.AuthKeyID, ephemeralNodes[0].AuthKeyID)
+	assert.Equal(t, nodeEph.UserID, ephemeralNodes[0].UserID)
+	assert.Equal(t, nodeEph.Hostname, ephemeralNodes[0].Hostname)
+}
--- a/hscontrol/db/preauth_keys.go
+++ b/hscontrol/db/preauth_keys.go
@ -10,6 +10,7 @@ import (

 	"github.com/juanfont/headscale/hscontrol/types"
 	"gorm.io/gorm"
+	"tailscale.com/types/ptr"
 )

 var (
@ -197,10 +198,9 @@ func ValidatePreAuthKey(tx *gorm.DB, k string) (*types.PreAuthKey, error) {
 	}

 	nodes := types.Nodes{}
-	pakID := uint(pak.ID)
 	if err := tx.
 		Preload("AuthKey").
-		Where(&types.Node{AuthKeyID: &pakID}).
+		Where(&types.Node{AuthKeyID: ptr.To(pak.ID)}).
 		Find(&nodes).Error; err != nil {
 		return nil, err
 	}
--- a/hscontrol/db/preauth_keys_test.go
+++ b/hscontrol/db/preauth_keys_test.go
@ -6,7 +6,7 @@ import (
 	"github.com/juanfont/headscale/hscontrol/types"
 	"github.com/juanfont/headscale/hscontrol/util"
 	"gopkg.in/check.v1"
-	"gorm.io/gorm"
+	"tailscale.com/types/ptr"
 )

 func (*Suite) TestCreatePreAuthKey(c *check.C) {
@ -76,13 +76,12 @@ func (*Suite) TestAlreadyUsedKey(c *check.C) {
 	pak, err := db.CreatePreAuthKey(user.Name, false, false, nil, nil)
 	c.Assert(err, check.IsNil)

-	pakID := uint(pak.ID)
 	node := types.Node{
 		ID:             0,
 		Hostname:       "testest",
 		UserID:         user.ID,
 		RegisterMethod: util.RegisterMethodAuthKey,
-		AuthKeyID:      &pakID,
+		AuthKeyID:      ptr.To(pak.ID),
 	}
 	trx := db.DB.Save(&node)
 	c.Assert(trx.Error, check.IsNil)
@ -99,13 +98,12 @@ func (*Suite) TestReusableBeingUsedKey(c *check.C) {
 	pak, err := db.CreatePreAuthKey(user.Name, true, false, nil, nil)
 	c.Assert(err, check.IsNil)

-	pakID := uint(pak.ID)
 	node := types.Node{
 		ID:             1,
 		Hostname:       "testest",
 		UserID:         user.ID,
 		RegisterMethod: util.RegisterMethodAuthKey,
-		AuthKeyID:      &pakID,
+		AuthKeyID:      ptr.To(pak.ID),
 	}
 	trx := db.DB.Save(&node)
 	c.Assert(trx.Error, check.IsNil)
@ -127,77 +125,6 @@ func (*Suite) TestNotReusableNotBeingUsedKey(c *check.C) {
 	c.Assert(key.ID, check.Equals, pak.ID)
 }

-func (*Suite) TestEphemeralKeyReusable(c *check.C) {
-	user, err := db.CreateUser("test7")
-	c.Assert(err, check.IsNil)
-
-	pak, err := db.CreatePreAuthKey(user.Name, true, true, nil, nil)
-	c.Assert(err, check.IsNil)
-
-	now := time.Now().Add(-time.Second * 30)
-	pakID := uint(pak.ID)
-	node := types.Node{
-		ID:             0,
-		Hostname:       "testest",
-		UserID:         user.ID,
-		RegisterMethod: util.RegisterMethodAuthKey,
-		LastSeen:       &now,
-		AuthKeyID:      &pakID,
-	}
-	trx := db.DB.Save(&node)
-	c.Assert(trx.Error, check.IsNil)
-
-	_, err = db.ValidatePreAuthKey(pak.Key)
-	c.Assert(err, check.IsNil)
-
-	_, err = db.getNode("test7", "testest")
-	c.Assert(err, check.IsNil)
-
-	db.Write(func(tx *gorm.DB) error {
-		DeleteExpiredEphemeralNodes(tx, time.Second*20)
-		return nil
-	})
-
-	// The machine record should have been deleted
-	_, err = db.getNode("test7", "testest")
-	c.Assert(err, check.NotNil)
-}
-
-func (*Suite) TestEphemeralKeyNotReusable(c *check.C) {
-	user, err := db.CreateUser("test7")
-	c.Assert(err, check.IsNil)
-
-	pak, err := db.CreatePreAuthKey(user.Name, false, true, nil, nil)
-	c.Assert(err, check.IsNil)
-
-	now := time.Now().Add(-time.Second * 30)
-	pakId := uint(pak.ID)
-	node := types.Node{
-		ID:             0,
-		Hostname:       "testest",
-		UserID:         user.ID,
-		RegisterMethod: util.RegisterMethodAuthKey,
-		LastSeen:       &now,
-		AuthKeyID:      &pakId,
-	}
-	db.DB.Save(&node)
-
-	_, err = db.ValidatePreAuthKey(pak.Key)
-	c.Assert(err, check.NotNil)
-
-	_, err = db.getNode("test7", "testest")
-	c.Assert(err, check.IsNil)
-
-	db.Write(func(tx *gorm.DB) error {
-		DeleteExpiredEphemeralNodes(tx, time.Second*20)
-		return nil
-	})
-
-	// The machine record should have been deleted
-	_, err = db.getNode("test7", "testest")
-	c.Assert(err, check.NotNil)
-}
-
 func (*Suite) TestExpirePreauthKey(c *check.C) {
 	user, err := db.CreateUser("test3")
 	c.Assert(err, check.IsNil)
--- a/hscontrol/db/routes_test.go
+++ b/hscontrol/db/routes_test.go
@ -14,6 +14,7 @@ import (
 	"gopkg.in/check.v1"
 	"gorm.io/gorm"
 	"tailscale.com/tailcfg"
+	"tailscale.com/types/ptr"
 )

 var smap = func(m map[types.NodeID]bool) *xsync.MapOf[types.NodeID, bool] {
@ -43,13 +44,12 @@ func (s *Suite) TestGetRoutes(c *check.C) {
 		RoutableIPs: []netip.Prefix{route},
 	}

-	pakID := uint(pak.ID)
 	node := types.Node{
 		ID:             0,
 		Hostname:       "test_get_route_node",
 		UserID:         user.ID,
 		RegisterMethod: util.RegisterMethodAuthKey,
-		AuthKeyID:      &pakID,
+		AuthKeyID:      ptr.To(pak.ID),
 		Hostinfo:       &hostInfo,
 	}
 	trx := db.DB.Save(&node)
@ -95,13 +95,12 @@ func (s *Suite) TestGetEnableRoutes(c *check.C) {
 		RoutableIPs: []netip.Prefix{route, route2},
 	}

-	pakID := uint(pak.ID)
 	node := types.Node{
 		ID:             0,
 		Hostname:       "test_enable_route_node",
 		UserID:         user.ID,
 		RegisterMethod: util.RegisterMethodAuthKey,
-		AuthKeyID:      &pakID,
+		AuthKeyID:      ptr.To(pak.ID),
 		Hostinfo:       &hostInfo,
 	}
 	trx := db.DB.Save(&node)
@ -169,13 +168,12 @@ func (s *Suite) TestIsUniquePrefix(c *check.C) {
 	hostInfo1 := tailcfg.Hostinfo{
 		RoutableIPs: []netip.Prefix{route, route2},
 	}
-	pakID := uint(pak.ID)
 	node1 := types.Node{
 		ID:             1,
 		Hostname:       "test_enable_route_node",
 		UserID:         user.ID,
 		RegisterMethod: util.RegisterMethodAuthKey,
-		AuthKeyID:      &pakID,
+		AuthKeyID:      ptr.To(pak.ID),
 		Hostinfo:       &hostInfo1,
 	}
 	trx := db.DB.Save(&node1)
@ -199,7 +197,7 @@ func (s *Suite) TestIsUniquePrefix(c *check.C) {
 		Hostname:       "test_enable_route_node",
 		UserID:         user.ID,
 		RegisterMethod: util.RegisterMethodAuthKey,
-		AuthKeyID:      &pakID,
+		AuthKeyID:      ptr.To(pak.ID),
 		Hostinfo:       &hostInfo2,
 	}
 	db.DB.Save(&node2)
@ -253,13 +251,12 @@ func (s *Suite) TestDeleteRoutes(c *check.C) {
 	}

 	now := time.Now()
-	pakID := uint(pak.ID)
 	node1 := types.Node{
 		ID:             1,
 		Hostname:       "test_enable_route_node",
 		UserID:         user.ID,
 		RegisterMethod: util.RegisterMethodAuthKey,
-		AuthKeyID:      &pakID,
+		AuthKeyID:      ptr.To(pak.ID),
 		Hostinfo:       &hostInfo1,
 		LastSeen:       &now,
 	}
--- a/hscontrol/db/suite_test.go
+++ b/hscontrol/db/suite_test.go
@ -36,10 +36,18 @@ func (s *Suite) ResetDB(c *check.C) {
 	// }

 	var err error
-	tmpDir, err = os.MkdirTemp("", "headscale-db-test-*")
+	db, err = newTestDB()
 	if err != nil {
 		c.Fatal(err)
 	}
+}
+
+func newTestDB() (*HSDatabase, error) {
+	var err error
+	tmpDir, err = os.MkdirTemp("", "headscale-db-test-*")
+	if err != nil {
+		return nil, err
+	}

 	log.Printf("database path: %s", tmpDir+"/headscale_test.db")

@ -53,6 +61,8 @@ func (s *Suite) ResetDB(c *check.C) {
 		"",
 	)
 	if err != nil {
-		c.Fatal(err)
+		return nil, err
 	}
+
+	return db, nil
 }
--- a/hscontrol/db/users_test.go
+++ b/hscontrol/db/users_test.go
@ -5,6 +5,7 @@ import (
 	"github.com/juanfont/headscale/hscontrol/util"
 	"gopkg.in/check.v1"
 	"gorm.io/gorm"
+	"tailscale.com/types/ptr"
 )

 func (s *Suite) TestCreateAndDestroyUser(c *check.C) {
@ -46,13 +47,12 @@ func (s *Suite) TestDestroyUserErrors(c *check.C) {
 	pak, err = db.CreatePreAuthKey(user.Name, false, false, nil, nil)
 	c.Assert(err, check.IsNil)

-	pakID := uint(pak.ID)
 	node := types.Node{
 		ID:             0,
 		Hostname:       "testnode",
 		UserID:         user.ID,
 		RegisterMethod: util.RegisterMethodAuthKey,
-		AuthKeyID:      &pakID,
+		AuthKeyID:      ptr.To(pak.ID),
 	}
 	trx := db.DB.Save(&node)
 	c.Assert(trx.Error, check.IsNil)
@ -100,13 +100,12 @@ func (s *Suite) TestSetMachineUser(c *check.C) {
 	pak, err := db.CreatePreAuthKey(oldUser.Name, false, false, nil, nil)
 	c.Assert(err, check.IsNil)

-	pakID := uint(pak.ID)
 	node := types.Node{
 		ID:             0,
 		Hostname:       "testnode",
 		UserID:         oldUser.ID,
 		RegisterMethod: util.RegisterMethodAuthKey,
-		AuthKeyID:      &pakID,
+		AuthKeyID:      ptr.To(pak.ID),
 	}
 	trx := db.DB.Save(&node)
 	c.Assert(trx.Error, check.IsNil)
--- a/hscontrol/poll.go
+++ b/hscontrol/poll.go
@ -135,6 +135,18 @@ func (m *mapSession) resetKeepAlive() {
 	m.keepAliveTicker.Reset(m.keepAlive)
 }

+func (m *mapSession) beforeServeLongPoll() {
+	if m.node.IsEphemeral() {
+		m.h.ephemeralGC.Cancel(m.node.ID)
+	}
+}
+
+func (m *mapSession) afterServeLongPoll() {
+	if m.node.IsEphemeral() {
+		m.h.ephemeralGC.Schedule(m.node.ID, m.h.cfg.EphemeralNodeInactivityTimeout)
+	}
+}
+
 // serve handles non-streaming requests.
 func (m *mapSession) serve() {
 	// TODO(kradalby): A set todos to harden:
@ -180,6 +192,8 @@ func (m *mapSession) serve() {
 //
 //nolint:gocyclo
 func (m *mapSession) serveLongPoll() {
+	m.beforeServeLongPoll()
+
 	// Clean up the session when the client disconnects
 	defer func() {
 		m.cancelChMu.Lock()
@ -197,6 +211,7 @@ func (m *mapSession) serveLongPoll() {
 			m.pollFailoverRoutes("node closing connection", m.node)
 		}

+		m.afterServeLongPoll()
 		m.infof("node has disconnected, mapSession: %p, chan: %p", m, m.ch)
 	}()

--- a/hscontrol/types/node.go
+++ b/hscontrol/types/node.go
@ -119,7 +119,7 @@ type Node struct {
 	ForcedTags StringList

 	// TODO(kradalby): This seems like irrelevant information?
-	AuthKeyID *uint       `sql:"DEFAULT:NULL"`
+	AuthKeyID *uint64     `sql:"DEFAULT:NULL"`
 	AuthKey   *PreAuthKey `gorm:"constraint:OnDelete:SET NULL;"`

 	LastSeen *time.Time
--- a/integration/general_test.go
+++ b/integration/general_test.go
@ -297,6 +297,122 @@ func TestEphemeral(t *testing.T) {
 	}
 }

+// TestEphemeral2006DeletedTooQuickly verifies that ephemeral nodes are not
+// deleted by accident if they are still online and active.
+func TestEphemeral2006DeletedTooQuickly(t *testing.T) {
+	IntegrationSkip(t)
+	t.Parallel()
+
+	scenario, err := NewScenario(dockertestMaxWait())
+	assertNoErr(t, err)
+	defer scenario.Shutdown()
+
+	spec := map[string]int{
+		"user1": len(MustTestVersions),
+		"user2": len(MustTestVersions),
+	}
+
+	headscale, err := scenario.Headscale(
+		hsic.WithTestName("ephemeral2006"),
+		hsic.WithConfigEnv(map[string]string{
+			"HEADSCALE_EPHEMERAL_NODE_INACTIVITY_TIMEOUT": "1m6s",
+		}),
+	)
+	assertNoErrHeadscaleEnv(t, err)
+
+	for userName, clientCount := range spec {
+		err = scenario.CreateUser(userName)
+		if err != nil {
+			t.Fatalf("failed to create user %s: %s", userName, err)
+		}
+
+		err = scenario.CreateTailscaleNodesInUser(userName, "all", clientCount, []tsic.Option{}...)
+		if err != nil {
+			t.Fatalf("failed to create tailscale nodes in user %s: %s", userName, err)
+		}
+
+		key, err := scenario.CreatePreAuthKey(userName, true, true)
+		if err != nil {
+			t.Fatalf("failed to create pre-auth key for user %s: %s", userName, err)
+		}
+
+		err = scenario.RunTailscaleUp(userName, headscale.GetEndpoint(), key.GetKey())
+		if err != nil {
+			t.Fatalf("failed to run tailscale up for user %s: %s", userName, err)
+		}
+	}
+
+	err = scenario.WaitForTailscaleSync()
+	assertNoErrSync(t, err)
+
+	allClients, err := scenario.ListTailscaleClients()
+	assertNoErrListClients(t, err)
+
+	allIps, err := scenario.ListTailscaleClientsIPs()
+	assertNoErrListClientIPs(t, err)
+
+	allAddrs := lo.Map(allIps, func(x netip.Addr, index int) string {
+		return x.String()
+	})
+
+	// All ephemeral nodes should be online and reachable.
+	success := pingAllHelper(t, allClients, allAddrs)
+	t.Logf("%d successful pings out of %d", success, len(allClients)*len(allIps))
+
+	// Take down all clients, this should start an expiry timer for each.
+	for _, client := range allClients {
+		err := client.Down()
+		if err != nil {
+			t.Fatalf("failed to take down client %s: %s", client.Hostname(), err)
+		}
+	}
+
+	// Wait a bit and bring up the clients again before the expiry
+	// time of the ephemeral nodes.
+	// Nodes should be able to reconnect and work fine.
+	time.Sleep(30 * time.Second)
+
+	for _, client := range allClients {
+		err := client.Up()
+		if err != nil {
+			t.Fatalf("failed to take down client %s: %s", client.Hostname(), err)
+		}
+	}
+	err = scenario.WaitForTailscaleSync()
+	assertNoErrSync(t, err)
+
+	success = pingAllHelper(t, allClients, allAddrs)
+	t.Logf("%d successful pings out of %d", success, len(allClients)*len(allIps))
+
+	// Take down all clients, this should start an expiry timer for each.
+	for _, client := range allClients {
+		err := client.Down()
+		if err != nil {
+			t.Fatalf("failed to take down client %s: %s", client.Hostname(), err)
+		}
+	}
+
+	// This time wait for all of the nodes to expire and check that they are no longer
+	// registered.
+	time.Sleep(3 * time.Minute)
+
+	for userName := range spec {
+		nodes, err := headscale.ListNodesInUser(userName)
+		if err != nil {
+			log.Error().
+				Err(err).
+				Str("user", userName).
+				Msg("Error listing nodes in user")
+
+			return
+		}
+
+		if len(nodes) != 0 {
+			t.Fatalf("expected no nodes, got %d in user %s", len(nodes), userName)
+		}
+	}
+}
+
 func TestPingAllByHostname(t *testing.T) {
 	IntegrationSkip(t)
 	t.Parallel()