headscale/hscontrol/state/persist_clobber_test.go
Kristoffer Dalby 2e2401833b state: persist live NodeStore node in persistNodeToDB
Avoids clobbering concurrent admin writes (tags, routes, rename).
2026-06-08 10:04:49 +02:00

71 lines
2.5 KiB
Go

package state
import (
"testing"
"github.com/stretchr/testify/assert"
"github.com/stretchr/testify/require"
"tailscale.com/tailcfg"
)
// TestPersistNodeDoesNotClobberConcurrentAdminWrite ensures that persisting a
// node snapshot captured earlier (as UpdateNodeFromMapRequest does at the top
// of its body) cannot overwrite a concurrent admin write (SetNodeTags) that
// landed in between. NodeStore is the source of truth; the database row must
// converge on it rather than reverting to the stale snapshot.
func TestPersistNodeDoesNotClobberConcurrentAdminWrite(t *testing.T) {
dbPath, s, nodeID := persistTestSetup(t)
pol := `{
"tagOwners": {"tag:foo": ["persist-user@"]},
"acls": [{"action": "accept", "src": ["*"], "dst": ["*:*"]}]
}`
_, err := s.SetPolicy([]byte(pol))
require.NoError(t, err)
before, ok := s.GetNodeByID(nodeID)
require.True(t, ok)
require.False(t, before.IsTagged(), "node should start user-owned")
require.True(t, before.UserID().Valid(), "node should start with a UserID")
// (1) Map-request captures the node snapshot (the stale view).
staleView, ok := s.nodeStore.GetNode(nodeID)
require.True(t, ok)
staleNode := staleView.AsStruct()
staleNode.Hostinfo = &tailcfg.Hostinfo{Hostname: "persist-node"}
staleView = staleNode.View()
// (2) Concurrent admin SetNodeTags lands in the window: NodeStore + DB
// become tagged and user ownership is cleared.
_, _, err = s.SetNodeTags(nodeID, []string{"tag:foo"})
require.NoError(t, err)
dbAfterAdmin, err := s.DB().GetNodeByID(nodeID)
require.NoError(t, err)
require.Equal(t, []string{"tag:foo"}, dbAfterAdmin.Tags.List(),
"precondition: admin SetNodeTags must have written the tag to the DB")
// (3) Map-request persists its stale snapshot.
_, _, err = s.persistNodeToDB(staleView)
require.NoError(t, err)
// The admin write must survive.
dbFinal, err := s.DB().GetNodeByID(nodeID)
require.NoError(t, err)
assert.Equal(t, []string{"tag:foo"}, dbFinal.Tags.List(),
"DB tags must reflect the admin SetNodeTags, not the stale persist")
assert.Nil(t, dbFinal.UserID,
"DB UserID must stay nil after tagging (tags XOR user ownership)")
// Restart: the divergence would surface here in production.
require.NoError(t, s.Close())
s2 := persistTestReopen(t, dbPath)
reloaded, ok := s2.GetNodeByID(nodeID)
require.True(t, ok, "node should reload from DB after restart")
assert.True(t, reloaded.IsTagged(),
"after restart the node must still be tagged")
assert.Equal(t, []string{"tag:foo"}, reloaded.AsStruct().Tags.List(),
"after restart the node must still carry tag:foo")
}