server: skip deleted and deleting namespaces when migrating intentions to config entries (#9186)

.changelog/9186.txt

@@ -0,0 +1,18 @@
+```release-note:bug
+server: skip deleted and deleting namespaces when migrating intentions to config entries
+```
+
+```release-note:breaking-change
+server: **(Enterprise only)** Pre-existing intentions defined with
+non-existent destination namespaces were non-functional and are erased during
+the upgrade process. This should not matter as these intentions had nothing to
+enforce.
+```
+
+```release-note:breaking-change
+server: **(OSS only)** Pre-existing intentions defined with either a source or
+destination namespace value that is not "default" are rewritten or deleted
+during the upgrade process. Wildcards first attempt to downgrade to "default"
+unless an intention already exists, otherwise these non-functional intentions
+are deleted.
+```

agent/consul/leader_intentions.go

@@ -100,6 +100,11 @@ func (s *Server) legacyIntentionMigration(ctx context.Context) error {
 			return err
 		}
 
+		entries, err = s.filterMigratedLegacyIntentions(entries)
+		if err != nil {
+			return err
+		}
+
 		// Totally cheat and repurpose one part of config entry replication
 		// here so we automatically get our writes rate limited.
 		_, err = s.reconcileLocalConfig(ctx, entries, structs.ConfigEntryUpsert)

agent/consul/leader_intentions_oss.go

@@ -84,3 +84,7 @@ func migrateIntentionsToConfigEntries(ixns structs.Intentions) []*structs.Servic
 
 	return structs.MigrateIntentions(output)
 }
+
+func (s *Server) filterMigratedLegacyIntentions(entries []structs.ConfigEntry) ([]structs.ConfigEntry, error) {
+	return entries, nil
+}

agent/consul/leader_intentions_oss_test.go

@@ -11,6 +11,13 @@ import (
 	"github.com/stretchr/testify/require"
 )
 
+func testLeader_LegacyIntentionMigrationHookEnterprise(_ *testing.T, _ *Server, _ bool) {
+}
+
+func appendLegacyIntentionsForMigrationTestEnterprise(_ *testing.T, _ *Server, ixns []*structs.Intention) []*structs.Intention {
+	return ixns
+}
+
 func TestMigrateIntentionsToConfigEntries(t *testing.T) {
 	compare := func(t *testing.T, got structs.Intentions, expect [][]string) {
 		t.Helper()

agent/consul/leader_intentions_test.go

@@ -425,6 +425,11 @@ func TestLeader_LegacyIntentionMigration(t *testing.T) {
 		makeIxn("contractor", "*", false),
 		makeIxn("*", "*", true),
 	}
+	ixns = appendLegacyIntentionsForMigrationTestEnterprise(t, s1pre, ixns)
+
+	testLeader_LegacyIntentionMigrationHookEnterprise(t, s1pre, true)
+
+	var retained []*structs.Intention
 	for _, ixn := range ixns {
 		ixn2 := *ixn
 		resp, err := s1pre.raftApply(structs.IntentionRequestType, &structs.IntentionRequest{
@@ -435,6 +440,10 @@ func TestLeader_LegacyIntentionMigration(t *testing.T) {
 		if respErr, ok := resp.(error); ok {
 			t.Fatalf("respErr: %v", respErr)
 		}
+
+		if _, present := ixn.Meta["unit-test-discarded"]; !present {
+			retained = append(retained, ixn)
+		}
 	}
 
 	mapify := func(ixns []*structs.Intention) map[string]*structs.Intention {
@@ -465,7 +474,7 @@ func TestLeader_LegacyIntentionMigration(t *testing.T) {
 			for k, expectV := range expect {
 				gotV, ok := gotM[k]
 				if !ok {
-					r.Errorf("results are missing key %q", k)
+					r.Errorf("results are missing key %q: %v", k, expectV)
 					continue
 				}
 
@@ -483,8 +492,14 @@ func TestLeader_LegacyIntentionMigration(t *testing.T) {
 	}
 
 	expectM := mapify(ixns)
+	expectRetainedM := mapify(retained)
+
+	require.True(t, t.Run("check initial intentions", func(t *testing.T) {
 		checkIntentions(t, s1pre, false, expectM)
+	}))
+	require.True(t, t.Run("check initial legacy intentions", func(t *testing.T) {
 		checkIntentions(t, s1pre, true, expectM)
+	}))
 
 	// Shutdown s1pre and restart it to trigger migration.
 	s1pre.Shutdown()
@@ -500,8 +515,7 @@ func TestLeader_LegacyIntentionMigration(t *testing.T) {
 
 	testrpc.WaitForLeader(t, s1.RPC, "dc1")
 
-	// check that all 7 intentions are present before migration
-	checkIntentions(t, s1, false, expectM)
+	testLeader_LegacyIntentionMigrationHookEnterprise(t, s1, false)
 
 	// Wait until the migration routine is complete.
 	retry.Run(t, func(r *retry.R) {
@@ -513,9 +527,13 @@ func TestLeader_LegacyIntentionMigration(t *testing.T) {
 	})
 
 	// check that all 7 intentions are present the general way after migration
-	checkIntentions(t, s1, false, expectM)
+	require.True(t, t.Run("check migrated intentions", func(t *testing.T) {
+		checkIntentions(t, s1, false, expectRetainedM)
+	}))
+	require.True(t, t.Run("check migrated legacy intentions", func(t *testing.T) {
 		// check that no intentions exist in the legacy table
 		checkIntentions(t, s1, true, map[string]*structs.Intention{})
+	}))
 
 	mapifyConfigs := func(entries interface{}) map[structs.ConfigEntryKindName]*structs.ServiceIntentionsConfigEntry {
 		m := make(map[structs.ConfigEntryKindName]*structs.ServiceIntentionsConfigEntry)
@@ -541,7 +559,7 @@ func TestLeader_LegacyIntentionMigration(t *testing.T) {
 	require.NoError(t, err)
 	gotConfigsM := mapifyConfigs(gotConfigs)
 
-	expectConfigs := structs.MigrateIntentions(ixns)
+	expectConfigs := structs.MigrateIntentions(retained)
 	for _, entry := range expectConfigs {
 		require.NoError(t, entry.LegacyNormalize()) // tidy them up the same way the write would
 	}

agent/consul/leader_routine_manager.go

@@ -12,8 +12,17 @@ import (
 type LeaderRoutine func(ctx context.Context) error
 
 type leaderRoutine struct {
-	running bool
 	cancel    context.CancelFunc
+	stoppedCh chan struct{} // closed when no longer running
+}
+
+func (r *leaderRoutine) running() bool {
+	select {
+	case <-r.stoppedCh:
+		return false
+	default:
+		return true
+	}
 }
 
 type LeaderRoutineManager struct {
@@ -41,7 +50,7 @@ func (m *LeaderRoutineManager) IsRunning(name string) bool {
 	defer m.lock.Unlock()
 
 	if routine, ok := m.routines[name]; ok {
-		return routine.running
+		return routine.running()
 	}
 
 	return false
@@ -55,7 +64,7 @@ func (m *LeaderRoutineManager) StartWithContext(parentCtx context.Context, name
 	m.lock.Lock()
 	defer m.lock.Unlock()
 
-	if instance, ok := m.routines[name]; ok && instance.running {
+	if instance, ok := m.routines[name]; ok && instance.running() {
 		return nil
 	}
 
@@ -65,11 +74,15 @@ func (m *LeaderRoutineManager) StartWithContext(parentCtx context.Context, name
 
 	ctx, cancel := context.WithCancel(parentCtx)
 	instance := &leaderRoutine{
-		running: true,
 		cancel:    cancel,
+		stoppedCh: make(chan struct{}),
 	}
 
 	go func() {
+		defer func() {
+			close(instance.stoppedCh)
+		}()
+
 		err := routine(ctx)
 		if err != nil && err != context.DeadlineExceeded && err != context.Canceled {
 			m.logger.Error("routine exited with error",
@@ -79,10 +92,6 @@ func (m *LeaderRoutineManager) StartWithContext(parentCtx context.Context, name
 		} else {
 			m.logger.Debug("stopped routine", "routine", name)
 		}
-
-		m.lock.Lock()
-		instance.running = false
-		m.lock.Unlock()
 	}()
 
 	m.routines[name] = instance
@@ -90,7 +99,19 @@ func (m *LeaderRoutineManager) StartWithContext(parentCtx context.Context, name
 	return nil
 }
 
-func (m *LeaderRoutineManager) Stop(name string) error {
+func (m *LeaderRoutineManager) Stop(name string) <-chan struct{} {
+	instance := m.stopInstance(name)
+	if instance == nil {
+		// Fabricate a closed channel so it won't block forever.
+		ch := make(chan struct{})
+		close(ch)
+		return ch
+	}
+
+	return instance.stoppedCh
+}
+
+func (m *LeaderRoutineManager) stopInstance(name string) *leaderRoutine {
 	m.lock.Lock()
 	defer m.lock.Unlock()
 
@@ -100,15 +121,16 @@ func (m *LeaderRoutineManager) Stop(name string) error {
 		return nil
 	}
 
-	if !instance.running {
-		return nil
+	if !instance.running() {
+		return instance
 	}
 
 	m.logger.Debug("stopping routine", "routine", name)
 	instance.cancel()
 
 	delete(m.routines, name)
-	return nil
+
+	return instance
 }
 
 func (m *LeaderRoutineManager) StopAll() {
@@ -116,7 +138,7 @@ func (m *LeaderRoutineManager) StopAll() {
 	defer m.lock.Unlock()
 
 	for name, routine := range m.routines {
-		if !routine.running {
+		if !routine.running() {
 			continue
 		}
 		m.logger.Debug("stopping routine", "routine", name)

agent/consul/leader_routine_manager_test.go

@@ -36,7 +36,9 @@ func TestLeaderRoutineManager(t *testing.T) {
 		require.Equal(r, uint32(1), atomic.LoadUint32(&runs))
 		require.Equal(r, uint32(1), atomic.LoadUint32(&running))
 	})
-	require.NoError(t, mgr.Stop("run"))
+	doneCh := mgr.Stop("run")
+	require.NotNil(t, doneCh)
+	<-doneCh
 
 	// ensure the background go routine was actually cancelled
 	retry.Run(t, func(r *retry.R) {
@@ -51,7 +53,10 @@ func TestLeaderRoutineManager(t *testing.T) {
 		require.Equal(r, uint32(1), atomic.LoadUint32(&running))
 	})
 
-	require.NoError(t, mgr.Stop("run"))
+	doneCh = mgr.Stop("run")
+	require.NotNil(t, doneCh)
+	<-doneCh
+
 	retry.Run(t, func(r *retry.R) {
 		require.Equal(r, uint32(0), atomic.LoadUint32(&running))
 	})