tags: delete persisted tag (#1255)

pkg/tags/tags.go

@@ -35,7 +35,8 @@ import (
 )
 
 const (
-	maxPage = 1000 // hard limit of page size
+	maxPage      = 1000 // hard limit of page size
+	tagKeyPrefix = "tags_"
 )
 
 var (
@@ -125,6 +126,13 @@ func (ts *Tags) Range(fn func(k, v interface{}) bool) {
 
 func (ts *Tags) Delete(k interface{}) {
 	ts.tags.Delete(k)
+
+	// k is a uint32, try to create the tag key and remove
+	// from statestore
+	if uid, ok := k.(uint32); ok && uid != 0 {
+		key := tagKey(uid)
+		_ = ts.stateStore.Delete(key)
+	}
 }
 
 func (ts *Tags) MarshalJSON() (out []byte, err error) {
@@ -192,7 +200,7 @@ func (ts *Tags) ListAll(ctx context.Context, offset, limit int) (t []*Tag, err e
 	}
 
 	// and then from statestore
-	err = ts.stateStore.Iterate("tags_", func(key, value []byte) (stop bool, err error) {
+	err = ts.stateStore.Iterate(tagKeyPrefix, func(key, value []byte) (stop bool, err error) {
 		if offset > 0 {
 			offset--
 			return false, nil
@@ -239,7 +247,7 @@ func decodeTagValueFromStore(value []byte) (*Tag, error) {
 
 // getTagFromStore get a given tag from the state store.
 func (ts *Tags) getTagFromStore(uid uint32) (*Tag, error) {
-	key := "tags_" + strconv.Itoa(int(uid))
+	key := tagKey(uid)
 	var data []byte
 	err := ts.stateStore.Get(key, &data)
 	if err != nil {
@@ -266,3 +274,7 @@ func (ts *Tags) Close() (err error) {
 	}
 	return nil
 }
+
+func tagKey(uid uint32) string {
+	return tagKeyPrefix + strconv.Itoa(int(uid))
+}

pkg/tags/tags_test.go

@@ -18,6 +18,7 @@ package tags
 
 import (
 	"context"
+	"errors"
 	"io/ioutil"
 	"sort"
 	"testing"
@@ -210,4 +211,21 @@ func TestPersistence(t *testing.T) {
 	if ta.Synced != rcvd2.Synced {
 		t.Fatalf("invalid synced: expected %d got %d", ta.Synced, rcvd2.Synced)
 	}
+
+	// regression test case: make sure that a persisted tag
+	// is flushed from statestore on Delete
+	ts.Delete(ta.Uid)
+
+	// simulate node closing down and booting up
+	err = ts.Close()
+	if err != nil {
+		t.Fatal(err)
+	}
+	ts = NewTags(mockStatestore, logger)
+
+	// get the tag after the node boot up
+	_, err = ts.Get(ta.Uid)
+	if !errors.Is(err, ErrNotFound) {
+		t.Fatal(err)
+	}
 }