firewalldb: move generic DB setup code to the DB.Start method

In this commit, a new `DeleteTempKVStores` method is added to the
`RulesDB` interface and this is called in the `DB`'s `Start` method.
This is done because regardless of the backend that we use for the
RulesDB, we want this clean-up code to run at start time. It also makes
more sense to have this call in a Start method rather than in a
constructor.

Author: ellemouton

firewalldb/db.go

@@ -39,7 +39,7 @@ func (db *DB) Start(ctx context.Context) error {
 		db.cancel = fn.Some(cancel)
 	})
 
-	return nil
+	return db.DeleteTempKVStores(ctx)
 }
 
 // Stop stops the firewall database operations.

firewalldb/kvdb_store.go

@@ -3,7 +3,6 @@ package firewalldb
 import (
 	"context"
 	"encoding/binary"
-	"errors"
 	"fmt"
 	"os"
 	"path/filepath"
@@ -112,18 +111,11 @@ func initDB(filepath string, firstInit bool) (*bbolt.DB, error) {
 			}
 		}
 
-		rulesBucket, err := tx.CreateBucketIfNotExists(rulesBucketKey)
+		_, err := tx.CreateBucketIfNotExists(rulesBucketKey)
 		if err != nil {
 			return err
 		}
 
-		// Delete everything under the "temp" key if such a bucket
-		// exists.
-		err = rulesBucket.DeleteBucket(tempBucketKey)
-		if err != nil && !errors.Is(err, bbolt.ErrBucketNotFound) {
-			return err
-		}
-
 		actionsBucket, err := tx.CreateBucketIfNotExists(
 			actionsBucketKey,
 		)

firewalldb/kvstores.go

@@ -2,6 +2,7 @@ package firewalldb
 
 import (
 	"context"
+	"errors"
 
 	"github.com/lightninglabs/lightning-terminal/session"
 	"go.etcd.io/bbolt"
@@ -103,6 +104,9 @@ type RulesDB interface {
 	// GetKVStores constructs a new rules.KVStores in a namespace defined
 	// by the rule name, group ID and feature name.
 	GetKVStores(rule string, groupID session.ID, feature string) KVStores
+
+	// DeleteTempKVStores deletes all temporary kv stores.
+	DeleteTempKVStores(ctx context.Context) error
 }
 
 // GetKVStores constructs a new rules.KVStores backed by a bbolt db.
@@ -124,6 +128,25 @@ func (db *BoltDB) GetKVStores(rule string, groupID session.ID,
 	}
 }
 
+// DeleteTempKVStores deletes all kv-stores in the temporary namespace.
+func (db *BoltDB) DeleteTempKVStores(_ context.Context) error {
+	return db.Update(func(tx *bbolt.Tx) error {
+		rulesBucket, err := tx.CreateBucketIfNotExists(rulesBucketKey)
+		if err != nil {
+			return err
+		}
+
+		// Delete everything under the "temp" key if such a bucket
+		// exists.
+		err = rulesBucket.DeleteBucket(tempBucketKey)
+		if err != nil && !errors.Is(err, bbolt.ErrBucketNotFound) {
+			return err
+		}
+
+		return nil
+	})
+}
+
 // kvStores implements the rules.KVStores interface.
 type kvStores struct {
 	ruleName    string

firewalldb/kvstores_test.go

@@ -4,7 +4,6 @@ import (
 	"bytes"
 	"context"
 	"fmt"
-	"os"
 	"testing"
 
 	"github.com/lightninglabs/lightning-terminal/session"
@@ -86,15 +85,21 @@ func testTempAndPermStores(t *testing.T, featureSpecificStore bool) {
 		featureName = "auto-fees"
 	}
 
-	db, err := NewBoltDB(tmpDir, "test.db", nil)
+	store, err := NewBoltDB(tmpDir, "test.db", nil)
 	require.NoError(t, err)
 	t.Cleanup(func() {
-		_ = db.Close()
+		_ = store.Close()
 	})
+	db := NewDB(store)
+	require.NoError(t, db.Start(ctx))
+
+	kvstores := db.GetKVStores(
+		"test-rule", [4]byte{1, 1, 1, 1}, featureName,
+	)
 
-	store := db.GetKVStores("test-rule", [4]byte{1, 1, 1, 1}, featureName)
+	err = kvstores.Update(ctx, func(ctx context.Context,
+		tx KVStoreTx) error {
 
-	err = store.Update(ctx, func(ctx context.Context, tx KVStoreTx) error {
 		// Set an item in the temp store.
 		err := tx.LocalTemp().Set(ctx, "test", []byte{4, 3, 2})
 		if err != nil {
@@ -112,7 +117,7 @@ func testTempAndPermStores(t *testing.T, featureSpecificStore bool) {
 		v1 []byte
 		v2 []byte
 	)
-	err = store.View(ctx, func(ctx context.Context, tx KVStoreTx) error {
+	err = kvstores.View(ctx, func(ctx context.Context, tx KVStoreTx) error {
 		b, err := tx.LocalTemp().Get(ctx, "test")
 		if err != nil {
 			return err
@@ -130,21 +135,15 @@ func testTempAndPermStores(t *testing.T, featureSpecificStore bool) {
 	require.True(t, bytes.Equal(v1, []byte{4, 3, 2}))
 	require.True(t, bytes.Equal(v2, []byte{6, 5, 4}))
 
-	// Close the db.
-	require.NoError(t, db.Close())
+	// Re-init the DB.
+	db = NewDB(store)
+	require.NoError(t, db.Start(ctx))
 
-	// Restart it.
-	db, err = NewBoltDB(tmpDir, "test.db", nil)
-	require.NoError(t, err)
-	t.Cleanup(func() {
-		_ = db.Close()
-		_ = os.RemoveAll(tmpDir)
-	})
-	store = db.GetKVStores("test-rule", [4]byte{1, 1, 1, 1}, featureName)
+	kvstores = db.GetKVStores("test-rule", [4]byte{1, 1, 1, 1}, featureName)
 
 	// The temp store should no longer have the stored value but the perm
 	// store should .
-	err = store.View(ctx, func(ctx context.Context, tx KVStoreTx) error {
+	err = kvstores.View(ctx, func(ctx context.Context, tx KVStoreTx) error {
 		b, err := tx.LocalTemp().Get(ctx, "test")
 		if err != nil {
 			return err