lntest: abstract db backup and restore

lntest/harness.go

@@ -1548,9 +1548,9 @@ func FileExists(path string) bool {
 	return true
 }
 
-// CopyAll copies all files and directories from srcDir to dstDir recursively.
+// copyAll copies all files and directories from srcDir to dstDir recursively.
 // Note that this function does not support links.
-func CopyAll(dstDir, srcDir string) error {
+func copyAll(dstDir, srcDir string) error {
 	entries, err := ioutil.ReadDir(srcDir)
 	if err != nil {
 		return err
@@ -1571,7 +1571,7 @@ func CopyAll(dstDir, srcDir string) error {
 				return err
 			}
 
-			err = CopyAll(dstPath, srcPath)
+			err = copyAll(dstPath, srcPath)
 			if err != nil {
 				return err
 			}
@@ -1582,3 +1582,43 @@ func CopyAll(dstDir, srcDir string) error {
 
 	return nil
 }
+
+// BackupDb creates a backup of the current database.
+func (n *NetworkHarness) BackupDb(hn *HarnessNode) error {
+	if hn.backupDbDir != "" {
+		return errors.New("backup already created")
+	}
+
+	// Backup files.
+	tempDir, err := ioutil.TempDir("", "past-state")
+	if err != nil {
+		return fmt.Errorf("unable to create temp db folder: %v", err)
+	}
+
+	if err := copyAll(tempDir, hn.DBDir()); err != nil {
+		return fmt.Errorf("unable to copy database files: %v", err)
+	}
+
+	hn.backupDbDir = tempDir
+
+	return nil
+}
+
+// RestoreDb restores a database backup.
+func (n *NetworkHarness) RestoreDb(hn *HarnessNode) error {
+	if hn.backupDbDir == "" {
+		return errors.New("no database backup created")
+	}
+
+	// Restore files.
+	if err := copyAll(hn.DBDir(), hn.backupDbDir); err != nil {
+		return fmt.Errorf("unable to copy database files: %v", err)
+	}
+
+	if err := os.RemoveAll(hn.backupDbDir); err != nil {
+		return fmt.Errorf("unable to remove backup dir: %v", err)
+	}
+	hn.backupDbDir = ""
+
+	return nil
+}

lntest/itest/lnd_test.go

@@ -6629,18 +6629,10 @@ func testRevokedCloseRetribution(net *lntest.NetworkHarness, t *harnessTest) {
 	// broadcast this soon to be revoked state.
 	bobStateNumPreCopy := bobChan.NumUpdates
 
-	// Create a temporary file to house Bob's database state at this
-	// particular point in history.
-	bobTempDbPath, err := ioutil.TempDir("", "bob-past-state")
-	if err != nil {
-		t.Fatalf("unable to create temp db folder: %v", err)
-	}
-	defer os.Remove(bobTempDbPath)
-
 	// With the temporary file created, copy Bob's current state into the
 	// temporary file we created above. Later after more updates, we'll
 	// restore this state.
-	if err := lntest.CopyAll(bobTempDbPath, net.Bob.DBDir()); err != nil {
+	if err := net.BackupDb(net.Bob); err != nil {
 		t.Fatalf("unable to copy database files: %v", err)
 	}
 
@@ -6666,7 +6658,7 @@ func testRevokedCloseRetribution(net *lntest.NetworkHarness, t *harnessTest) {
 	// state. With this, we essentially force Bob to travel back in time
 	// within the channel's history.
 	if err = net.RestartNode(net.Bob, func() error {
-		return lntest.CopyAll(net.Bob.DBDir(), bobTempDbPath)
+		return net.RestoreDb(net.Bob)
 	}); err != nil {
 		t.Fatalf("unable to restart node: %v", err)
 	}
@@ -6872,18 +6864,10 @@ func testRevokedCloseRetributionZeroValueRemoteOutput(net *lntest.NetworkHarness
 	// broadcast this soon to be revoked state.
 	carolStateNumPreCopy := carolChan.NumUpdates
 
-	// Create a temporary file to house Carol's database state at this
-	// particular point in history.
-	carolTempDbPath, err := ioutil.TempDir("", "carol-past-state")
-	if err != nil {
-		t.Fatalf("unable to create temp db folder: %v", err)
-	}
-	defer os.Remove(carolTempDbPath)
-
 	// With the temporary file created, copy Carol's current state into the
 	// temporary file we created above. Later after more updates, we'll
 	// restore this state.
-	if err := lntest.CopyAll(carolTempDbPath, carol.DBDir()); err != nil {
+	if err := net.BackupDb(carol); err != nil {
 		t.Fatalf("unable to copy database files: %v", err)
 	}
 
@@ -6908,7 +6892,7 @@ func testRevokedCloseRetributionZeroValueRemoteOutput(net *lntest.NetworkHarness
 	// state. With this, we essentially force Carol to travel back in time
 	// within the channel's history.
 	if err = net.RestartNode(carol, func() error {
-		return lntest.CopyAll(carol.DBDir(), carolTempDbPath)
+		return net.RestoreDb(carol)
 	}); err != nil {
 		t.Fatalf("unable to restart node: %v", err)
 	}
@@ -7185,18 +7169,10 @@ func testRevokedCloseRetributionRemoteHodl(net *lntest.NetworkHarness,
 	// to her channel.
 	checkCarolNumUpdatesAtLeast(1)
 
-	// Create a temporary file to house Carol's database state at this
-	// particular point in history.
-	carolTempDbPath, err := ioutil.TempDir("", "carol-past-state")
-	if err != nil {
-		t.Fatalf("unable to create temp db folder: %v", err)
-	}
-	defer os.Remove(carolTempDbPath)
-
 	// With the temporary file created, copy Carol's current state into the
 	// temporary file we created above. Later after more updates, we'll
 	// restore this state.
-	if err := lntest.CopyAll(carolTempDbPath, carol.DBDir()); err != nil {
+	if err := net.BackupDb(carol); err != nil {
 		t.Fatalf("unable to copy database files: %v", err)
 	}
 
@@ -7230,7 +7206,7 @@ func testRevokedCloseRetributionRemoteHodl(net *lntest.NetworkHarness,
 	// state. With this, we essentially force Carol to travel back in time
 	// within the channel's history.
 	if err = net.RestartNode(carol, func() error {
-		return lntest.CopyAll(carol.DBDir(), carolTempDbPath)
+		return net.RestoreDb(carol)
 	}); err != nil {
 		t.Fatalf("unable to restart node: %v", err)
 	}
@@ -7618,18 +7594,10 @@ func testRevokedCloseRetributionAltruistWatchtowerCase(
 	// broadcast this soon to be revoked state.
 	carolStateNumPreCopy := carolChan.NumUpdates
 
-	// Create a temporary file to house Carol's database state at this
-	// particular point in history.
-	carolTempDbPath, err := ioutil.TempDir("", "carol-past-state")
-	if err != nil {
-		t.Fatalf("unable to create temp db folder: %v", err)
-	}
-	defer os.Remove(carolTempDbPath)
-
 	// With the temporary file created, copy Carol's current state into the
 	// temporary file we created above. Later after more updates, we'll
 	// restore this state.
-	if err := lntest.CopyAll(carolTempDbPath, carol.DBDir()); err != nil {
+	if err := net.BackupDb(carol); err != nil {
 		t.Fatalf("unable to copy database files: %v", err)
 	}
 
@@ -7688,7 +7656,7 @@ func testRevokedCloseRetributionAltruistWatchtowerCase(
 	// state. With this, we essentially force Carol to travel back in time
 	// within the channel's history.
 	if err = net.RestartNode(carol, func() error {
-		return lntest.CopyAll(carol.DBDir(), carolTempDbPath)
+		return net.RestoreDb(carol)
 	}); err != nil {
 		t.Fatalf("unable to restart node: %v", err)
 	}
@@ -8158,18 +8126,10 @@ func testDataLossProtection(net *lntest.NetworkHarness, t *harnessTest) {
 		// revoke this state.
 		stateNumPreCopy := nodeChan.NumUpdates
 
-		// Create a temporary file to house the database state at this
-		// particular point in history.
-		tempDbPath, err := ioutil.TempDir("", node.Name()+"-past-state")
-		if err != nil {
-			t.Fatalf("unable to create temp db folder: %v", err)
-		}
-		defer os.Remove(tempDbPath)
-
 		// With the temporary file created, copy the current state into
 		// the temporary file we created above. Later after more
 		// updates, we'll restore this state.
-		if err := lntest.CopyAll(tempDbPath, node.DBDir()); err != nil {
+		if err := net.BackupDb(node); err != nil {
 			t.Fatalf("unable to copy database files: %v", err)
 		}
 
@@ -8196,7 +8156,7 @@ func testDataLossProtection(net *lntest.NetworkHarness, t *harnessTest) {
 		// force the node to travel back in time within the channel's
 		// history.
 		if err = net.RestartNode(node, func() error {
-			return lntest.CopyAll(node.DBDir(), tempDbPath)
+			return net.RestoreDb(node)
 		}); err != nil {
 			t.Fatalf("unable to restart node: %v", err)
 		}

lntest/node.go

@@ -389,6 +389,9 @@ type HarnessNode struct {
 	WalletKitClient  walletrpc.WalletKitClient
 	Watchtower       watchtowerrpc.WatchtowerClient
 	WatchtowerClient wtclientrpc.WatchtowerClientClient
+
+	// backupDbDir is the path where a database backup is stored, if any.
+	backupDbDir string
 }
 
 // Assert *HarnessNode implements the lnrpc.LightningClient interface.
@@ -1098,6 +1101,13 @@ func (hn *HarnessNode) SetExtraArgs(extraArgs []string) {
 
 // cleanup cleans up all the temporary files created by the node's process.
 func (hn *HarnessNode) cleanup() error {
+	if hn.backupDbDir != "" {
+		err := os.RemoveAll(hn.backupDbDir)
+		if err != nil {
+			return fmt.Errorf("unable to remove backup dir: %v", err)
+		}
+	}
+
 	return os.RemoveAll(hn.Cfg.BaseDir)
 }