main,bdkwallet: implement safe startup logic for BDK wallet

bdkwallet/manager.go

@@ -26,14 +26,25 @@ type Manager struct {
 	wallet Wallet // wallet does not need a mutex as it's done in Rust
 }
 
-func NewManager(config ManagerConfig) (*Manager, error) {
-	log.Info("Starting the BDK wallet manager.")
-	walletDir := filepath.Join(config.DataDir, defaultWalletPath)
+func WalletDir(dataDir string) string {
+	return filepath.Join(dataDir, defaultWalletPath)
+}
+
+func DoesWalletDirExist(dataDir string) (bool, error) {
+	walletDir := WalletDir(dataDir)
 	if _, err := os.Stat(walletDir); err != nil {
-		if !os.IsNotExist(err) {
-			return nil, err
+		if os.IsNotExist(err) {
+			return false, nil
 		}
-		os.MkdirAll(walletDir, os.ModePerm)
+		return false, err
+	}
+	return true, nil
+}
+
+func NewManager(config ManagerConfig) (*Manager, error) {
+	walletDir := WalletDir(config.DataDir)
+	if err := os.MkdirAll(walletDir, os.ModePerm); err != nil {
+		return nil, err
 	}
 
 	dbPath := filepath.Join(walletDir, defaultWalletFileName)
@@ -60,6 +71,7 @@ func NewManager(config ManagerConfig) (*Manager, error) {
 		config.Chain.Subscribe(m.handleBlockchainNotification)
 	}
 
+	log.Info("Started the BDK wallet manager.")
 	return &m, nil
 }
 

config.go

@@ -216,6 +216,7 @@ type config struct {
 	RegisterAddressToWatchOnlyWallet                     []string `long:"registeraddresstowatchonlywallet" description:"Registers addresses to be watched to the watch only wallet. Must have --watchonlywallet enabled"`
 	RegisterExtendedPubKeysToWatchOnlyWallet             []string `long:"registerextendedpubkeystowatchonlywallet" description:"Registers extended pubkeys to be watched to the watch only wallet. Must have --watchonlywallet enabled."`
 	RegisterExtendedPubKeysWithAddrTypeToWatchOnlyWallet []string `long:"registerextendedpubkeyswithaddresstypetowatchonlywallet" description:"Registers extended pubkeys to be watched to the watch only wallet and let's the user override the hd type of the extended public key. Must have --watchonlywallet enabled. Format: '<extendedpubkey>:<address type>. Supported address types: '{p2pkh, p2wpkh, p2sh}'"`
+	BdkWallet                                            bool     `long:"bdkwallet" description:"Enable the BDK wallet."`
 
 	// Electrum server options.
 	ElectrumListeners    []string `long:"electrumlisteners" description:"Interface/port for the electrum server to listen to. (default 50001). Electrum server is only enabled when --watchonlywallet is enabled"`

server.go

@@ -3533,16 +3533,17 @@ func newServer(listenAddrs, agentBlacklist, agentWhitelist []string,
 		}
 	}
 
-	// auto create bdk wallet manager
-	// TODO: We should let the user disable this!
-	s.bdkWallet, err = bdkwallet.NewManager(bdkwallet.ManagerConfig{
-		Chain:       s.chain,
-		TxMemPool:   s.txMemPool,
-		ChainParams: chainParams,
-		DataDir:     cfg.DataDir,
-	})
-	if err != nil {
-		return nil, err
+	if cfg.BdkWallet {
+		// Setup BDK wallet if it is enabled.
+		s.bdkWallet, err = bdkwallet.NewManager(bdkwallet.ManagerConfig{
+			Chain:       s.chain,
+			TxMemPool:   s.txMemPool,
+			ChainParams: chainParams,
+			DataDir:     cfg.DataDir,
+		})
+		if err != nil {
+			return nil, err
+		}
 	}
 
 	if !cfg.DisableRPC {

utreexod.go

@@ -16,6 +16,7 @@ import (
 	"runtime/pprof"
 	"runtime/trace"
 
+	"github.com/utreexo/utreexod/bdkwallet"
 	"github.com/utreexo/utreexod/blockchain"
 	"github.com/utreexo/utreexod/blockchain/indexers"
 	"github.com/utreexo/utreexod/database"
@@ -177,6 +178,21 @@ func btcdMain(serverChan chan<- *server) error {
 			btcdLog.Error(err)
 			return err
 		}
+
+		// If the node had been run with wallet enabled but it now re-started with wallet disabled.
+		var walletDirExists bool
+		if walletDirExists, err = bdkwallet.DoesWalletDirExist(cfg.DataDir); err != nil {
+			btcdLog.Error(err)
+			return err
+		}
+		if walletDirExists && !cfg.BdkWallet {
+			err = fmt.Errorf("BDK wallet is disabled but this node has been previously "+
+				"started with BDK wallet enabled with walletdir of \"%v\". Please "+
+				"completely remove the walletdir to start the node without wallet.",
+				bdkwallet.WalletDir(cfg.DataDir))
+			btcdLog.Error(err)
+			return err
+		}
 	}
 
 	// Drop indexes and exit if requested.