refactor(nodebuilder): use external flock library (#3253)

This PR is prompted by #3246. While looking through the code and understanding how `IsLocked` worked there, I realized that our fslock lib was missing a feature. Instead of asking @mastergaurang94 to fix it, I decided to completely migrate over to a more [comprehensive locking solution](https://github.com/gofrs/flock), which additionally:
* avoids the need custom code to maintain(NIHS)
* solves the problem of locking being annoying after an ungraceful shutdown
* gives us Windows and other niche OS support
	* as well as works around niche FS edge-cases

go.mod

@@ -22,6 +22,7 @@ require (
 	github.com/filecoin-project/dagstore v0.5.6
 	github.com/filecoin-project/go-jsonrpc v0.3.1
 	github.com/gammazero/workerpool v1.1.3
+	github.com/gofrs/flock v0.8.1
 	github.com/gogo/protobuf v1.3.3
 	github.com/golang/mock v1.6.0
 	github.com/gorilla/mux v1.8.1

nodebuilder/config.go

@@ -1,13 +1,14 @@
 package nodebuilder
 
 import (
+	"fmt"
 	"io"
 	"os"
 
 	"github.com/BurntSushi/toml"
+	"github.com/gofrs/flock"
 	"github.com/imdario/mergo"
 
-	"github.com/celestiaorg/celestia-node/libs/fslock"
 	"github.com/celestiaorg/celestia-node/nodebuilder/core"
 	"github.com/celestiaorg/celestia-node/nodebuilder/das"
 	"github.com/celestiaorg/celestia-node/nodebuilder/gateway"
@@ -91,14 +92,15 @@ func RemoveConfig(path string) (err error) {
 		return
 	}
 
-	flock, err := fslock.Lock(lockPath(path))
+	flk := flock.New(lockPath(path))
+	ok, err := flk.TryLock()
 	if err != nil {
-		if err == fslock.ErrLocked {
-			err = ErrOpened
-		}
-		return
+		return fmt.Errorf("locking file: %w", err)
+	}
+	defer flk.Close()
+	if !ok {
+		return ErrOpened
 	}
-	defer flock.Unlock() //nolint: errcheck
 
 	return removeConfig(configPath(path))
 }
@@ -117,14 +119,15 @@ func UpdateConfig(tp node.Type, path string) (err error) {
 		return err
 	}
 
-	flock, err := fslock.Lock(lockPath(path))
+	flk := flock.New(lockPath(path))
+	ok, err := flk.TryLock()
 	if err != nil {
-		if err == fslock.ErrLocked {
-			err = ErrOpened
-		}
-		return err
+		return fmt.Errorf("locking file: %w", err)
+	}
+	defer flk.Close()
+	if !ok {
+		return ErrOpened
 	}
-	defer flock.Unlock() //nolint: errcheck
 
 	newCfg := DefaultConfig(tp)
 

nodebuilder/init.go

@@ -8,11 +8,11 @@ import (
 	"github.com/cosmos/cosmos-sdk/crypto/hd"
 	"github.com/cosmos/cosmos-sdk/crypto/keyring"
 	sdk "github.com/cosmos/cosmos-sdk/types"
+	"github.com/gofrs/flock"
 
 	"github.com/celestiaorg/celestia-app/app"
 	"github.com/celestiaorg/celestia-app/app/encoding"
 
-	"github.com/celestiaorg/celestia-node/libs/fslock"
 	"github.com/celestiaorg/celestia-node/libs/utils"
 	"github.com/celestiaorg/celestia-node/nodebuilder/node"
 	"github.com/celestiaorg/celestia-node/nodebuilder/state"
@@ -35,14 +35,15 @@ func Init(cfg Config, path string, tp node.Type) error {
 		return err
 	}
 
-	flock, err := fslock.Lock(lockPath(path))
+	flk := flock.New(lockPath(path))
+	ok, err := flk.TryLock()
 	if err != nil {
-		if err == fslock.ErrLocked {
-			return ErrOpened
-		}
-		return err
+		return fmt.Errorf("locking file: %w", err)
+	}
+	defer flk.Close()
+	if !ok {
+		return ErrOpened
 	}
-	defer flock.Unlock() //nolint: errcheck
 
 	ksPath := keysPath(path)
 	err = initDir(ksPath)
@@ -82,14 +83,15 @@ func Reset(path string, tp node.Type) error {
 	}
 	log.Infof("Resetting %s Node Store over '%s'", tp, path)
 
-	flock, err := fslock.Lock(lockPath(path))
+	flk := flock.New(lockPath(path))
+	ok, err := flk.TryLock()
 	if err != nil {
-		if err == fslock.ErrLocked {
-			return ErrOpened
-		}
-		return err
+		return fmt.Errorf("locking file: %w", err)
+	}
+	defer flk.Close()
+	if !ok {
+		return ErrOpened
 	}
-	defer flock.Unlock() //nolint: errcheck
 
 	err = resetDir(dataPath(path))
 	if err != nil {

nodebuilder/init_test.go

@@ -7,13 +7,13 @@ import (
 	"github.com/cosmos/cosmos-sdk/crypto/hd"
 	"github.com/cosmos/cosmos-sdk/crypto/keyring"
 	sdk "github.com/cosmos/cosmos-sdk/types"
+	"github.com/gofrs/flock"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 
 	"github.com/celestiaorg/celestia-app/app"
 	"github.com/celestiaorg/celestia-app/app/encoding"
 
-	"github.com/celestiaorg/celestia-node/libs/fslock"
 	"github.com/celestiaorg/celestia-node/nodebuilder/node"
 )
 
@@ -58,9 +58,10 @@ func TestIsInitForNonExistDir(t *testing.T) {
 
 func TestInitErrForLockedDir(t *testing.T) {
 	dir := t.TempDir()
-	flock, err := fslock.Lock(lockPath(dir))
+	flk := flock.New(lockPath(dir))
+	_, err := flk.TryLock()
 	require.NoError(t, err)
-	defer flock.Unlock() //nolint:errcheck
+	defer flk.Close()
 	nodes := []node.Type{node.Light, node.Bridge}
 
 	for _, node := range nodes {

nodebuilder/store.go

@@ -10,11 +10,11 @@ import (
 
 	"github.com/cosmos/cosmos-sdk/crypto/keyring"
 	"github.com/dgraph-io/badger/v4/options"
+	"github.com/gofrs/flock"
 	"github.com/ipfs/go-datastore"
 	dsbadger "github.com/ipfs/go-ds-badger4"
 	"github.com/mitchellh/go-homedir"
 
-	"github.com/celestiaorg/celestia-node/libs/fslock"
 	"github.com/celestiaorg/celestia-node/libs/keystore"
 	"github.com/celestiaorg/celestia-node/share"
 )
@@ -58,28 +58,29 @@ func OpenStore(path string, ring keyring.Keyring) (Store, error) {
 		return nil, err
 	}
 
-	flock, err := fslock.Lock(lockPath(path))
+	flk := flock.New(lockPath(path))
+	ok, err := flk.TryLock()
 	if err != nil {
-		if err == fslock.ErrLocked {
-			return nil, ErrOpened
-		}
-		return nil, err
+		return nil, fmt.Errorf("locking file: %w", err)
 	}
-
-	ok := IsInit(path)
 	if !ok {
-		flock.Unlock() //nolint:errcheck
-		return nil, ErrNotInited
+		return nil, ErrOpened
+	}
+
+	if !IsInit(path) {
+		err := errors.Join(ErrNotInited, flk.Close())
+		return nil, err
 	}
 
 	ks, err := keystore.NewFSKeystore(keysPath(path), ring)
 	if err != nil {
+		err = errors.Join(err, flk.Close())
 		return nil, err
 	}
 
 	return &fsStore{
 		path:    path,
-		dirLock: flock,
+		dirLock: flk,
 		keys:    ks,
 	}, nil
 }
@@ -131,7 +132,7 @@ func (f *fsStore) Datastore() (datastore.Batching, error) {
 }
 
 func (f *fsStore) Close() (err error) {
-	err = errors.Join(err, f.dirLock.Unlock())
+	err = errors.Join(err, f.dirLock.Close())
 	f.dataMu.Lock()
 	if f.data != nil {
 		err = errors.Join(err, f.data.Close())
@@ -146,7 +147,7 @@ type fsStore struct {
 	dataMu  sync.Mutex
 	data    datastore.Batching
 	keys    keystore.Keystore
-	dirLock *fslock.Locker // protects directory
+	dirLock *flock.Flock // protects directory
 }
 
 func storePath(path string) (string, error) {
@@ -158,7 +159,7 @@ func configPath(base string) string {
 }
 
 func lockPath(base string) string {
-	return filepath.Join(base, "lock")
+	return filepath.Join(base, ".lock")
 }
 
 func keysPath(base string) string {