add read-only mode for key-value store and update store-info command

Author: tac0turtle

pkg/cmd/store.go

@@ -71,7 +71,9 @@ var StoreP2PInspectCmd = &cobra.Command{
 	Use:   "store-info",
 	Short: "Inspect the go-header (P2P) stores and display their tail/head entries",
 	Long: `Opens the datastore used by the node's go-header services and reports
-the current height, head, and tail information for both the header and data stores.`,
+the current height, head, and tail information for both the header and data stores.
+The datastore is opened in read-only mode so that it can run against mounted snapshots
+or other read-only environments without requiring write access.`,
 	RunE: func(cmd *cobra.Command, args []string) error {
 		nodeConfig, err := ParseConfig(cmd)
 		if err != nil {
@@ -85,7 +87,7 @@ the current height, head, and tail information for both the header and data stor
 
 		dbName := resolveDBName(cmd)
 
-		rawStore, err := store.NewDefaultKVStore(nodeConfig.RootDir, nodeConfig.DBPath, dbName)
+		rawStore, err := store.NewDefaultReadOnlyKVStore(nodeConfig.RootDir, nodeConfig.DBPath, dbName)
 		if err != nil {
 			return fmt.Errorf("failed to open datastore: %w", err)
 		}

pkg/store/kv.go

@@ -13,8 +13,22 @@ import (
 
 // NewDefaultKVStore creates instance of default key-value store.
 func NewDefaultKVStore(rootDir, dbPath, dbName string) (ds.Batching, error) {
+	return newDefaultKVStore(rootDir, dbPath, dbName, nil)
+}
+
+// NewDefaultReadOnlyKVStore creates a key-value store opened in badger's read-only mode.
+//
+// This is useful for tools that only inspect state (such as store-info) where the
+// underlying data directory might be mounted read-only.
+func NewDefaultReadOnlyKVStore(rootDir, dbPath, dbName string) (ds.Batching, error) {
+	opts := badger4.DefaultOptions
+	opts.Options = opts.Options.WithReadOnly(true)
+	return newDefaultKVStore(rootDir, dbPath, dbName, &opts)
+}
+
+func newDefaultKVStore(rootDir, dbPath, dbName string, options *badger4.Options) (ds.Batching, error) {
 	path := filepath.Join(rootify(rootDir, dbPath), dbName)
-	return badger4.NewDatastore(path, nil)
+	return badger4.NewDatastore(path, options)
 }
 
 // PrefixEntries retrieves all entries in the datastore whose keys have the supplied prefix

pkg/store/kv_test.go

@@ -0,0 +1,36 @@
+package store
+
+import (
+	"context"
+	"testing"
+
+	ds "github.com/ipfs/go-datastore"
+	"github.com/stretchr/testify/require"
+)
+
+func TestNewDefaultReadOnlyKVStore(t *testing.T) {
+	t.Parallel()
+
+	ctx := context.Background()
+	rootDir := t.TempDir()
+	const dbPath = "db"
+	const dbName = "test"
+
+	writable, err := NewDefaultKVStore(rootDir, dbPath, dbName)
+	require.NoError(t, err)
+	require.NoError(t, writable.Put(ctx, ds.NewKey("/foo"), []byte("bar")))
+	require.NoError(t, writable.Close())
+
+	readOnly, err := NewDefaultReadOnlyKVStore(rootDir, dbPath, dbName)
+	require.NoError(t, err)
+	t.Cleanup(func() {
+		_ = readOnly.Close()
+	})
+
+	val, err := readOnly.Get(ctx, ds.NewKey("/foo"))
+	require.NoError(t, err)
+	require.Equal(t, []byte("bar"), val)
+
+	err = readOnly.Put(ctx, ds.NewKey("/foo"), []byte("baz"))
+	require.Error(t, err, "writing to a read-only store should fail")
+}

pkg/sync/sync_service.go

@@ -169,6 +169,7 @@ func (syncService *SyncService[H]) WriteToStoreAndBroadcast(ctx context.Context,
 		}
 
 		syncService.logger.Error().Err(err).Msg("failed to broadcast")
+		panic(err)
 	}
 
 	return nil