auto convert v7 root checkpoint in payloadless mode for localnet

Author: zhangchiqing

integration/localnet/builder/bootstrap.go

@@ -15,6 +15,7 @@ import (
 	"time"
 
 	"github.com/go-yaml/yaml"
+	"github.com/rs/zerolog"
 
 	"github.com/onflow/flow-go/cmd/build"
 	"github.com/onflow/flow-go/ledger/complete/wal"
@@ -862,6 +863,32 @@ func prepareLedgerService(dockerServices Services, flowNodeContainerConfigs []te
 	// Create symlinks for V7 checkpoint (payloadless)
 	v7Filename := bootstrapFilenames.FilenameWALRootCheckpoint + wal.V7FileSuffix
 	checkpointSourceV7 := filepath.Join(bootstrapExecutionStateDir, v7Filename)
+
+	// In payloadless mode a spork only produces a V6 root.checkpoint, and the
+	// ledger service has no bootstrapper of its own to convert it. Convert the V6
+	// root checkpoint into a V7 root checkpoint here (once, at bootstrap time);
+	// the symlink block below then seeds the ledger service's trie directory from
+	// it. On restart the ledger factory finds an existing V7 checkpoint (this root
+	// or a newer numbered one written by the compactor), so no conversion is
+	// needed at runtime. The os.Stat guard makes a re-run of `make bootstrap`
+	// idempotent and avoids ConvertCheckpointV6ToV7's "output exists" rejection.
+	if payloadless {
+		if _, err := os.Stat(checkpointSourceV7); errors.Is(err, fs.ErrNotExist) {
+			logger := zerolog.New(os.Stderr).With().Timestamp().Logger()
+			if convertErr := wal.ConvertCheckpointV6ToV7(
+				bootstrapExecutionStateDir,
+				bootstrapFilenames.FilenameWALRootCheckpoint,
+				bootstrapExecutionStateDir,
+				v7Filename,
+				logger,
+				16,
+			); convertErr != nil {
+				panic(fmt.Errorf("failed to convert V6 root checkpoint to V7 for payloadless ledger service: %w", convertErr))
+			}
+			fmt.Printf("converted V6 root checkpoint to V7 in %s\n", bootstrapExecutionStateDir)
+		}
+	}
+
 	if _, err := os.Stat(checkpointSourceV7); err == nil {
 		// V7 checkpoint exists, create symlinks on host
 		_, err = wal.SoftlinkCheckpointFile(v7Filename, bootstrapExecutionStateDir, trieDir)