Merge pull request #11277 from filecoin-project/0919_jie_flip_flags

Feat: Lotus Daemon CLI: Auto remove existing chain if importing chain file or snapshot

CHANGELOG.md

@@ -1,6 +1,7 @@
 # Lotus changelog
 
 # UNRELEASED
+- chore: Auto remove local chain data when importing chain file or snapshot ([filecoin-project/lotus#11277](https://github.com/filecoin-project/lotus/pull/11277))
 
 ## New features
 - feat: Added new tracing API (**HIGHLY EXPERIMENTAL**) supporting two RPC methods: `trace_block` and `trace_replayBlockTransactions` ([filecoin-project/lotus#11100](https://github.com/filecoin-project/lotus/pull/11100))

cmd/lotus/daemon.go

@@ -269,7 +269,37 @@ var DaemonCmd = &cli.Command{
 			}
 		}
 
-		if cctx.Bool("remove-existing-chain") {
+		chainfile := cctx.String("import-chain")
+		snapshot := cctx.String("import-snapshot")
+		willImportChain := false
+		if chainfile != "" || snapshot != "" {
+			if chainfile != "" && snapshot != "" {
+				return fmt.Errorf("cannot specify both 'import-snapshot' and 'import-chain'")
+			}
+			willImportChain = true
+		}
+
+		willRemoveChain := cctx.Bool("remove-existing-chain")
+		if willImportChain && !willRemoveChain {
+			// Confirm with the user about the intention to remove chain data.
+			reader := bufio.NewReader(os.Stdin)
+			fmt.Print("Importing chain or snapshot will by default delete existing local chain data. Do you want to proceed and delete? (yes/no): ")
+			userInput, err := reader.ReadString('\n')
+			if err != nil {
+				return xerrors.Errorf("reading user input: %w", err)
+			}
+			userInput = strings.ToLower(strings.TrimSpace(userInput))
+
+			if userInput == "yes" {
+				willRemoveChain = true
+			} else if userInput == "no" {
+				willRemoveChain = false
+			} else {
+				return fmt.Errorf("invalid input. please answer with 'yes' or 'no'")
+			}
+		}
+
+		if willRemoveChain {
 			lr, err := repo.NewFS(cctx.String("repo"))
 			if err != nil {
 				return xerrors.Errorf("error opening fs repo: %w", err)
@@ -289,12 +319,7 @@ var DaemonCmd = &cli.Command{
 			}
 		}
 
-		chainfile := cctx.String("import-chain")
-		snapshot := cctx.String("import-snapshot")
-		if chainfile != "" || snapshot != "" {
-			if chainfile != "" && snapshot != "" {
-				return fmt.Errorf("cannot specify both 'import-snapshot' and 'import-chain'")
-			}
+		if willImportChain {
 			var issnapshot bool
 			if chainfile == "" {
 				chainfile = snapshot