Support offline backups

cmd/lotus-shed/datastore.go

@@ -47,7 +47,7 @@ var datastoreListCmd = &cli.Command{
 	},
 	ArgsUsage: "[namespace prefix]",
 	Action: func(cctx *cli.Context) error {
-		logging.SetLogLevel("badger", "ERROR") // nolint:errchec
+		logging.SetLogLevel("badger", "ERROR") // nolint:errcheck
 
 		r, err := repo.NewFS(cctx.String("repo"))
 		if err != nil {

cmd/lotus-storage-miner/backup.go

@@ -2,11 +2,16 @@ package main
 
 import (
 	"fmt"
+	"os"
 
+	logging "github.com/ipfs/go-log/v2"
+	"github.com/mitchellh/go-homedir"
 	"github.com/urfave/cli/v2"
 	"golang.org/x/xerrors"
 
 	lcli "github.com/filecoin-project/lotus/cli"
+	"github.com/filecoin-project/lotus/lib/backupds"
+	"github.com/filecoin-project/lotus/node/repo"
 )
 
 var backupCmd = &cli.Command{
@@ -14,29 +19,97 @@ var backupCmd = &cli.Command{
 	Usage: "Create node metadata backup",
 	Description: `The backup command writes a copy of node metadata under the specified path
 
+Online backups:
 For security reasons, the daemon must be have LOTUS_BACKUP_BASE_PATH env var set
 to a path where backup files are supposed to be saved, and the path specified in
 this command must be within this base path`,
+	Flags: []cli.Flag{
+		&cli.BoolFlag{
+			Name:  "offline",
+			Usage: "create backup without the node running",
+		},
+	},
 	ArgsUsage: "[backup file path]",
-	Flags:     []cli.Flag{},
 	Action: func(cctx *cli.Context) error {
-		api, closer, err := lcli.GetStorageMinerAPI(cctx)
-		if err != nil {
-			return err
-		}
-		defer closer()
-
 		if cctx.Args().Len() != 1 {
 			return xerrors.Errorf("expected 1 argument")
 		}
 
-		err = api.CreateBackup(lcli.ReqContext(cctx), cctx.Args().First())
-		if err != nil {
-			return err
+		if cctx.Bool("offline") {
+			return offlineBackup(cctx)
 		}
 
-		fmt.Println("Success")
-
-		return nil
+		return onlineBackup(cctx)
 	},
 }
+
+func offlineBackup(cctx *cli.Context) error {
+	logging.SetLogLevel("badger", "ERROR") // nolint:errcheck
+
+	repoPath := cctx.String(FlagMinerRepo)
+	r, err := repo.NewFS(repoPath)
+	if err != nil {
+		return err
+	}
+
+	ok, err := r.Exists()
+	if err != nil {
+		return err
+	}
+	if !ok {
+		return xerrors.Errorf("repo at '%s' is not initialized", cctx.String(FlagMinerRepo))
+	}
+
+	lr, err := r.Lock(repo.StorageMiner)
+	if err != nil {
+		return xerrors.Errorf("locking repo: %w", err)
+	}
+	defer lr.Close() // nolint:errcheck
+
+	mds, err := lr.Datastore("/metadata")
+	if err != nil {
+		return xerrors.Errorf("getting metadata datastore: %w", err)
+	}
+
+	bds := backupds.Wrap(mds)
+
+	fpath, err := homedir.Expand(cctx.Args().First())
+	if err != nil {
+		return xerrors.Errorf("expanding file path: %w", err)
+	}
+
+	out, err := os.OpenFile(fpath, os.O_CREATE|os.O_WRONLY, 0644)
+	if err != nil {
+		return xerrors.Errorf("opening backup file %s: %w", fpath, err)
+	}
+
+	if err := bds.Backup(out); err != nil {
+		if cerr := out.Close(); cerr != nil {
+			log.Errorw("error closing backup file while handling backup error", "closeErr", cerr, "backupErr", err)
+		}
+		return xerrors.Errorf("backup error: %w", err)
+	}
+
+	if err := out.Close(); err != nil {
+		return xerrors.Errorf("closing backup file: %w", err)
+	}
+
+	return nil
+}
+
+func onlineBackup(cctx *cli.Context) error {
+	api, closer, err := lcli.GetStorageMinerAPI(cctx)
+	if err != nil {
+		return xerrors.Errorf("getting api: %w (if the node isn't running you can use the --offline flag)", err)
+	}
+	defer closer()
+
+	err = api.CreateBackup(lcli.ReqContext(cctx), cctx.Args().First())
+	if err != nil {
+		return err
+	}
+
+	fmt.Println("Success")
+
+	return nil
+}