Database: Add restore command

internal/commands/restore.go

@@ -0,0 +1,163 @@
+package commands
+
+import (
+	"bytes"
+	"context"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os/exec"
+	"path/filepath"
+	"regexp"
+	"time"
+
+	"github.com/photoprism/photoprism/internal/entity"
+	"github.com/photoprism/photoprism/pkg/fs"
+	"github.com/photoprism/photoprism/pkg/txt"
+
+	"github.com/photoprism/photoprism/internal/config"
+	"github.com/urfave/cli"
+)
+
+// RestoreCommand configures the backup cli command.
+var RestoreCommand = cli.Command{
+	Name:   "restore",
+	Usage:  "Restores the index from a backup",
+	Flags:  restoreFlags,
+	Action: restoreAction,
+}
+
+var restoreFlags = []cli.Flag{
+	cli.BoolFlag{
+		Name:  "force, f",
+		Usage: "overwrite existing index",
+	},
+}
+
+// restoreAction restores a database backup.
+func restoreAction(ctx *cli.Context) error {
+	start := time.Now()
+
+	conf := config.NewConfig(ctx)
+
+	_, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	if err := conf.Init(); err != nil {
+		return err
+	}
+
+	// Use command argument as backup file name.
+	fileName := ctx.Args().First()
+
+	// If empty, use default backup file name.
+	if fileName == "" {
+		backupPath := filepath.Join(conf.BackupPath(), conf.DatabaseDriver())
+
+		matches, err := filepath.Glob(filepath.Join(regexp.QuoteMeta(backupPath), "*.sql"))
+
+		if err != nil {
+			return err
+		}
+
+		if len(matches) == 0 {
+			log.Errorf("no backup files found in %s", backupPath)
+			return nil
+		}
+
+		fileName = matches[len(matches)-1]
+	}
+
+	if !fs.FileExists(fileName) {
+		log.Errorf("backup file not found: %s", fileName)
+		return nil
+	}
+
+	counts := struct{ Photos int }{}
+
+	conf.Db().Unscoped().Table("photos").
+		Select("COUNT(*) AS photos").
+		Take(&counts)
+
+	if counts.Photos == 0 {
+		// Do nothing;
+	} else if !ctx.Bool("force") {
+		return fmt.Errorf("use --force to replace exisisting index with %d photos", counts.Photos)
+	} else {
+		log.Warnf("replacing existing index with %d photos", counts.Photos)
+	}
+
+	log.Infof("restoring index from %s", txt.Quote(fileName))
+
+	sqlBackup, err := ioutil.ReadFile(fileName)
+
+	if err != nil {
+		return err
+	}
+
+	entity.SetDbProvider(conf)
+	tables := entity.Entities
+
+	var cmd *exec.Cmd
+
+	switch conf.DatabaseDriver() {
+	case config.MySQL:
+		cmd = exec.Command(
+			conf.MysqlBin(),
+			"-h", conf.DatabaseHost(),
+			"-P", conf.DatabasePortString(),
+			"-u", conf.DatabaseUser(),
+			"-p"+conf.DatabasePassword(),
+			"-f",
+			conf.DatabaseName(),
+		)
+	case config.SQLite:
+		log.Infoln("dropping existing tables")
+		tables.Drop()
+		cmd = exec.Command(
+			conf.SqliteBin(),
+			conf.DatabaseDsn(),
+		)
+	default:
+		return fmt.Errorf("unsupported database type: %s", conf.DatabaseDriver())
+	}
+
+	// Fetch command output.
+	var out bytes.Buffer
+	var stderr bytes.Buffer
+	cmd.Stdout = &out
+	cmd.Stderr = &stderr
+
+	stdin, err := cmd.StdinPipe()
+
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	go func() {
+		defer stdin.Close()
+		if _, err := io.WriteString(stdin, string(sqlBackup)); err != nil {
+			log.Errorf(err.Error())
+		}
+	}()
+
+	// Run backup command.
+	if err := cmd.Run(); err != nil {
+		if stderr.String() != "" {
+			log.Debugln(stderr.String())
+			log.Warnf("index could not be restored completely")
+		}
+	}
+
+	log.Infoln("migrating database")
+
+	conf.InitDb()
+
+	elapsed := time.Since(start)
+
+	log.Infof("database restored in %s", elapsed)
+
+	conf.Shutdown()
+
+	return nil
+}