add revertprovider subcommand

Fixes #233

cmd/revertprovider.go

@@ -0,0 +1,53 @@
+package cmd
+
+import (
+	"os"
+
+	"github.com/rs/zerolog"
+	"github.com/spf13/cobra"
+	"github.com/spf13/viper"
+
+	"github.com/drakkan/sftpgo/config"
+	"github.com/drakkan/sftpgo/dataprovider"
+	"github.com/drakkan/sftpgo/logger"
+	"github.com/drakkan/sftpgo/utils"
+)
+
+var (
+	revertProviderTargetVersion int
+	revertProviderCmd           = &cobra.Command{
+		Use:   "revertprovider",
+		Short: "Revert the configured data provider to a previous version",
+		Long: `This command reads the data provider connection details from the specified
+configuration file and restore the provider schema and/or data to a previous version.
+This command is not supported for the memory provider.
+
+Please take a look at the usage below to customize the options.`,
+		Run: func(cmd *cobra.Command, args []string) {
+			logger.DisableLogger()
+			logger.EnableConsoleLogger(zerolog.DebugLevel)
+			configDir = utils.CleanDirInput(configDir)
+			err := config.LoadConfig(configDir, configFile)
+			if err != nil {
+				logger.WarnToConsole("Unable to initialize data provider, config load error: %v", err)
+				return
+			}
+			providerConf := config.GetProviderConf()
+			logger.InfoToConsole("Reverting provider: %#v config file: %#v target version %v", providerConf.Driver,
+				viper.ConfigFileUsed(), revertProviderTargetVersion)
+			err = dataprovider.RevertDatabase(providerConf, configDir, revertProviderTargetVersion)
+			if err != nil {
+				logger.WarnToConsole("Error reverting provider: %v", err)
+				os.Exit(1)
+			}
+			logger.InfoToConsole("Data provider successfully reverted")
+		},
+	}
+)
+
+func init() {
+	addConfigFlags(revertProviderCmd)
+	revertProviderCmd.Flags().IntVar(&revertProviderTargetVersion, "to-version", 0, `4 means the version supported in v1.0.0-v1.2.x`)
+
+	rootCmd.AddCommand(revertProviderCmd)
+}