cli: add db reset command

Close #2576.

cli/server/server.go

@@ -73,6 +73,13 @@ func NewCommands() []cli.Command {
 			Usage: "use if dump is incremental",
 		},
 	)
+	var cfgHeightFlags = make([]cli.Flag, len(cfgFlags)+1)
+	copy(cfgHeightFlags, cfgFlags)
+	cfgHeightFlags[len(cfgHeightFlags)-1] = cli.UintFlag{
+		Name:     "height",
+		Usage:    "Height of the state to reset DB to",
+		Required: true,
+	}
 	return []cli.Command{
 		{
 			Name:      "node",
@@ -99,6 +106,13 @@ func NewCommands() []cli.Command {
 					Action:    restoreDB,
 					Flags:     cfgCountInFlags,
 				},
+				{
+					Name:      "reset",
+					Usage:     "reset database to the previous state",
+					UsageText: "neo-go db reset --height height [--config-path path] [-p/-m/-t]",
+					Action:    resetDB,
+					Flags:     cfgHeightFlags,
+				},
 			},
 		},
 	}
@@ -302,6 +316,35 @@ func restoreDB(ctx *cli.Context) error {
 	return nil
 }
 
+func resetDB(ctx *cli.Context) error {
+	if err := cmdargs.EnsureNone(ctx); err != nil {
+		return err
+	}
+	cfg, err := options.GetConfigFromContext(ctx)
+	if err != nil {
+		return cli.NewExitError(err, 1)
+	}
+	h := uint32(ctx.Uint("height"))
+
+	log, logCloser, err := options.HandleLoggingParams(ctx.Bool("debug"), cfg.ApplicationConfiguration)
+	if err != nil {
+		return cli.NewExitError(err, 1)
+	}
+	if logCloser != nil {
+		defer func() { _ = logCloser() }()
+	}
+	chain, err := initBlockChain(cfg, log)
+	if err != nil {
+		return cli.NewExitError(fmt.Errorf("failed to create Blockchain instance: %w", err), 1)
+	}
+
+	err = chain.Reset(h)
+	if err != nil {
+		return cli.NewExitError(fmt.Errorf("failed to reset chain state to height %d: %w", h, err), 1)
+	}
+	return nil
+}
+
 func mkOracle(config config.OracleConfiguration, magic netmode.Magic, chain *core.Blockchain, serv *network.Server, log *zap.Logger) (*oracle.Oracle, error) {
 	if !config.Enabled {
 		return nil, nil

cli/server/server_test.go

@@ -351,3 +351,18 @@ func TestInitBlockChain(t *testing.T) {
 		require.Error(t, err)
 	})
 }
+
+func TestResetDB(t *testing.T) {
+	d := t.TempDir()
+	err := os.Chdir(d)
+	require.NoError(t, err)
+	t.Cleanup(func() { require.NoError(t, os.Chdir(serverTestWD)) })
+	set := flag.NewFlagSet("flagSet", flag.ExitOnError)
+	set.String("config-path", filepath.Join(serverTestWD, "..", "..", "config"), "")
+	set.Bool("privnet", true, "")
+	set.Bool("debug", true, "")
+	set.Int("height", 0, "")
+	ctx := cli.NewContext(cli.NewApp(), set, nil)
+	err = resetDB(ctx)
+	require.NoError(t, err)
+}

docs/cli.md

@@ -89,13 +89,23 @@ Typical scenarios when this can be useful (without full node restart):
  * updating TLS certificates for the RPC server
  * resolving operational issues
 
-### DB import/exports
+### DB import/exports/reset
 
 Node operates using some database as a backend to store blockchain data. NeoGo
 allows to dump chain into a file from the database (when node is stopped) or to
 import blocks from a file into the database (also when node is stopped). Use
 `db` command for that.
 
+NeoGo allows to reset the node state to a particular point. It is possible for
+those nodes that do store complete chain state or for nodes with `RemoveUntraceableBlocks`
+setting on that are not yet reached `MaxTraceableBlocks` number of blocks. Use
+`db reset` command with the target block specified to roll back all the changes
+made since the target block (not including changes made by the specified block
+acceptance). The set of changes to be removed includes blocks, transactions,
+execution results, contract storage changes, MPT-related auxiliary data and NEP
+transfers data. Some stale MPT nodes may be left in storage after reset.
+Once DB reset is finished, the node can be started in a regular manner.
+
 ## Smart contracts
 
 Use `contract` command to create/compile/deploy/invoke/debug smart contracts,