storj/storagenode/gracefulexit/worker.go

// Copyright (C) 2019 Storj Labs, Inc.
// See LICENSE for copying information.

package gracefulexit

import (
	"bytes"
	"context"
	"io"
	"os"
	"time"

	"github.com/zeebo/errs"
	"go.uber.org/zap"

	"storj.io/common/errs2"
	"storj.io/common/memory"
	"storj.io/common/pb"
	"storj.io/common/rpc"
	"storj.io/common/rpc/rpcstatus"
	"storj.io/common/signing"
	"storj.io/common/storj"
	"storj.io/common/sync2"
	"storj.io/storj/storagenode/pieces"
	"storj.io/storj/storagenode/piecestore"
	"storj.io/storj/storagenode/satellites"
	"storj.io/storj/storagenode/trust"
	"storj.io/uplink/private/ecclient"
)

// Worker is responsible for completing the graceful exit for a given satellite.
type Worker struct {
	log                *zap.Logger
	store              *pieces.Store
	trust              *trust.Pool
	satelliteDB        satellites.DB
	dialer             rpc.Dialer
	limiter            *sync2.Limiter
	satelliteURL       storj.NodeURL
	ecclient           ecclient.Client
	minBytesPerSecond  memory.Size
	minDownloadTimeout time.Duration
}

// NewWorker instantiates Worker.
func NewWorker(log *zap.Logger, store *pieces.Store, trust *trust.Pool, satelliteDB satellites.DB, dialer rpc.Dialer, satelliteURL storj.NodeURL, config Config) *Worker {
	return &Worker{
		log:                log,
		store:              store,
		trust:              trust,
		satelliteDB:        satelliteDB,
		dialer:             dialer,
		limiter:            sync2.NewLimiter(config.NumConcurrentTransfers),
		satelliteURL:       satelliteURL,
		ecclient:           ecclient.NewClient(log, dialer, 0),
		minBytesPerSecond:  config.MinBytesPerSecond,
		minDownloadTimeout: config.MinDownloadTimeout,
	}
}

// Run calls the satellite endpoint, transfers pieces, validates, and responds with success or failure.
// It also marks the satellite finished once all the pieces have been transferred.
func (worker *Worker) Run(ctx context.Context, done func()) (err error) {
	defer mon.Task()(&ctx)(&err)
	defer done()

	worker.log.Debug("running worker")

	conn, err := worker.dialer.DialNodeURL(ctx, worker.satelliteURL)
	if err != nil {
		return errs.Wrap(err)
	}
	defer func() {
		err = errs.Combine(err, conn.Close())
	}()

	client := pb.NewDRPCSatelliteGracefulExitClient(conn)

	c, err := client.Process(ctx)
	if err != nil {
		return errs.Wrap(err)
	}

	for {
		response, err := c.Recv()
		if errs.Is(err, io.EOF) {
			// Done
			return nil
		}
		if errs2.IsRPC(err, rpcstatus.FailedPrecondition) {
			// delete the entry from satellite table and inform graceful exit has failed to start
			deleteErr := worker.satelliteDB.CancelGracefulExit(ctx, worker.satelliteURL.ID)
			if deleteErr != nil {
				// TODO: what to do now?
				return errs.Combine(deleteErr, err)
			}
			return errs.Wrap(err)
		}
		if err != nil {
			// TODO what happened
			return errs.Wrap(err)
		}

		switch msg := response.GetMessage().(type) {
		case *pb.SatelliteMessage_NotReady:
			return nil

		case *pb.SatelliteMessage_TransferPiece:
			transferPieceMsg := msg.TransferPiece
			worker.limiter.Go(ctx, func() {
				err = worker.transferPiece(ctx, transferPieceMsg, c)
				if err != nil {
					worker.log.Error("failed to transfer piece.",
						zap.Stringer("Satellite ID", worker.satelliteURL.ID),
						zap.Error(errs.Wrap(err)))
				}
			})

		case *pb.SatelliteMessage_DeletePiece:
			deletePieceMsg := msg.DeletePiece
			worker.limiter.Go(ctx, func() {
				pieceID := deletePieceMsg.OriginalPieceId
				err := worker.deleteOnePiece(ctx, pieceID)
				if err != nil {
					worker.log.Error("failed to delete piece.",
						zap.Stringer("Satellite ID", worker.satelliteURL.ID),
						zap.Stringer("Piece ID", pieceID),
						zap.Error(errs.Wrap(err)))
				}
			})

		case *pb.SatelliteMessage_ExitFailed:
			worker.log.Error("graceful exit failed.",
				zap.Stringer("Satellite ID", worker.satelliteURL.ID),
				zap.Stringer("reason", msg.ExitFailed.Reason))

			exitFailedBytes, err := pb.Marshal(msg.ExitFailed)
			if err != nil {
				worker.log.Error("failed to marshal exit failed message.")
			}
			err = worker.satelliteDB.CompleteGracefulExit(ctx, worker.satelliteURL.ID, time.Now(), satellites.ExitFailed, exitFailedBytes)
			return errs.Wrap(err)

		case *pb.SatelliteMessage_ExitCompleted:
			worker.log.Info("graceful exit completed.", zap.Stringer("Satellite ID", worker.satelliteURL.ID))

			exitCompletedBytes, err := pb.Marshal(msg.ExitCompleted)
			if err != nil {
				worker.log.Error("failed to marshal exit completed message.")
			}

			err = worker.satelliteDB.CompleteGracefulExit(ctx, worker.satelliteURL.ID, time.Now(), satellites.ExitSucceeded, exitCompletedBytes)
			if err != nil {
				return errs.Wrap(err)
			}
			// delete all remaining pieces
			err = worker.deleteAllPieces(ctx)
			if err != nil {
				return errs.Wrap(err)
			}
			// delete everything left in blobs folder of specific satellites
			err = worker.store.DeleteSatelliteBlobs(ctx, worker.satelliteURL.ID)
			return errs.Wrap(err)
		default:
			// TODO handle err
			worker.log.Error("unknown graceful exit message.", zap.Stringer("Satellite ID", worker.satelliteURL.ID))
		}
	}
}

type gracefulExitStream interface {
	Context() context.Context
	Send(*pb.StorageNodeMessage) error
	Recv() (*pb.SatelliteMessage, error)
}

func (worker *Worker) transferPiece(ctx context.Context, transferPiece *pb.TransferPiece, c gracefulExitStream) error {
	pieceID := transferPiece.OriginalPieceId
	reader, err := worker.store.Reader(ctx, worker.satelliteURL.ID, pieceID)
	if err != nil {
		transferErr := pb.TransferFailed_UNKNOWN
		if errs.Is(err, os.ErrNotExist) {
			transferErr = pb.TransferFailed_NOT_FOUND
		}
		worker.log.Error("failed to get piece reader.",
			zap.Stringer("Satellite ID", worker.satelliteURL.ID),
			zap.Stringer("Piece ID", pieceID),
			zap.Error(errs.Wrap(err)))
		worker.handleFailure(ctx, transferErr, pieceID, c.Send)
		return err
	}

	addrLimit := transferPiece.GetAddressedOrderLimit()
	pk := transferPiece.PrivateKey

	originalHash, originalOrderLimit, err := worker.store.GetHashAndLimit(ctx, worker.satelliteURL.ID, pieceID, reader)
	if err != nil {
		worker.log.Error("failed to get piece hash and order limit.",
			zap.Stringer("Satellite ID", worker.satelliteURL.ID),
			zap.Stringer("Piece ID", pieceID),
			zap.Error(errs.Wrap(err)))
		worker.handleFailure(ctx, pb.TransferFailed_UNKNOWN, pieceID, c.Send)
		return err
	}

	satelliteSigner, err := worker.trust.GetSignee(ctx, worker.satelliteURL.ID)
	if err != nil {
		worker.log.Error("failed to get satellite signer identity from trust store!",
			zap.Stringer("Satellite ID", worker.satelliteURL.ID),
			zap.Error(errs.Wrap(err)))
		worker.handleFailure(ctx, pb.TransferFailed_UNKNOWN, pieceID, c.Send)
		return err
	}

	// verify the satellite signature on the original order limit; if we hand in something
	// with an invalid signature, the satellite will assume we're cheating and disqualify
	// immediately.
	err = signing.VerifyOrderLimitSignature(ctx, satelliteSigner, &originalOrderLimit)
	if err != nil {
		worker.log.Error("The order limit stored for this piece does not have a valid signature from the owning satellite! It was verified before storing, so something went wrong in storage. We have to report this to the satellite as a missing piece.",
			zap.Stringer("Satellite ID", worker.satelliteURL.ID),
			zap.Stringer("Piece ID", pieceID),
			zap.Error(errs.Wrap(err)))
		worker.handleFailure(ctx, pb.TransferFailed_NOT_FOUND, pieceID, c.Send)
		return err
	}

	// verify that the public key on the order limit signed the original piece hash; if we
	// hand in something with an invalid signature, the satellite will assume we're cheating
	// and disqualify immediately.
	err = signing.VerifyUplinkPieceHashSignature(ctx, originalOrderLimit.UplinkPublicKey, &originalHash)
	if err != nil {
		worker.log.Error("The piece hash stored for this piece does not have a valid signature from the public key stored in the order limit! It was verified before storing, so something went wrong in storage. We have to report this to the satellite as a missing piece.",
			zap.Stringer("Satellite ID", worker.satelliteURL.ID),
			zap.Stringer("Piece ID", pieceID),
			zap.Error(errs.Wrap(err)))
		worker.handleFailure(ctx, pb.TransferFailed_NOT_FOUND, pieceID, c.Send)
	}

	if worker.minBytesPerSecond == 0 {
		// set minBytesPerSecond to default 5KiB if set to 0
		worker.minBytesPerSecond = 5 * memory.KiB
	}
	maxTransferTime := time.Duration(int64(time.Second) * originalHash.PieceSize / worker.minBytesPerSecond.Int64())
	if maxTransferTime < worker.minDownloadTimeout {
		maxTransferTime = worker.minDownloadTimeout
	}
	putCtx, cancel := context.WithTimeout(ctx, maxTransferTime)
	defer cancel()

	pieceHash, peerID, err := worker.ecclient.PutPiece(putCtx, ctx, addrLimit, pk, reader)
	if err != nil {
		if piecestore.ErrVerifyUntrusted.Has(err) {
			worker.log.Error("failed hash verification.",
				zap.Stringer("Satellite ID", worker.satelliteURL.ID),
				zap.Stringer("Piece ID", pieceID),
				zap.Error(errs.Wrap(err)))
			worker.handleFailure(ctx, pb.TransferFailed_HASH_VERIFICATION, pieceID, c.Send)
		} else {
			worker.log.Error("failed to put piece.",
				zap.Stringer("Satellite ID", worker.satelliteURL.ID),
				zap.Stringer("Piece ID", pieceID),
				zap.Error(errs.Wrap(err)))
			// TODO look at error type to decide on the transfer error
			worker.handleFailure(ctx, pb.TransferFailed_STORAGE_NODE_UNAVAILABLE, pieceID, c.Send)
		}
		return err
	}

	if !bytes.Equal(originalHash.Hash, pieceHash.Hash) {
		worker.log.Error("piece hash from new storagenode does not match",
			zap.Stringer("Storagenode ID", addrLimit.Limit.StorageNodeId),
			zap.Stringer("Satellite ID", worker.satelliteURL.ID),
			zap.Stringer("Piece ID", pieceID))
		worker.handleFailure(ctx, pb.TransferFailed_HASH_VERIFICATION, pieceID, c.Send)
		return Error.New("piece hash from new storagenode does not match")
	}
	if pieceHash.PieceId != addrLimit.Limit.PieceId {
		worker.log.Error("piece id from new storagenode does not match order limit",
			zap.Stringer("Storagenode ID", addrLimit.Limit.StorageNodeId),
			zap.Stringer("Satellite ID", worker.satelliteURL.ID),
			zap.Stringer("Piece ID", pieceID))
		worker.handleFailure(ctx, pb.TransferFailed_HASH_VERIFICATION, pieceID, c.Send)
		return Error.New("piece id from new storagenode does not match order limit")
	}

	signee := signing.SigneeFromPeerIdentity(peerID)
	err = signing.VerifyPieceHashSignature(ctx, signee, pieceHash)
	if err != nil {
		worker.log.Error("invalid piece hash signature from new storagenode",
			zap.Stringer("Storagenode ID", addrLimit.Limit.StorageNodeId),
			zap.Stringer("Satellite ID", worker.satelliteURL.ID),
			zap.Stringer("Piece ID", pieceID),
			zap.Error(errs.Wrap(err)))
		worker.handleFailure(ctx, pb.TransferFailed_HASH_VERIFICATION, pieceID, c.Send)
		return err
	}

	success := &pb.StorageNodeMessage{
		Message: &pb.StorageNodeMessage_Succeeded{
			Succeeded: &pb.TransferSucceeded{
				OriginalPieceId:      transferPiece.OriginalPieceId,
				OriginalPieceHash:    &originalHash,
				OriginalOrderLimit:   &originalOrderLimit,
				ReplacementPieceHash: pieceHash,
			},
		},
	}
	worker.log.Info("piece transferred to new storagenode",
		zap.Stringer("Storagenode ID", addrLimit.Limit.StorageNodeId),
		zap.Stringer("Satellite ID", worker.satelliteURL.ID),
		zap.Stringer("Piece ID", pieceID))
	return c.Send(success)
}

// deleteOnePiece deletes one piece stored for a satellite.
func (worker *Worker) deleteOnePiece(ctx context.Context, pieceID storj.PieceID) error {
	piece, err := worker.store.Reader(ctx, worker.satelliteURL.ID, pieceID)
	if err != nil {
		if !errs2.IsCanceled(err) {
			worker.log.Debug("failed to retrieve piece info", zap.Stringer("Satellite ID", worker.satelliteURL.ID),
				zap.Stringer("Piece ID", pieceID), zap.Error(err))
		}
		return err
	}
	err = worker.deletePiece(ctx, pieceID)
	if err != nil {
		worker.log.Debug("failed to retrieve piece info", zap.Stringer("Satellite ID", worker.satelliteURL.ID), zap.Error(err))
		return err
	}
	// update graceful exit progress
	size := piece.Size()
	return worker.satelliteDB.UpdateGracefulExit(ctx, worker.satelliteURL.ID, size)
}

// deletePiece deletes one piece stored for a satellite, without updating satellite Graceful Exit status.
func (worker *Worker) deletePiece(ctx context.Context, pieceID storj.PieceID) error {
	err := worker.store.Delete(ctx, worker.satelliteURL.ID, pieceID)
	if err != nil {
		worker.log.Debug("failed to delete a piece",
			zap.Stringer("Satellite ID", worker.satelliteURL.ID),
			zap.Stringer("Piece ID", pieceID),
			zap.Error(err))
		delErr := worker.store.DeleteFailed(ctx, pieces.ExpiredInfo{
			SatelliteID: worker.satelliteURL.ID,
			PieceID:     pieceID,
			InPieceInfo: true,
		}, time.Now().UTC())
		if delErr != nil {
			worker.log.Debug("failed to mark a deletion failure for a piece",
				zap.Stringer("Satellite ID", worker.satelliteURL.ID),
				zap.Stringer("Piece ID", pieceID), zap.Error(err))
		}
		return errs.Combine(err, delErr)
	}
	worker.log.Debug("delete piece",
		zap.Stringer("Satellite ID", worker.satelliteURL.ID),
		zap.Stringer("Piece ID", pieceID))
	return err
}

// deleteAllPieces deletes pieces stored for a satellite.
func (worker *Worker) deleteAllPieces(ctx context.Context) error {
	var totalDeleted int64
	err := worker.store.WalkSatellitePieces(ctx, worker.satelliteURL.ID, func(piece pieces.StoredPieceAccess) error {
		err := worker.deletePiece(ctx, piece.PieceID())
		if err == nil {
			_, size, err := piece.Size(ctx)
			if err != nil {
				worker.log.Debug("failed to retrieve piece info", zap.Stringer("Satellite ID", worker.satelliteURL.ID),
					zap.Stringer("Piece ID", piece.PieceID()), zap.Error(err))
			}
			totalDeleted += size
		}
		return err
	})
	if err != nil && !errs2.IsCanceled(err) {
		worker.log.Debug("failed to retrieve piece info", zap.Stringer("Satellite ID", worker.satelliteURL.ID), zap.Error(err))
	}
	// update graceful exit progress
	return worker.satelliteDB.UpdateGracefulExit(ctx, worker.satelliteURL.ID, totalDeleted)
}

func (worker *Worker) handleFailure(ctx context.Context, transferError pb.TransferFailed_Error, pieceID pb.PieceID, send func(*pb.StorageNodeMessage) error) {
	failure := &pb.StorageNodeMessage{
		Message: &pb.StorageNodeMessage_Failed{
			Failed: &pb.TransferFailed{
				OriginalPieceId: pieceID,
				Error:           transferError,
			},
		},
	}

	sendErr := send(failure)
	if sendErr != nil {
		worker.log.Error("unable to send failure.", zap.Stringer("Satellite ID", worker.satelliteURL.ID))
	}
}

// Close halts the worker.
func (worker *Worker) Close() error {
	worker.limiter.Wait()
	return nil
}