minio/cmd/warm-backend.go
2021-05-06 08:52:02 -07:00

140 lines
3.3 KiB
Go

// Copyright (c) 2015-2021 MinIO, Inc.
//
// This file is part of MinIO Object Storage stack
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
package cmd
import (
"bytes"
"context"
"errors"
"fmt"
"io"
"github.com/minio/madmin-go"
)
// WarmBackendGetOpts is used to express byte ranges within an object. The zero
// value represents the entire byte range of an object.
type WarmBackendGetOpts struct {
startOffset int64
length int64
}
// WarmBackend provides interface to be implemented by remote tier backends
type WarmBackend interface {
Put(ctx context.Context, object string, r io.Reader, length int64) error
Get(ctx context.Context, object string, opts WarmBackendGetOpts) (io.ReadCloser, error)
Remove(ctx context.Context, object string) error
InUse(ctx context.Context) (bool, error)
}
const probeObject = "probeobject"
// checkWarmBackend checks if tier config credentials have sufficient privileges
// to perform all operations defined in the WarmBackend interface.
func checkWarmBackend(ctx context.Context, w WarmBackend) error {
var empty bytes.Reader
err := w.Put(ctx, probeObject, &empty, 0)
if err != nil {
return tierPermErr{
Op: tierPut,
Err: err,
}
}
_, err = w.Get(ctx, probeObject, WarmBackendGetOpts{})
if err != nil {
switch {
case isErrBucketNotFound(err):
return errTierBucketNotFound
case isErrSignatureDoesNotMatch(err):
return errTierInvalidCredentials
default:
return tierPermErr{
Op: tierGet,
Err: err,
}
}
}
if err = w.Remove(ctx, probeObject); err != nil {
return tierPermErr{
Op: tierDelete,
Err: err,
}
}
return err
}
type tierOp uint8
const (
_ tierOp = iota
tierGet
tierPut
tierDelete
)
func (op tierOp) String() string {
switch op {
case tierGet:
return "GET"
case tierPut:
return "PUT"
case tierDelete:
return "DELETE"
}
return "UNKNOWN"
}
type tierPermErr struct {
Op tierOp
Err error
}
func (te tierPermErr) Error() string {
return fmt.Sprintf("failed to perform %s %v", te.Op, te.Err)
}
func errIsTierPermError(err error) bool {
var tpErr tierPermErr
return errors.As(err, &tpErr)
}
// newWarmBackend instantiates the tier type specific WarmBackend, runs
// checkWarmBackend on it.
func newWarmBackend(ctx context.Context, tier madmin.TierConfig) (d WarmBackend, err error) {
switch tier.Type {
case madmin.S3:
d, err = newWarmBackendS3(*tier.S3)
case madmin.Azure:
d, err = newWarmBackendAzure(*tier.Azure)
case madmin.GCS:
d, err = newWarmBackendGCS(*tier.GCS)
default:
return nil, errTierTypeUnsupported
}
if err != nil {
return nil, errTierTypeUnsupported
}
err = checkWarmBackend(ctx, d)
if err != nil {
return nil, err
}
return d, nil
}