agola/internal/objectstorage/s3.go

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// Copyright 2019 Sorint.lab
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied
// See the License for the specific language governing permissions and
// limitations under the License.
package objectstorage
import (
"io"
"io/ioutil"
"net/http"
"os"
"strings"
minio "github.com/minio/minio-go"
errors "golang.org/x/xerrors"
)
type S3Storage struct {
bucket string
minioClient *minio.Client
// minio core client user for low level api
minioCore *minio.Core
}
func NewS3(bucket, location, endpoint, accessKeyID, secretAccessKey string, secure bool) (*S3Storage, error) {
minioClient, err := minio.New(endpoint, accessKeyID, secretAccessKey, secure)
if err != nil {
return nil, err
}
minioCore, err := minio.NewCore(endpoint, accessKeyID, secretAccessKey, secure)
if err != nil {
return nil, err
}
exists, err := minioClient.BucketExists(bucket)
if err != nil {
return nil, errors.Errorf("cannot check if bucket %q in location %q exits: %w", bucket, location, err)
}
if !exists {
if err := minioClient.MakeBucket(bucket, location); err != nil {
return nil, errors.Errorf("cannot create bucket %q in location %q: %w", bucket, location, err)
}
}
return &S3Storage{
bucket: bucket,
minioClient: minioClient,
minioCore: minioCore,
}, nil
}
func (s *S3Storage) Stat(p string) (*ObjectInfo, error) {
oi, err := s.minioClient.StatObject(s.bucket, p, minio.StatObjectOptions{})
if err != nil {
merr := minio.ToErrorResponse(err)
if merr.StatusCode == http.StatusNotFound {
return nil, NewErrNotExist(errors.Errorf("object %q doesn't exist", p))
}
return nil, merr
}
return &ObjectInfo{Path: p, LastModified: oi.LastModified, Size: oi.Size}, nil
}
func (s *S3Storage) ReadObject(filepath string) (ReadSeekCloser, error) {
if _, err := s.minioClient.StatObject(s.bucket, filepath, minio.StatObjectOptions{}); err != nil {
merr := minio.ToErrorResponse(err)
if merr.StatusCode == http.StatusNotFound {
return nil, NewErrNotExist(errors.Errorf("object %q doesn't exist", filepath))
}
return nil, merr
}
return s.minioClient.GetObject(s.bucket, filepath, minio.GetObjectOptions{})
}
func (s *S3Storage) WriteObject(filepath string, data io.Reader, size int64, persist bool) error {
// if size is not specified, limit max object size to defaultMaxObjectSize so
// minio client will not calculate a very big part size using tons of ram.
// An alternative is to write the file locally so we can calculate the size and
// then put it. See commented out code below.
if size >= 0 {
lr := io.LimitReader(data, size)
_, err := s.minioClient.PutObject(s.bucket, filepath, lr, size, minio.PutObjectOptions{ContentType: "application/octet-stream"})
return err
}
// hack to know the real file size or minio will do this in memory with big memory usage since s3 doesn't support real streaming of unknown sizes
// TODO(sgotti) wait for minio client to expose an api to provide the max object size so we can remove this
tmpfile, err := ioutil.TempFile(os.TempDir(), "s3")
if err != nil {
return err
}
defer tmpfile.Close()
defer os.Remove(tmpfile.Name())
size, err = io.Copy(tmpfile, data)
if err != nil {
return err
}
if _, err := tmpfile.Seek(0, 0); err != nil {
return err
}
_, err = s.minioClient.PutObject(s.bucket, filepath, tmpfile, size, minio.PutObjectOptions{ContentType: "application/octet-stream"})
return err
}
func (s *S3Storage) DeleteObject(filepath string) error {
return s.minioClient.RemoveObject(s.bucket, filepath)
}
func (s *S3Storage) List(prefix, startWith, delimiter string, doneCh <-chan struct{}) <-chan ObjectInfo {
objectCh := make(chan ObjectInfo, 1)
if len(delimiter) > 1 {
objectCh <- ObjectInfo{
Err: errors.Errorf("wrong delimiter %q", delimiter),
}
return objectCh
}
// remove leading slash
if strings.HasPrefix(prefix, "/") {
prefix = strings.TrimPrefix(prefix, "/")
}
if strings.HasPrefix(startWith, "/") {
startWith = strings.TrimPrefix(startWith, "/")
}
// Initiate list objects goroutine here.
go func(objectCh chan<- ObjectInfo) {
defer close(objectCh)
// Save continuationToken for next request.
var continuationToken string
for {
// Get list of objects a maximum of 1000 per request.
result, err := s.minioCore.ListObjectsV2(s.bucket, prefix, continuationToken, false, delimiter, 1000, startWith)
if err != nil {
objectCh <- ObjectInfo{
Err: err,
}
return
}
// If contents are available loop through and send over channel.
for _, object := range result.Contents {
select {
// Send object content.
case objectCh <- ObjectInfo{Path: object.Key, LastModified: object.LastModified, Size: object.Size}:
// If receives done from the caller, return here.
case <-doneCh:
return
}
}
// If continuation token present, save it for next request.
if result.NextContinuationToken != "" {
continuationToken = result.NextContinuationToken
}
// Listing ends result is not truncated, return right here.
if !result.IsTruncated {
return
}
}
}(objectCh)
return objectCh
}