/
gcs.go
177 lines (150 loc) · 4.63 KB
/
gcs.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
// Licensed to the Apache Software Foundation (ASF) under one or more
// contributor license agreements. See the NOTICE file distributed with
// this work for additional information regarding copyright ownership.
// The ASF licenses this file to You 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 gcs contains a Google Cloud Storage (GCS) implementation of the
// Beam file system.
package gcs
import (
"context"
"fmt"
"io"
"path/filepath"
"strings"
"cloud.google.com/go/storage"
"github.com/apache/beam/sdks/v2/go/pkg/beam/internal/errors"
"github.com/apache/beam/sdks/v2/go/pkg/beam/io/filesystem"
"github.com/apache/beam/sdks/v2/go/pkg/beam/log"
"github.com/apache/beam/sdks/v2/go/pkg/beam/util/gcsx"
"google.golang.org/api/iterator"
"google.golang.org/api/option"
)
func init() {
filesystem.Register("gs", New)
}
type fs struct {
client *storage.Client
}
// New creates a new Google Cloud Storage filesystem using application
// default credentials. If it fails, it falls back to unauthenticated
// access.
func New(ctx context.Context) filesystem.Interface {
client, err := storage.NewClient(ctx, option.WithScopes(storage.ScopeReadWrite))
if err != nil {
log.Warnf(ctx, "Warning: falling back to unauthenticated GCS access: %v", err)
client, err = storage.NewClient(ctx, option.WithoutAuthentication())
if err != nil {
panic(errors.Wrapf(err, "failed to create GCS client"))
}
}
return &fs{client: client}
}
func (f *fs) Close() error {
return f.client.Close()
}
func (f *fs) List(ctx context.Context, glob string) ([]string, error) {
bucket, object, err := gcsx.ParseObject(glob)
if err != nil {
return nil, err
}
var candidates []string
if index := strings.Index(object, "*"); index > 0 {
// We handle globs by list all candidates and matching them here.
// For now, we assume * is the first matching character to make a
// prefix listing and not list the entire bucket.
it := f.client.Bucket(bucket).Objects(ctx, &storage.Query{
Prefix: object[:index],
})
for {
obj, err := it.Next()
if err == iterator.Done {
break
}
if err != nil {
return nil, err
}
match, err := filepath.Match(object, obj.Name)
if err != nil {
return nil, err
}
if match {
candidates = append(candidates, obj.Name)
}
}
} else {
// Single object.
candidates = []string{object}
}
var ret []string
for _, obj := range candidates {
ret = append(ret, fmt.Sprintf("gs://%v/%v", bucket, obj))
}
return ret, nil
}
func (f *fs) OpenRead(ctx context.Context, filename string) (io.ReadCloser, error) {
bucket, object, err := gcsx.ParseObject(filename)
if err != nil {
return nil, err
}
return f.client.Bucket(bucket).Object(object).NewReader(ctx)
}
// TODO(herohde) 7/12/2017: should we create the bucket in OpenWrite? For now, "no".
func (f *fs) OpenWrite(ctx context.Context, filename string) (io.WriteCloser, error) {
bucket, object, err := gcsx.ParseObject(filename)
if err != nil {
return nil, err
}
return f.client.Bucket(bucket).Object(object).NewWriter(ctx), nil
}
func (f *fs) Size(ctx context.Context, filename string) (int64, error) {
bucket, object, err := gcsx.ParseObject(filename)
if err != nil {
return -1, err
}
obj := f.client.Bucket(bucket).Object(object)
attrs, err := obj.Attrs(ctx)
if err != nil {
return -1, err
}
return attrs.Size, nil
}
// Remove the named file from the filesystem.
func (f *fs) Remove(ctx context.Context, filename string) error {
bucket, object, err := gcsx.ParseObject(filename)
if err != nil {
return err
}
obj := f.client.Bucket(bucket).Object(object)
return obj.Delete(ctx)
}
// Copy copies from srcpath to the dstpath.
func (f *fs) Copy(ctx context.Context, srcpath, dstpath string) error {
bucket, src, err := gcsx.ParseObject(srcpath)
if err != nil {
return err
}
srcobj := f.client.Bucket(bucket).Object(src)
bucket, dst, err := gcsx.ParseObject(dstpath)
if err != nil {
return err
}
dstobj := f.client.Bucket(bucket).Object(dst)
cp := dstobj.CopierFrom(srcobj)
_, err = cp.Run(ctx)
return err
}
// Compile time check for interface implementations.
var (
_ filesystem.Remover = ((*fs)(nil))
_ filesystem.Copier = ((*fs)(nil))
)