forked from hashicorp/vault
-
Notifications
You must be signed in to change notification settings - Fork 2
/
s3.go
197 lines (166 loc) · 4.24 KB
/
s3.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
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
package physical
import (
"bytes"
"fmt"
"io"
"os"
"sort"
"strings"
"time"
"github.com/armon/go-metrics"
"github.com/aws/aws-sdk-go/aws"
"github.com/aws/aws-sdk-go/aws/awserr"
"github.com/aws/aws-sdk-go/aws/credentials"
"github.com/aws/aws-sdk-go/aws/credentials/ec2rolecreds"
"github.com/aws/aws-sdk-go/aws/session"
"github.com/aws/aws-sdk-go/service/s3"
)
// S3Backend is a physical backend that stores data
// within an S3 bucket.
type S3Backend struct {
bucket string
client *s3.S3
}
// newS3Backend constructs a S3 backend using a pre-existing
// bucket. Credentials can be provided to the backend, sourced
// from the environment, AWS credential files or by IAM role.
func newS3Backend(conf map[string]string) (Backend, error) {
bucket, ok := conf["bucket"]
if !ok {
bucket = os.Getenv("AWS_S3_BUCKET")
if bucket == "" {
return nil, fmt.Errorf("'bucket' must be set")
}
}
access_key, ok := conf["access_key"]
if !ok {
access_key = ""
}
secret_key, ok := conf["secret_key"]
if !ok {
secret_key = ""
}
session_token, ok := conf["session_token"]
if !ok {
session_token = ""
}
endpoint, ok := conf["endpoint"]
if !ok {
endpoint = os.Getenv("AWS_S3_ENDPOINT")
}
region, ok := conf["region"]
if !ok {
region = os.Getenv("AWS_DEFAULT_REGION")
if region == "" {
region = "us-east-1"
}
}
creds := credentials.NewChainCredentials([]credentials.Provider{
&credentials.StaticProvider{Value: credentials.Value{
AccessKeyID: access_key,
SecretAccessKey: secret_key,
SessionToken: session_token,
}},
&credentials.EnvProvider{},
&credentials.SharedCredentialsProvider{Filename: "", Profile: ""},
&ec2rolecreds.EC2RoleProvider{},
})
s3conn := s3.New(session.New(&aws.Config{
Credentials: creds,
Endpoint: aws.String(endpoint),
Region: aws.String(region),
}))
_, err := s3conn.HeadBucket(&s3.HeadBucketInput{Bucket: &bucket})
if err != nil {
return nil, fmt.Errorf("unable to access bucket '%s': %v", bucket, err)
}
s := &S3Backend{
client: s3conn,
bucket: bucket,
}
return s, nil
}
// Put is used to insert or update an entry
func (s *S3Backend) Put(entry *Entry) error {
defer metrics.MeasureSince([]string{"s3", "put"}, time.Now())
_, err := s.client.PutObject(&s3.PutObjectInput{
Bucket: aws.String(s.bucket),
Key: aws.String(entry.Key),
Body: bytes.NewReader(entry.Value),
})
if err != nil {
return err
}
return nil
}
// Get is used to fetch an entry
func (s *S3Backend) Get(key string) (*Entry, error) {
defer metrics.MeasureSince([]string{"s3", "get"}, time.Now())
resp, err := s.client.GetObject(&s3.GetObjectInput{
Bucket: aws.String(s.bucket),
Key: aws.String(key),
})
if awsErr, ok := err.(awserr.RequestFailure); ok {
// Return nil on 404s, error on anything else
if awsErr.StatusCode() == 404 {
return nil, nil
} else {
return nil, err
}
}
data := make([]byte, *resp.ContentLength)
_, err = io.ReadFull(resp.Body, data)
if err != nil {
return nil, err
}
ent := &Entry{
Key: key,
Value: data,
}
return ent, nil
}
// Delete is used to permanently delete an entry
func (s *S3Backend) Delete(key string) error {
defer metrics.MeasureSince([]string{"s3", "delete"}, time.Now())
_, err := s.client.DeleteObject(&s3.DeleteObjectInput{
Bucket: aws.String(s.bucket),
Key: aws.String(key),
})
if err != nil {
return err
}
return nil
}
// List is used to list all the keys under a given
// prefix, up to the next prefix.
func (s *S3Backend) List(prefix string) ([]string, error) {
defer metrics.MeasureSince([]string{"s3", "list"}, time.Now())
resp, err := s.client.ListObjects(&s3.ListObjectsInput{
Bucket: aws.String(s.bucket),
Prefix: aws.String(prefix),
})
if err != nil {
return nil, err
}
keys := []string{}
for _, key := range resp.Contents {
key := strings.TrimPrefix(*key.Key, prefix)
if i := strings.Index(key, "/"); i == -1 {
// Add objects only from the current 'folder'
keys = append(keys, key)
} else if i != -1 {
// Add truncated 'folder' paths
keys = appendIfMissing(keys, key[:i+1])
}
}
sort.Strings(keys)
return keys, nil
}
func appendIfMissing(slice []string, i string) []string {
for _, ele := range slice {
if ele == i {
return slice
}
}
return append(slice, i)
}