-
Notifications
You must be signed in to change notification settings - Fork 9.5k
/
client.go
569 lines (467 loc) · 14.6 KB
/
client.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
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
// Copyright (c) HashiCorp, Inc.
// SPDX-License-Identifier: BUSL-1.1
package s3
import (
"bytes"
"context"
"crypto/md5"
"encoding/base64"
"encoding/hex"
"encoding/json"
"errors"
"fmt"
"log"
"time"
"github.com/aws/aws-sdk-go-v2/aws"
"github.com/aws/aws-sdk-go-v2/feature/s3/manager"
"github.com/aws/aws-sdk-go-v2/service/dynamodb"
dynamodbtypes "github.com/aws/aws-sdk-go-v2/service/dynamodb/types"
"github.com/aws/aws-sdk-go-v2/service/s3"
s3types "github.com/aws/aws-sdk-go-v2/service/s3/types"
baselogging "github.com/hashicorp/aws-sdk-go-base/v2/logging"
"github.com/hashicorp/go-hclog"
multierror "github.com/hashicorp/go-multierror"
uuid "github.com/hashicorp/go-uuid"
"github.com/hashicorp/terraform/internal/states/remote"
"github.com/hashicorp/terraform/internal/states/statemgr"
)
const (
// s3EncryptionAlgorithm = s3types.ServerSideEncryptionAes256
s3EncryptionAlgorithm = "AES256"
// Store the last saved serial in dynamo with this suffix for consistency checks.
stateIDSuffix = "-md5"
)
type RemoteClient struct {
s3Client *s3.Client
dynClient *dynamodb.Client
bucketName string
path string
serverSideEncryption bool
customerEncryptionKey []byte
acl string
kmsKeyID string
ddbTable string
skipS3Checksum bool
}
var (
// The amount of time we will retry a state waiting for it to match the
// expected checksum.
consistencyRetryTimeout = 10 * time.Second
// delay when polling the state
consistencyRetryPollInterval = 2 * time.Second
)
// test hook called when checksums don't match
var testChecksumHook func()
func (c *RemoteClient) Get() (payload *remote.Payload, err error) {
ctx := context.TODO()
log := c.logger(operationClientGet)
ctx, baselog := baselogging.NewHcLogger(ctx, log)
ctx = baselogging.RegisterLogger(ctx, baselog)
log.Info("Downloading remote state")
deadline := time.Now().Add(consistencyRetryTimeout)
// If we have a checksum, and the returned payload doesn't match, we retry
// up until deadline.
for {
payload, err = c.get(ctx)
if err != nil {
return nil, err
}
// If the remote state was manually removed the payload will be nil,
// but if there's still a digest entry for that state we will still try
// to compare the MD5 below.
var digest []byte
if payload != nil {
digest = payload.MD5
}
// verify that this state is what we expect
if expected, err := c.getMD5(ctx); err != nil {
log.Warn("failed to fetch state MD5",
"error", err,
)
} else if len(expected) > 0 && !bytes.Equal(expected, digest) {
log.Warn("state MD5 mismatch",
"expected", expected,
"actual", digest,
)
if testChecksumHook != nil {
testChecksumHook()
}
if time.Now().Before(deadline) {
time.Sleep(consistencyRetryPollInterval)
log.Info("retrying S3 RemoteClient.Get")
continue
}
return nil, newBadChecksumError(c.bucketName, c.path, digest, expected)
}
break
}
return payload, err
}
func (c *RemoteClient) get(ctx context.Context) (*remote.Payload, error) {
headInput := &s3.HeadObjectInput{
Bucket: aws.String(c.bucketName),
Key: aws.String(c.path),
}
if c.serverSideEncryption && c.customerEncryptionKey != nil {
headInput.SSECustomerKey = aws.String(base64.StdEncoding.EncodeToString(c.customerEncryptionKey))
headInput.SSECustomerAlgorithm = aws.String(s3EncryptionAlgorithm)
headInput.SSECustomerKeyMD5 = aws.String(c.getSSECustomerKeyMD5())
}
headOut, err := c.s3Client.HeadObject(ctx, headInput)
if err != nil {
switch {
case IsA[*s3types.NoSuchBucket](err):
return nil, fmt.Errorf(errS3NoSuchBucket, c.bucketName, err)
case IsA[*s3types.NotFound](err):
return nil, nil
}
return nil, fmt.Errorf("Unable to access object %q in S3 bucket %q: %w", c.path, c.bucketName, err)
}
// Pre-allocate the full buffer to avoid re-allocations and GC
buf := make([]byte, int(aws.ToInt64(headOut.ContentLength)))
w := manager.NewWriteAtBuffer(buf)
downloadInput := &s3.GetObjectInput{
Bucket: aws.String(c.bucketName),
Key: aws.String(c.path),
}
if c.serverSideEncryption && c.customerEncryptionKey != nil {
downloadInput.SSECustomerKey = aws.String(base64.StdEncoding.EncodeToString(c.customerEncryptionKey))
downloadInput.SSECustomerAlgorithm = aws.String(s3EncryptionAlgorithm)
downloadInput.SSECustomerKeyMD5 = aws.String(c.getSSECustomerKeyMD5())
}
downloader := manager.NewDownloader(c.s3Client)
_, err = downloader.Download(ctx, w, downloadInput)
if err != nil {
switch {
case IsA[*s3types.NoSuchBucket](err):
return nil, fmt.Errorf(errS3NoSuchBucket, c.bucketName, err)
case IsA[*s3types.NoSuchKey](err):
return nil, nil
}
return nil, fmt.Errorf("Unable to access object %q in S3 bucket %q: %w", c.path, c.bucketName, err)
}
sum := md5.Sum(w.Bytes())
payload := &remote.Payload{
Data: w.Bytes(),
MD5: sum[:],
}
// If there was no data, then return nil
if len(payload.Data) == 0 {
return nil, nil
}
return payload, nil
}
func (c *RemoteClient) Put(data []byte) error {
return c.put(data)
}
func (c *RemoteClient) put(data []byte, optFns ...func(*s3.Options)) error {
ctx := context.TODO()
log := c.logger(operationClientPut)
ctx, baselog := baselogging.NewHcLogger(ctx, log)
ctx = baselogging.RegisterLogger(ctx, baselog)
contentType := "application/json"
sum := md5.Sum(data)
input := &s3.PutObjectInput{
ContentType: aws.String(contentType),
Body: bytes.NewReader(data),
Bucket: aws.String(c.bucketName),
Key: aws.String(c.path),
}
if !c.skipS3Checksum {
input.ChecksumAlgorithm = s3types.ChecksumAlgorithmSha256
}
if c.serverSideEncryption {
if c.kmsKeyID != "" {
input.SSEKMSKeyId = aws.String(c.kmsKeyID)
input.ServerSideEncryption = s3types.ServerSideEncryptionAwsKms
} else if c.customerEncryptionKey != nil {
input.SSECustomerKey = aws.String(base64.StdEncoding.EncodeToString(c.customerEncryptionKey))
input.SSECustomerAlgorithm = aws.String(string(s3EncryptionAlgorithm))
input.SSECustomerKeyMD5 = aws.String(c.getSSECustomerKeyMD5())
} else {
input.ServerSideEncryption = s3EncryptionAlgorithm
}
}
if c.acl != "" {
input.ACL = s3types.ObjectCannedACL(c.acl)
}
log.Info("Uploading remote state")
uploader := manager.NewUploader(c.s3Client, func(u *manager.Uploader) {
u.ClientOptions = optFns
})
_, err := uploader.Upload(ctx, input)
if err != nil {
return fmt.Errorf("failed to upload state: %w", err)
}
if err := c.putMD5(ctx, sum[:]); err != nil {
// if this errors out, we unfortunately have to error out altogether,
// since the next Get will inevitably fail.
return fmt.Errorf("failed to store state MD5: %w", err)
}
return nil
}
func (c *RemoteClient) Delete() error {
ctx := context.TODO()
log := c.logger(operationClientDelete)
ctx, baselog := baselogging.NewHcLogger(ctx, log)
ctx = baselogging.RegisterLogger(ctx, baselog)
log.Info("Deleting remote state")
_, err := c.s3Client.DeleteObject(ctx, &s3.DeleteObjectInput{
Bucket: aws.String(c.bucketName),
Key: aws.String(c.path),
})
if err != nil {
return err
}
if err := c.deleteMD5(ctx); err != nil {
log.Error("deleting state MD5",
"error", err,
)
}
return nil
}
func (c *RemoteClient) Lock(info *statemgr.LockInfo) (string, error) {
ctx := context.TODO()
log := c.logger(operationLockerLock)
if c.ddbTable == "" {
return "", nil
}
info.Path = c.lockPath()
if info.ID == "" {
lockID, err := uuid.GenerateUUID()
if err != nil {
return "", err
}
info.ID = lockID
}
log = logWithLockInfo(log, info)
ctx, baselog := baselogging.NewHcLogger(ctx, log)
ctx = baselogging.RegisterLogger(ctx, baselog)
log.Info("Locking remote state")
putParams := &dynamodb.PutItemInput{
Item: map[string]dynamodbtypes.AttributeValue{
"LockID": &dynamodbtypes.AttributeValueMemberS{
Value: c.lockPath(),
},
"Info": &dynamodbtypes.AttributeValueMemberS{
Value: string(info.Marshal()),
},
},
TableName: aws.String(c.ddbTable),
ConditionExpression: aws.String("attribute_not_exists(LockID)"),
}
_, err := c.dynClient.PutItem(ctx, putParams)
if err != nil {
lockInfo, infoErr := c.getLockInfo(ctx)
if infoErr != nil {
err = multierror.Append(err, infoErr)
}
lockErr := &statemgr.LockError{
Err: err,
Info: lockInfo,
}
return "", lockErr
}
return info.ID, nil
}
func (c *RemoteClient) Unlock(id string) error {
ctx := context.TODO()
log := c.logger(operationLockerUnlock)
log = logWithLockID(log, id)
ctx, baselog := baselogging.NewHcLogger(ctx, log)
ctx = baselogging.RegisterLogger(ctx, baselog)
if c.ddbTable == "" {
return nil
}
lockErr := &statemgr.LockError{}
log.Info("Unlocking remote state")
// TODO: store the path and lock ID in separate fields, and have proper
// projection expression only delete the lock if both match, rather than
// checking the ID from the info field first.
lockInfo, err := c.getLockInfo(ctx)
if err != nil {
lockErr.Err = fmt.Errorf("failed to retrieve lock info for lock ID %q: %s", id, err)
return lockErr
}
lockErr.Info = lockInfo
if lockInfo.ID != id {
lockErr.Err = fmt.Errorf("lock ID %q does not match existing lock (%q)", id, lockInfo.ID)
return lockErr
}
params := &dynamodb.DeleteItemInput{
Key: map[string]dynamodbtypes.AttributeValue{
"LockID": &dynamodbtypes.AttributeValueMemberS{
Value: c.lockPath(),
},
},
TableName: aws.String(c.ddbTable),
}
_, err = c.dynClient.DeleteItem(ctx, params)
if err != nil {
lockErr.Err = err
return lockErr
}
return nil
}
func (c *RemoteClient) getMD5(ctx context.Context) ([]byte, error) {
if c.ddbTable == "" {
return nil, nil
}
getParams := &dynamodb.GetItemInput{
Key: map[string]dynamodbtypes.AttributeValue{
"LockID": &dynamodbtypes.AttributeValueMemberS{
Value: c.lockPath() + stateIDSuffix,
},
},
ProjectionExpression: aws.String("LockID, Digest"),
TableName: aws.String(c.ddbTable),
ConsistentRead: aws.Bool(true),
}
resp, err := c.dynClient.GetItem(ctx, getParams)
if err != nil {
return nil, fmt.Errorf("Unable to retrieve item from DynamoDB table %q: %w", c.ddbTable, err)
}
var val string
if v, ok := resp.Item["Digest"]; ok {
if v, ok := v.(*dynamodbtypes.AttributeValueMemberS); ok {
val = v.Value
}
}
sum, err := hex.DecodeString(val)
if err != nil || len(sum) != md5.Size {
return nil, errors.New("invalid md5")
}
return sum, nil
}
// store the hash of the state so that clients can check for stale state files.
func (c *RemoteClient) putMD5(ctx context.Context, sum []byte) error {
if c.ddbTable == "" {
return nil
}
if len(sum) != md5.Size {
return errors.New("invalid payload md5")
}
putParams := &dynamodb.PutItemInput{
Item: map[string]dynamodbtypes.AttributeValue{
"LockID": &dynamodbtypes.AttributeValueMemberS{
Value: c.lockPath() + stateIDSuffix,
},
"Digest": &dynamodbtypes.AttributeValueMemberS{
Value: hex.EncodeToString(sum),
},
},
TableName: aws.String(c.ddbTable),
}
_, err := c.dynClient.PutItem(ctx, putParams)
if err != nil {
log.Printf("[WARN] failed to record state serial in dynamodb: %s", err)
}
return nil
}
// remove the hash value for a deleted state
func (c *RemoteClient) deleteMD5(ctx context.Context) error {
if c.ddbTable == "" {
return nil
}
params := &dynamodb.DeleteItemInput{
Key: map[string]dynamodbtypes.AttributeValue{
"LockID": &dynamodbtypes.AttributeValueMemberS{
Value: c.lockPath() + stateIDSuffix,
},
},
TableName: aws.String(c.ddbTable),
}
if _, err := c.dynClient.DeleteItem(ctx, params); err != nil {
return fmt.Errorf("Unable to delete item from DynamoDB table %q: %w", c.ddbTable, err)
}
return nil
}
func (c *RemoteClient) getLockInfo(ctx context.Context) (*statemgr.LockInfo, error) {
getParams := &dynamodb.GetItemInput{
Key: map[string]dynamodbtypes.AttributeValue{
"LockID": &dynamodbtypes.AttributeValueMemberS{
Value: c.lockPath(),
},
},
ProjectionExpression: aws.String("LockID, Info"),
TableName: aws.String(c.ddbTable),
ConsistentRead: aws.Bool(true),
}
resp, err := c.dynClient.GetItem(ctx, getParams)
if err != nil {
return nil, fmt.Errorf("Unable to retrieve item from DynamoDB table %q: %w", c.ddbTable, err)
}
var infoData string
if v, ok := resp.Item["Info"]; ok {
if v, ok := v.(*dynamodbtypes.AttributeValueMemberS); ok {
infoData = v.Value
}
}
lockInfo := &statemgr.LockInfo{}
err = json.Unmarshal([]byte(infoData), lockInfo)
if err != nil {
return nil, err
}
return lockInfo, nil
}
func (c *RemoteClient) lockPath() string {
return fmt.Sprintf("%s/%s", c.bucketName, c.path)
}
func (c *RemoteClient) getSSECustomerKeyMD5() string {
b := md5.Sum(c.customerEncryptionKey)
return base64.StdEncoding.EncodeToString(b[:])
}
// logger returns the S3 backend logger configured with the client's bucket and path and the operation
func (c *RemoteClient) logger(operation string) hclog.Logger {
log := logger().With(
logKeyBucket, c.bucketName,
logKeyPath, c.path,
)
return logWithOperation(log, operation)
}
var _ error = badChecksumError{}
type badChecksumError struct {
bucket, key string
digest, expected []byte
}
func newBadChecksumError(bucket, key string, digest, expected []byte) badChecksumError {
return badChecksumError{
bucket: bucket,
key: key,
digest: digest,
expected: expected,
}
}
func (err badChecksumError) Error() string {
return fmt.Sprintf(`state data in S3 does not have the expected content.
The checksum calculated for the state stored in S3 does not match the checksum
stored in DynamoDB.
Bucket: %[1]s
Key: %[2]s
Calculated checksum: %[3]x
Stored checksum: %[4]x
This may be caused by unusually long delays in S3 processing a previous state
update. Please wait for a minute or two and try again.
%[5]s
`, err.bucket, err.key, err.digest, err.expected, err.resolutionMsg())
}
func (err badChecksumError) resolutionMsg() string {
if len(err.digest) > 0 {
return fmt.Sprintf(
`If this problem persists, and neither S3 nor DynamoDB are experiencing an
outage, you may need to manually verify the remote state and update the Digest
value stored in the DynamoDB table to the following value: %x`,
err.expected,
)
} else {
return `If this problem persists, and neither S3 nor DynamoDB are experiencing an
outage, you may need to manually verify the remote state and remove the Digest
value stored in the DynamoDB table`
}
}
const errS3NoSuchBucket = `S3 bucket %q does not exist.
The referenced S3 bucket must have been previously created. If the S3 bucket
was created within the last minute, please wait for a minute or two and try
again.
Error: %s
`