/usr/share/gocode/src/github.com/docker/libnetwork/datastore/datastore.go is in golang-github-docker-libnetwork-dev 0.8.0-dev.2+git20170202.599.45b4086-3.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 | package datastore
import (
"fmt"
"log"
"reflect"
"strings"
"sync"
"time"
"github.com/docker/libkv"
"github.com/docker/libkv/store"
"github.com/docker/libnetwork/discoverapi"
"github.com/docker/libnetwork/types"
)
//DataStore exported
type DataStore interface {
// GetObject gets data from datastore and unmarshals to the specified object
GetObject(key string, o KVObject) error
// PutObject adds a new Record based on an object into the datastore
PutObject(kvObject KVObject) error
// PutObjectAtomic provides an atomic add and update operation for a Record
PutObjectAtomic(kvObject KVObject) error
// DeleteObject deletes a record
DeleteObject(kvObject KVObject) error
// DeleteObjectAtomic performs an atomic delete operation
DeleteObjectAtomic(kvObject KVObject) error
// DeleteTree deletes a record
DeleteTree(kvObject KVObject) error
// Watchable returns whether the store is watchable or not
Watchable() bool
// Watch for changes on a KVObject
Watch(kvObject KVObject, stopCh <-chan struct{}) (<-chan KVObject, error)
// RestartWatch retriggers stopped Watches
RestartWatch()
// Active returns if the store is active
Active() bool
// List returns of a list of KVObjects belonging to the parent
// key. The caller must pass a KVObject of the same type as
// the objects that need to be listed
List(string, KVObject) ([]KVObject, error)
// Scope returns the scope of the store
Scope() string
// KVStore returns access to the KV Store
KVStore() store.Store
// Close closes the data store
Close()
}
// ErrKeyModified is raised for an atomic update when the update is working on a stale state
var (
ErrKeyModified = store.ErrKeyModified
ErrKeyNotFound = store.ErrKeyNotFound
)
type datastore struct {
scope string
store store.Store
cache *cache
watchCh chan struct{}
active bool
sequential bool
sync.Mutex
}
// KVObject is Key/Value interface used by objects to be part of the DataStore
type KVObject interface {
// Key method lets an object provide the Key to be used in KV Store
Key() []string
// KeyPrefix method lets an object return immediate parent key that can be used for tree walk
KeyPrefix() []string
// Value method lets an object marshal its content to be stored in the KV store
Value() []byte
// SetValue is used by the datastore to set the object's value when loaded from the data store.
SetValue([]byte) error
// Index method returns the latest DB Index as seen by the object
Index() uint64
// SetIndex method allows the datastore to store the latest DB Index into the object
SetIndex(uint64)
// True if the object exists in the datastore, false if it hasn't been stored yet.
// When SetIndex() is called, the object has been stored.
Exists() bool
// DataScope indicates the storage scope of the KV object
DataScope() string
// Skip provides a way for a KV Object to avoid persisting it in the KV Store
Skip() bool
}
// KVConstructor interface defines methods which can construct a KVObject from another.
type KVConstructor interface {
// New returns a new object which is created based on the
// source object
New() KVObject
// CopyTo deep copies the contents of the implementing object
// to the passed destination object
CopyTo(KVObject) error
}
// ScopeCfg represents Datastore configuration.
type ScopeCfg struct {
Client ScopeClientCfg
}
// ScopeClientCfg represents Datastore Client-only mode configuration
type ScopeClientCfg struct {
Provider string
Address string
Config *store.Config
}
const (
// LocalScope indicates to store the KV object in local datastore such as boltdb
LocalScope = "local"
// GlobalScope indicates to store the KV object in global datastore such as consul/etcd/zookeeper
GlobalScope = "global"
defaultPrefix = "/var/lib/docker/network/files"
)
const (
// NetworkKeyPrefix is the prefix for network key in the kv store
NetworkKeyPrefix = "network"
// EndpointKeyPrefix is the prefix for endpoint key in the kv store
EndpointKeyPrefix = "endpoint"
)
var (
defaultScopes = makeDefaultScopes()
)
func makeDefaultScopes() map[string]*ScopeCfg {
def := make(map[string]*ScopeCfg)
def[LocalScope] = &ScopeCfg{
Client: ScopeClientCfg{
Provider: string(store.BOLTDB),
Address: defaultPrefix + "/local-kv.db",
Config: &store.Config{
Bucket: "libnetwork",
ConnectionTimeout: time.Minute,
},
},
}
return def
}
var defaultRootChain = []string{"docker", "network", "v1.0"}
var rootChain = defaultRootChain
// DefaultScopes returns a map of default scopes and its config for clients to use.
func DefaultScopes(dataDir string) map[string]*ScopeCfg {
if dataDir != "" {
defaultScopes[LocalScope].Client.Address = dataDir + "/network/files/local-kv.db"
return defaultScopes
}
defaultScopes[LocalScope].Client.Address = defaultPrefix + "/local-kv.db"
return defaultScopes
}
// IsValid checks if the scope config has valid configuration.
func (cfg *ScopeCfg) IsValid() bool {
if cfg == nil ||
strings.TrimSpace(cfg.Client.Provider) == "" ||
strings.TrimSpace(cfg.Client.Address) == "" {
return false
}
return true
}
//Key provides convenient method to create a Key
func Key(key ...string) string {
keychain := append(rootChain, key...)
str := strings.Join(keychain, "/")
return str + "/"
}
//ParseKey provides convenient method to unpack the key to complement the Key function
func ParseKey(key string) ([]string, error) {
chain := strings.Split(strings.Trim(key, "/"), "/")
// The key must atleast be equal to the rootChain in order to be considered as valid
if len(chain) <= len(rootChain) || !reflect.DeepEqual(chain[0:len(rootChain)], rootChain) {
return nil, types.BadRequestErrorf("invalid Key : %s", key)
}
return chain[len(rootChain):], nil
}
// newClient used to connect to KV Store
func newClient(scope string, kv string, addr string, config *store.Config, cached bool) (DataStore, error) {
if cached && scope != LocalScope {
return nil, fmt.Errorf("caching supported only for scope %s", LocalScope)
}
sequential := false
if scope == LocalScope {
sequential = true
}
if config == nil {
config = &store.Config{}
}
var addrs []string
if kv == string(store.BOLTDB) {
// Parse file path
addrs = strings.Split(addr, ",")
} else {
// Parse URI
parts := strings.SplitN(addr, "/", 2)
addrs = strings.Split(parts[0], ",")
// Add the custom prefix to the root chain
if len(parts) == 2 {
rootChain = append([]string{parts[1]}, defaultRootChain...)
}
}
store, err := libkv.NewStore(store.Backend(kv), addrs, config)
if err != nil {
return nil, err
}
ds := &datastore{scope: scope, store: store, active: true, watchCh: make(chan struct{}), sequential: sequential}
if cached {
ds.cache = newCache(ds)
}
return ds, nil
}
// NewDataStore creates a new instance of LibKV data store
func NewDataStore(scope string, cfg *ScopeCfg) (DataStore, error) {
if cfg == nil || cfg.Client.Provider == "" || cfg.Client.Address == "" {
c, ok := defaultScopes[scope]
if !ok || c.Client.Provider == "" || c.Client.Address == "" {
return nil, fmt.Errorf("unexpected scope %s without configuration passed", scope)
}
cfg = c
}
var cached bool
if scope == LocalScope {
cached = true
}
return newClient(scope, cfg.Client.Provider, cfg.Client.Address, cfg.Client.Config, cached)
}
// NewDataStoreFromConfig creates a new instance of LibKV data store starting from the datastore config data
func NewDataStoreFromConfig(dsc discoverapi.DatastoreConfigData) (DataStore, error) {
var (
ok bool
sCfgP *store.Config
)
sCfgP, ok = dsc.Config.(*store.Config)
if !ok && dsc.Config != nil {
return nil, fmt.Errorf("cannot parse store configuration: %v", dsc.Config)
}
scopeCfg := &ScopeCfg{
Client: ScopeClientCfg{
Address: dsc.Address,
Provider: dsc.Provider,
Config: sCfgP,
},
}
ds, err := NewDataStore(dsc.Scope, scopeCfg)
if err != nil {
return nil, fmt.Errorf("failed to construct datastore client from datastore configuration %v: %v", dsc, err)
}
return ds, err
}
func (ds *datastore) Close() {
ds.store.Close()
}
func (ds *datastore) Scope() string {
return ds.scope
}
func (ds *datastore) Active() bool {
return ds.active
}
func (ds *datastore) Watchable() bool {
return ds.scope != LocalScope
}
func (ds *datastore) Watch(kvObject KVObject, stopCh <-chan struct{}) (<-chan KVObject, error) {
sCh := make(chan struct{})
ctor, ok := kvObject.(KVConstructor)
if !ok {
return nil, fmt.Errorf("error watching object type %T, object does not implement KVConstructor interface", kvObject)
}
kvpCh, err := ds.store.Watch(Key(kvObject.Key()...), sCh)
if err != nil {
return nil, err
}
kvoCh := make(chan KVObject)
go func() {
retry_watch:
var err error
// Make sure to get a new instance of watch channel
ds.Lock()
watchCh := ds.watchCh
ds.Unlock()
loop:
for {
select {
case <-stopCh:
close(sCh)
return
case kvPair := <-kvpCh:
// If the backend KV store gets reset libkv's go routine
// for the watch can exit resulting in a nil value in
// channel.
if kvPair == nil {
ds.Lock()
ds.active = false
ds.Unlock()
break loop
}
dstO := ctor.New()
if err = dstO.SetValue(kvPair.Value); err != nil {
log.Printf("Could not unmarshal kvpair value = %s", string(kvPair.Value))
break
}
dstO.SetIndex(kvPair.LastIndex)
kvoCh <- dstO
}
}
// Wait on watch channel for a re-trigger when datastore becomes active
<-watchCh
kvpCh, err = ds.store.Watch(Key(kvObject.Key()...), sCh)
if err != nil {
log.Printf("Could not watch the key %s in store: %v", Key(kvObject.Key()...), err)
}
goto retry_watch
}()
return kvoCh, nil
}
func (ds *datastore) RestartWatch() {
ds.Lock()
defer ds.Unlock()
ds.active = true
watchCh := ds.watchCh
ds.watchCh = make(chan struct{})
close(watchCh)
}
func (ds *datastore) KVStore() store.Store {
return ds.store
}
// PutObjectAtomic adds a new Record based on an object into the datastore
func (ds *datastore) PutObjectAtomic(kvObject KVObject) error {
var (
previous *store.KVPair
pair *store.KVPair
err error
)
if ds.sequential {
ds.Lock()
defer ds.Unlock()
}
if kvObject == nil {
return types.BadRequestErrorf("invalid KV Object : nil")
}
kvObjValue := kvObject.Value()
if kvObjValue == nil {
return types.BadRequestErrorf("invalid KV Object with a nil Value for key %s", Key(kvObject.Key()...))
}
if kvObject.Skip() {
goto add_cache
}
if kvObject.Exists() {
previous = &store.KVPair{Key: Key(kvObject.Key()...), LastIndex: kvObject.Index()}
} else {
previous = nil
}
_, pair, err = ds.store.AtomicPut(Key(kvObject.Key()...), kvObjValue, previous, nil)
if err != nil {
if err == store.ErrKeyExists {
return ErrKeyModified
}
return err
}
kvObject.SetIndex(pair.LastIndex)
add_cache:
if ds.cache != nil {
// If persistent store is skipped, sequencing needs to
// happen in cache.
return ds.cache.add(kvObject, kvObject.Skip())
}
return nil
}
// PutObject adds a new Record based on an object into the datastore
func (ds *datastore) PutObject(kvObject KVObject) error {
if ds.sequential {
ds.Lock()
defer ds.Unlock()
}
if kvObject == nil {
return types.BadRequestErrorf("invalid KV Object : nil")
}
if kvObject.Skip() {
goto add_cache
}
if err := ds.putObjectWithKey(kvObject, kvObject.Key()...); err != nil {
return err
}
add_cache:
if ds.cache != nil {
// If persistent store is skipped, sequencing needs to
// happen in cache.
return ds.cache.add(kvObject, kvObject.Skip())
}
return nil
}
func (ds *datastore) putObjectWithKey(kvObject KVObject, key ...string) error {
kvObjValue := kvObject.Value()
if kvObjValue == nil {
return types.BadRequestErrorf("invalid KV Object with a nil Value for key %s", Key(kvObject.Key()...))
}
return ds.store.Put(Key(key...), kvObjValue, nil)
}
// GetObject returns a record matching the key
func (ds *datastore) GetObject(key string, o KVObject) error {
if ds.sequential {
ds.Lock()
defer ds.Unlock()
}
if ds.cache != nil {
return ds.cache.get(key, o)
}
kvPair, err := ds.store.Get(key)
if err != nil {
return err
}
if err := o.SetValue(kvPair.Value); err != nil {
return err
}
// Make sure the object has a correct view of the DB index in
// case we need to modify it and update the DB.
o.SetIndex(kvPair.LastIndex)
return nil
}
func (ds *datastore) ensureParent(parent string) error {
exists, err := ds.store.Exists(parent)
if err != nil {
return err
}
if exists {
return nil
}
return ds.store.Put(parent, []byte{}, &store.WriteOptions{IsDir: true})
}
func (ds *datastore) List(key string, kvObject KVObject) ([]KVObject, error) {
if ds.sequential {
ds.Lock()
defer ds.Unlock()
}
if ds.cache != nil {
return ds.cache.list(kvObject)
}
// Bail out right away if the kvObject does not implement KVConstructor
ctor, ok := kvObject.(KVConstructor)
if !ok {
return nil, fmt.Errorf("error listing objects, object does not implement KVConstructor interface")
}
// Make sure the parent key exists
if err := ds.ensureParent(key); err != nil {
return nil, err
}
kvList, err := ds.store.List(key)
if err != nil {
return nil, err
}
var kvol []KVObject
for _, kvPair := range kvList {
if len(kvPair.Value) == 0 {
continue
}
dstO := ctor.New()
if err := dstO.SetValue(kvPair.Value); err != nil {
return nil, err
}
// Make sure the object has a correct view of the DB index in
// case we need to modify it and update the DB.
dstO.SetIndex(kvPair.LastIndex)
kvol = append(kvol, dstO)
}
return kvol, nil
}
// DeleteObject unconditionally deletes a record from the store
func (ds *datastore) DeleteObject(kvObject KVObject) error {
if ds.sequential {
ds.Lock()
defer ds.Unlock()
}
// cleaup the cache first
if ds.cache != nil {
// If persistent store is skipped, sequencing needs to
// happen in cache.
ds.cache.del(kvObject, kvObject.Skip())
}
if kvObject.Skip() {
return nil
}
return ds.store.Delete(Key(kvObject.Key()...))
}
// DeleteObjectAtomic performs atomic delete on a record
func (ds *datastore) DeleteObjectAtomic(kvObject KVObject) error {
if ds.sequential {
ds.Lock()
defer ds.Unlock()
}
if kvObject == nil {
return types.BadRequestErrorf("invalid KV Object : nil")
}
previous := &store.KVPair{Key: Key(kvObject.Key()...), LastIndex: kvObject.Index()}
if kvObject.Skip() {
goto del_cache
}
if _, err := ds.store.AtomicDelete(Key(kvObject.Key()...), previous); err != nil {
if err == store.ErrKeyExists {
return ErrKeyModified
}
return err
}
del_cache:
// cleanup the cache only if AtomicDelete went through successfully
if ds.cache != nil {
// If persistent store is skipped, sequencing needs to
// happen in cache.
return ds.cache.del(kvObject, kvObject.Skip())
}
return nil
}
// DeleteTree unconditionally deletes a record from the store
func (ds *datastore) DeleteTree(kvObject KVObject) error {
if ds.sequential {
ds.Lock()
defer ds.Unlock()
}
// cleaup the cache first
if ds.cache != nil {
// If persistent store is skipped, sequencing needs to
// happen in cache.
ds.cache.del(kvObject, kvObject.Skip())
}
if kvObject.Skip() {
return nil
}
return ds.store.DeleteTree(Key(kvObject.KeyPrefix()...))
}
|