1 // Copyright (C) The Arvados Authors. All rights reserved.
3 // SPDX-License-Identifier: Apache-2.0
5 /* Provides low-level Get/Put primitives for accessing Arvados Keep blocks. */
23 "git.curoverse.com/arvados.git/sdk/go/arvadosclient"
24 "git.curoverse.com/arvados.git/sdk/go/streamer"
27 // A Keep "block" is 64MB.
28 const BLOCKSIZE = 64 * 1024 * 1024
31 DefaultRequestTimeout = 20 * time.Second
32 DefaultConnectTimeout = 2 * time.Second
33 DefaultTLSHandshakeTimeout = 4 * time.Second
34 DefaultKeepAlive = 180 * time.Second
36 DefaultProxyRequestTimeout = 300 * time.Second
37 DefaultProxyConnectTimeout = 30 * time.Second
38 DefaultProxyTLSHandshakeTimeout = 10 * time.Second
39 DefaultProxyKeepAlive = 120 * time.Second
42 // Error interface with an error and boolean indicating whether the error is temporary
43 type Error interface {
48 // multipleResponseError is of type Error
49 type multipleResponseError struct {
54 func (e *multipleResponseError) Temporary() bool {
58 // BlockNotFound is a multipleResponseError where isTemp is false
59 var BlockNotFound = &ErrNotFound{multipleResponseError{
60 error: errors.New("Block not found"),
64 // ErrNotFound is a multipleResponseError where isTemp can be true or false
65 type ErrNotFound struct {
69 type InsufficientReplicasError error
71 type OversizeBlockError error
73 var ErrOversizeBlock = OversizeBlockError(errors.New("Exceeded maximum block size (" + strconv.Itoa(BLOCKSIZE) + ")"))
74 var MissingArvadosApiHost = errors.New("Missing required environment variable ARVADOS_API_HOST")
75 var MissingArvadosApiToken = errors.New("Missing required environment variable ARVADOS_API_TOKEN")
76 var InvalidLocatorError = errors.New("Invalid locator")
78 // ErrNoSuchKeepServer is returned when GetIndex is invoked with a UUID with no matching keep server
79 var ErrNoSuchKeepServer = errors.New("No keep server matching the given UUID is found")
81 // ErrIncompleteIndex is returned when the Index response does not end with a new empty line
82 var ErrIncompleteIndex = errors.New("Got incomplete index")
84 const X_Keep_Desired_Replicas = "X-Keep-Desired-Replicas"
85 const X_Keep_Replicas_Stored = "X-Keep-Replicas-Stored"
87 type HTTPClient interface {
88 Do(*http.Request) (*http.Response, error)
91 // Information about Arvados and Keep servers.
92 type KeepClient struct {
93 Arvados *arvadosclient.ArvadosClient
95 localRoots map[string]string
96 writableLocalRoots map[string]string
97 gatewayRoots map[string]string
101 BlockCache *BlockCache
103 // set to 1 if all writable services are of disk type, otherwise 0
104 replicasPerService int
106 // Any non-disk typed services found in the list of keepservers?
109 // Disable automatic discovery of keep services
110 disableDiscovery bool
113 // MakeKeepClient creates a new KeepClient, calls
114 // DiscoverKeepServices(), and returns when the client is ready to
116 func MakeKeepClient(arv *arvadosclient.ArvadosClient) (*KeepClient, error) {
118 return kc, kc.discoverServices()
121 // New creates a new KeepClient. Service discovery will occur on the
122 // next read/write operation.
123 func New(arv *arvadosclient.ArvadosClient) *KeepClient {
124 defaultReplicationLevel := 2
125 value, err := arv.Discovery("defaultCollectionReplication")
127 v, ok := value.(float64)
129 defaultReplicationLevel = int(v)
134 Want_replicas: defaultReplicationLevel,
139 // Put a block given the block hash, a reader, and the number of bytes
140 // to read from the reader (which must be between 0 and BLOCKSIZE).
142 // Returns the locator for the written block, the number of replicas
143 // written, and an error.
145 // Returns an InsufficientReplicasError if 0 <= replicas <
146 // kc.Wants_replicas.
147 func (kc *KeepClient) PutHR(hash string, r io.Reader, dataBytes int64) (string, int, error) {
148 // Buffer for reads from 'r'
151 if dataBytes > BLOCKSIZE {
152 return "", 0, ErrOversizeBlock
154 bufsize = int(dataBytes)
159 t := streamer.AsyncStreamFromReader(bufsize, HashCheckingReader{r, md5.New(), hash})
162 return kc.putReplicas(hash, t, dataBytes)
165 // PutHB writes a block to Keep. The hash of the bytes is given in
166 // hash, and the data is given in buf.
168 // Return values are the same as for PutHR.
169 func (kc *KeepClient) PutHB(hash string, buf []byte) (string, int, error) {
170 t := streamer.AsyncStreamFromSlice(buf)
172 return kc.putReplicas(hash, t, int64(len(buf)))
175 // PutB writes a block to Keep. It computes the hash itself.
177 // Return values are the same as for PutHR.
178 func (kc *KeepClient) PutB(buffer []byte) (string, int, error) {
179 hash := fmt.Sprintf("%x", md5.Sum(buffer))
180 return kc.PutHB(hash, buffer)
183 // PutR writes a block to Keep. It first reads all data from r into a buffer
184 // in order to compute the hash.
186 // Return values are the same as for PutHR.
188 // If the block hash and data size are known, PutHR is more efficient.
189 func (kc *KeepClient) PutR(r io.Reader) (locator string, replicas int, err error) {
190 if buffer, err := ioutil.ReadAll(r); err != nil {
193 return kc.PutB(buffer)
197 func (kc *KeepClient) getOrHead(method string, locator string) (io.ReadCloser, int64, string, error) {
198 if strings.HasPrefix(locator, "d41d8cd98f00b204e9800998ecf8427e+0") {
199 return ioutil.NopCloser(bytes.NewReader(nil)), 0, "", nil
204 tries_remaining := 1 + kc.Retries
206 serversToTry := kc.getSortedRoots(locator)
208 numServers := len(serversToTry)
211 var retryList []string
213 for tries_remaining > 0 {
217 for _, host := range serversToTry {
218 url := host + "/" + locator
220 req, err := http.NewRequest(method, url, nil)
222 errs = append(errs, fmt.Sprintf("%s: %v", url, err))
225 req.Header.Add("Authorization", fmt.Sprintf("OAuth2 %s", kc.Arvados.ApiToken))
226 resp, err := kc.httpClient().Do(req)
228 // Probably a network error, may be transient,
230 errs = append(errs, fmt.Sprintf("%s: %v", url, err))
231 retryList = append(retryList, host)
232 } else if resp.StatusCode != http.StatusOK {
234 respbody, _ = ioutil.ReadAll(&io.LimitedReader{R: resp.Body, N: 4096})
236 errs = append(errs, fmt.Sprintf("%s: HTTP %d %q",
237 url, resp.StatusCode, bytes.TrimSpace(respbody)))
239 if resp.StatusCode == 408 ||
240 resp.StatusCode == 429 ||
241 resp.StatusCode >= 500 {
242 // Timeout, too many requests, or other
243 // server side failure, transient
244 // error, can try again.
245 retryList = append(retryList, host)
246 } else if resp.StatusCode == 404 {
249 } else if resp.ContentLength < 0 {
250 // Missing Content-Length
252 return nil, 0, "", fmt.Errorf("Missing Content-Length of block")
256 return HashCheckingReader{
259 Check: locator[0:32],
260 }, resp.ContentLength, url, nil
263 return nil, resp.ContentLength, url, nil
268 serversToTry = retryList
270 DebugPrintf("DEBUG: %s %s failed: %v", method, locator, errs)
273 if count404 == numServers {
276 err = &ErrNotFound{multipleResponseError{
277 error: fmt.Errorf("%s %s failed: %v", method, locator, errs),
278 isTemp: len(serversToTry) > 0,
281 return nil, 0, "", err
284 // Get() retrieves a block, given a locator. Returns a reader, the
285 // expected data length, the URL the block is being fetched from, and
288 // If the block checksum does not match, the final Read() on the
289 // reader returned by this method will return a BadChecksum error
291 func (kc *KeepClient) Get(locator string) (io.ReadCloser, int64, string, error) {
292 return kc.getOrHead("GET", locator)
295 // Ask() verifies that a block with the given hash is available and
296 // readable, according to at least one Keep service. Unlike Get, it
297 // does not retrieve the data or verify that the data content matches
298 // the hash specified by the locator.
300 // Returns the data size (content length) reported by the Keep service
301 // and the URI reporting the data size.
302 func (kc *KeepClient) Ask(locator string) (int64, string, error) {
303 _, size, url, err := kc.getOrHead("HEAD", locator)
304 return size, url, err
307 // GetIndex retrieves a list of blocks stored on the given server whose hashes
308 // begin with the given prefix. The returned reader will return an error (other
309 // than EOF) if the complete index cannot be retrieved.
311 // This is meant to be used only by system components and admin tools.
312 // It will return an error unless the client is using a "data manager token"
313 // recognized by the Keep services.
314 func (kc *KeepClient) GetIndex(keepServiceUUID, prefix string) (io.Reader, error) {
315 url := kc.LocalRoots()[keepServiceUUID]
317 return nil, ErrNoSuchKeepServer
325 req, err := http.NewRequest("GET", url, nil)
330 req.Header.Add("Authorization", fmt.Sprintf("OAuth2 %s", kc.Arvados.ApiToken))
331 resp, err := kc.httpClient().Do(req)
336 defer resp.Body.Close()
338 if resp.StatusCode != http.StatusOK {
339 return nil, fmt.Errorf("Got http status code: %d", resp.StatusCode)
343 respBody, err = ioutil.ReadAll(resp.Body)
348 // Got index; verify that it is complete
349 // The response should be "\n" if no locators matched the prefix
350 // Else, it should be a list of locators followed by a blank line
351 if !bytes.Equal(respBody, []byte("\n")) && !bytes.HasSuffix(respBody, []byte("\n\n")) {
352 return nil, ErrIncompleteIndex
355 // Got complete index; strip the trailing newline and send
356 return bytes.NewReader(respBody[0 : len(respBody)-1]), nil
359 // LocalRoots() returns the map of local (i.e., disk and proxy) Keep
360 // services: uuid -> baseURI.
361 func (kc *KeepClient) LocalRoots() map[string]string {
362 kc.discoverServices()
364 defer kc.lock.RUnlock()
368 // GatewayRoots() returns the map of Keep remote gateway services:
370 func (kc *KeepClient) GatewayRoots() map[string]string {
371 kc.discoverServices()
373 defer kc.lock.RUnlock()
374 return kc.gatewayRoots
377 // WritableLocalRoots() returns the map of writable local Keep services:
379 func (kc *KeepClient) WritableLocalRoots() map[string]string {
380 kc.discoverServices()
382 defer kc.lock.RUnlock()
383 return kc.writableLocalRoots
386 // SetServiceRoots disables service discovery and updates the
387 // localRoots and gatewayRoots maps, without disrupting operations
388 // that are already in progress.
390 // The supplied maps must not be modified after calling
392 func (kc *KeepClient) SetServiceRoots(locals, writables, gateways map[string]string) {
393 kc.disableDiscovery = true
394 kc.setServiceRoots(locals, writables, gateways)
397 func (kc *KeepClient) setServiceRoots(locals, writables, gateways map[string]string) {
399 defer kc.lock.Unlock()
400 kc.localRoots = locals
401 kc.writableLocalRoots = writables
402 kc.gatewayRoots = gateways
405 // getSortedRoots returns a list of base URIs of Keep services, in the
406 // order they should be attempted in order to retrieve content for the
408 func (kc *KeepClient) getSortedRoots(locator string) []string {
410 for _, hint := range strings.Split(locator, "+") {
411 if len(hint) < 7 || hint[0:2] != "K@" {
412 // Not a service hint.
416 // +K@abcde means fetch from proxy at
417 // keep.abcde.arvadosapi.com
418 found = append(found, "https://keep."+hint[2:]+".arvadosapi.com")
419 } else if len(hint) == 29 {
420 // +K@abcde-abcde-abcdeabcdeabcde means fetch
421 // from gateway with given uuid
422 if gwURI, ok := kc.GatewayRoots()[hint[2:]]; ok {
423 found = append(found, gwURI)
425 // else this hint is no use to us; carry on.
428 // After trying all usable service hints, fall back to local roots.
429 found = append(found, NewRootSorter(kc.LocalRoots(), locator[0:32]).GetSortedRoots()...)
433 func (kc *KeepClient) cache() *BlockCache {
434 if kc.BlockCache != nil {
437 return DefaultBlockCache
441 func (kc *KeepClient) ClearBlockCache() {
446 // There are four global http.Client objects for the four
447 // possible permutations of TLS behavior (verify/skip-verify)
448 // and timeout settings (proxy/non-proxy).
449 defaultClient = map[bool]map[bool]HTTPClient{
450 // defaultClient[false] is used for verified TLS reqs
452 // defaultClient[true] is used for unverified
453 // (insecure) TLS reqs
456 defaultClientMtx sync.Mutex
459 // httpClient returns the HTTPClient field if it's not nil, otherwise
460 // whichever of the four global http.Client objects is suitable for
461 // the current environment (i.e., TLS verification on/off, keep
462 // services are/aren't proxies).
463 func (kc *KeepClient) httpClient() HTTPClient {
464 if kc.HTTPClient != nil {
467 defaultClientMtx.Lock()
468 defer defaultClientMtx.Unlock()
469 if c, ok := defaultClient[kc.Arvados.ApiInsecure][kc.foundNonDiskSvc]; ok {
473 var requestTimeout, connectTimeout, keepAlive, tlsTimeout time.Duration
474 if kc.foundNonDiskSvc {
475 // Use longer timeouts when connecting to a proxy,
476 // because this usually means the intervening network
478 requestTimeout = DefaultProxyRequestTimeout
479 connectTimeout = DefaultProxyConnectTimeout
480 tlsTimeout = DefaultProxyTLSHandshakeTimeout
481 keepAlive = DefaultProxyKeepAlive
483 requestTimeout = DefaultRequestTimeout
484 connectTimeout = DefaultConnectTimeout
485 tlsTimeout = DefaultTLSHandshakeTimeout
486 keepAlive = DefaultKeepAlive
489 transport, ok := http.DefaultTransport.(*http.Transport)
494 // Evidently the application has replaced
495 // http.DefaultTransport with a different type, so we
496 // need to build our own from scratch using the Go 1.8
498 transport = &http.Transport{
500 IdleConnTimeout: 90 * time.Second,
501 ExpectContinueTimeout: time.Second,
504 transport.DialContext = (&net.Dialer{
505 Timeout: connectTimeout,
506 KeepAlive: keepAlive,
509 transport.TLSHandshakeTimeout = tlsTimeout
510 transport.TLSClientConfig = arvadosclient.MakeTLSConfig(kc.Arvados.ApiInsecure)
512 Timeout: requestTimeout,
513 Transport: transport,
515 defaultClient[kc.Arvados.ApiInsecure][kc.foundNonDiskSvc] = c
519 type Locator struct {
521 Size int // -1 if data size is not known
522 Hints []string // Including the size hint, if any
525 func (loc *Locator) String() string {
527 if len(loc.Hints) > 0 {
528 s = s + "+" + strings.Join(loc.Hints, "+")
533 var locatorMatcher = regexp.MustCompile("^([0-9a-f]{32})([+](.*))?$")
535 func MakeLocator(path string) (*Locator, error) {
536 sm := locatorMatcher.FindStringSubmatch(path)
538 return nil, InvalidLocatorError
540 loc := Locator{Hash: sm[1], Size: -1}
542 loc.Hints = strings.Split(sm[3], "+")
544 loc.Hints = []string{}
546 if len(loc.Hints) > 0 {
547 if size, err := strconv.Atoi(loc.Hints[0]); err == nil {