lib/controller/federation.go

   1 // Copyright (C) The Arvados Authors. All rights reserved.
   2 //
   3 // SPDX-License-Identifier: AGPL-3.0
   4
   5 package controller
   6
   7 import (
   8         "bufio"
   9         "bytes"
  10         "context"
  11         "crypto/md5"
  12         "database/sql"
  13         "encoding/json"
  14         "fmt"
  15         "io"
  16         "io/ioutil"
  17         "net/http"
  18         "net/url"
  19         "regexp"
  20         "strings"
  21         "sync"
  22
  23         "git.curoverse.com/arvados.git/sdk/go/arvados"
  24         "git.curoverse.com/arvados.git/sdk/go/auth"
  25         "git.curoverse.com/arvados.git/sdk/go/httpserver"
  26         "git.curoverse.com/arvados.git/sdk/go/keepclient"
  27 )
  28
  29 var pathPattern = `^/arvados/v1/%s(/([0-9a-z]{5})-%s-[0-9a-z]{15})?(.*)$`
  30 var wfRe = regexp.MustCompile(fmt.Sprintf(pathPattern, "workflows", "7fd4e"))
  31 var containersRe = regexp.MustCompile(fmt.Sprintf(pathPattern, "containers", "dz642"))
  32 var containerRequestsRe = regexp.MustCompile(fmt.Sprintf(pathPattern, "container_requests", "xvhdp"))
  33 var collectionRe = regexp.MustCompile(fmt.Sprintf(pathPattern, "collections", "4zz18"))
  34 var collectionByPDHRe = regexp.MustCompile(`^/arvados/v1/collections/([0-9a-fA-F]{32}\+[0-9]+)+$`)
  35
  36 type genericFederatedRequestHandler struct {
  37         next    http.Handler
  38         handler *Handler
  39         matcher *regexp.Regexp
  40 }
  41
  42 type collectionFederatedRequestHandler struct {
  43         next    http.Handler
  44         handler *Handler
  45 }
  46
  47 func (h *Handler) remoteClusterRequest(remoteID string, w http.ResponseWriter, req *http.Request, filter ResponseFilter) {
  48         remote, ok := h.Cluster.RemoteClusters[remoteID]
  49         if !ok {
  50                 httpserver.Error(w, "no proxy available for cluster "+remoteID, http.StatusNotFound)
  51                 return
  52         }
  53         scheme := remote.Scheme
  54         if scheme == "" {
  55                 scheme = "https"
  56         }
  57         err := h.saltAuthToken(req, remoteID)
  58         if err != nil {
  59                 httpserver.Error(w, err.Error(), http.StatusBadRequest)
  60                 return
  61         }
  62         urlOut := &url.URL{
  63                 Scheme:   scheme,
  64                 Host:     remote.Host,
  65                 Path:     req.URL.Path,
  66                 RawPath:  req.URL.RawPath,
  67                 RawQuery: req.URL.RawQuery,
  68         }
  69         client := h.secureClient
  70         if remote.Insecure {
  71                 client = h.insecureClient
  72         }
  73         h.proxy.Do(w, req, urlOut, client, filter)
  74 }
  75
  76 // Buffer request body, parse form parameters in request, and then
  77 // replace original body with the buffer so it can be re-read by
  78 // downstream proxy steps.
  79 func loadParamsFromForm(req *http.Request) error {
  80         var postBody *bytes.Buffer
  81         if req.Body != nil && req.Header.Get("Content-Type") == "application/x-www-form-urlencoded" {
  82                 var cl int64
  83                 if req.ContentLength > 0 {
  84                         cl = req.ContentLength
  85                 }
  86                 postBody = bytes.NewBuffer(make([]byte, 0, cl))
  87                 originalBody := req.Body
  88                 defer originalBody.Close()
  89                 req.Body = ioutil.NopCloser(io.TeeReader(req.Body, postBody))
  90         }
  91
  92         err := req.ParseForm()
  93         if err != nil {
  94                 return err
  95         }
  96
  97         if req.Body != nil && postBody != nil {
  98                 req.Body = ioutil.NopCloser(postBody)
  99         }
 100         return nil
 101 }
 102
 103 type multiClusterQueryResponseCollector struct {
 104         responses []map[string]interface{}
 105         error     error
 106         kind      string
 107         clusterID string
 108 }
 109
 110 func (c *multiClusterQueryResponseCollector) collectResponse(resp *http.Response,
 111         requestError error) (newResponse *http.Response, err error) {
 112         if requestError != nil {
 113                 c.error = requestError
 114                 return nil, nil
 115         }
 116
 117         defer resp.Body.Close()
 118         var loadInto struct {
 119                 Kind   string                   `json:"kind"`
 120                 Items  []map[string]interface{} `json:"items"`
 121                 Errors []string                 `json:"errors"`
 122         }
 123         err = json.NewDecoder(resp.Body).Decode(&loadInto)
 124
 125         if err != nil {
 126                 c.error = fmt.Errorf("error fetching from %v (%v): %v", c.clusterID, resp.Status, err)
 127                 return nil, nil
 128         }
 129         if resp.StatusCode != http.StatusOK {
 130                 c.error = fmt.Errorf("error fetching from %v (%v): %v", c.clusterID, resp.Status, loadInto.Errors)
 131                 return nil, nil
 132         }
 133
 134         c.responses = loadInto.Items
 135         c.kind = loadInto.Kind
 136
 137         return nil, nil
 138 }
 139
 140 func (h *genericFederatedRequestHandler) remoteQueryUUIDs(w http.ResponseWriter,
 141         req *http.Request,
 142         clusterID string, uuids []string) (rp []map[string]interface{}, kind string, err error) {
 143
 144         found := make(map[string]bool)
 145         prev_len_uuids := len(uuids) + 1
 146         // Loop while
 147         // (1) there are more uuids to query
 148         // (2) we're making progress - on each iteration the set of
 149         // uuids we are expecting for must shrink.
 150         for len(uuids) > 0 && len(uuids) < prev_len_uuids {
 151                 var remoteReq http.Request
 152                 remoteReq.Header = req.Header
 153                 remoteReq.Method = "POST"
 154                 remoteReq.URL = &url.URL{Path: req.URL.Path}
 155                 remoteParams := make(url.Values)
 156                 remoteParams.Set("_method", "GET")
 157                 remoteParams.Set("count", "none")
 158                 if req.Form.Get("select") != "" {
 159                         remoteParams.Set("select", req.Form.Get("select"))
 160                 }
 161                 content, err := json.Marshal(uuids)
 162                 if err != nil {
 163                         return nil, "", err
 164                 }
 165                 remoteParams["filters"] = []string{fmt.Sprintf(`[["uuid", "in", %s]]`, content)}
 166                 enc := remoteParams.Encode()
 167                 remoteReq.Body = ioutil.NopCloser(bytes.NewBufferString(enc))
 168
 169                 rc := multiClusterQueryResponseCollector{clusterID: clusterID}
 170
 171                 if clusterID == h.handler.Cluster.ClusterID {
 172                         h.handler.localClusterRequest(w, &remoteReq,
 173                                 rc.collectResponse)
 174                 } else {
 175                         h.handler.remoteClusterRequest(clusterID, w, &remoteReq,
 176                                 rc.collectResponse)
 177                 }
 178                 if rc.error != nil {
 179                         return nil, "", rc.error
 180                 }
 181
 182                 kind = rc.kind
 183
 184                 if len(rc.responses) == 0 {
 185                         // We got zero responses, no point in doing
 186                         // another query.
 187                         return rp, kind, nil
 188                 }
 189
 190                 rp = append(rp, rc.responses...)
 191
 192                 // Go through the responses and determine what was
 193                 // returned.  If there are remaining items, loop
 194                 // around and do another request with just the
 195                 // stragglers.
 196                 for _, i := range rc.responses {
 197                         uuid, ok := i["uuid"].(string)
 198                         if ok {
 199                                 found[uuid] = true
 200                         }
 201                 }
 202
 203                 l := []string{}
 204                 for _, u := range uuids {
 205                         if !found[u] {
 206                                 l = append(l, u)
 207                         }
 208                 }
 209                 prev_len_uuids = len(uuids)
 210                 uuids = l
 211         }
 212
 213         return rp, kind, nil
 214 }
 215
 216 func (h *genericFederatedRequestHandler) handleMultiClusterQuery(w http.ResponseWriter,
 217         req *http.Request, clusterId *string) bool {
 218
 219         var filters [][]interface{}
 220         err := json.Unmarshal([]byte(req.Form.Get("filters")), &filters)
 221         if err != nil {
 222                 httpserver.Error(w, err.Error(), http.StatusBadRequest)
 223                 return true
 224         }
 225
 226         // Split the list of uuids by prefix
 227         queryClusters := make(map[string][]string)
 228         expectCount := 0
 229         for _, filter := range filters {
 230                 if len(filter) != 3 {
 231                         return false
 232                 }
 233
 234                 if lhs, ok := filter[0].(string); !ok || lhs != "uuid" {
 235                         return false
 236                 }
 237
 238                 op, ok := filter[1].(string)
 239                 if !ok {
 240                         return false
 241                 }
 242
 243                 if op == "in" {
 244                         if rhs, ok := filter[2].([]interface{}); ok {
 245                                 for _, i := range rhs {
 246                                         if u, ok := i.(string); ok {
 247                                                 *clusterId = u[0:5]
 248                                                 queryClusters[u[0:5]] = append(queryClusters[u[0:5]], u)
 249                                                 expectCount += 1
 250                                         }
 251                                 }
 252                         }
 253                 } else if op == "=" {
 254                         if u, ok := filter[2].(string); ok {
 255                                 *clusterId = u[0:5]
 256                                 queryClusters[u[0:5]] = append(queryClusters[u[0:5]], u)
 257                                 expectCount += 1
 258                         }
 259                 } else {
 260                         return false
 261                 }
 262
 263         }
 264
 265         if len(queryClusters) <= 1 {
 266                 // Query does not search for uuids across multiple
 267                 // clusters.
 268                 return false
 269         }
 270
 271         // Validations
 272         count := req.Form.Get("count")
 273         if count != "" && count != `none` && count != `"none"` {
 274                 httpserver.Error(w, "Federated multi-object query must have 'count=none'", http.StatusBadRequest)
 275                 return true
 276         }
 277         if req.Form.Get("limit") != "" || req.Form.Get("offset") != "" || req.Form.Get("order") != "" {
 278                 httpserver.Error(w, "Federated multi-object may not provide 'limit', 'offset' or 'order'.", http.StatusBadRequest)
 279                 return true
 280         }
 281         if expectCount > h.handler.Cluster.RequestLimits.GetMaxItemsPerResponse() {
 282                 httpserver.Error(w, fmt.Sprintf("Federated multi-object request for %v objects which is more than max page size %v.",
 283                         expectCount, h.handler.Cluster.RequestLimits.GetMaxItemsPerResponse()), http.StatusBadRequest)
 284                 return true
 285         }
 286         if req.Form.Get("select") != "" {
 287                 foundUUID := false
 288                 var selects []string
 289                 err := json.Unmarshal([]byte(req.Form.Get("select")), &selects)
 290                 if err != nil {
 291                         httpserver.Error(w, err.Error(), http.StatusBadRequest)
 292                         return true
 293                 }
 294
 295                 for _, r := range selects {
 296                         if r == "uuid" {
 297                                 foundUUID = true
 298                                 break
 299                         }
 300                 }
 301                 if !foundUUID {
 302                         httpserver.Error(w, "Federated multi-object request must include 'uuid' in 'select'", http.StatusBadRequest)
 303                         return true
 304                 }
 305         }
 306
 307         // Perform concurrent requests to each cluster
 308
 309         // use channel as a semaphore to limit the number of concurrent
 310         // requests at a time
 311         sem := make(chan bool, h.handler.Cluster.RequestLimits.GetMultiClusterRequestConcurrency())
 312         defer close(sem)
 313         wg := sync.WaitGroup{}
 314
 315         req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
 316         mtx := sync.Mutex{}
 317         errors := []error{}
 318         var completeResponses []map[string]interface{}
 319         var kind string
 320
 321         for k, v := range queryClusters {
 322                 if len(v) == 0 {
 323                         // Nothing to query
 324                         continue
 325                 }
 326
 327                 // blocks until it can put a value into the
 328                 // channel (which has a max queue capacity)
 329                 sem <- true
 330                 wg.Add(1)
 331                 go func(k string, v []string) {
 332                         rp, kn, err := h.remoteQueryUUIDs(w, req, k, v)
 333                         mtx.Lock()
 334                         if err == nil {
 335                                 completeResponses = append(completeResponses, rp...)
 336                                 kind = kn
 337                         } else {
 338                                 errors = append(errors, err)
 339                         }
 340                         mtx.Unlock()
 341                         wg.Done()
 342                         <-sem
 343                 }(k, v)
 344         }
 345         wg.Wait()
 346
 347         if len(errors) > 0 {
 348                 var strerr []string
 349                 for _, e := range errors {
 350                         strerr = append(strerr, e.Error())
 351                 }
 352                 httpserver.Errors(w, strerr, http.StatusBadGateway)
 353                 return true
 354         }
 355
 356         w.Header().Set("Content-Type", "application/json")
 357         w.WriteHeader(http.StatusOK)
 358         itemList := make(map[string]interface{})
 359         itemList["items"] = completeResponses
 360         itemList["kind"] = kind
 361         json.NewEncoder(w).Encode(itemList)
 362
 363         return true
 364 }
 365
 366 func (h *genericFederatedRequestHandler) ServeHTTP(w http.ResponseWriter, req *http.Request) {
 367         m := h.matcher.FindStringSubmatch(req.URL.Path)
 368         clusterId := ""
 369
 370         if len(m) > 0 && m[2] != "" {
 371                 clusterId = m[2]
 372         }
 373
 374         // Get form parameters from URL and form body (if POST).
 375         if err := loadParamsFromForm(req); err != nil {
 376                 httpserver.Error(w, err.Error(), http.StatusBadRequest)
 377                 return
 378         }
 379
 380         // Check if the parameters have an explicit cluster_id
 381         if req.Form.Get("cluster_id") != "" {
 382                 clusterId = req.Form.Get("cluster_id")
 383         }
 384
 385         // Handle the POST-as-GET special case (workaround for large
 386         // GET requests that potentially exceed maximum URL length,
 387         // like multi-object queries where the filter has 100s of
 388         // items)
 389         effectiveMethod := req.Method
 390         if req.Method == "POST" && req.Form.Get("_method") != "" {
 391                 effectiveMethod = req.Form.Get("_method")
 392         }
 393
 394         if effectiveMethod == "GET" &&
 395                 clusterId == "" &&
 396                 req.Form.Get("filters") != "" &&
 397                 h.handleMultiClusterQuery(w, req, &clusterId) {
 398                 return
 399         }
 400
 401         if clusterId == "" || clusterId == h.handler.Cluster.ClusterID {
 402                 h.next.ServeHTTP(w, req)
 403         } else {
 404                 h.handler.remoteClusterRequest(clusterId, w, req, nil)
 405         }
 406 }
 407
 408 type rewriteSignaturesClusterId struct {
 409         clusterID  string
 410         expectHash string
 411 }
 412
 413 func (rw rewriteSignaturesClusterId) rewriteSignatures(resp *http.Response, requestError error) (newResponse *http.Response, err error) {
 414         if requestError != nil {
 415                 return resp, requestError
 416         }
 417
 418         if resp.StatusCode != 200 {
 419                 return resp, nil
 420         }
 421
 422         originalBody := resp.Body
 423         defer originalBody.Close()
 424
 425         var col arvados.Collection
 426         err = json.NewDecoder(resp.Body).Decode(&col)
 427         if err != nil {
 428                 return nil, err
 429         }
 430
 431         // rewriting signatures will make manifest text 5-10% bigger so calculate
 432         // capacity accordingly
 433         updatedManifest := bytes.NewBuffer(make([]byte, 0, int(float64(len(col.ManifestText))*1.1)))
 434
 435         hasher := md5.New()
 436         mw := io.MultiWriter(hasher, updatedManifest)
 437         sz := 0
 438
 439         scanner := bufio.NewScanner(strings.NewReader(col.ManifestText))
 440         scanner.Buffer(make([]byte, 1048576), len(col.ManifestText))
 441         for scanner.Scan() {
 442                 line := scanner.Text()
 443                 tokens := strings.Split(line, " ")
 444                 if len(tokens) < 3 {
 445                         return nil, fmt.Errorf("Invalid stream (<3 tokens): %q", line)
 446                 }
 447
 448                 n, err := mw.Write([]byte(tokens[0]))
 449                 if err != nil {
 450                         return nil, fmt.Errorf("Error updating manifest: %v", err)
 451                 }
 452                 sz += n
 453                 for _, token := range tokens[1:] {
 454                         n, err = mw.Write([]byte(" "))
 455                         if err != nil {
 456                                 return nil, fmt.Errorf("Error updating manifest: %v", err)
 457                         }
 458                         sz += n
 459
 460                         m := keepclient.SignedLocatorRe.FindStringSubmatch(token)
 461                         if m != nil {
 462                                 // Rewrite the block signature to be a remote signature
 463                                 _, err = fmt.Fprintf(updatedManifest, "%s%s%s+R%s-%s%s", m[1], m[2], m[3], rw.clusterID, m[5][2:], m[8])
 464                                 if err != nil {
 465                                         return nil, fmt.Errorf("Error updating manifest: %v", err)
 466                                 }
 467
 468                                 // for hash checking, ignore signatures
 469                                 n, err = fmt.Fprintf(hasher, "%s%s", m[1], m[2])
 470                                 if err != nil {
 471                                         return nil, fmt.Errorf("Error updating manifest: %v", err)
 472                                 }
 473                                 sz += n
 474                         } else {
 475                                 n, err = mw.Write([]byte(token))
 476                                 if err != nil {
 477                                         return nil, fmt.Errorf("Error updating manifest: %v", err)
 478                                 }
 479                                 sz += n
 480                         }
 481                 }
 482                 n, err = mw.Write([]byte("\n"))
 483                 if err != nil {
 484                         return nil, fmt.Errorf("Error updating manifest: %v", err)
 485                 }
 486                 sz += n
 487         }
 488
 489         // Check that expected hash is consistent with
 490         // portable_data_hash field of the returned record
 491         if rw.expectHash == "" {
 492                 rw.expectHash = col.PortableDataHash
 493         } else if rw.expectHash != col.PortableDataHash {
 494                 return nil, fmt.Errorf("portable_data_hash %q on returned record did not match expected hash %q ", rw.expectHash, col.PortableDataHash)
 495         }
 496
 497         // Certify that the computed hash of the manifest_text matches our expectation
 498         sum := hasher.Sum(nil)
 499         computedHash := fmt.Sprintf("%x+%v", sum, sz)
 500         if computedHash != rw.expectHash {
 501                 return nil, fmt.Errorf("Computed manifest_text hash %q did not match expected hash %q", computedHash, rw.expectHash)
 502         }
 503
 504         col.ManifestText = updatedManifest.String()
 505
 506         newbody, err := json.Marshal(col)
 507         if err != nil {
 508                 return nil, err
 509         }
 510
 511         buf := bytes.NewBuffer(newbody)
 512         resp.Body = ioutil.NopCloser(buf)
 513         resp.ContentLength = int64(buf.Len())
 514         resp.Header.Set("Content-Length", fmt.Sprintf("%v", buf.Len()))
 515
 516         return resp, nil
 517 }
 518
 519 func filterLocalClusterResponse(resp *http.Response, requestError error) (newResponse *http.Response, err error) {
 520         if requestError != nil {
 521                 return resp, requestError
 522         }
 523
 524         if resp.StatusCode == 404 {
 525                 // Suppress returning this result, because we want to
 526                 // search the federation.
 527                 return nil, nil
 528         }
 529         return resp, nil
 530 }
 531
 532 type searchRemoteClusterForPDH struct {
 533         pdh           string
 534         remoteID      string
 535         mtx           *sync.Mutex
 536         sentResponse  *bool
 537         sharedContext *context.Context
 538         cancelFunc    func()
 539         errors        *[]string
 540         statusCode    *int
 541 }
 542
 543 func (s *searchRemoteClusterForPDH) filterRemoteClusterResponse(resp *http.Response, requestError error) (newResponse *http.Response, err error) {
 544         s.mtx.Lock()
 545         defer s.mtx.Unlock()
 546
 547         if *s.sentResponse {
 548                 // Another request already returned a response
 549                 return nil, nil
 550         }
 551
 552         if requestError != nil {
 553                 *s.errors = append(*s.errors, fmt.Sprintf("Request error contacting %q: %v", s.remoteID, requestError))
 554                 // Record the error and suppress response
 555                 return nil, nil
 556         }
 557
 558         if resp.StatusCode != 200 {
 559                 // Suppress returning unsuccessful result.  Maybe
 560                 // another request will find it.
 561                 // TODO collect and return error responses.
 562                 *s.errors = append(*s.errors, fmt.Sprintf("Response from %q: %v", s.remoteID, resp.Status))
 563                 if resp.StatusCode != 404 {
 564                         // Got a non-404 error response, convert into BadGateway
 565                         *s.statusCode = http.StatusBadGateway
 566                 }
 567                 return nil, nil
 568         }
 569
 570         s.mtx.Unlock()
 571
 572         // This reads the response body.  We don't want to hold the
 573         // lock while doing this because other remote requests could
 574         // also have made it to this point, and we don't want a
 575         // slow response holding the lock to block a faster response
 576         // that is waiting on the lock.
 577         newResponse, err = rewriteSignaturesClusterId{s.remoteID, s.pdh}.rewriteSignatures(resp, nil)
 578
 579         s.mtx.Lock()
 580
 581         if *s.sentResponse {
 582                 // Another request already returned a response
 583                 return nil, nil
 584         }
 585
 586         if err != nil {
 587                 // Suppress returning unsuccessful result.  Maybe
 588                 // another request will be successful.
 589                 *s.errors = append(*s.errors, fmt.Sprintf("Error parsing response from %q: %v", s.remoteID, err))
 590                 return nil, nil
 591         }
 592
 593         // We have a successful response.  Suppress/cancel all the
 594         // other requests/responses.
 595         *s.sentResponse = true
 596         s.cancelFunc()
 597
 598         return newResponse, nil
 599 }
 600
 601 func (h *collectionFederatedRequestHandler) ServeHTTP(w http.ResponseWriter, req *http.Request) {
 602         if req.Method != "GET" {
 603                 // Only handle GET requests right now
 604                 h.next.ServeHTTP(w, req)
 605                 return
 606         }
 607
 608         m := collectionByPDHRe.FindStringSubmatch(req.URL.Path)
 609         if len(m) != 2 {
 610                 // Not a collection PDH GET request
 611                 m = collectionRe.FindStringSubmatch(req.URL.Path)
 612                 clusterId := ""
 613
 614                 if len(m) > 0 {
 615                         clusterId = m[2]
 616                 }
 617
 618                 if clusterId != "" && clusterId != h.handler.Cluster.ClusterID {
 619                         // request for remote collection by uuid
 620                         h.handler.remoteClusterRequest(clusterId, w, req,
 621                                 rewriteSignaturesClusterId{clusterId, ""}.rewriteSignatures)
 622                         return
 623                 }
 624                 // not a collection UUID request, or it is a request
 625                 // for a local UUID, either way, continue down the
 626                 // handler stack.
 627                 h.next.ServeHTTP(w, req)
 628                 return
 629         }
 630
 631         // Request for collection by PDH.  Search the federation.
 632
 633         // First, query the local cluster.
 634         if h.handler.localClusterRequest(w, req, filterLocalClusterResponse) {
 635                 return
 636         }
 637
 638         sharedContext, cancelFunc := context.WithCancel(req.Context())
 639         defer cancelFunc()
 640         req = req.WithContext(sharedContext)
 641
 642         // Create a goroutine for each cluster in the
 643         // RemoteClusters map.  The first valid result gets
 644         // returned to the client.  When that happens, all
 645         // other outstanding requests are cancelled or
 646         // suppressed.
 647         sentResponse := false
 648         mtx := sync.Mutex{}
 649         wg := sync.WaitGroup{}
 650         var errors []string
 651         var errorCode int = 404
 652
 653         // use channel as a semaphore to limit the number of concurrent
 654         // requests at a time
 655         sem := make(chan bool, h.handler.Cluster.RequestLimits.GetMultiClusterRequestConcurrency())
 656         defer close(sem)
 657         for remoteID := range h.handler.Cluster.RemoteClusters {
 658                 // blocks until it can put a value into the
 659                 // channel (which has a max queue capacity)
 660                 sem <- true
 661                 if sentResponse {
 662                         break
 663                 }
 664                 search := &searchRemoteClusterForPDH{m[1], remoteID, &mtx, &sentResponse,
 665                         &sharedContext, cancelFunc, &errors, &errorCode}
 666                 wg.Add(1)
 667                 go func() {
 668                         h.handler.remoteClusterRequest(search.remoteID, w, req, search.filterRemoteClusterResponse)
 669                         wg.Done()
 670                         <-sem
 671                 }()
 672         }
 673         wg.Wait()
 674
 675         if sentResponse {
 676                 return
 677         }
 678
 679         // No successful responses, so return the error
 680         httpserver.Errors(w, errors, errorCode)
 681 }
 682
 683 func (h *Handler) setupProxyRemoteCluster(next http.Handler) http.Handler {
 684         mux := http.NewServeMux()
 685         mux.Handle("/arvados/v1/workflows", &genericFederatedRequestHandler{next, h, wfRe})
 686         mux.Handle("/arvados/v1/workflows/", &genericFederatedRequestHandler{next, h, wfRe})
 687         mux.Handle("/arvados/v1/containers", &genericFederatedRequestHandler{next, h, containersRe})
 688         mux.Handle("/arvados/v1/containers/", &genericFederatedRequestHandler{next, h, containersRe})
 689         mux.Handle("/arvados/v1/container_requests", &genericFederatedRequestHandler{next, h, containerRequestsRe})
 690         mux.Handle("/arvados/v1/container_requests/", &genericFederatedRequestHandler{next, h, containerRequestsRe})
 691         mux.Handle("/arvados/v1/collections", next)
 692         mux.Handle("/arvados/v1/collections/", &collectionFederatedRequestHandler{next, h})
 693         mux.Handle("/", next)
 694
 695         return http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
 696                 parts := strings.Split(req.Header.Get("Authorization"), "/")
 697                 alreadySalted := (len(parts) == 3 && parts[0] == "Bearer v2" && len(parts[2]) == 40)
 698
 699                 if alreadySalted ||
 700                         strings.Index(req.Header.Get("Via"), "arvados-controller") != -1 {
 701                         // The token is already salted, or this is a
 702                         // request from another instance of
 703                         // arvados-controller.  In either case, we
 704                         // don't want to proxy this query, so just
 705                         // continue down the instance handler stack.
 706                         next.ServeHTTP(w, req)
 707                         return
 708                 }
 709
 710                 mux.ServeHTTP(w, req)
 711         })
 712
 713         return mux
 714 }
 715
 716 type CurrentUser struct {
 717         Authorization arvados.APIClientAuthorization
 718         UUID          string
 719 }
 720
 721 func (h *Handler) validateAPItoken(req *http.Request, user *CurrentUser) error {
 722         db, err := h.db(req)
 723         if err != nil {
 724                 return err
 725         }
 726         return db.QueryRowContext(req.Context(), `SELECT api_client_authorizations.uuid, users.uuid FROM api_client_authorizations JOIN users on api_client_authorizations.user_id=users.id WHERE api_token=$1 AND (expires_at IS NULL OR expires_at > current_timestamp) LIMIT 1`, user.Authorization.APIToken).Scan(&user.Authorization.UUID, &user.UUID)
 727 }
 728
 729 // Extract the auth token supplied in req, and replace it with a
 730 // salted token for the remote cluster.
 731 func (h *Handler) saltAuthToken(req *http.Request, remote string) error {
 732         creds := auth.NewCredentials()
 733         creds.LoadTokensFromHTTPRequest(req)
 734         if len(creds.Tokens) == 0 && req.Header.Get("Content-Type") == "application/x-www-form-encoded" {
 735                 // Override ParseForm's 10MiB limit by ensuring
 736                 // req.Body is a *http.maxBytesReader.
 737                 req.Body = http.MaxBytesReader(nil, req.Body, 1<<28) // 256MiB. TODO: use MaxRequestSize from discovery doc or config.
 738                 if err := creds.LoadTokensFromHTTPRequestBody(req); err != nil {
 739                         return err
 740                 }
 741                 // Replace req.Body with a buffer that re-encodes the
 742                 // form without api_token, in case we end up
 743                 // forwarding the request.
 744                 if req.PostForm != nil {
 745                         req.PostForm.Del("api_token")
 746                 }
 747                 req.Body = ioutil.NopCloser(bytes.NewBufferString(req.PostForm.Encode()))
 748         }
 749         if len(creds.Tokens) == 0 {
 750                 return nil
 751         }
 752         token, err := auth.SaltToken(creds.Tokens[0], remote)
 753         if err == auth.ErrObsoleteToken {
 754                 // If the token exists in our own database, salt it
 755                 // for the remote. Otherwise, assume it was issued by
 756                 // the remote, and pass it through unmodified.
 757                 currentUser := CurrentUser{Authorization: arvados.APIClientAuthorization{APIToken: creds.Tokens[0]}}
 758                 err = h.validateAPItoken(req, &currentUser)
 759                 if err == sql.ErrNoRows {
 760                         // Not ours; pass through unmodified.
 761                         token = currentUser.Authorization.APIToken
 762                 } else if err != nil {
 763                         return err
 764                 } else {
 765                         // Found; make V2 version and salt it.
 766                         token, err = auth.SaltToken(currentUser.Authorization.TokenV2(), remote)
 767                         if err != nil {
 768                                 return err
 769                         }
 770                 }
 771         } else if err != nil {
 772                 return err
 773         }
 774         req.Header.Set("Authorization", "Bearer "+token)
 775
 776         // Remove api_token=... from the the query string, in case we
 777         // end up forwarding the request.
 778         if values, err := url.ParseQuery(req.URL.RawQuery); err != nil {
 779                 return err
 780         } else if _, ok := values["api_token"]; ok {
 781                 delete(values, "api_token")
 782                 req.URL.RawQuery = values.Encode()
 783         }
 784         return nil
 785 }