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         "log"
  18         "net/http"
  19         "net/url"
  20         "regexp"
  21         "strings"
  22         "sync"
  23
  24         "git.curoverse.com/arvados.git/sdk/go/arvados"
  25         "git.curoverse.com/arvados.git/sdk/go/auth"
  26         "git.curoverse.com/arvados.git/sdk/go/httpserver"
  27         "git.curoverse.com/arvados.git/sdk/go/keepclient"
  28 )
  29
  30 var pathPattern = `^/arvados/v1/%s(/([0-9a-z]{5})-%s-[0-9a-z]{15})?(.*)$`
  31 var wfRe = regexp.MustCompile(fmt.Sprintf(pathPattern, "workflows", "7fd4e"))
  32 var containersRe = regexp.MustCompile(fmt.Sprintf(pathPattern, "containers", "dz642"))
  33 var containerRequestsRe = regexp.MustCompile(fmt.Sprintf(pathPattern, "container_requests", "xvhdp"))
  34 var collectionRe = regexp.MustCompile(fmt.Sprintf(pathPattern, "collections", "4zz18"))
  35 var collectionByPDHRe = regexp.MustCompile(`^/arvados/v1/collections/([0-9a-fA-F]{32}\+[0-9]+)+$`)
  36
  37 type genericFederatedRequestHandler struct {
  38         next    http.Handler
  39         handler *Handler
  40         matcher *regexp.Regexp
  41 }
  42
  43 type collectionFederatedRequestHandler struct {
  44         next    http.Handler
  45         handler *Handler
  46 }
  47
  48 func (h *Handler) remoteClusterRequest(remoteID string, w http.ResponseWriter, req *http.Request, filter ResponseFilter) {
  49         remote, ok := h.Cluster.RemoteClusters[remoteID]
  50         if !ok {
  51                 err := fmt.Errorf("no proxy available for cluster %v", remoteID)
  52                 if filter != nil {
  53                         _, err = filter(nil, err)
  54                 }
  55                 if err != nil {
  56                         httpserver.Error(w, err.Error(), http.StatusNotFound)
  57                 }
  58                 return
  59         }
  60         scheme := remote.Scheme
  61         if scheme == "" {
  62                 scheme = "https"
  63         }
  64         req, err := h.saltAuthToken(req, remoteID)
  65         if err != nil {
  66                 if filter != nil {
  67                         _, err = filter(nil, err)
  68                 }
  69                 if err != nil {
  70                         httpserver.Error(w, err.Error(), http.StatusBadRequest)
  71                 }
  72                 return
  73         }
  74         urlOut := &url.URL{
  75                 Scheme:   scheme,
  76                 Host:     remote.Host,
  77                 Path:     req.URL.Path,
  78                 RawPath:  req.URL.RawPath,
  79                 RawQuery: req.URL.RawQuery,
  80         }
  81         client := h.secureClient
  82         if remote.Insecure {
  83                 client = h.insecureClient
  84         }
  85         h.proxy.Do(w, req, urlOut, client, filter)
  86 }
  87
  88 // Buffer request body, parse form parameters in request, and then
  89 // replace original body with the buffer so it can be re-read by
  90 // downstream proxy steps.
  91 func loadParamsFromForm(req *http.Request) error {
  92         var postBody *bytes.Buffer
  93         if req.Body != nil && req.Header.Get("Content-Type") == "application/x-www-form-urlencoded" {
  94                 var cl int64
  95                 if req.ContentLength > 0 {
  96                         cl = req.ContentLength
  97                 }
  98                 postBody = bytes.NewBuffer(make([]byte, 0, cl))
  99                 originalBody := req.Body
 100                 defer originalBody.Close()
 101                 req.Body = ioutil.NopCloser(io.TeeReader(req.Body, postBody))
 102         }
 103
 104         err := req.ParseForm()
 105         if err != nil {
 106                 return err
 107         }
 108
 109         if req.Body != nil && postBody != nil {
 110                 req.Body = ioutil.NopCloser(postBody)
 111         }
 112         return nil
 113 }
 114
 115 type multiClusterQueryResponseCollector struct {
 116         responses []map[string]interface{}
 117         error     error
 118         kind      string
 119         clusterID string
 120 }
 121
 122 func (c *multiClusterQueryResponseCollector) collectResponse(resp *http.Response,
 123         requestError error) (newResponse *http.Response, err error) {
 124         if requestError != nil {
 125                 c.error = requestError
 126                 return nil, nil
 127         }
 128
 129         defer resp.Body.Close()
 130         var loadInto struct {
 131                 Kind   string                   `json:"kind"`
 132                 Items  []map[string]interface{} `json:"items"`
 133                 Errors []string                 `json:"errors"`
 134         }
 135         err = json.NewDecoder(resp.Body).Decode(&loadInto)
 136
 137         if err != nil {
 138                 c.error = fmt.Errorf("error fetching from %v (%v): %v", c.clusterID, resp.Status, err)
 139                 return nil, nil
 140         }
 141         if resp.StatusCode != http.StatusOK {
 142                 c.error = fmt.Errorf("error fetching from %v (%v): %v", c.clusterID, resp.Status, loadInto.Errors)
 143                 return nil, nil
 144         }
 145
 146         c.responses = loadInto.Items
 147         c.kind = loadInto.Kind
 148
 149         return nil, nil
 150 }
 151
 152 func (h *genericFederatedRequestHandler) remoteQueryUUIDs(w http.ResponseWriter,
 153         req *http.Request,
 154         clusterID string, uuids []string) (rp []map[string]interface{}, kind string, err error) {
 155
 156         found := make(map[string]bool)
 157         prev_len_uuids := len(uuids) + 1
 158         // Loop while
 159         // (1) there are more uuids to query
 160         // (2) we're making progress - on each iteration the set of
 161         // uuids we are expecting for must shrink.
 162         for len(uuids) > 0 && len(uuids) < prev_len_uuids {
 163                 var remoteReq http.Request
 164                 remoteReq.Header = req.Header
 165                 remoteReq.Method = "POST"
 166                 remoteReq.URL = &url.URL{Path: req.URL.Path}
 167                 remoteParams := make(url.Values)
 168                 remoteParams.Set("_method", "GET")
 169                 remoteParams.Set("count", "none")
 170                 if req.Form.Get("select") != "" {
 171                         remoteParams.Set("select", req.Form.Get("select"))
 172                 }
 173                 content, err := json.Marshal(uuids)
 174                 if err != nil {
 175                         return nil, "", err
 176                 }
 177                 remoteParams["filters"] = []string{fmt.Sprintf(`[["uuid", "in", %s]]`, content)}
 178                 enc := remoteParams.Encode()
 179                 remoteReq.Body = ioutil.NopCloser(bytes.NewBufferString(enc))
 180
 181                 rc := multiClusterQueryResponseCollector{clusterID: clusterID}
 182
 183                 if clusterID == h.handler.Cluster.ClusterID {
 184                         h.handler.localClusterRequest(w, &remoteReq,
 185                                 rc.collectResponse)
 186                 } else {
 187                         h.handler.remoteClusterRequest(clusterID, w, &remoteReq,
 188                                 rc.collectResponse)
 189                 }
 190                 if rc.error != nil {
 191                         return nil, "", rc.error
 192                 }
 193
 194                 kind = rc.kind
 195
 196                 if len(rc.responses) == 0 {
 197                         // We got zero responses, no point in doing
 198                         // another query.
 199                         return rp, kind, nil
 200                 }
 201
 202                 rp = append(rp, rc.responses...)
 203
 204                 // Go through the responses and determine what was
 205                 // returned.  If there are remaining items, loop
 206                 // around and do another request with just the
 207                 // stragglers.
 208                 for _, i := range rc.responses {
 209                         uuid, ok := i["uuid"].(string)
 210                         if ok {
 211                                 found[uuid] = true
 212                         }
 213                 }
 214
 215                 l := []string{}
 216                 for _, u := range uuids {
 217                         if !found[u] {
 218                                 l = append(l, u)
 219                         }
 220                 }
 221                 prev_len_uuids = len(uuids)
 222                 uuids = l
 223         }
 224
 225         return rp, kind, nil
 226 }
 227
 228 func (h *genericFederatedRequestHandler) handleMultiClusterQuery(w http.ResponseWriter,
 229         req *http.Request, clusterId *string) bool {
 230
 231         var filters [][]interface{}
 232         err := json.Unmarshal([]byte(req.Form.Get("filters")), &filters)
 233         if err != nil {
 234                 httpserver.Error(w, err.Error(), http.StatusBadRequest)
 235                 return true
 236         }
 237
 238         // Split the list of uuids by prefix
 239         queryClusters := make(map[string][]string)
 240         expectCount := 0
 241         for _, filter := range filters {
 242                 if len(filter) != 3 {
 243                         return false
 244                 }
 245
 246                 if lhs, ok := filter[0].(string); !ok || lhs != "uuid" {
 247                         return false
 248                 }
 249
 250                 op, ok := filter[1].(string)
 251                 if !ok {
 252                         return false
 253                 }
 254
 255                 if op == "in" {
 256                         if rhs, ok := filter[2].([]interface{}); ok {
 257                                 for _, i := range rhs {
 258                                         if u, ok := i.(string); ok {
 259                                                 *clusterId = u[0:5]
 260                                                 queryClusters[u[0:5]] = append(queryClusters[u[0:5]], u)
 261                                                 expectCount += 1
 262                                         }
 263                                 }
 264                         }
 265                 } else if op == "=" {
 266                         if u, ok := filter[2].(string); ok {
 267                                 *clusterId = u[0:5]
 268                                 queryClusters[u[0:5]] = append(queryClusters[u[0:5]], u)
 269                                 expectCount += 1
 270                         }
 271                 } else {
 272                         return false
 273                 }
 274
 275         }
 276
 277         if len(queryClusters) <= 1 {
 278                 // Query does not search for uuids across multiple
 279                 // clusters.
 280                 return false
 281         }
 282
 283         // Validations
 284         count := req.Form.Get("count")
 285         if count != "" && count != `none` && count != `"none"` {
 286                 httpserver.Error(w, "Federated multi-object query must have 'count=none'", http.StatusBadRequest)
 287                 return true
 288         }
 289         if req.Form.Get("limit") != "" || req.Form.Get("offset") != "" || req.Form.Get("order") != "" {
 290                 httpserver.Error(w, "Federated multi-object may not provide 'limit', 'offset' or 'order'.", http.StatusBadRequest)
 291                 return true
 292         }
 293         if expectCount > h.handler.Cluster.RequestLimits.GetMaxItemsPerResponse() {
 294                 httpserver.Error(w, fmt.Sprintf("Federated multi-object request for %v objects which is more than max page size %v.",
 295                         expectCount, h.handler.Cluster.RequestLimits.GetMaxItemsPerResponse()), http.StatusBadRequest)
 296                 return true
 297         }
 298         if req.Form.Get("select") != "" {
 299                 foundUUID := false
 300                 var selects []string
 301                 err := json.Unmarshal([]byte(req.Form.Get("select")), &selects)
 302                 if err != nil {
 303                         httpserver.Error(w, err.Error(), http.StatusBadRequest)
 304                         return true
 305                 }
 306
 307                 for _, r := range selects {
 308                         if r == "uuid" {
 309                                 foundUUID = true
 310                                 break
 311                         }
 312                 }
 313                 if !foundUUID {
 314                         httpserver.Error(w, "Federated multi-object request must include 'uuid' in 'select'", http.StatusBadRequest)
 315                         return true
 316                 }
 317         }
 318
 319         // Perform concurrent requests to each cluster
 320
 321         // use channel as a semaphore to limit the number of concurrent
 322         // requests at a time
 323         sem := make(chan bool, h.handler.Cluster.RequestLimits.GetMultiClusterRequestConcurrency())
 324         defer close(sem)
 325         wg := sync.WaitGroup{}
 326
 327         req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
 328         mtx := sync.Mutex{}
 329         errors := []error{}
 330         var completeResponses []map[string]interface{}
 331         var kind string
 332
 333         for k, v := range queryClusters {
 334                 if len(v) == 0 {
 335                         // Nothing to query
 336                         continue
 337                 }
 338
 339                 // blocks until it can put a value into the
 340                 // channel (which has a max queue capacity)
 341                 sem <- true
 342                 wg.Add(1)
 343                 go func(k string, v []string) {
 344                         rp, kn, err := h.remoteQueryUUIDs(w, req, k, v)
 345                         mtx.Lock()
 346                         if err == nil {
 347                                 completeResponses = append(completeResponses, rp...)
 348                                 kind = kn
 349                         } else {
 350                                 errors = append(errors, err)
 351                         }
 352                         mtx.Unlock()
 353                         wg.Done()
 354                         <-sem
 355                 }(k, v)
 356         }
 357         wg.Wait()
 358
 359         if len(errors) > 0 {
 360                 var strerr []string
 361                 for _, e := range errors {
 362                         strerr = append(strerr, e.Error())
 363                 }
 364                 httpserver.Errors(w, strerr, http.StatusBadGateway)
 365                 return true
 366         }
 367
 368         w.Header().Set("Content-Type", "application/json")
 369         w.WriteHeader(http.StatusOK)
 370         itemList := make(map[string]interface{})
 371         itemList["items"] = completeResponses
 372         itemList["kind"] = kind
 373         json.NewEncoder(w).Encode(itemList)
 374
 375         return true
 376 }
 377
 378 func (h *genericFederatedRequestHandler) ServeHTTP(w http.ResponseWriter, req *http.Request) {
 379         m := h.matcher.FindStringSubmatch(req.URL.Path)
 380         clusterId := ""
 381
 382         if len(m) > 0 && m[2] != "" {
 383                 clusterId = m[2]
 384         }
 385
 386         // Get form parameters from URL and form body (if POST).
 387         if err := loadParamsFromForm(req); err != nil {
 388                 httpserver.Error(w, err.Error(), http.StatusBadRequest)
 389                 return
 390         }
 391
 392         // Check if the parameters have an explicit cluster_id
 393         if req.Form.Get("cluster_id") != "" {
 394                 clusterId = req.Form.Get("cluster_id")
 395         }
 396
 397         // Handle the POST-as-GET special case (workaround for large
 398         // GET requests that potentially exceed maximum URL length,
 399         // like multi-object queries where the filter has 100s of
 400         // items)
 401         effectiveMethod := req.Method
 402         if req.Method == "POST" && req.Form.Get("_method") != "" {
 403                 effectiveMethod = req.Form.Get("_method")
 404         }
 405
 406         if effectiveMethod == "GET" &&
 407                 clusterId == "" &&
 408                 req.Form.Get("filters") != "" &&
 409                 h.handleMultiClusterQuery(w, req, &clusterId) {
 410                 return
 411         }
 412
 413         if clusterId == "" || clusterId == h.handler.Cluster.ClusterID {
 414                 h.next.ServeHTTP(w, req)
 415         } else {
 416                 h.handler.remoteClusterRequest(clusterId, w, req, nil)
 417         }
 418 }
 419
 420 type rewriteSignaturesClusterId struct {
 421         clusterID  string
 422         expectHash string
 423 }
 424
 425 func (rw rewriteSignaturesClusterId) rewriteSignatures(resp *http.Response, requestError error) (newResponse *http.Response, err error) {
 426         if requestError != nil {
 427                 return resp, requestError
 428         }
 429
 430         if resp.StatusCode != 200 {
 431                 return resp, nil
 432         }
 433
 434         originalBody := resp.Body
 435         defer originalBody.Close()
 436
 437         var col arvados.Collection
 438         err = json.NewDecoder(resp.Body).Decode(&col)
 439         if err != nil {
 440                 return nil, err
 441         }
 442
 443         // rewriting signatures will make manifest text 5-10% bigger so calculate
 444         // capacity accordingly
 445         updatedManifest := bytes.NewBuffer(make([]byte, 0, int(float64(len(col.ManifestText))*1.1)))
 446
 447         hasher := md5.New()
 448         mw := io.MultiWriter(hasher, updatedManifest)
 449         sz := 0
 450
 451         scanner := bufio.NewScanner(strings.NewReader(col.ManifestText))
 452         scanner.Buffer(make([]byte, 1048576), len(col.ManifestText))
 453         for scanner.Scan() {
 454                 line := scanner.Text()
 455                 tokens := strings.Split(line, " ")
 456                 if len(tokens) < 3 {
 457                         return nil, fmt.Errorf("Invalid stream (<3 tokens): %q", line)
 458                 }
 459
 460                 n, err := mw.Write([]byte(tokens[0]))
 461                 if err != nil {
 462                         return nil, fmt.Errorf("Error updating manifest: %v", err)
 463                 }
 464                 sz += n
 465                 for _, token := range tokens[1:] {
 466                         n, err = mw.Write([]byte(" "))
 467                         if err != nil {
 468                                 return nil, fmt.Errorf("Error updating manifest: %v", err)
 469                         }
 470                         sz += n
 471
 472                         m := keepclient.SignedLocatorRe.FindStringSubmatch(token)
 473                         if m != nil {
 474                                 // Rewrite the block signature to be a remote signature
 475                                 _, err = fmt.Fprintf(updatedManifest, "%s%s%s+R%s-%s%s", m[1], m[2], m[3], rw.clusterID, m[5][2:], m[8])
 476                                 if err != nil {
 477                                         return nil, fmt.Errorf("Error updating manifest: %v", err)
 478                                 }
 479
 480                                 // for hash checking, ignore signatures
 481                                 n, err = fmt.Fprintf(hasher, "%s%s", m[1], m[2])
 482                                 if err != nil {
 483                                         return nil, fmt.Errorf("Error updating manifest: %v", err)
 484                                 }
 485                                 sz += n
 486                         } else {
 487                                 n, err = mw.Write([]byte(token))
 488                                 if err != nil {
 489                                         return nil, fmt.Errorf("Error updating manifest: %v", err)
 490                                 }
 491                                 sz += n
 492                         }
 493                 }
 494                 n, err = mw.Write([]byte("\n"))
 495                 if err != nil {
 496                         return nil, fmt.Errorf("Error updating manifest: %v", err)
 497                 }
 498                 sz += n
 499         }
 500
 501         // Check that expected hash is consistent with
 502         // portable_data_hash field of the returned record
 503         if rw.expectHash == "" {
 504                 rw.expectHash = col.PortableDataHash
 505         } else if rw.expectHash != col.PortableDataHash {
 506                 return nil, fmt.Errorf("portable_data_hash %q on returned record did not match expected hash %q ", rw.expectHash, col.PortableDataHash)
 507         }
 508
 509         // Certify that the computed hash of the manifest_text matches our expectation
 510         sum := hasher.Sum(nil)
 511         computedHash := fmt.Sprintf("%x+%v", sum, sz)
 512         if computedHash != rw.expectHash {
 513                 return nil, fmt.Errorf("Computed manifest_text hash %q did not match expected hash %q", computedHash, rw.expectHash)
 514         }
 515
 516         col.ManifestText = updatedManifest.String()
 517
 518         newbody, err := json.Marshal(col)
 519         if err != nil {
 520                 return nil, err
 521         }
 522
 523         buf := bytes.NewBuffer(newbody)
 524         resp.Body = ioutil.NopCloser(buf)
 525         resp.ContentLength = int64(buf.Len())
 526         resp.Header.Set("Content-Length", fmt.Sprintf("%v", buf.Len()))
 527
 528         return resp, nil
 529 }
 530
 531 func filterLocalClusterResponse(resp *http.Response, requestError error) (newResponse *http.Response, err error) {
 532         if requestError != nil {
 533                 return resp, requestError
 534         }
 535
 536         if resp.StatusCode == 404 {
 537                 // Suppress returning this result, because we want to
 538                 // search the federation.
 539                 return nil, nil
 540         }
 541         return resp, nil
 542 }
 543
 544 type searchRemoteClusterForPDH struct {
 545         pdh           string
 546         remoteID      string
 547         mtx           *sync.Mutex
 548         sentResponse  *bool
 549         sharedContext *context.Context
 550         cancelFunc    func()
 551         errors        *[]string
 552         statusCode    *int
 553 }
 554
 555 func (s *searchRemoteClusterForPDH) filterRemoteClusterResponse(resp *http.Response, requestError error) (newResponse *http.Response, err error) {
 556         s.mtx.Lock()
 557         defer s.mtx.Unlock()
 558
 559         if *s.sentResponse {
 560                 // Another request already returned a response
 561                 return nil, nil
 562         }
 563
 564         if requestError != nil {
 565                 *s.errors = append(*s.errors, fmt.Sprintf("Request error contacting %q: %v", s.remoteID, requestError))
 566                 // Record the error and suppress response
 567                 return nil, nil
 568         }
 569
 570         if resp.StatusCode != 200 {
 571                 // Suppress returning unsuccessful result.  Maybe
 572                 // another request will find it.
 573                 // TODO collect and return error responses.
 574                 *s.errors = append(*s.errors, fmt.Sprintf("Response from %q: %v", s.remoteID, resp.Status))
 575                 if resp.StatusCode != 404 {
 576                         // Got a non-404 error response, convert into BadGateway
 577                         *s.statusCode = http.StatusBadGateway
 578                 }
 579                 return nil, nil
 580         }
 581
 582         s.mtx.Unlock()
 583
 584         // This reads the response body.  We don't want to hold the
 585         // lock while doing this because other remote requests could
 586         // also have made it to this point, and we don't want a
 587         // slow response holding the lock to block a faster response
 588         // that is waiting on the lock.
 589         newResponse, err = rewriteSignaturesClusterId{s.remoteID, s.pdh}.rewriteSignatures(resp, nil)
 590
 591         s.mtx.Lock()
 592
 593         if *s.sentResponse {
 594                 // Another request already returned a response
 595                 return nil, nil
 596         }
 597
 598         if err != nil {
 599                 // Suppress returning unsuccessful result.  Maybe
 600                 // another request will be successful.
 601                 *s.errors = append(*s.errors, fmt.Sprintf("Error parsing response from %q: %v", s.remoteID, err))
 602                 return nil, nil
 603         }
 604
 605         // We have a successful response.  Suppress/cancel all the
 606         // other requests/responses.
 607         *s.sentResponse = true
 608         s.cancelFunc()
 609
 610         return newResponse, nil
 611 }
 612
 613 func (h *collectionFederatedRequestHandler) ServeHTTP(w http.ResponseWriter, req *http.Request) {
 614         if req.Method != "GET" {
 615                 // Only handle GET requests right now
 616                 h.next.ServeHTTP(w, req)
 617                 return
 618         }
 619
 620         m := collectionByPDHRe.FindStringSubmatch(req.URL.Path)
 621         if len(m) != 2 {
 622                 // Not a collection PDH GET request
 623                 m = collectionRe.FindStringSubmatch(req.URL.Path)
 624                 clusterId := ""
 625
 626                 if len(m) > 0 {
 627                         clusterId = m[2]
 628                 }
 629
 630                 if clusterId != "" && clusterId != h.handler.Cluster.ClusterID {
 631                         // request for remote collection by uuid
 632                         h.handler.remoteClusterRequest(clusterId, w, req,
 633                                 rewriteSignaturesClusterId{clusterId, ""}.rewriteSignatures)
 634                         return
 635                 }
 636                 // not a collection UUID request, or it is a request
 637                 // for a local UUID, either way, continue down the
 638                 // handler stack.
 639                 h.next.ServeHTTP(w, req)
 640                 return
 641         }
 642
 643         // Request for collection by PDH.  Search the federation.
 644
 645         // First, query the local cluster.
 646         if h.handler.localClusterRequest(w, req, filterLocalClusterResponse) {
 647                 return
 648         }
 649
 650         sharedContext, cancelFunc := context.WithCancel(req.Context())
 651         defer cancelFunc()
 652         req = req.WithContext(sharedContext)
 653
 654         // Create a goroutine for each cluster in the
 655         // RemoteClusters map.  The first valid result gets
 656         // returned to the client.  When that happens, all
 657         // other outstanding requests are cancelled or
 658         // suppressed.
 659         sentResponse := false
 660         mtx := sync.Mutex{}
 661         wg := sync.WaitGroup{}
 662         var errors []string
 663         var errorCode int = 404
 664
 665         // use channel as a semaphore to limit the number of concurrent
 666         // requests at a time
 667         sem := make(chan bool, h.handler.Cluster.RequestLimits.GetMultiClusterRequestConcurrency())
 668         defer close(sem)
 669         for remoteID := range h.handler.Cluster.RemoteClusters {
 670                 if remoteID == h.handler.Cluster.ClusterID {
 671                         // No need to query local cluster again
 672                         continue
 673                 }
 674                 // blocks until it can put a value into the
 675                 // channel (which has a max queue capacity)
 676                 sem <- true
 677                 if sentResponse {
 678                         break
 679                 }
 680                 search := &searchRemoteClusterForPDH{m[1], remoteID, &mtx, &sentResponse,
 681                         &sharedContext, cancelFunc, &errors, &errorCode}
 682                 wg.Add(1)
 683                 go func() {
 684                         h.handler.remoteClusterRequest(search.remoteID, w, req, search.filterRemoteClusterResponse)
 685                         wg.Done()
 686                         <-sem
 687                 }()
 688         }
 689         wg.Wait()
 690
 691         if sentResponse {
 692                 return
 693         }
 694
 695         // No successful responses, so return the error
 696         httpserver.Errors(w, errors, errorCode)
 697 }
 698
 699 func (h *Handler) setupProxyRemoteCluster(next http.Handler) http.Handler {
 700         mux := http.NewServeMux()
 701         mux.Handle("/arvados/v1/workflows", &genericFederatedRequestHandler{next, h, wfRe})
 702         mux.Handle("/arvados/v1/workflows/", &genericFederatedRequestHandler{next, h, wfRe})
 703         mux.Handle("/arvados/v1/containers", &genericFederatedRequestHandler{next, h, containersRe})
 704         mux.Handle("/arvados/v1/containers/", &genericFederatedRequestHandler{next, h, containersRe})
 705         mux.Handle("/arvados/v1/container_requests", &genericFederatedRequestHandler{next, h, containerRequestsRe})
 706         mux.Handle("/arvados/v1/container_requests/", &genericFederatedRequestHandler{next, h, containerRequestsRe})
 707         mux.Handle("/arvados/v1/collections", next)
 708         mux.Handle("/arvados/v1/collections/", &collectionFederatedRequestHandler{next, h})
 709         mux.Handle("/", next)
 710
 711         return http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
 712                 parts := strings.Split(req.Header.Get("Authorization"), "/")
 713                 alreadySalted := (len(parts) == 3 && parts[0] == "Bearer v2" && len(parts[2]) == 40)
 714
 715                 if alreadySalted ||
 716                         strings.Index(req.Header.Get("Via"), "arvados-controller") != -1 {
 717                         // The token is already salted, or this is a
 718                         // request from another instance of
 719                         // arvados-controller.  In either case, we
 720                         // don't want to proxy this query, so just
 721                         // continue down the instance handler stack.
 722                         next.ServeHTTP(w, req)
 723                         return
 724                 }
 725
 726                 mux.ServeHTTP(w, req)
 727         })
 728
 729         return mux
 730 }
 731
 732 type CurrentUser struct {
 733         Authorization arvados.APIClientAuthorization
 734         UUID          string
 735 }
 736
 737 func (h *Handler) validateAPItoken(req *http.Request, user *CurrentUser) error {
 738         db, err := h.db(req)
 739         if err != nil {
 740                 return err
 741         }
 742         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)
 743 }
 744
 745 // Extract the auth token supplied in req, and replace it with a
 746 // salted token for the remote cluster.
 747 func (h *Handler) saltAuthToken(req *http.Request, remote string) (updatedReq *http.Request, err error) {
 748         updatedReq = (&http.Request{
 749                 Method:        req.Method,
 750                 URL:           req.URL,
 751                 Header:        req.Header,
 752                 Body:          req.Body,
 753                 ContentLength: req.ContentLength,
 754                 Host:          req.Host,
 755         }).WithContext(req.Context())
 756
 757         creds := auth.NewCredentials()
 758         creds.LoadTokensFromHTTPRequest(updatedReq)
 759         if len(creds.Tokens) == 0 && updatedReq.Header.Get("Content-Type") == "application/x-www-form-encoded" {
 760                 // Override ParseForm's 10MiB limit by ensuring
 761                 // req.Body is a *http.maxBytesReader.
 762                 updatedReq.Body = http.MaxBytesReader(nil, updatedReq.Body, 1<<28) // 256MiB. TODO: use MaxRequestSize from discovery doc or config.
 763                 if err := creds.LoadTokensFromHTTPRequestBody(updatedReq); err != nil {
 764                         return nil, err
 765                 }
 766                 // Replace req.Body with a buffer that re-encodes the
 767                 // form without api_token, in case we end up
 768                 // forwarding the request.
 769                 if updatedReq.PostForm != nil {
 770                         updatedReq.PostForm.Del("api_token")
 771                 }
 772                 updatedReq.Body = ioutil.NopCloser(bytes.NewBufferString(updatedReq.PostForm.Encode()))
 773         }
 774         if len(creds.Tokens) == 0 {
 775                 return updatedReq, nil
 776         }
 777
 778         token, err := auth.SaltToken(creds.Tokens[0], remote)
 779
 780         log.Printf("Salting %q %q to get %q %q", creds.Tokens[0], remote, token, err)
 781         if err == auth.ErrObsoleteToken {
 782                 // If the token exists in our own database, salt it
 783                 // for the remote. Otherwise, assume it was issued by
 784                 // the remote, and pass it through unmodified.
 785                 currentUser := CurrentUser{Authorization: arvados.APIClientAuthorization{APIToken: creds.Tokens[0]}}
 786                 err = h.validateAPItoken(req, &currentUser)
 787                 if err == sql.ErrNoRows {
 788                         // Not ours; pass through unmodified.
 789                         token = currentUser.Authorization.APIToken
 790                 } else if err != nil {
 791                         return nil, err
 792                 } else {
 793                         // Found; make V2 version and salt it.
 794                         token, err = auth.SaltToken(currentUser.Authorization.TokenV2(), remote)
 795                         if err != nil {
 796                                 return nil, err
 797                         }
 798                 }
 799         } else if err != nil {
 800                 return nil, err
 801         }
 802         updatedReq.Header = http.Header{}
 803         for k, v := range req.Header {
 804                 if k == "Authorization" {
 805                         updatedReq.Header[k] = []string{"Bearer " + token}
 806                 } else {
 807                         updatedReq.Header[k] = v
 808                 }
 809         }
 810
 811         log.Printf("Salted %q %q to get %q", creds.Tokens[0], remote, token)
 812
 813         // Remove api_token=... from the the query string, in case we
 814         // end up forwarding the request.
 815         if values, err := url.ParseQuery(updatedReq.URL.RawQuery); err != nil {
 816                 return nil, err
 817         } else if _, ok := values["api_token"]; ok {
 818                 delete(values, "api_token")
 819                 updatedReq.URL = &url.URL{
 820                         Scheme:   req.URL.Scheme,
 821                         Host:     req.URL.Host,
 822                         Path:     req.URL.Path,
 823                         RawPath:  req.URL.RawPath,
 824                         RawQuery: values.Encode(),
 825                 }
 826         }
 827         return updatedReq, nil
 828 }