services/keepproxy/keepproxy.go

   1 // Copyright (C) The Arvados Authors. All rights reserved.
   2 //
   3 // SPDX-License-Identifier: AGPL-3.0
   4
   5 package main
   6
   7 import (
   8         "errors"
   9         "flag"
  10         "fmt"
  11         "io"
  12         "io/ioutil"
  13         "net"
  14         "net/http"
  15         "os"
  16         "os/signal"
  17         "regexp"
  18         "strings"
  19         "sync"
  20         "syscall"
  21         "time"
  22
  23         "git.arvados.org/arvados.git/lib/config"
  24         "git.arvados.org/arvados.git/sdk/go/arvados"
  25         "git.arvados.org/arvados.git/sdk/go/arvadosclient"
  26         "git.arvados.org/arvados.git/sdk/go/health"
  27         "git.arvados.org/arvados.git/sdk/go/httpserver"
  28         "git.arvados.org/arvados.git/sdk/go/keepclient"
  29         "github.com/coreos/go-systemd/daemon"
  30         "github.com/ghodss/yaml"
  31         "github.com/gorilla/mux"
  32         log "github.com/sirupsen/logrus"
  33 )
  34
  35 var version = "dev"
  36
  37 var (
  38         listener net.Listener
  39         router   http.Handler
  40 )
  41
  42 const rfc3339NanoFixed = "2006-01-02T15:04:05.000000000Z07:00"
  43
  44 func configure(logger log.FieldLogger, args []string) (*arvados.Cluster, error) {
  45         flags := flag.NewFlagSet(args[0], flag.ExitOnError)
  46
  47         dumpConfig := flags.Bool("dump-config", false, "write current configuration to stdout and exit")
  48         getVersion := flags.Bool("version", false, "Print version information and exit.")
  49
  50         loader := config.NewLoader(os.Stdin, logger)
  51         loader.SetupFlags(flags)
  52
  53         args = loader.MungeLegacyConfigArgs(logger, args[1:], "-legacy-keepproxy-config")
  54         flags.Parse(args)
  55
  56         // Print version information if requested
  57         if *getVersion {
  58                 fmt.Printf("keepproxy %s\n", version)
  59                 return nil, nil
  60         }
  61
  62         cfg, err := loader.Load()
  63         if err != nil {
  64                 return nil, err
  65         }
  66         cluster, err := cfg.GetCluster("")
  67         if err != nil {
  68                 return nil, err
  69         }
  70
  71         if *dumpConfig {
  72                 out, err := yaml.Marshal(cfg)
  73                 if err != nil {
  74                         return nil, err
  75                 }
  76                 if _, err := os.Stdout.Write(out); err != nil {
  77                         return nil, err
  78                 }
  79                 return nil, nil
  80         }
  81         return cluster, nil
  82 }
  83
  84 func main() {
  85         logger := log.New()
  86         logger.Formatter = &log.JSONFormatter{
  87                 TimestampFormat: rfc3339NanoFixed,
  88         }
  89
  90         cluster, err := configure(logger, os.Args)
  91         if err != nil {
  92                 log.Fatal(err)
  93         }
  94         if cluster == nil {
  95                 return
  96         }
  97
  98         log.Printf("keepproxy %s started", version)
  99
 100         if err := run(logger, cluster); err != nil {
 101                 log.Fatal(err)
 102         }
 103
 104         log.Println("shutting down")
 105 }
 106
 107 func run(logger log.FieldLogger, cluster *arvados.Cluster) error {
 108         client, err := arvados.NewClientFromConfig(cluster)
 109         if err != nil {
 110                 return err
 111         }
 112         client.AuthToken = cluster.SystemRootToken
 113
 114         arv, err := arvadosclient.New(client)
 115         if err != nil {
 116                 return fmt.Errorf("Error setting up arvados client %v", err)
 117         }
 118
 119         // If a config file is available, use the keepstores defined there
 120         // instead of the legacy autodiscover mechanism via the API server
 121         for k := range cluster.Services.Keepstore.InternalURLs {
 122                 arv.KeepServiceURIs = append(arv.KeepServiceURIs, strings.TrimRight(k.String(), "/"))
 123         }
 124
 125         if cluster.SystemLogs.LogLevel == "debug" {
 126                 keepclient.DebugPrintf = log.Printf
 127         }
 128         kc, err := keepclient.MakeKeepClient(arv)
 129         if err != nil {
 130                 return fmt.Errorf("Error setting up keep client %v", err)
 131         }
 132         keepclient.RefreshServiceDiscoveryOnSIGHUP()
 133
 134         if cluster.Collections.DefaultReplication > 0 {
 135                 kc.Want_replicas = cluster.Collections.DefaultReplication
 136         }
 137
 138         var listen arvados.URL
 139         for listen = range cluster.Services.Keepproxy.InternalURLs {
 140                 break
 141         }
 142
 143         var lErr error
 144         listener, lErr = net.Listen("tcp", listen.Host)
 145         if lErr != nil {
 146                 return fmt.Errorf("listen(%s): %v", listen.Host, lErr)
 147         }
 148
 149         if _, err := daemon.SdNotify(false, "READY=1"); err != nil {
 150                 log.Printf("Error notifying init daemon: %v", err)
 151         }
 152         log.Println("listening at", listener.Addr())
 153
 154         // Shut down the server gracefully (by closing the listener)
 155         // if SIGTERM is received.
 156         term := make(chan os.Signal, 1)
 157         go func(sig <-chan os.Signal) {
 158                 s := <-sig
 159                 log.Println("caught signal:", s)
 160                 listener.Close()
 161         }(term)
 162         signal.Notify(term, syscall.SIGTERM)
 163         signal.Notify(term, syscall.SIGINT)
 164
 165         // Start serving requests.
 166         router = MakeRESTRouter(kc, time.Duration(keepclient.DefaultProxyRequestTimeout), cluster, logger)
 167         return http.Serve(listener, httpserver.AddRequestIDs(httpserver.LogRequests(router)))
 168 }
 169
 170 type APITokenCache struct {
 171         tokens     map[string]int64
 172         tokenUser  map[string]*arvados.User
 173         lock       sync.Mutex
 174         expireTime int64
 175 }
 176
 177 // RememberToken caches the token and set an expire time.  If we already have
 178 // an expire time on the token, it is not updated.
 179 func (cache *APITokenCache) RememberToken(token string, user *arvados.User) {
 180         cache.lock.Lock()
 181         defer cache.lock.Unlock()
 182
 183         now := time.Now().Unix()
 184         if cache.tokens[token] == 0 {
 185                 cache.tokens[token] = now + cache.expireTime
 186         }
 187         cache.tokenUser[token] = user
 188 }
 189
 190 // RecallToken checks if the cached token is known and still believed to be
 191 // valid.
 192 func (cache *APITokenCache) RecallToken(token string) (bool, *arvados.User) {
 193         cache.lock.Lock()
 194         defer cache.lock.Unlock()
 195
 196         now := time.Now().Unix()
 197         if cache.tokens[token] == 0 {
 198                 // Unknown token
 199                 return false, nil
 200         } else if now < cache.tokens[token] {
 201                 // Token is known and still valid
 202                 return true, cache.tokenUser[token]
 203         } else {
 204                 // Token is expired
 205                 cache.tokens[token] = 0
 206                 return false, nil
 207         }
 208 }
 209
 210 // GetRemoteAddress returns a string with the remote address for the request.
 211 // If the X-Forwarded-For header is set and has a non-zero length, it returns a
 212 // string made from a comma separated list of all the remote addresses,
 213 // starting with the one(s) from the X-Forwarded-For header.
 214 func GetRemoteAddress(req *http.Request) string {
 215         if xff := req.Header.Get("X-Forwarded-For"); xff != "" {
 216                 return xff + "," + req.RemoteAddr
 217         }
 218         return req.RemoteAddr
 219 }
 220
 221 func (h *proxyHandler) CheckAuthorizationHeader(req *http.Request) (pass bool, tok string, user *arvados.User) {
 222         parts := strings.SplitN(req.Header.Get("Authorization"), " ", 2)
 223         if len(parts) < 2 || !(parts[0] == "OAuth2" || parts[0] == "Bearer") || len(parts[1]) == 0 {
 224                 return false, "", nil
 225         }
 226         tok = parts[1]
 227
 228         // Tokens are validated differently depending on what kind of
 229         // operation is being performed. For example, tokens in
 230         // collection-sharing links permit GET requests, but not
 231         // PUT requests.
 232         var op string
 233         if req.Method == "GET" || req.Method == "HEAD" {
 234                 op = "read"
 235         } else {
 236                 op = "write"
 237         }
 238
 239         if ok, user := h.APITokenCache.RecallToken(op + ":" + tok); ok {
 240                 // Valid in the cache, short circuit
 241                 return true, tok, user
 242         }
 243
 244         var err error
 245         arv := *h.KeepClient.Arvados
 246         arv.ApiToken = tok
 247         arv.RequestID = req.Header.Get("X-Request-Id")
 248         user = &arvados.User{}
 249         userCurrentError := arv.Call("GET", "users", "", "current", nil, user)
 250         if op == "read" {
 251                 // scoped token this will fail the user current check,
 252                 // but if it is a download operation and they can read
 253                 // the keep_services table, it's okay.
 254                 err = arv.Call("HEAD", "keep_services", "", "accessible", nil, nil)
 255         } else {
 256                 err = userCurrentError
 257         }
 258         if err != nil {
 259                 log.Printf("%s: CheckAuthorizationHeader error: %v", GetRemoteAddress(req), err)
 260                 return false, "", nil
 261         }
 262
 263         if userCurrentError == nil && user.IsAdmin {
 264                 // checking userCurrentError is probably redundant,
 265                 // IsAdmin would be false anyway. But can't hurt.
 266                 if op == "read" && !h.cluster.Collections.KeepproxyPermission.Admin.Download {
 267                         return false, "", nil
 268                 }
 269                 if op == "write" && !h.cluster.Collections.KeepproxyPermission.Admin.Upload {
 270                         return false, "", nil
 271                 }
 272         } else {
 273                 if op == "read" && !h.cluster.Collections.KeepproxyPermission.User.Download {
 274                         return false, "", nil
 275                 }
 276                 if op == "write" && !h.cluster.Collections.KeepproxyPermission.User.Upload {
 277                         return false, "", nil
 278                 }
 279         }
 280
 281         // Success!  Update cache
 282         h.APITokenCache.RememberToken(op+":"+tok, user)
 283
 284         return true, tok, user
 285 }
 286
 287 // We need to make a private copy of the default http transport early
 288 // in initialization, then make copies of our private copy later. It
 289 // won't be safe to copy http.DefaultTransport itself later, because
 290 // its private mutexes might have already been used. (Without this,
 291 // the test suite sometimes panics "concurrent map writes" in
 292 // net/http.(*Transport).removeIdleConnLocked().)
 293 var defaultTransport = *(http.DefaultTransport.(*http.Transport))
 294
 295 type proxyHandler struct {
 296         http.Handler
 297         *keepclient.KeepClient
 298         *APITokenCache
 299         timeout   time.Duration
 300         transport *http.Transport
 301         logger    log.FieldLogger
 302         cluster   *arvados.Cluster
 303 }
 304
 305 // MakeRESTRouter returns an http.Handler that passes GET and PUT
 306 // requests to the appropriate handlers.
 307 func MakeRESTRouter(kc *keepclient.KeepClient, timeout time.Duration, cluster *arvados.Cluster, logger log.FieldLogger) http.Handler {
 308         rest := mux.NewRouter()
 309
 310         transport := defaultTransport
 311         transport.DialContext = (&net.Dialer{
 312                 Timeout:   keepclient.DefaultConnectTimeout,
 313                 KeepAlive: keepclient.DefaultKeepAlive,
 314                 DualStack: true,
 315         }).DialContext
 316         transport.TLSClientConfig = arvadosclient.MakeTLSConfig(kc.Arvados.ApiInsecure)
 317         transport.TLSHandshakeTimeout = keepclient.DefaultTLSHandshakeTimeout
 318
 319         h := &proxyHandler{
 320                 Handler:    rest,
 321                 KeepClient: kc,
 322                 timeout:    timeout,
 323                 transport:  &transport,
 324                 APITokenCache: &APITokenCache{
 325                         tokens:     make(map[string]int64),
 326                         tokenUser:  make(map[string]*arvados.User),
 327                         expireTime: 300,
 328                 },
 329                 logger:  logger,
 330                 cluster: cluster,
 331         }
 332
 333         rest.HandleFunc(`/{locator:[0-9a-f]{32}\+.*}`, h.Get).Methods("GET", "HEAD")
 334         rest.HandleFunc(`/{locator:[0-9a-f]{32}}`, h.Get).Methods("GET", "HEAD")
 335
 336         // List all blocks
 337         rest.HandleFunc(`/index`, h.Index).Methods("GET")
 338
 339         // List blocks whose hash has the given prefix
 340         rest.HandleFunc(`/index/{prefix:[0-9a-f]{0,32}}`, h.Index).Methods("GET")
 341
 342         rest.HandleFunc(`/{locator:[0-9a-f]{32}\+.*}`, h.Put).Methods("PUT")
 343         rest.HandleFunc(`/{locator:[0-9a-f]{32}}`, h.Put).Methods("PUT")
 344         rest.HandleFunc(`/`, h.Put).Methods("POST")
 345         rest.HandleFunc(`/{any}`, h.Options).Methods("OPTIONS")
 346         rest.HandleFunc(`/`, h.Options).Methods("OPTIONS")
 347
 348         rest.Handle("/_health/{check}", &health.Handler{
 349                 Token:  cluster.ManagementToken,
 350                 Prefix: "/_health/",
 351         }).Methods("GET")
 352
 353         rest.NotFoundHandler = InvalidPathHandler{}
 354         return h
 355 }
 356
 357 var errLoopDetected = errors.New("loop detected")
 358
 359 func (h *proxyHandler) checkLoop(resp http.ResponseWriter, req *http.Request) error {
 360         if via := req.Header.Get("Via"); strings.Index(via, " "+viaAlias) >= 0 {
 361                 h.logger.Printf("proxy loop detected (request has Via: %q): perhaps keepproxy is misidentified by gateway config as an external client, or its keep_services record does not have service_type=proxy?", via)
 362                 http.Error(resp, errLoopDetected.Error(), http.StatusInternalServerError)
 363                 return errLoopDetected
 364         }
 365         return nil
 366 }
 367
 368 func SetCorsHeaders(resp http.ResponseWriter) {
 369         resp.Header().Set("Access-Control-Allow-Methods", "GET, HEAD, POST, PUT, OPTIONS")
 370         resp.Header().Set("Access-Control-Allow-Origin", "*")
 371         resp.Header().Set("Access-Control-Allow-Headers", "Authorization, Content-Length, Content-Type, X-Keep-Desired-Replicas")
 372         resp.Header().Set("Access-Control-Max-Age", "86486400")
 373 }
 374
 375 type InvalidPathHandler struct{}
 376
 377 func (InvalidPathHandler) ServeHTTP(resp http.ResponseWriter, req *http.Request) {
 378         log.Printf("%s: %s %s unroutable", GetRemoteAddress(req), req.Method, req.URL.Path)
 379         http.Error(resp, "Bad request", http.StatusBadRequest)
 380 }
 381
 382 func (h *proxyHandler) Options(resp http.ResponseWriter, req *http.Request) {
 383         log.Printf("%s: %s %s", GetRemoteAddress(req), req.Method, req.URL.Path)
 384         SetCorsHeaders(resp)
 385 }
 386
 387 var errBadAuthorizationHeader = errors.New("Missing or invalid Authorization header, or method not allowed")
 388 var errContentLengthMismatch = errors.New("Actual length != expected content length")
 389 var errMethodNotSupported = errors.New("Method not supported")
 390
 391 var removeHint, _ = regexp.Compile("\\+K@[a-z0-9]{5}(\\+|$)")
 392
 393 func (h *proxyHandler) Get(resp http.ResponseWriter, req *http.Request) {
 394         if err := h.checkLoop(resp, req); err != nil {
 395                 return
 396         }
 397         SetCorsHeaders(resp)
 398         resp.Header().Set("Via", req.Proto+" "+viaAlias)
 399
 400         locator := mux.Vars(req)["locator"]
 401         var err error
 402         var status int
 403         var expectLength, responseLength int64
 404         var proxiedURI = "-"
 405
 406         defer func() {
 407                 log.Println(GetRemoteAddress(req), req.Method, req.URL.Path, status, expectLength, responseLength, proxiedURI, err)
 408                 if status != http.StatusOK {
 409                         http.Error(resp, err.Error(), status)
 410                 }
 411         }()
 412
 413         kc := h.makeKeepClient(req)
 414
 415         var pass bool
 416         var tok string
 417         var user *arvados.User
 418         if pass, tok, user = h.CheckAuthorizationHeader(req); !pass {
 419                 status, err = http.StatusForbidden, errBadAuthorizationHeader
 420                 return
 421         }
 422
 423         // Copy ArvadosClient struct and use the client's API token
 424         arvclient := *kc.Arvados
 425         arvclient.ApiToken = tok
 426         kc.Arvados = &arvclient
 427
 428         var reader io.ReadCloser
 429
 430         locator = removeHint.ReplaceAllString(locator, "$1")
 431
 432         if locator != "" {
 433                 parts := strings.SplitN(locator, "+", 3)
 434                 if len(parts) >= 2 {
 435                         logger := h.logger
 436                         if user != nil {
 437                                 logger = logger.WithField("user_uuid", user.UUID).
 438                                         WithField("user_full_name", user.FullName)
 439                         }
 440                         logger.WithField("locator", fmt.Sprintf("%s+%s", parts[0], parts[1])).Infof("Block download")
 441                 }
 442         }
 443
 444         switch req.Method {
 445         case "HEAD":
 446                 expectLength, proxiedURI, err = kc.Ask(locator)
 447         case "GET":
 448                 reader, expectLength, proxiedURI, err = kc.Get(locator)
 449                 if reader != nil {
 450                         defer reader.Close()
 451                 }
 452         default:
 453                 status, err = http.StatusNotImplemented, errMethodNotSupported
 454                 return
 455         }
 456
 457         if expectLength == -1 {
 458                 log.Println("Warning:", GetRemoteAddress(req), req.Method, proxiedURI, "Content-Length not provided")
 459         }
 460
 461         switch respErr := err.(type) {
 462         case nil:
 463                 status = http.StatusOK
 464                 resp.Header().Set("Content-Length", fmt.Sprint(expectLength))
 465                 switch req.Method {
 466                 case "HEAD":
 467                         responseLength = 0
 468                 case "GET":
 469                         responseLength, err = io.Copy(resp, reader)
 470                         if err == nil && expectLength > -1 && responseLength != expectLength {
 471                                 err = errContentLengthMismatch
 472                         }
 473                 }
 474         case keepclient.Error:
 475                 if respErr == keepclient.BlockNotFound {
 476                         status = http.StatusNotFound
 477                 } else if respErr.Temporary() {
 478                         status = http.StatusBadGateway
 479                 } else {
 480                         status = 422
 481                 }
 482         default:
 483                 status = http.StatusInternalServerError
 484         }
 485 }
 486
 487 var errLengthRequired = errors.New(http.StatusText(http.StatusLengthRequired))
 488 var errLengthMismatch = errors.New("Locator size hint does not match Content-Length header")
 489
 490 func (h *proxyHandler) Put(resp http.ResponseWriter, req *http.Request) {
 491         if err := h.checkLoop(resp, req); err != nil {
 492                 return
 493         }
 494         SetCorsHeaders(resp)
 495         resp.Header().Set("Via", "HTTP/1.1 "+viaAlias)
 496
 497         kc := h.makeKeepClient(req)
 498
 499         var err error
 500         var expectLength int64
 501         var status = http.StatusInternalServerError
 502         var wroteReplicas int
 503         var locatorOut string = "-"
 504
 505         defer func() {
 506                 log.Println(GetRemoteAddress(req), req.Method, req.URL.Path, status, expectLength, kc.Want_replicas, wroteReplicas, locatorOut, err)
 507                 if status != http.StatusOK {
 508                         http.Error(resp, err.Error(), status)
 509                 }
 510         }()
 511
 512         locatorIn := mux.Vars(req)["locator"]
 513
 514         // Check if the client specified storage classes
 515         if req.Header.Get("X-Keep-Storage-Classes") != "" {
 516                 var scl []string
 517                 for _, sc := range strings.Split(req.Header.Get("X-Keep-Storage-Classes"), ",") {
 518                         scl = append(scl, strings.Trim(sc, " "))
 519                 }
 520                 kc.StorageClasses = scl
 521         }
 522
 523         _, err = fmt.Sscanf(req.Header.Get("Content-Length"), "%d", &expectLength)
 524         if err != nil || expectLength < 0 {
 525                 err = errLengthRequired
 526                 status = http.StatusLengthRequired
 527                 return
 528         }
 529
 530         if locatorIn != "" {
 531                 var loc *keepclient.Locator
 532                 if loc, err = keepclient.MakeLocator(locatorIn); err != nil {
 533                         status = http.StatusBadRequest
 534                         return
 535                 } else if loc.Size > 0 && int64(loc.Size) != expectLength {
 536                         err = errLengthMismatch
 537                         status = http.StatusBadRequest
 538                         return
 539                 }
 540         }
 541
 542         var pass bool
 543         var tok string
 544         var user *arvados.User
 545         if pass, tok, user = h.CheckAuthorizationHeader(req); !pass {
 546                 err = errBadAuthorizationHeader
 547                 status = http.StatusForbidden
 548                 return
 549         }
 550
 551         // Copy ArvadosClient struct and use the client's API token
 552         arvclient := *kc.Arvados
 553         arvclient.ApiToken = tok
 554         kc.Arvados = &arvclient
 555
 556         // Check if the client specified the number of replicas
 557         if req.Header.Get("X-Keep-Desired-Replicas") != "" {
 558                 var r int
 559                 _, err := fmt.Sscanf(req.Header.Get(keepclient.XKeepDesiredReplicas), "%d", &r)
 560                 if err == nil {
 561                         kc.Want_replicas = r
 562                 }
 563         }
 564
 565         // Now try to put the block through
 566         if locatorIn == "" {
 567                 bytes, err2 := ioutil.ReadAll(req.Body)
 568                 if err2 != nil {
 569                         err = fmt.Errorf("Error reading request body: %s", err2)
 570                         status = http.StatusInternalServerError
 571                         return
 572                 }
 573                 locatorOut, wroteReplicas, err = kc.PutB(bytes)
 574         } else {
 575                 locatorOut, wroteReplicas, err = kc.PutHR(locatorIn, req.Body, expectLength)
 576         }
 577
 578         if locatorOut != "" {
 579                 parts := strings.SplitN(locatorOut, "+", 3)
 580                 if len(parts) >= 2 {
 581                         logger := h.logger
 582                         if user != nil {
 583                                 logger = logger.WithField("user_uuid", user.UUID).
 584                                         WithField("user_full_name", user.FullName)
 585                         }
 586                         logger.WithField("locator", fmt.Sprintf("%s+%s", parts[0], parts[1])).Infof("Block upload")
 587                 }
 588         }
 589
 590         // Tell the client how many successful PUTs we accomplished
 591         resp.Header().Set(keepclient.XKeepReplicasStored, fmt.Sprintf("%d", wroteReplicas))
 592
 593         switch err.(type) {
 594         case nil:
 595                 status = http.StatusOK
 596                 _, err = io.WriteString(resp, locatorOut)
 597
 598         case keepclient.OversizeBlockError:
 599                 // Too much data
 600                 status = http.StatusRequestEntityTooLarge
 601
 602         case keepclient.InsufficientReplicasError:
 603                 if wroteReplicas > 0 {
 604                         // At least one write is considered success.  The
 605                         // client can decide if getting less than the number of
 606                         // replications it asked for is a fatal error.
 607                         status = http.StatusOK
 608                         _, err = io.WriteString(resp, locatorOut)
 609                 } else {
 610                         status = http.StatusServiceUnavailable
 611                 }
 612
 613         default:
 614                 status = http.StatusBadGateway
 615         }
 616 }
 617
 618 // ServeHTTP implementation for IndexHandler
 619 // Supports only GET requests for /index/{prefix:[0-9a-f]{0,32}}
 620 // For each keep server found in LocalRoots:
 621 //   Invokes GetIndex using keepclient
 622 //   Expects "complete" response (terminating with blank new line)
 623 //   Aborts on any errors
 624 // Concatenates responses from all those keep servers and returns
 625 func (h *proxyHandler) Index(resp http.ResponseWriter, req *http.Request) {
 626         SetCorsHeaders(resp)
 627
 628         prefix := mux.Vars(req)["prefix"]
 629         var err error
 630         var status int
 631
 632         defer func() {
 633                 if status != http.StatusOK {
 634                         http.Error(resp, err.Error(), status)
 635                 }
 636         }()
 637
 638         kc := h.makeKeepClient(req)
 639         ok, token, _ := h.CheckAuthorizationHeader(req)
 640         if !ok {
 641                 status, err = http.StatusForbidden, errBadAuthorizationHeader
 642                 return
 643         }
 644
 645         // Copy ArvadosClient struct and use the client's API token
 646         arvclient := *kc.Arvados
 647         arvclient.ApiToken = token
 648         kc.Arvados = &arvclient
 649
 650         // Only GET method is supported
 651         if req.Method != "GET" {
 652                 status, err = http.StatusNotImplemented, errMethodNotSupported
 653                 return
 654         }
 655
 656         // Get index from all LocalRoots and write to resp
 657         var reader io.Reader
 658         for uuid := range kc.LocalRoots() {
 659                 reader, err = kc.GetIndex(uuid, prefix)
 660                 if err != nil {
 661                         status = http.StatusBadGateway
 662                         return
 663                 }
 664
 665                 _, err = io.Copy(resp, reader)
 666                 if err != nil {
 667                         status = http.StatusBadGateway
 668                         return
 669                 }
 670         }
 671
 672         // Got index from all the keep servers and wrote to resp
 673         status = http.StatusOK
 674         resp.Write([]byte("\n"))
 675 }
 676
 677 func (h *proxyHandler) makeKeepClient(req *http.Request) *keepclient.KeepClient {
 678         kc := *h.KeepClient
 679         kc.RequestID = req.Header.Get("X-Request-Id")
 680         kc.HTTPClient = &proxyClient{
 681                 client: &http.Client{
 682                         Timeout:   h.timeout,
 683                         Transport: h.transport,
 684                 },
 685                 proto: req.Proto,
 686         }
 687         return &kc
 688 }