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         "syscall"
  20         "time"
  21
  22         "git.arvados.org/arvados.git/lib/config"
  23         "git.arvados.org/arvados.git/sdk/go/arvados"
  24         "git.arvados.org/arvados.git/sdk/go/arvadosclient"
  25         "git.arvados.org/arvados.git/sdk/go/health"
  26         "git.arvados.org/arvados.git/sdk/go/httpserver"
  27         "git.arvados.org/arvados.git/sdk/go/keepclient"
  28         "github.com/coreos/go-systemd/daemon"
  29         "github.com/ghodss/yaml"
  30         "github.com/gorilla/mux"
  31         lru "github.com/hashicorp/golang-lru"
  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 TokenCacheEntry struct {
 171         expire int64
 172         user   *arvados.User
 173 }
 174
 175 type APITokenCache struct {
 176         tokens     *lru.TwoQueueCache
 177         expireTime int64
 178 }
 179
 180 // RememberToken caches the token and set an expire time.  If the
 181 // token is already in the cache, it is not updated.
 182 func (cache *APITokenCache) RememberToken(token string, user *arvados.User) {
 183         now := time.Now().Unix()
 184         _, ok := cache.tokens.Get(token)
 185         if !ok {
 186                 cache.tokens.Add(token, TokenCacheEntry{
 187                         expire: now + cache.expireTime,
 188                         user:   user,
 189                 })
 190         }
 191 }
 192
 193 // RecallToken checks if the cached token is known and still believed to be
 194 // valid.
 195 func (cache *APITokenCache) RecallToken(token string) (bool, *arvados.User) {
 196         val, ok := cache.tokens.Get(token)
 197         if !ok {
 198                 return false, nil
 199         }
 200
 201         cacheEntry := val.(TokenCacheEntry)
 202         now := time.Now().Unix()
 203         if now < cacheEntry.expire {
 204                 // Token is known and still valid
 205                 return true, cacheEntry.user
 206         } else {
 207                 // Token is expired
 208                 cache.tokens.Remove(token)
 209                 return false, nil
 210         }
 211 }
 212
 213 // GetRemoteAddress returns a string with the remote address for the request.
 214 // If the X-Forwarded-For header is set and has a non-zero length, it returns a
 215 // string made from a comma separated list of all the remote addresses,
 216 // starting with the one(s) from the X-Forwarded-For header.
 217 func GetRemoteAddress(req *http.Request) string {
 218         if xff := req.Header.Get("X-Forwarded-For"); xff != "" {
 219                 return xff + "," + req.RemoteAddr
 220         }
 221         return req.RemoteAddr
 222 }
 223
 224 func (h *proxyHandler) CheckAuthorizationHeader(req *http.Request) (pass bool, tok string, user *arvados.User) {
 225         parts := strings.SplitN(req.Header.Get("Authorization"), " ", 2)
 226         if len(parts) < 2 || !(parts[0] == "OAuth2" || parts[0] == "Bearer") || len(parts[1]) == 0 {
 227                 return false, "", nil
 228         }
 229         tok = parts[1]
 230
 231         // Tokens are validated differently depending on what kind of
 232         // operation is being performed. For example, tokens in
 233         // collection-sharing links permit GET requests, but not
 234         // PUT requests.
 235         var op string
 236         if req.Method == "GET" || req.Method == "HEAD" {
 237                 op = "read"
 238         } else {
 239                 op = "write"
 240         }
 241
 242         if ok, user := h.APITokenCache.RecallToken(op + ":" + tok); ok {
 243                 // Valid in the cache, short circuit
 244                 return true, tok, user
 245         }
 246
 247         var err error
 248         arv := *h.KeepClient.Arvados
 249         arv.ApiToken = tok
 250         arv.RequestID = req.Header.Get("X-Request-Id")
 251         user = &arvados.User{}
 252         userCurrentError := arv.Call("GET", "users", "", "current", nil, user)
 253         err = userCurrentError
 254         if err != nil && op == "read" {
 255                 apiError, ok := err.(arvadosclient.APIServerError)
 256                 if ok && apiError.HttpStatusCode == http.StatusForbidden {
 257                         // If it was a scoped "sharing" token it will
 258                         // return 403 instead of 401 for the current
 259                         // user check.  If it is a download operation
 260                         // and they have permission to read the
 261                         // keep_services table, we can allow it.
 262                         err = arv.Call("HEAD", "keep_services", "", "accessible", nil, nil)
 263                 }
 264         }
 265         if err != nil {
 266                 log.Printf("%s: CheckAuthorizationHeader error: %v", GetRemoteAddress(req), err)
 267                 return false, "", nil
 268         }
 269
 270         if userCurrentError == nil && user.IsAdmin {
 271                 // checking userCurrentError is probably redundant,
 272                 // IsAdmin would be false anyway. But can't hurt.
 273                 if op == "read" && !h.cluster.Collections.KeepproxyPermission.Admin.Download {
 274                         return false, "", nil
 275                 }
 276                 if op == "write" && !h.cluster.Collections.KeepproxyPermission.Admin.Upload {
 277                         return false, "", nil
 278                 }
 279         } else {
 280                 if op == "read" && !h.cluster.Collections.KeepproxyPermission.User.Download {
 281                         return false, "", nil
 282                 }
 283                 if op == "write" && !h.cluster.Collections.KeepproxyPermission.User.Upload {
 284                         return false, "", nil
 285                 }
 286         }
 287
 288         // Success!  Update cache
 289         h.APITokenCache.RememberToken(op+":"+tok, user)
 290
 291         return true, tok, user
 292 }
 293
 294 // We need to make a private copy of the default http transport early
 295 // in initialization, then make copies of our private copy later. It
 296 // won't be safe to copy http.DefaultTransport itself later, because
 297 // its private mutexes might have already been used. (Without this,
 298 // the test suite sometimes panics "concurrent map writes" in
 299 // net/http.(*Transport).removeIdleConnLocked().)
 300 var defaultTransport = *(http.DefaultTransport.(*http.Transport))
 301
 302 type proxyHandler struct {
 303         http.Handler
 304         *keepclient.KeepClient
 305         *APITokenCache
 306         timeout   time.Duration
 307         transport *http.Transport
 308         logger    log.FieldLogger
 309         cluster   *arvados.Cluster
 310 }
 311
 312 // MakeRESTRouter returns an http.Handler that passes GET and PUT
 313 // requests to the appropriate handlers.
 314 func MakeRESTRouter(kc *keepclient.KeepClient, timeout time.Duration, cluster *arvados.Cluster, logger log.FieldLogger) http.Handler {
 315         rest := mux.NewRouter()
 316
 317         transport := defaultTransport
 318         transport.DialContext = (&net.Dialer{
 319                 Timeout:   keepclient.DefaultConnectTimeout,
 320                 KeepAlive: keepclient.DefaultKeepAlive,
 321                 DualStack: true,
 322         }).DialContext
 323         transport.TLSClientConfig = arvadosclient.MakeTLSConfig(kc.Arvados.ApiInsecure)
 324         transport.TLSHandshakeTimeout = keepclient.DefaultTLSHandshakeTimeout
 325
 326         cacheQ, err := lru.New2Q(500)
 327         if err != nil {
 328                 panic("Could not create 2Q")
 329         }
 330
 331         h := &proxyHandler{
 332                 Handler:    rest,
 333                 KeepClient: kc,
 334                 timeout:    timeout,
 335                 transport:  &transport,
 336                 APITokenCache: &APITokenCache{
 337                         tokens:     cacheQ,
 338                         expireTime: 300,
 339                 },
 340                 logger:  logger,
 341                 cluster: cluster,
 342         }
 343
 344         rest.HandleFunc(`/{locator:[0-9a-f]{32}\+.*}`, h.Get).Methods("GET", "HEAD")
 345         rest.HandleFunc(`/{locator:[0-9a-f]{32}}`, h.Get).Methods("GET", "HEAD")
 346
 347         // List all blocks
 348         rest.HandleFunc(`/index`, h.Index).Methods("GET")
 349
 350         // List blocks whose hash has the given prefix
 351         rest.HandleFunc(`/index/{prefix:[0-9a-f]{0,32}}`, h.Index).Methods("GET")
 352
 353         rest.HandleFunc(`/{locator:[0-9a-f]{32}\+.*}`, h.Put).Methods("PUT")
 354         rest.HandleFunc(`/{locator:[0-9a-f]{32}}`, h.Put).Methods("PUT")
 355         rest.HandleFunc(`/`, h.Put).Methods("POST")
 356         rest.HandleFunc(`/{any}`, h.Options).Methods("OPTIONS")
 357         rest.HandleFunc(`/`, h.Options).Methods("OPTIONS")
 358
 359         rest.Handle("/_health/{check}", &health.Handler{
 360                 Token:  cluster.ManagementToken,
 361                 Prefix: "/_health/",
 362         }).Methods("GET")
 363
 364         rest.NotFoundHandler = InvalidPathHandler{}
 365         return h
 366 }
 367
 368 var errLoopDetected = errors.New("loop detected")
 369
 370 func (h *proxyHandler) checkLoop(resp http.ResponseWriter, req *http.Request) error {
 371         if via := req.Header.Get("Via"); strings.Index(via, " "+viaAlias) >= 0 {
 372                 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)
 373                 http.Error(resp, errLoopDetected.Error(), http.StatusInternalServerError)
 374                 return errLoopDetected
 375         }
 376         return nil
 377 }
 378
 379 func SetCorsHeaders(resp http.ResponseWriter) {
 380         resp.Header().Set("Access-Control-Allow-Methods", "GET, HEAD, POST, PUT, OPTIONS")
 381         resp.Header().Set("Access-Control-Allow-Origin", "*")
 382         resp.Header().Set("Access-Control-Allow-Headers", "Authorization, Content-Length, Content-Type, X-Keep-Desired-Replicas")
 383         resp.Header().Set("Access-Control-Max-Age", "86486400")
 384 }
 385
 386 type InvalidPathHandler struct{}
 387
 388 func (InvalidPathHandler) ServeHTTP(resp http.ResponseWriter, req *http.Request) {
 389         log.Printf("%s: %s %s unroutable", GetRemoteAddress(req), req.Method, req.URL.Path)
 390         http.Error(resp, "Bad request", http.StatusBadRequest)
 391 }
 392
 393 func (h *proxyHandler) Options(resp http.ResponseWriter, req *http.Request) {
 394         log.Printf("%s: %s %s", GetRemoteAddress(req), req.Method, req.URL.Path)
 395         SetCorsHeaders(resp)
 396 }
 397
 398 var errBadAuthorizationHeader = errors.New("Missing or invalid Authorization header, or method not allowed")
 399 var errContentLengthMismatch = errors.New("Actual length != expected content length")
 400 var errMethodNotSupported = errors.New("Method not supported")
 401
 402 var removeHint, _ = regexp.Compile("\\+K@[a-z0-9]{5}(\\+|$)")
 403
 404 func (h *proxyHandler) Get(resp http.ResponseWriter, req *http.Request) {
 405         if err := h.checkLoop(resp, req); err != nil {
 406                 return
 407         }
 408         SetCorsHeaders(resp)
 409         resp.Header().Set("Via", req.Proto+" "+viaAlias)
 410
 411         locator := mux.Vars(req)["locator"]
 412         var err error
 413         var status int
 414         var expectLength, responseLength int64
 415         var proxiedURI = "-"
 416
 417         defer func() {
 418                 log.Println(GetRemoteAddress(req), req.Method, req.URL.Path, status, expectLength, responseLength, proxiedURI, err)
 419                 if status != http.StatusOK {
 420                         http.Error(resp, err.Error(), status)
 421                 }
 422         }()
 423
 424         kc := h.makeKeepClient(req)
 425
 426         var pass bool
 427         var tok string
 428         var user *arvados.User
 429         if pass, tok, user = h.CheckAuthorizationHeader(req); !pass {
 430                 status, err = http.StatusForbidden, errBadAuthorizationHeader
 431                 return
 432         }
 433
 434         // Copy ArvadosClient struct and use the client's API token
 435         arvclient := *kc.Arvados
 436         arvclient.ApiToken = tok
 437         kc.Arvados = &arvclient
 438
 439         var reader io.ReadCloser
 440
 441         locator = removeHint.ReplaceAllString(locator, "$1")
 442
 443         if locator != "" {
 444                 parts := strings.SplitN(locator, "+", 3)
 445                 if len(parts) >= 2 {
 446                         logger := h.logger
 447                         if user != nil {
 448                                 logger = logger.WithField("user_uuid", user.UUID).
 449                                         WithField("user_full_name", user.FullName)
 450                         }
 451                         logger.WithField("locator", fmt.Sprintf("%s+%s", parts[0], parts[1])).Infof("Block download")
 452                 }
 453         }
 454
 455         switch req.Method {
 456         case "HEAD":
 457                 expectLength, proxiedURI, err = kc.Ask(locator)
 458         case "GET":
 459                 reader, expectLength, proxiedURI, err = kc.Get(locator)
 460                 if reader != nil {
 461                         defer reader.Close()
 462                 }
 463         default:
 464                 status, err = http.StatusNotImplemented, errMethodNotSupported
 465                 return
 466         }
 467
 468         if expectLength == -1 {
 469                 log.Println("Warning:", GetRemoteAddress(req), req.Method, proxiedURI, "Content-Length not provided")
 470         }
 471
 472         switch respErr := err.(type) {
 473         case nil:
 474                 status = http.StatusOK
 475                 resp.Header().Set("Content-Length", fmt.Sprint(expectLength))
 476                 switch req.Method {
 477                 case "HEAD":
 478                         responseLength = 0
 479                 case "GET":
 480                         responseLength, err = io.Copy(resp, reader)
 481                         if err == nil && expectLength > -1 && responseLength != expectLength {
 482                                 err = errContentLengthMismatch
 483                         }
 484                 }
 485         case keepclient.Error:
 486                 if respErr == keepclient.BlockNotFound {
 487                         status = http.StatusNotFound
 488                 } else if respErr.Temporary() {
 489                         status = http.StatusBadGateway
 490                 } else {
 491                         status = 422
 492                 }
 493         default:
 494                 status = http.StatusInternalServerError
 495         }
 496 }
 497
 498 var errLengthRequired = errors.New(http.StatusText(http.StatusLengthRequired))
 499 var errLengthMismatch = errors.New("Locator size hint does not match Content-Length header")
 500
 501 func (h *proxyHandler) Put(resp http.ResponseWriter, req *http.Request) {
 502         if err := h.checkLoop(resp, req); err != nil {
 503                 return
 504         }
 505         SetCorsHeaders(resp)
 506         resp.Header().Set("Via", "HTTP/1.1 "+viaAlias)
 507
 508         kc := h.makeKeepClient(req)
 509
 510         var err error
 511         var expectLength int64
 512         var status = http.StatusInternalServerError
 513         var wroteReplicas int
 514         var locatorOut string = "-"
 515
 516         defer func() {
 517                 log.Println(GetRemoteAddress(req), req.Method, req.URL.Path, status, expectLength, kc.Want_replicas, wroteReplicas, locatorOut, err)
 518                 if status != http.StatusOK {
 519                         http.Error(resp, err.Error(), status)
 520                 }
 521         }()
 522
 523         locatorIn := mux.Vars(req)["locator"]
 524
 525         // Check if the client specified storage classes
 526         if req.Header.Get("X-Keep-Storage-Classes") != "" {
 527                 var scl []string
 528                 for _, sc := range strings.Split(req.Header.Get("X-Keep-Storage-Classes"), ",") {
 529                         scl = append(scl, strings.Trim(sc, " "))
 530                 }
 531                 kc.StorageClasses = scl
 532         }
 533
 534         _, err = fmt.Sscanf(req.Header.Get("Content-Length"), "%d", &expectLength)
 535         if err != nil || expectLength < 0 {
 536                 err = errLengthRequired
 537                 status = http.StatusLengthRequired
 538                 return
 539         }
 540
 541         if locatorIn != "" {
 542                 var loc *keepclient.Locator
 543                 if loc, err = keepclient.MakeLocator(locatorIn); err != nil {
 544                         status = http.StatusBadRequest
 545                         return
 546                 } else if loc.Size > 0 && int64(loc.Size) != expectLength {
 547                         err = errLengthMismatch
 548                         status = http.StatusBadRequest
 549                         return
 550                 }
 551         }
 552
 553         var pass bool
 554         var tok string
 555         var user *arvados.User
 556         if pass, tok, user = h.CheckAuthorizationHeader(req); !pass {
 557                 err = errBadAuthorizationHeader
 558                 status = http.StatusForbidden
 559                 return
 560         }
 561
 562         // Copy ArvadosClient struct and use the client's API token
 563         arvclient := *kc.Arvados
 564         arvclient.ApiToken = tok
 565         kc.Arvados = &arvclient
 566
 567         // Check if the client specified the number of replicas
 568         if req.Header.Get("X-Keep-Desired-Replicas") != "" {
 569                 var r int
 570                 _, err := fmt.Sscanf(req.Header.Get(keepclient.XKeepDesiredReplicas), "%d", &r)
 571                 if err == nil {
 572                         kc.Want_replicas = r
 573                 }
 574         }
 575
 576         // Now try to put the block through
 577         if locatorIn == "" {
 578                 bytes, err2 := ioutil.ReadAll(req.Body)
 579                 if err2 != nil {
 580                         err = fmt.Errorf("Error reading request body: %s", err2)
 581                         status = http.StatusInternalServerError
 582                         return
 583                 }
 584                 locatorOut, wroteReplicas, err = kc.PutB(bytes)
 585         } else {
 586                 locatorOut, wroteReplicas, err = kc.PutHR(locatorIn, req.Body, expectLength)
 587         }
 588
 589         if locatorOut != "" {
 590                 parts := strings.SplitN(locatorOut, "+", 3)
 591                 if len(parts) >= 2 {
 592                         logger := h.logger
 593                         if user != nil {
 594                                 logger = logger.WithField("user_uuid", user.UUID).
 595                                         WithField("user_full_name", user.FullName)
 596                         }
 597                         logger.WithField("locator", fmt.Sprintf("%s+%s", parts[0], parts[1])).Infof("Block upload")
 598                 }
 599         }
 600
 601         // Tell the client how many successful PUTs we accomplished
 602         resp.Header().Set(keepclient.XKeepReplicasStored, fmt.Sprintf("%d", wroteReplicas))
 603
 604         switch err.(type) {
 605         case nil:
 606                 status = http.StatusOK
 607                 _, err = io.WriteString(resp, locatorOut)
 608
 609         case keepclient.OversizeBlockError:
 610                 // Too much data
 611                 status = http.StatusRequestEntityTooLarge
 612
 613         case keepclient.InsufficientReplicasError:
 614                 if wroteReplicas > 0 {
 615                         // At least one write is considered success.  The
 616                         // client can decide if getting less than the number of
 617                         // replications it asked for is a fatal error.
 618                         status = http.StatusOK
 619                         _, err = io.WriteString(resp, locatorOut)
 620                 } else {
 621                         status = http.StatusServiceUnavailable
 622                 }
 623
 624         default:
 625                 status = http.StatusBadGateway
 626         }
 627 }
 628
 629 // ServeHTTP implementation for IndexHandler
 630 // Supports only GET requests for /index/{prefix:[0-9a-f]{0,32}}
 631 // For each keep server found in LocalRoots:
 632 //   Invokes GetIndex using keepclient
 633 //   Expects "complete" response (terminating with blank new line)
 634 //   Aborts on any errors
 635 // Concatenates responses from all those keep servers and returns
 636 func (h *proxyHandler) Index(resp http.ResponseWriter, req *http.Request) {
 637         SetCorsHeaders(resp)
 638
 639         prefix := mux.Vars(req)["prefix"]
 640         var err error
 641         var status int
 642
 643         defer func() {
 644                 if status != http.StatusOK {
 645                         http.Error(resp, err.Error(), status)
 646                 }
 647         }()
 648
 649         kc := h.makeKeepClient(req)
 650         ok, token, _ := h.CheckAuthorizationHeader(req)
 651         if !ok {
 652                 status, err = http.StatusForbidden, errBadAuthorizationHeader
 653                 return
 654         }
 655
 656         // Copy ArvadosClient struct and use the client's API token
 657         arvclient := *kc.Arvados
 658         arvclient.ApiToken = token
 659         kc.Arvados = &arvclient
 660
 661         // Only GET method is supported
 662         if req.Method != "GET" {
 663                 status, err = http.StatusNotImplemented, errMethodNotSupported
 664                 return
 665         }
 666
 667         // Get index from all LocalRoots and write to resp
 668         var reader io.Reader
 669         for uuid := range kc.LocalRoots() {
 670                 reader, err = kc.GetIndex(uuid, prefix)
 671                 if err != nil {
 672                         status = http.StatusBadGateway
 673                         return
 674                 }
 675
 676                 _, err = io.Copy(resp, reader)
 677                 if err != nil {
 678                         status = http.StatusBadGateway
 679                         return
 680                 }
 681         }
 682
 683         // Got index from all the keep servers and wrote to resp
 684         status = http.StatusOK
 685         resp.Write([]byte("\n"))
 686 }
 687
 688 func (h *proxyHandler) makeKeepClient(req *http.Request) *keepclient.KeepClient {
 689         kc := *h.KeepClient
 690         kc.RequestID = req.Header.Get("X-Request-Id")
 691         kc.HTTPClient = &proxyClient{
 692                 client: &http.Client{
 693                         Timeout:   h.timeout,
 694                         Transport: h.transport,
 695                 },
 696                 proto: req.Proto,
 697         }
 698         return &kc
 699 }