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.curoverse.com/arvados.git/sdk/go/arvados"
  24         "git.curoverse.com/arvados.git/sdk/go/arvadosclient"
  25         "git.curoverse.com/arvados.git/sdk/go/config"
  26         "git.curoverse.com/arvados.git/sdk/go/health"
  27         "git.curoverse.com/arvados.git/sdk/go/httpserver"
  28         "git.curoverse.com/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 type Config struct {
  38         Client          arvados.Client
  39         Listen          string
  40         DisableGet      bool
  41         DisablePut      bool
  42         DefaultReplicas int
  43         Timeout         arvados.Duration
  44         PIDFile         string
  45         Debug           bool
  46         ManagementToken string
  47 }
  48
  49 func DefaultConfig() *Config {
  50         return &Config{
  51                 Listen:  ":25107",
  52                 Timeout: arvados.Duration(15 * time.Second),
  53         }
  54 }
  55
  56 var (
  57         listener net.Listener
  58         router   http.Handler
  59 )
  60
  61 const rfc3339NanoFixed = "2006-01-02T15:04:05.000000000Z07:00"
  62
  63 func main() {
  64         log.SetFormatter(&log.JSONFormatter{
  65                 TimestampFormat: rfc3339NanoFixed,
  66         })
  67
  68         cfg := DefaultConfig()
  69
  70         flagset := flag.NewFlagSet("keepproxy", flag.ExitOnError)
  71         flagset.Usage = usage
  72
  73         const deprecated = " (DEPRECATED -- use config file instead)"
  74         flagset.StringVar(&cfg.Listen, "listen", cfg.Listen, "Local port to listen on."+deprecated)
  75         flagset.BoolVar(&cfg.DisableGet, "no-get", cfg.DisableGet, "Disable GET operations."+deprecated)
  76         flagset.BoolVar(&cfg.DisablePut, "no-put", cfg.DisablePut, "Disable PUT operations."+deprecated)
  77         flagset.IntVar(&cfg.DefaultReplicas, "default-replicas", cfg.DefaultReplicas, "Default number of replicas to write if not specified by the client. If 0, use site default."+deprecated)
  78         flagset.StringVar(&cfg.PIDFile, "pid", cfg.PIDFile, "Path to write pid file."+deprecated)
  79         timeoutSeconds := flagset.Int("timeout", int(time.Duration(cfg.Timeout)/time.Second), "Timeout (in seconds) on requests to internal Keep services."+deprecated)
  80         flagset.StringVar(&cfg.ManagementToken, "management-token", cfg.ManagementToken, "Authorization token to be included in all health check requests.")
  81
  82         var cfgPath string
  83         const defaultCfgPath = "/etc/arvados/keepproxy/keepproxy.yml"
  84         flagset.StringVar(&cfgPath, "config", defaultCfgPath, "Configuration file `path`")
  85         dumpConfig := flagset.Bool("dump-config", false, "write current configuration to stdout and exit")
  86         getVersion := flagset.Bool("version", false, "Print version information and exit.")
  87         flagset.Parse(os.Args[1:])
  88
  89         // Print version information if requested
  90         if *getVersion {
  91                 fmt.Printf("keepproxy %s\n", version)
  92                 return
  93         }
  94
  95         err := config.LoadFile(cfg, cfgPath)
  96         if err != nil {
  97                 h := os.Getenv("ARVADOS_API_HOST")
  98                 t := os.Getenv("ARVADOS_API_TOKEN")
  99                 if h == "" || t == "" || !os.IsNotExist(err) || cfgPath != defaultCfgPath {
 100                         log.Fatal(err)
 101                 }
 102                 log.Print("DEPRECATED: No config file found, but ARVADOS_API_HOST and ARVADOS_API_TOKEN environment variables are set. Please use a config file instead.")
 103                 cfg.Client.APIHost = h
 104                 cfg.Client.AuthToken = t
 105                 if regexp.MustCompile("^(?i:1|yes|true)$").MatchString(os.Getenv("ARVADOS_API_HOST_INSECURE")) {
 106                         cfg.Client.Insecure = true
 107                 }
 108                 if y, err := yaml.Marshal(cfg); err == nil && !*dumpConfig {
 109                         log.Print("Current configuration:\n", string(y))
 110                 }
 111                 cfg.Timeout = arvados.Duration(time.Duration(*timeoutSeconds) * time.Second)
 112         }
 113
 114         if *dumpConfig {
 115                 log.Fatal(config.DumpAndExit(cfg))
 116         }
 117
 118         log.Printf("keepproxy %s started", version)
 119
 120         arv, err := arvadosclient.New(&cfg.Client)
 121         if err != nil {
 122                 log.Fatalf("Error setting up arvados client %s", err.Error())
 123         }
 124
 125         if cfg.Debug {
 126                 keepclient.DebugPrintf = log.Printf
 127         }
 128         kc, err := keepclient.MakeKeepClient(arv)
 129         if err != nil {
 130                 log.Fatalf("Error setting up keep client %s", err.Error())
 131         }
 132         keepclient.RefreshServiceDiscoveryOnSIGHUP()
 133
 134         if cfg.PIDFile != "" {
 135                 f, err := os.Create(cfg.PIDFile)
 136                 if err != nil {
 137                         log.Fatal(err)
 138                 }
 139                 defer f.Close()
 140                 err = syscall.Flock(int(f.Fd()), syscall.LOCK_EX|syscall.LOCK_NB)
 141                 if err != nil {
 142                         log.Fatalf("flock(%s): %s", cfg.PIDFile, err)
 143                 }
 144                 defer os.Remove(cfg.PIDFile)
 145                 err = f.Truncate(0)
 146                 if err != nil {
 147                         log.Fatalf("truncate(%s): %s", cfg.PIDFile, err)
 148                 }
 149                 _, err = fmt.Fprint(f, os.Getpid())
 150                 if err != nil {
 151                         log.Fatalf("write(%s): %s", cfg.PIDFile, err)
 152                 }
 153                 err = f.Sync()
 154                 if err != nil {
 155                         log.Fatal("sync(%s): %s", cfg.PIDFile, err)
 156                 }
 157         }
 158
 159         if cfg.DefaultReplicas > 0 {
 160                 kc.Want_replicas = cfg.DefaultReplicas
 161         }
 162
 163         listener, err = net.Listen("tcp", cfg.Listen)
 164         if err != nil {
 165                 log.Fatalf("listen(%s): %s", cfg.Listen, err)
 166         }
 167         if _, err := daemon.SdNotify(false, "READY=1"); err != nil {
 168                 log.Printf("Error notifying init daemon: %v", err)
 169         }
 170         log.Println("Listening at", listener.Addr())
 171
 172         // Shut down the server gracefully (by closing the listener)
 173         // if SIGTERM is received.
 174         term := make(chan os.Signal, 1)
 175         go func(sig <-chan os.Signal) {
 176                 s := <-sig
 177                 log.Println("caught signal:", s)
 178                 listener.Close()
 179         }(term)
 180         signal.Notify(term, syscall.SIGTERM)
 181         signal.Notify(term, syscall.SIGINT)
 182
 183         // Start serving requests.
 184         router = MakeRESTRouter(!cfg.DisableGet, !cfg.DisablePut, kc, time.Duration(cfg.Timeout), cfg.ManagementToken)
 185         http.Serve(listener, httpserver.AddRequestIDs(httpserver.LogRequests(nil, router)))
 186
 187         log.Println("shutting down")
 188 }
 189
 190 type ApiTokenCache struct {
 191         tokens     map[string]int64
 192         lock       sync.Mutex
 193         expireTime int64
 194 }
 195
 196 // Cache the token and set an expire time.  If we already have an expire time
 197 // on the token, it is not updated.
 198 func (this *ApiTokenCache) RememberToken(token string) {
 199         this.lock.Lock()
 200         defer this.lock.Unlock()
 201
 202         now := time.Now().Unix()
 203         if this.tokens[token] == 0 {
 204                 this.tokens[token] = now + this.expireTime
 205         }
 206 }
 207
 208 // Check if the cached token is known and still believed to be valid.
 209 func (this *ApiTokenCache) RecallToken(token string) bool {
 210         this.lock.Lock()
 211         defer this.lock.Unlock()
 212
 213         now := time.Now().Unix()
 214         if this.tokens[token] == 0 {
 215                 // Unknown token
 216                 return false
 217         } else if now < this.tokens[token] {
 218                 // Token is known and still valid
 219                 return true
 220         } else {
 221                 // Token is expired
 222                 this.tokens[token] = 0
 223                 return false
 224         }
 225 }
 226
 227 func GetRemoteAddress(req *http.Request) string {
 228         if xff := req.Header.Get("X-Forwarded-For"); xff != "" {
 229                 return xff + "," + req.RemoteAddr
 230         }
 231         return req.RemoteAddr
 232 }
 233
 234 func CheckAuthorizationHeader(kc *keepclient.KeepClient, cache *ApiTokenCache, req *http.Request) (pass bool, tok string) {
 235         parts := strings.SplitN(req.Header.Get("Authorization"), " ", 2)
 236         if len(parts) < 2 || !(parts[0] == "OAuth2" || parts[0] == "Bearer") || len(parts[1]) == 0 {
 237                 return false, ""
 238         }
 239         tok = parts[1]
 240
 241         // Tokens are validated differently depending on what kind of
 242         // operation is being performed. For example, tokens in
 243         // collection-sharing links permit GET requests, but not
 244         // PUT requests.
 245         var op string
 246         if req.Method == "GET" || req.Method == "HEAD" {
 247                 op = "read"
 248         } else {
 249                 op = "write"
 250         }
 251
 252         if cache.RecallToken(op + ":" + tok) {
 253                 // Valid in the cache, short circuit
 254                 return true, tok
 255         }
 256
 257         var err error
 258         arv := *kc.Arvados
 259         arv.ApiToken = tok
 260         arv.RequestID = req.Header.Get("X-Request-Id")
 261         if op == "read" {
 262                 err = arv.Call("HEAD", "keep_services", "", "accessible", nil, nil)
 263         } else {
 264                 err = arv.Call("HEAD", "users", "", "current", nil, nil)
 265         }
 266         if err != nil {
 267                 log.Printf("%s: CheckAuthorizationHeader error: %v", GetRemoteAddress(req), err)
 268                 return false, ""
 269         }
 270
 271         // Success!  Update cache
 272         cache.RememberToken(op + ":" + tok)
 273
 274         return true, tok
 275 }
 276
 277 // We need to make a private copy of the default http transport early
 278 // in initialization, then make copies of our private copy later. It
 279 // won't be safe to copy http.DefaultTransport itself later, because
 280 // its private mutexes might have already been used. (Without this,
 281 // the test suite sometimes panics "concurrent map writes" in
 282 // net/http.(*Transport).removeIdleConnLocked().)
 283 var defaultTransport = *(http.DefaultTransport.(*http.Transport))
 284
 285 type proxyHandler struct {
 286         http.Handler
 287         *keepclient.KeepClient
 288         *ApiTokenCache
 289         timeout   time.Duration
 290         transport *http.Transport
 291 }
 292
 293 // MakeRESTRouter returns an http.Handler that passes GET and PUT
 294 // requests to the appropriate handlers.
 295 func MakeRESTRouter(enable_get bool, enable_put bool, kc *keepclient.KeepClient, timeout time.Duration, mgmtToken string) http.Handler {
 296         rest := mux.NewRouter()
 297
 298         transport := defaultTransport
 299         transport.DialContext = (&net.Dialer{
 300                 Timeout:   keepclient.DefaultConnectTimeout,
 301                 KeepAlive: keepclient.DefaultKeepAlive,
 302                 DualStack: true,
 303         }).DialContext
 304         transport.TLSClientConfig = arvadosclient.MakeTLSConfig(kc.Arvados.ApiInsecure)
 305         transport.TLSHandshakeTimeout = keepclient.DefaultTLSHandshakeTimeout
 306
 307         h := &proxyHandler{
 308                 Handler:    rest,
 309                 KeepClient: kc,
 310                 timeout:    timeout,
 311                 transport:  &transport,
 312                 ApiTokenCache: &ApiTokenCache{
 313                         tokens:     make(map[string]int64),
 314                         expireTime: 300,
 315                 },
 316         }
 317
 318         if enable_get {
 319                 rest.HandleFunc(`/{locator:[0-9a-f]{32}\+.*}`, h.Get).Methods("GET", "HEAD")
 320                 rest.HandleFunc(`/{locator:[0-9a-f]{32}}`, h.Get).Methods("GET", "HEAD")
 321
 322                 // List all blocks
 323                 rest.HandleFunc(`/index`, h.Index).Methods("GET")
 324
 325                 // List blocks whose hash has the given prefix
 326                 rest.HandleFunc(`/index/{prefix:[0-9a-f]{0,32}}`, h.Index).Methods("GET")
 327         }
 328
 329         if enable_put {
 330                 rest.HandleFunc(`/{locator:[0-9a-f]{32}\+.*}`, h.Put).Methods("PUT")
 331                 rest.HandleFunc(`/{locator:[0-9a-f]{32}}`, h.Put).Methods("PUT")
 332                 rest.HandleFunc(`/`, h.Put).Methods("POST")
 333                 rest.HandleFunc(`/{any}`, h.Options).Methods("OPTIONS")
 334                 rest.HandleFunc(`/`, h.Options).Methods("OPTIONS")
 335         }
 336
 337         rest.Handle("/_health/{check}", &health.Handler{
 338                 Token:  mgmtToken,
 339                 Prefix: "/_health/",
 340         }).Methods("GET")
 341
 342         rest.NotFoundHandler = InvalidPathHandler{}
 343         return h
 344 }
 345
 346 var errLoopDetected = errors.New("loop detected")
 347
 348 func (*proxyHandler) checkLoop(resp http.ResponseWriter, req *http.Request) error {
 349         if via := req.Header.Get("Via"); strings.Index(via, " "+viaAlias) >= 0 {
 350                 log.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)
 351                 http.Error(resp, errLoopDetected.Error(), http.StatusInternalServerError)
 352                 return errLoopDetected
 353         }
 354         return nil
 355 }
 356
 357 func SetCorsHeaders(resp http.ResponseWriter) {
 358         resp.Header().Set("Access-Control-Allow-Methods", "GET, HEAD, POST, PUT, OPTIONS")
 359         resp.Header().Set("Access-Control-Allow-Origin", "*")
 360         resp.Header().Set("Access-Control-Allow-Headers", "Authorization, Content-Length, Content-Type, X-Keep-Desired-Replicas")
 361         resp.Header().Set("Access-Control-Max-Age", "86486400")
 362 }
 363
 364 type InvalidPathHandler struct{}
 365
 366 func (InvalidPathHandler) ServeHTTP(resp http.ResponseWriter, req *http.Request) {
 367         log.Printf("%s: %s %s unroutable", GetRemoteAddress(req), req.Method, req.URL.Path)
 368         http.Error(resp, "Bad request", http.StatusBadRequest)
 369 }
 370
 371 func (h *proxyHandler) Options(resp http.ResponseWriter, req *http.Request) {
 372         log.Printf("%s: %s %s", GetRemoteAddress(req), req.Method, req.URL.Path)
 373         SetCorsHeaders(resp)
 374 }
 375
 376 var BadAuthorizationHeader = errors.New("Missing or invalid Authorization header")
 377 var ContentLengthMismatch = errors.New("Actual length != expected content length")
 378 var MethodNotSupported = errors.New("Method not supported")
 379
 380 var removeHint, _ = regexp.Compile("\\+K@[a-z0-9]{5}(\\+|$)")
 381
 382 func (h *proxyHandler) Get(resp http.ResponseWriter, req *http.Request) {
 383         if err := h.checkLoop(resp, req); err != nil {
 384                 return
 385         }
 386         SetCorsHeaders(resp)
 387         resp.Header().Set("Via", req.Proto+" "+viaAlias)
 388
 389         locator := mux.Vars(req)["locator"]
 390         var err error
 391         var status int
 392         var expectLength, responseLength int64
 393         var proxiedURI = "-"
 394
 395         defer func() {
 396                 log.Println(GetRemoteAddress(req), req.Method, req.URL.Path, status, expectLength, responseLength, proxiedURI, err)
 397                 if status != http.StatusOK {
 398                         http.Error(resp, err.Error(), status)
 399                 }
 400         }()
 401
 402         kc := h.makeKeepClient(req)
 403
 404         var pass bool
 405         var tok string
 406         if pass, tok = CheckAuthorizationHeader(kc, h.ApiTokenCache, req); !pass {
 407                 status, err = http.StatusForbidden, BadAuthorizationHeader
 408                 return
 409         }
 410
 411         // Copy ArvadosClient struct and use the client's API token
 412         arvclient := *kc.Arvados
 413         arvclient.ApiToken = tok
 414         kc.Arvados = &arvclient
 415
 416         var reader io.ReadCloser
 417
 418         locator = removeHint.ReplaceAllString(locator, "$1")
 419
 420         switch req.Method {
 421         case "HEAD":
 422                 expectLength, proxiedURI, err = kc.Ask(locator)
 423         case "GET":
 424                 reader, expectLength, proxiedURI, err = kc.Get(locator)
 425                 if reader != nil {
 426                         defer reader.Close()
 427                 }
 428         default:
 429                 status, err = http.StatusNotImplemented, MethodNotSupported
 430                 return
 431         }
 432
 433         if expectLength == -1 {
 434                 log.Println("Warning:", GetRemoteAddress(req), req.Method, proxiedURI, "Content-Length not provided")
 435         }
 436
 437         switch respErr := err.(type) {
 438         case nil:
 439                 status = http.StatusOK
 440                 resp.Header().Set("Content-Length", fmt.Sprint(expectLength))
 441                 switch req.Method {
 442                 case "HEAD":
 443                         responseLength = 0
 444                 case "GET":
 445                         responseLength, err = io.Copy(resp, reader)
 446                         if err == nil && expectLength > -1 && responseLength != expectLength {
 447                                 err = ContentLengthMismatch
 448                         }
 449                 }
 450         case keepclient.Error:
 451                 if respErr == keepclient.BlockNotFound {
 452                         status = http.StatusNotFound
 453                 } else if respErr.Temporary() {
 454                         status = http.StatusBadGateway
 455                 } else {
 456                         status = 422
 457                 }
 458         default:
 459                 status = http.StatusInternalServerError
 460         }
 461 }
 462
 463 var LengthRequiredError = errors.New(http.StatusText(http.StatusLengthRequired))
 464 var LengthMismatchError = errors.New("Locator size hint does not match Content-Length header")
 465
 466 func (h *proxyHandler) Put(resp http.ResponseWriter, req *http.Request) {
 467         if err := h.checkLoop(resp, req); err != nil {
 468                 return
 469         }
 470         SetCorsHeaders(resp)
 471         resp.Header().Set("Via", "HTTP/1.1 "+viaAlias)
 472
 473         kc := h.makeKeepClient(req)
 474
 475         var err error
 476         var expectLength int64
 477         var status = http.StatusInternalServerError
 478         var wroteReplicas int
 479         var locatorOut string = "-"
 480
 481         defer func() {
 482                 log.Println(GetRemoteAddress(req), req.Method, req.URL.Path, status, expectLength, kc.Want_replicas, wroteReplicas, locatorOut, err)
 483                 if status != http.StatusOK {
 484                         http.Error(resp, err.Error(), status)
 485                 }
 486         }()
 487
 488         locatorIn := mux.Vars(req)["locator"]
 489
 490         // Check if the client specified storage classes
 491         if req.Header.Get("X-Keep-Storage-Classes") != "" {
 492                 var scl []string
 493                 for _, sc := range strings.Split(req.Header.Get("X-Keep-Storage-Classes"), ",") {
 494                         scl = append(scl, strings.Trim(sc, " "))
 495                 }
 496                 kc.StorageClasses = scl
 497         }
 498
 499         _, err = fmt.Sscanf(req.Header.Get("Content-Length"), "%d", &expectLength)
 500         if err != nil || expectLength < 0 {
 501                 err = LengthRequiredError
 502                 status = http.StatusLengthRequired
 503                 return
 504         }
 505
 506         if locatorIn != "" {
 507                 var loc *keepclient.Locator
 508                 if loc, err = keepclient.MakeLocator(locatorIn); err != nil {
 509                         status = http.StatusBadRequest
 510                         return
 511                 } else if loc.Size > 0 && int64(loc.Size) != expectLength {
 512                         err = LengthMismatchError
 513                         status = http.StatusBadRequest
 514                         return
 515                 }
 516         }
 517
 518         var pass bool
 519         var tok string
 520         if pass, tok = CheckAuthorizationHeader(kc, h.ApiTokenCache, req); !pass {
 521                 err = BadAuthorizationHeader
 522                 status = http.StatusForbidden
 523                 return
 524         }
 525
 526         // Copy ArvadosClient struct and use the client's API token
 527         arvclient := *kc.Arvados
 528         arvclient.ApiToken = tok
 529         kc.Arvados = &arvclient
 530
 531         // Check if the client specified the number of replicas
 532         if req.Header.Get("X-Keep-Desired-Replicas") != "" {
 533                 var r int
 534                 _, err := fmt.Sscanf(req.Header.Get(keepclient.X_Keep_Desired_Replicas), "%d", &r)
 535                 if err == nil {
 536                         kc.Want_replicas = r
 537                 }
 538         }
 539
 540         // Now try to put the block through
 541         if locatorIn == "" {
 542                 bytes, err2 := ioutil.ReadAll(req.Body)
 543                 if err2 != nil {
 544                         _ = errors.New(fmt.Sprintf("Error reading request body: %s", err2))
 545                         status = http.StatusInternalServerError
 546                         return
 547                 }
 548                 locatorOut, wroteReplicas, err = kc.PutB(bytes)
 549         } else {
 550                 locatorOut, wroteReplicas, err = kc.PutHR(locatorIn, req.Body, expectLength)
 551         }
 552
 553         // Tell the client how many successful PUTs we accomplished
 554         resp.Header().Set(keepclient.X_Keep_Replicas_Stored, fmt.Sprintf("%d", wroteReplicas))
 555
 556         switch err.(type) {
 557         case nil:
 558                 status = http.StatusOK
 559                 _, err = io.WriteString(resp, locatorOut)
 560
 561         case keepclient.OversizeBlockError:
 562                 // Too much data
 563                 status = http.StatusRequestEntityTooLarge
 564
 565         case keepclient.InsufficientReplicasError:
 566                 if wroteReplicas > 0 {
 567                         // At least one write is considered success.  The
 568                         // client can decide if getting less than the number of
 569                         // replications it asked for is a fatal error.
 570                         status = http.StatusOK
 571                         _, err = io.WriteString(resp, locatorOut)
 572                 } else {
 573                         status = http.StatusServiceUnavailable
 574                 }
 575
 576         default:
 577                 status = http.StatusBadGateway
 578         }
 579 }
 580
 581 // ServeHTTP implementation for IndexHandler
 582 // Supports only GET requests for /index/{prefix:[0-9a-f]{0,32}}
 583 // For each keep server found in LocalRoots:
 584 //   Invokes GetIndex using keepclient
 585 //   Expects "complete" response (terminating with blank new line)
 586 //   Aborts on any errors
 587 // Concatenates responses from all those keep servers and returns
 588 func (h *proxyHandler) Index(resp http.ResponseWriter, req *http.Request) {
 589         SetCorsHeaders(resp)
 590
 591         prefix := mux.Vars(req)["prefix"]
 592         var err error
 593         var status int
 594
 595         defer func() {
 596                 if status != http.StatusOK {
 597                         http.Error(resp, err.Error(), status)
 598                 }
 599         }()
 600
 601         kc := h.makeKeepClient(req)
 602         ok, token := CheckAuthorizationHeader(kc, h.ApiTokenCache, req)
 603         if !ok {
 604                 status, err = http.StatusForbidden, BadAuthorizationHeader
 605                 return
 606         }
 607
 608         // Copy ArvadosClient struct and use the client's API token
 609         arvclient := *kc.Arvados
 610         arvclient.ApiToken = token
 611         kc.Arvados = &arvclient
 612
 613         // Only GET method is supported
 614         if req.Method != "GET" {
 615                 status, err = http.StatusNotImplemented, MethodNotSupported
 616                 return
 617         }
 618
 619         // Get index from all LocalRoots and write to resp
 620         var reader io.Reader
 621         for uuid := range kc.LocalRoots() {
 622                 reader, err = kc.GetIndex(uuid, prefix)
 623                 if err != nil {
 624                         status = http.StatusBadGateway
 625                         return
 626                 }
 627
 628                 _, err = io.Copy(resp, reader)
 629                 if err != nil {
 630                         status = http.StatusBadGateway
 631                         return
 632                 }
 633         }
 634
 635         // Got index from all the keep servers and wrote to resp
 636         status = http.StatusOK
 637         resp.Write([]byte("\n"))
 638 }
 639
 640 func (h *proxyHandler) makeKeepClient(req *http.Request) *keepclient.KeepClient {
 641         kc := *h.KeepClient
 642         kc.RequestID = req.Header.Get("X-Request-Id")
 643         kc.HTTPClient = &proxyClient{
 644                 client: &http.Client{
 645                         Timeout:   h.timeout,
 646                         Transport: h.transport,
 647                 },
 648                 proto: req.Proto,
 649         }
 650         return &kc
 651 }