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         log "github.com/Sirupsen/logrus"
  30         "github.com/coreos/go-systemd/daemon"
  31         "github.com/ghodss/yaml"
  32         "github.com/gorilla/mux"
  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(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 type proxyHandler struct {
 278         http.Handler
 279         *keepclient.KeepClient
 280         *ApiTokenCache
 281         timeout   time.Duration
 282         transport *http.Transport
 283 }
 284
 285 // MakeRESTRouter returns an http.Handler that passes GET and PUT
 286 // requests to the appropriate handlers.
 287 func MakeRESTRouter(enable_get bool, enable_put bool, kc *keepclient.KeepClient, timeout time.Duration, mgmtToken string) http.Handler {
 288         rest := mux.NewRouter()
 289
 290         transport := *(http.DefaultTransport.(*http.Transport))
 291         transport.DialContext = (&net.Dialer{
 292                 Timeout:   keepclient.DefaultConnectTimeout,
 293                 KeepAlive: keepclient.DefaultKeepAlive,
 294                 DualStack: true,
 295         }).DialContext
 296         transport.TLSClientConfig = arvadosclient.MakeTLSConfig(kc.Arvados.ApiInsecure)
 297         transport.TLSHandshakeTimeout = keepclient.DefaultTLSHandshakeTimeout
 298
 299         h := &proxyHandler{
 300                 Handler:    rest,
 301                 KeepClient: kc,
 302                 timeout:    timeout,
 303                 transport:  &transport,
 304                 ApiTokenCache: &ApiTokenCache{
 305                         tokens:     make(map[string]int64),
 306                         expireTime: 300,
 307                 },
 308         }
 309
 310         if enable_get {
 311                 rest.HandleFunc(`/{locator:[0-9a-f]{32}\+.*}`, h.Get).Methods("GET", "HEAD")
 312                 rest.HandleFunc(`/{locator:[0-9a-f]{32}}`, h.Get).Methods("GET", "HEAD")
 313
 314                 // List all blocks
 315                 rest.HandleFunc(`/index`, h.Index).Methods("GET")
 316
 317                 // List blocks whose hash has the given prefix
 318                 rest.HandleFunc(`/index/{prefix:[0-9a-f]{0,32}}`, h.Index).Methods("GET")
 319         }
 320
 321         if enable_put {
 322                 rest.HandleFunc(`/{locator:[0-9a-f]{32}\+.*}`, h.Put).Methods("PUT")
 323                 rest.HandleFunc(`/{locator:[0-9a-f]{32}}`, h.Put).Methods("PUT")
 324                 rest.HandleFunc(`/`, h.Put).Methods("POST")
 325                 rest.HandleFunc(`/{any}`, h.Options).Methods("OPTIONS")
 326                 rest.HandleFunc(`/`, h.Options).Methods("OPTIONS")
 327         }
 328
 329         rest.Handle("/_health/{check}", &health.Handler{
 330                 Token:  mgmtToken,
 331                 Prefix: "/_health/",
 332         }).Methods("GET")
 333
 334         rest.NotFoundHandler = InvalidPathHandler{}
 335         return h
 336 }
 337
 338 var errLoopDetected = errors.New("loop detected")
 339
 340 func (*proxyHandler) checkLoop(resp http.ResponseWriter, req *http.Request) error {
 341         if via := req.Header.Get("Via"); strings.Index(via, " "+viaAlias) >= 0 {
 342                 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)
 343                 http.Error(resp, errLoopDetected.Error(), http.StatusInternalServerError)
 344                 return errLoopDetected
 345         }
 346         return nil
 347 }
 348
 349 func SetCorsHeaders(resp http.ResponseWriter) {
 350         resp.Header().Set("Access-Control-Allow-Methods", "GET, HEAD, POST, PUT, OPTIONS")
 351         resp.Header().Set("Access-Control-Allow-Origin", "*")
 352         resp.Header().Set("Access-Control-Allow-Headers", "Authorization, Content-Length, Content-Type, X-Keep-Desired-Replicas")
 353         resp.Header().Set("Access-Control-Max-Age", "86486400")
 354 }
 355
 356 type InvalidPathHandler struct{}
 357
 358 func (InvalidPathHandler) ServeHTTP(resp http.ResponseWriter, req *http.Request) {
 359         log.Printf("%s: %s %s unroutable", GetRemoteAddress(req), req.Method, req.URL.Path)
 360         http.Error(resp, "Bad request", http.StatusBadRequest)
 361 }
 362
 363 func (h *proxyHandler) Options(resp http.ResponseWriter, req *http.Request) {
 364         log.Printf("%s: %s %s", GetRemoteAddress(req), req.Method, req.URL.Path)
 365         SetCorsHeaders(resp)
 366 }
 367
 368 var BadAuthorizationHeader = errors.New("Missing or invalid Authorization header")
 369 var ContentLengthMismatch = errors.New("Actual length != expected content length")
 370 var MethodNotSupported = errors.New("Method not supported")
 371
 372 var removeHint, _ = regexp.Compile("\\+K@[a-z0-9]{5}(\\+|$)")
 373
 374 func (h *proxyHandler) Get(resp http.ResponseWriter, req *http.Request) {
 375         if err := h.checkLoop(resp, req); err != nil {
 376                 return
 377         }
 378         SetCorsHeaders(resp)
 379         resp.Header().Set("Via", req.Proto+" "+viaAlias)
 380
 381         locator := mux.Vars(req)["locator"]
 382         var err error
 383         var status int
 384         var expectLength, responseLength int64
 385         var proxiedURI = "-"
 386
 387         defer func() {
 388                 log.Println(GetRemoteAddress(req), req.Method, req.URL.Path, status, expectLength, responseLength, proxiedURI, err)
 389                 if status != http.StatusOK {
 390                         http.Error(resp, err.Error(), status)
 391                 }
 392         }()
 393
 394         kc := h.makeKeepClient(req)
 395
 396         var pass bool
 397         var tok string
 398         if pass, tok = CheckAuthorizationHeader(kc, h.ApiTokenCache, req); !pass {
 399                 status, err = http.StatusForbidden, BadAuthorizationHeader
 400                 return
 401         }
 402
 403         // Copy ArvadosClient struct and use the client's API token
 404         arvclient := *kc.Arvados
 405         arvclient.ApiToken = tok
 406         kc.Arvados = &arvclient
 407
 408         var reader io.ReadCloser
 409
 410         locator = removeHint.ReplaceAllString(locator, "$1")
 411
 412         switch req.Method {
 413         case "HEAD":
 414                 expectLength, proxiedURI, err = kc.Ask(locator)
 415         case "GET":
 416                 reader, expectLength, proxiedURI, err = kc.Get(locator)
 417                 if reader != nil {
 418                         defer reader.Close()
 419                 }
 420         default:
 421                 status, err = http.StatusNotImplemented, MethodNotSupported
 422                 return
 423         }
 424
 425         if expectLength == -1 {
 426                 log.Println("Warning:", GetRemoteAddress(req), req.Method, proxiedURI, "Content-Length not provided")
 427         }
 428
 429         switch respErr := err.(type) {
 430         case nil:
 431                 status = http.StatusOK
 432                 resp.Header().Set("Content-Length", fmt.Sprint(expectLength))
 433                 switch req.Method {
 434                 case "HEAD":
 435                         responseLength = 0
 436                 case "GET":
 437                         responseLength, err = io.Copy(resp, reader)
 438                         if err == nil && expectLength > -1 && responseLength != expectLength {
 439                                 err = ContentLengthMismatch
 440                         }
 441                 }
 442         case keepclient.Error:
 443                 if respErr == keepclient.BlockNotFound {
 444                         status = http.StatusNotFound
 445                 } else if respErr.Temporary() {
 446                         status = http.StatusBadGateway
 447                 } else {
 448                         status = 422
 449                 }
 450         default:
 451                 status = http.StatusInternalServerError
 452         }
 453 }
 454
 455 var LengthRequiredError = errors.New(http.StatusText(http.StatusLengthRequired))
 456 var LengthMismatchError = errors.New("Locator size hint does not match Content-Length header")
 457
 458 func (h *proxyHandler) Put(resp http.ResponseWriter, req *http.Request) {
 459         if err := h.checkLoop(resp, req); err != nil {
 460                 return
 461         }
 462         SetCorsHeaders(resp)
 463         resp.Header().Set("Via", "HTTP/1.1 "+viaAlias)
 464
 465         kc := h.makeKeepClient(req)
 466
 467         var err error
 468         var expectLength int64
 469         var status = http.StatusInternalServerError
 470         var wroteReplicas int
 471         var locatorOut string = "-"
 472
 473         defer func() {
 474                 log.Println(GetRemoteAddress(req), req.Method, req.URL.Path, status, expectLength, kc.Want_replicas, wroteReplicas, locatorOut, err)
 475                 if status != http.StatusOK {
 476                         http.Error(resp, err.Error(), status)
 477                 }
 478         }()
 479
 480         locatorIn := mux.Vars(req)["locator"]
 481
 482         _, err = fmt.Sscanf(req.Header.Get("Content-Length"), "%d", &expectLength)
 483         if err != nil || expectLength < 0 {
 484                 err = LengthRequiredError
 485                 status = http.StatusLengthRequired
 486                 return
 487         }
 488
 489         if locatorIn != "" {
 490                 var loc *keepclient.Locator
 491                 if loc, err = keepclient.MakeLocator(locatorIn); err != nil {
 492                         status = http.StatusBadRequest
 493                         return
 494                 } else if loc.Size > 0 && int64(loc.Size) != expectLength {
 495                         err = LengthMismatchError
 496                         status = http.StatusBadRequest
 497                         return
 498                 }
 499         }
 500
 501         var pass bool
 502         var tok string
 503         if pass, tok = CheckAuthorizationHeader(kc, h.ApiTokenCache, req); !pass {
 504                 err = BadAuthorizationHeader
 505                 status = http.StatusForbidden
 506                 return
 507         }
 508
 509         // Copy ArvadosClient struct and use the client's API token
 510         arvclient := *kc.Arvados
 511         arvclient.ApiToken = tok
 512         kc.Arvados = &arvclient
 513
 514         // Check if the client specified the number of replicas
 515         if req.Header.Get("X-Keep-Desired-Replicas") != "" {
 516                 var r int
 517                 _, err := fmt.Sscanf(req.Header.Get(keepclient.X_Keep_Desired_Replicas), "%d", &r)
 518                 if err == nil {
 519                         kc.Want_replicas = r
 520                 }
 521         }
 522
 523         // Now try to put the block through
 524         if locatorIn == "" {
 525                 bytes, err2 := ioutil.ReadAll(req.Body)
 526                 if err2 != nil {
 527                         _ = errors.New(fmt.Sprintf("Error reading request body: %s", err2))
 528                         status = http.StatusInternalServerError
 529                         return
 530                 }
 531                 locatorOut, wroteReplicas, err = kc.PutB(bytes)
 532         } else {
 533                 locatorOut, wroteReplicas, err = kc.PutHR(locatorIn, req.Body, expectLength)
 534         }
 535
 536         // Tell the client how many successful PUTs we accomplished
 537         resp.Header().Set(keepclient.X_Keep_Replicas_Stored, fmt.Sprintf("%d", wroteReplicas))
 538
 539         switch err.(type) {
 540         case nil:
 541                 status = http.StatusOK
 542                 _, err = io.WriteString(resp, locatorOut)
 543
 544         case keepclient.OversizeBlockError:
 545                 // Too much data
 546                 status = http.StatusRequestEntityTooLarge
 547
 548         case keepclient.InsufficientReplicasError:
 549                 if wroteReplicas > 0 {
 550                         // At least one write is considered success.  The
 551                         // client can decide if getting less than the number of
 552                         // replications it asked for is a fatal error.
 553                         status = http.StatusOK
 554                         _, err = io.WriteString(resp, locatorOut)
 555                 } else {
 556                         status = http.StatusServiceUnavailable
 557                 }
 558
 559         default:
 560                 status = http.StatusBadGateway
 561         }
 562 }
 563
 564 // ServeHTTP implementation for IndexHandler
 565 // Supports only GET requests for /index/{prefix:[0-9a-f]{0,32}}
 566 // For each keep server found in LocalRoots:
 567 //   Invokes GetIndex using keepclient
 568 //   Expects "complete" response (terminating with blank new line)
 569 //   Aborts on any errors
 570 // Concatenates responses from all those keep servers and returns
 571 func (h *proxyHandler) Index(resp http.ResponseWriter, req *http.Request) {
 572         SetCorsHeaders(resp)
 573
 574         prefix := mux.Vars(req)["prefix"]
 575         var err error
 576         var status int
 577
 578         defer func() {
 579                 if status != http.StatusOK {
 580                         http.Error(resp, err.Error(), status)
 581                 }
 582         }()
 583
 584         kc := h.makeKeepClient(req)
 585         ok, token := CheckAuthorizationHeader(kc, h.ApiTokenCache, req)
 586         if !ok {
 587                 status, err = http.StatusForbidden, BadAuthorizationHeader
 588                 return
 589         }
 590
 591         // Copy ArvadosClient struct and use the client's API token
 592         arvclient := *kc.Arvados
 593         arvclient.ApiToken = token
 594         kc.Arvados = &arvclient
 595
 596         // Only GET method is supported
 597         if req.Method != "GET" {
 598                 status, err = http.StatusNotImplemented, MethodNotSupported
 599                 return
 600         }
 601
 602         // Get index from all LocalRoots and write to resp
 603         var reader io.Reader
 604         for uuid := range kc.LocalRoots() {
 605                 reader, err = kc.GetIndex(uuid, prefix)
 606                 if err != nil {
 607                         status = http.StatusBadGateway
 608                         return
 609                 }
 610
 611                 _, err = io.Copy(resp, reader)
 612                 if err != nil {
 613                         status = http.StatusBadGateway
 614                         return
 615                 }
 616         }
 617
 618         // Got index from all the keep servers and wrote to resp
 619         status = http.StatusOK
 620         resp.Write([]byte("\n"))
 621 }
 622
 623 func (h *proxyHandler) makeKeepClient(req *http.Request) *keepclient.KeepClient {
 624         kc := *h.KeepClient
 625         kc.RequestID = req.Header.Get("X-Request-Id")
 626         kc.HTTPClient = &proxyClient{
 627                 client: &http.Client{
 628                         Timeout:   h.timeout,
 629                         Transport: h.transport,
 630                 },
 631                 proto: req.Proto,
 632         }
 633         return &kc
 634 }