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         "log"
  14         "net"
  15         "net/http"
  16         "os"
  17         "os/signal"
  18         "regexp"
  19         "strings"
  20         "sync"
  21         "syscall"
  22         "time"
  23
  24         "git.curoverse.com/arvados.git/sdk/go/arvados"
  25         "git.curoverse.com/arvados.git/sdk/go/arvadosclient"
  26         "git.curoverse.com/arvados.git/sdk/go/config"
  27         "git.curoverse.com/arvados.git/sdk/go/health"
  28         "git.curoverse.com/arvados.git/sdk/go/keepclient"
  29         arvadosVersion "git.curoverse.com/arvados.git/sdk/go/version"
  30         "github.com/coreos/go-systemd/daemon"
  31         "github.com/ghodss/yaml"
  32         "github.com/gorilla/mux"
  33 )
  34
  35 type Config struct {
  36         Client          arvados.Client
  37         Listen          string
  38         DisableGet      bool
  39         DisablePut      bool
  40         DefaultReplicas int
  41         Timeout         arvados.Duration
  42         PIDFile         string
  43         Debug           bool
  44         ManagementToken string
  45 }
  46
  47 func DefaultConfig() *Config {
  48         return &Config{
  49                 Listen:  ":25107",
  50                 Timeout: arvados.Duration(15 * time.Second),
  51         }
  52 }
  53
  54 var (
  55         listener net.Listener
  56         router   http.Handler
  57 )
  58
  59 func main() {
  60         cfg := DefaultConfig()
  61
  62         flagset := flag.NewFlagSet("keepproxy", flag.ExitOnError)
  63         flagset.Usage = usage
  64
  65         const deprecated = " (DEPRECATED -- use config file instead)"
  66         flagset.StringVar(&cfg.Listen, "listen", cfg.Listen, "Local port to listen on."+deprecated)
  67         flagset.BoolVar(&cfg.DisableGet, "no-get", cfg.DisableGet, "Disable GET operations."+deprecated)
  68         flagset.BoolVar(&cfg.DisablePut, "no-put", cfg.DisablePut, "Disable PUT operations."+deprecated)
  69         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)
  70         flagset.StringVar(&cfg.PIDFile, "pid", cfg.PIDFile, "Path to write pid file."+deprecated)
  71         timeoutSeconds := flagset.Int("timeout", int(time.Duration(cfg.Timeout)/time.Second), "Timeout (in seconds) on requests to internal Keep services."+deprecated)
  72         flagset.StringVar(&cfg.ManagementToken, "management-token", cfg.ManagementToken, "Authorization token to be included in all health check requests.")
  73
  74         var cfgPath string
  75         const defaultCfgPath = "/etc/arvados/keepproxy/keepproxy.yml"
  76         flagset.StringVar(&cfgPath, "config", defaultCfgPath, "Configuration file `path`")
  77         dumpConfig := flagset.Bool("dump-config", false, "write current configuration to stdout and exit")
  78         getVersion := flagset.Bool("version", false, "Print version information and exit.")
  79         flagset.Parse(os.Args[1:])
  80
  81         // Print version information if requested
  82         if *getVersion {
  83                 fmt.Printf("Version: %s\n", arvadosVersion.GetVersion())
  84                 os.Exit(0)
  85         }
  86
  87         err := config.LoadFile(cfg, cfgPath)
  88         if err != nil {
  89                 h := os.Getenv("ARVADOS_API_HOST")
  90                 t := os.Getenv("ARVADOS_API_TOKEN")
  91                 if h == "" || t == "" || !os.IsNotExist(err) || cfgPath != defaultCfgPath {
  92                         log.Fatal(err)
  93                 }
  94                 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.")
  95                 cfg.Client.APIHost = h
  96                 cfg.Client.AuthToken = t
  97                 if regexp.MustCompile("^(?i:1|yes|true)$").MatchString(os.Getenv("ARVADOS_API_HOST_INSECURE")) {
  98                         cfg.Client.Insecure = true
  99                 }
 100                 if y, err := yaml.Marshal(cfg); err == nil && !*dumpConfig {
 101                         log.Print("Current configuration:\n", string(y))
 102                 }
 103                 cfg.Timeout = arvados.Duration(time.Duration(*timeoutSeconds) * time.Second)
 104         }
 105
 106         if *dumpConfig {
 107                 log.Fatal(config.DumpAndExit(cfg))
 108         }
 109
 110         log.Printf("keepproxy %q started", arvadosVersion.GetVersion())
 111
 112         arv, err := arvadosclient.New(&cfg.Client)
 113         if err != nil {
 114                 log.Fatalf("Error setting up arvados client %s", err.Error())
 115         }
 116
 117         if cfg.Debug {
 118                 keepclient.DebugPrintf = log.Printf
 119         }
 120         kc, err := keepclient.MakeKeepClient(arv)
 121         if err != nil {
 122                 log.Fatalf("Error setting up keep client %s", err.Error())
 123         }
 124         keepclient.RefreshServiceDiscoveryOnSIGHUP()
 125
 126         if cfg.PIDFile != "" {
 127                 f, err := os.Create(cfg.PIDFile)
 128                 if err != nil {
 129                         log.Fatal(err)
 130                 }
 131                 defer f.Close()
 132                 err = syscall.Flock(int(f.Fd()), syscall.LOCK_EX|syscall.LOCK_NB)
 133                 if err != nil {
 134                         log.Fatalf("flock(%s): %s", cfg.PIDFile, err)
 135                 }
 136                 defer os.Remove(cfg.PIDFile)
 137                 err = f.Truncate(0)
 138                 if err != nil {
 139                         log.Fatalf("truncate(%s): %s", cfg.PIDFile, err)
 140                 }
 141                 _, err = fmt.Fprint(f, os.Getpid())
 142                 if err != nil {
 143                         log.Fatalf("write(%s): %s", cfg.PIDFile, err)
 144                 }
 145                 err = f.Sync()
 146                 if err != nil {
 147                         log.Fatal("sync(%s): %s", cfg.PIDFile, err)
 148                 }
 149         }
 150
 151         if cfg.DefaultReplicas > 0 {
 152                 kc.Want_replicas = cfg.DefaultReplicas
 153         }
 154
 155         listener, err = net.Listen("tcp", cfg.Listen)
 156         if err != nil {
 157                 log.Fatalf("listen(%s): %s", cfg.Listen, err)
 158         }
 159         if _, err := daemon.SdNotify(false, "READY=1"); err != nil {
 160                 log.Printf("Error notifying init daemon: %v", err)
 161         }
 162         log.Println("Listening at", listener.Addr())
 163
 164         // Shut down the server gracefully (by closing the listener)
 165         // if SIGTERM is received.
 166         term := make(chan os.Signal, 1)
 167         go func(sig <-chan os.Signal) {
 168                 s := <-sig
 169                 log.Println("caught signal:", s)
 170                 listener.Close()
 171         }(term)
 172         signal.Notify(term, syscall.SIGTERM)
 173         signal.Notify(term, syscall.SIGINT)
 174
 175         // Start serving requests.
 176         router = MakeRESTRouter(!cfg.DisableGet, !cfg.DisablePut, kc, time.Duration(cfg.Timeout), cfg.ManagementToken)
 177         http.Serve(listener, router)
 178
 179         log.Println("shutting down")
 180 }
 181
 182 type ApiTokenCache struct {
 183         tokens     map[string]int64
 184         lock       sync.Mutex
 185         expireTime int64
 186 }
 187
 188 // Cache the token and set an expire time.  If we already have an expire time
 189 // on the token, it is not updated.
 190 func (this *ApiTokenCache) RememberToken(token string) {
 191         this.lock.Lock()
 192         defer this.lock.Unlock()
 193
 194         now := time.Now().Unix()
 195         if this.tokens[token] == 0 {
 196                 this.tokens[token] = now + this.expireTime
 197         }
 198 }
 199
 200 // Check if the cached token is known and still believed to be valid.
 201 func (this *ApiTokenCache) RecallToken(token string) bool {
 202         this.lock.Lock()
 203         defer this.lock.Unlock()
 204
 205         now := time.Now().Unix()
 206         if this.tokens[token] == 0 {
 207                 // Unknown token
 208                 return false
 209         } else if now < this.tokens[token] {
 210                 // Token is known and still valid
 211                 return true
 212         } else {
 213                 // Token is expired
 214                 this.tokens[token] = 0
 215                 return false
 216         }
 217 }
 218
 219 func GetRemoteAddress(req *http.Request) string {
 220         if xff := req.Header.Get("X-Forwarded-For"); xff != "" {
 221                 return xff + "," + req.RemoteAddr
 222         }
 223         return req.RemoteAddr
 224 }
 225
 226 func CheckAuthorizationHeader(kc *keepclient.KeepClient, cache *ApiTokenCache, req *http.Request) (pass bool, tok string) {
 227         var auth string
 228         if auth = req.Header.Get("Authorization"); auth == "" {
 229                 return false, ""
 230         }
 231
 232         _, err := fmt.Sscanf(auth, "OAuth2 %s", &tok)
 233         if err != nil {
 234                 // Scanning error
 235                 return false, ""
 236         }
 237
 238         if cache.RecallToken(tok) {
 239                 // Valid in the cache, short circuit
 240                 return true, tok
 241         }
 242
 243         arv := *kc.Arvados
 244         arv.ApiToken = tok
 245         if err := arv.Call("HEAD", "users", "", "current", nil, nil); err != nil {
 246                 log.Printf("%s: CheckAuthorizationHeader error: %v", GetRemoteAddress(req), err)
 247                 return false, ""
 248         }
 249
 250         // Success!  Update cache
 251         cache.RememberToken(tok)
 252
 253         return true, tok
 254 }
 255
 256 type proxyHandler struct {
 257         http.Handler
 258         *keepclient.KeepClient
 259         *ApiTokenCache
 260         timeout   time.Duration
 261         transport *http.Transport
 262 }
 263
 264 // MakeRESTRouter returns an http.Handler that passes GET and PUT
 265 // requests to the appropriate handlers.
 266 func MakeRESTRouter(enable_get bool, enable_put bool, kc *keepclient.KeepClient, timeout time.Duration, mgmtToken string) http.Handler {
 267         rest := mux.NewRouter()
 268
 269         transport := *(http.DefaultTransport.(*http.Transport))
 270         transport.DialContext = (&net.Dialer{
 271                 Timeout:   keepclient.DefaultConnectTimeout,
 272                 KeepAlive: keepclient.DefaultKeepAlive,
 273                 DualStack: true,
 274         }).DialContext
 275         transport.TLSClientConfig = arvadosclient.MakeTLSConfig(kc.Arvados.ApiInsecure)
 276         transport.TLSHandshakeTimeout = keepclient.DefaultTLSHandshakeTimeout
 277
 278         h := &proxyHandler{
 279                 Handler:    rest,
 280                 KeepClient: kc,
 281                 timeout:    timeout,
 282                 transport:  &transport,
 283                 ApiTokenCache: &ApiTokenCache{
 284                         tokens:     make(map[string]int64),
 285                         expireTime: 300,
 286                 },
 287         }
 288
 289         if enable_get {
 290                 rest.HandleFunc(`/{locator:[0-9a-f]{32}\+.*}`, h.Get).Methods("GET", "HEAD")
 291                 rest.HandleFunc(`/{locator:[0-9a-f]{32}}`, h.Get).Methods("GET", "HEAD")
 292
 293                 // List all blocks
 294                 rest.HandleFunc(`/index`, h.Index).Methods("GET")
 295
 296                 // List blocks whose hash has the given prefix
 297                 rest.HandleFunc(`/index/{prefix:[0-9a-f]{0,32}}`, h.Index).Methods("GET")
 298         }
 299
 300         if enable_put {
 301                 rest.HandleFunc(`/{locator:[0-9a-f]{32}\+.*}`, h.Put).Methods("PUT")
 302                 rest.HandleFunc(`/{locator:[0-9a-f]{32}}`, h.Put).Methods("PUT")
 303                 rest.HandleFunc(`/`, h.Put).Methods("POST")
 304                 rest.HandleFunc(`/{any}`, h.Options).Methods("OPTIONS")
 305                 rest.HandleFunc(`/`, h.Options).Methods("OPTIONS")
 306         }
 307
 308         rest.Handle("/_health/{check}", &health.Handler{
 309                 Token:  mgmtToken,
 310                 Prefix: "/_health/",
 311         }).Methods("GET")
 312
 313         rest.NotFoundHandler = InvalidPathHandler{}
 314         return h
 315 }
 316
 317 var errLoopDetected = errors.New("loop detected")
 318
 319 func (*proxyHandler) checkLoop(resp http.ResponseWriter, req *http.Request) error {
 320         if via := req.Header.Get("Via"); strings.Index(via, " "+viaAlias) >= 0 {
 321                 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)
 322                 http.Error(resp, errLoopDetected.Error(), http.StatusInternalServerError)
 323                 return errLoopDetected
 324         }
 325         return nil
 326 }
 327
 328 func SetCorsHeaders(resp http.ResponseWriter) {
 329         resp.Header().Set("Access-Control-Allow-Methods", "GET, HEAD, POST, PUT, OPTIONS")
 330         resp.Header().Set("Access-Control-Allow-Origin", "*")
 331         resp.Header().Set("Access-Control-Allow-Headers", "Authorization, Content-Length, Content-Type, X-Keep-Desired-Replicas")
 332         resp.Header().Set("Access-Control-Max-Age", "86486400")
 333 }
 334
 335 type InvalidPathHandler struct{}
 336
 337 func (InvalidPathHandler) ServeHTTP(resp http.ResponseWriter, req *http.Request) {
 338         log.Printf("%s: %s %s unroutable", GetRemoteAddress(req), req.Method, req.URL.Path)
 339         http.Error(resp, "Bad request", http.StatusBadRequest)
 340 }
 341
 342 func (h *proxyHandler) Options(resp http.ResponseWriter, req *http.Request) {
 343         log.Printf("%s: %s %s", GetRemoteAddress(req), req.Method, req.URL.Path)
 344         SetCorsHeaders(resp)
 345 }
 346
 347 var BadAuthorizationHeader = errors.New("Missing or invalid Authorization header")
 348 var ContentLengthMismatch = errors.New("Actual length != expected content length")
 349 var MethodNotSupported = errors.New("Method not supported")
 350
 351 var removeHint, _ = regexp.Compile("\\+K@[a-z0-9]{5}(\\+|$)")
 352
 353 func (h *proxyHandler) Get(resp http.ResponseWriter, req *http.Request) {
 354         if err := h.checkLoop(resp, req); err != nil {
 355                 return
 356         }
 357         SetCorsHeaders(resp)
 358         resp.Header().Set("Via", req.Proto+" "+viaAlias)
 359
 360         locator := mux.Vars(req)["locator"]
 361         var err error
 362         var status int
 363         var expectLength, responseLength int64
 364         var proxiedURI = "-"
 365
 366         defer func() {
 367                 log.Println(GetRemoteAddress(req), req.Method, req.URL.Path, status, expectLength, responseLength, proxiedURI, err)
 368                 if status != http.StatusOK {
 369                         http.Error(resp, err.Error(), status)
 370                 }
 371         }()
 372
 373         kc := h.makeKeepClient(req)
 374
 375         var pass bool
 376         var tok string
 377         if pass, tok = CheckAuthorizationHeader(kc, h.ApiTokenCache, req); !pass {
 378                 status, err = http.StatusForbidden, BadAuthorizationHeader
 379                 return
 380         }
 381
 382         // Copy ArvadosClient struct and use the client's API token
 383         arvclient := *kc.Arvados
 384         arvclient.ApiToken = tok
 385         kc.Arvados = &arvclient
 386
 387         var reader io.ReadCloser
 388
 389         locator = removeHint.ReplaceAllString(locator, "$1")
 390
 391         switch req.Method {
 392         case "HEAD":
 393                 expectLength, proxiedURI, err = kc.Ask(locator)
 394         case "GET":
 395                 reader, expectLength, proxiedURI, err = kc.Get(locator)
 396                 if reader != nil {
 397                         defer reader.Close()
 398                 }
 399         default:
 400                 status, err = http.StatusNotImplemented, MethodNotSupported
 401                 return
 402         }
 403
 404         if expectLength == -1 {
 405                 log.Println("Warning:", GetRemoteAddress(req), req.Method, proxiedURI, "Content-Length not provided")
 406         }
 407
 408         switch respErr := err.(type) {
 409         case nil:
 410                 status = http.StatusOK
 411                 resp.Header().Set("Content-Length", fmt.Sprint(expectLength))
 412                 switch req.Method {
 413                 case "HEAD":
 414                         responseLength = 0
 415                 case "GET":
 416                         responseLength, err = io.Copy(resp, reader)
 417                         if err == nil && expectLength > -1 && responseLength != expectLength {
 418                                 err = ContentLengthMismatch
 419                         }
 420                 }
 421         case keepclient.Error:
 422                 if respErr == keepclient.BlockNotFound {
 423                         status = http.StatusNotFound
 424                 } else if respErr.Temporary() {
 425                         status = http.StatusBadGateway
 426                 } else {
 427                         status = 422
 428                 }
 429         default:
 430                 status = http.StatusInternalServerError
 431         }
 432 }
 433
 434 var LengthRequiredError = errors.New(http.StatusText(http.StatusLengthRequired))
 435 var LengthMismatchError = errors.New("Locator size hint does not match Content-Length header")
 436
 437 func (h *proxyHandler) Put(resp http.ResponseWriter, req *http.Request) {
 438         if err := h.checkLoop(resp, req); err != nil {
 439                 return
 440         }
 441         SetCorsHeaders(resp)
 442         resp.Header().Set("Via", "HTTP/1.1 "+viaAlias)
 443
 444         kc := h.makeKeepClient(req)
 445
 446         var err error
 447         var expectLength int64
 448         var status = http.StatusInternalServerError
 449         var wroteReplicas int
 450         var locatorOut string = "-"
 451
 452         defer func() {
 453                 log.Println(GetRemoteAddress(req), req.Method, req.URL.Path, status, expectLength, kc.Want_replicas, wroteReplicas, locatorOut, err)
 454                 if status != http.StatusOK {
 455                         http.Error(resp, err.Error(), status)
 456                 }
 457         }()
 458
 459         locatorIn := mux.Vars(req)["locator"]
 460
 461         _, err = fmt.Sscanf(req.Header.Get("Content-Length"), "%d", &expectLength)
 462         if err != nil || expectLength < 0 {
 463                 err = LengthRequiredError
 464                 status = http.StatusLengthRequired
 465                 return
 466         }
 467
 468         if locatorIn != "" {
 469                 var loc *keepclient.Locator
 470                 if loc, err = keepclient.MakeLocator(locatorIn); err != nil {
 471                         status = http.StatusBadRequest
 472                         return
 473                 } else if loc.Size > 0 && int64(loc.Size) != expectLength {
 474                         err = LengthMismatchError
 475                         status = http.StatusBadRequest
 476                         return
 477                 }
 478         }
 479
 480         var pass bool
 481         var tok string
 482         if pass, tok = CheckAuthorizationHeader(kc, h.ApiTokenCache, req); !pass {
 483                 err = BadAuthorizationHeader
 484                 status = http.StatusForbidden
 485                 return
 486         }
 487
 488         // Copy ArvadosClient struct and use the client's API token
 489         arvclient := *kc.Arvados
 490         arvclient.ApiToken = tok
 491         kc.Arvados = &arvclient
 492
 493         // Check if the client specified the number of replicas
 494         if req.Header.Get("X-Keep-Desired-Replicas") != "" {
 495                 var r int
 496                 _, err := fmt.Sscanf(req.Header.Get(keepclient.X_Keep_Desired_Replicas), "%d", &r)
 497                 if err == nil {
 498                         kc.Want_replicas = r
 499                 }
 500         }
 501
 502         // Now try to put the block through
 503         if locatorIn == "" {
 504                 if bytes, err := ioutil.ReadAll(req.Body); err != nil {
 505                         err = errors.New(fmt.Sprintf("Error reading request body: %s", err))
 506                         status = http.StatusInternalServerError
 507                         return
 508                 } else {
 509                         locatorOut, wroteReplicas, err = kc.PutB(bytes)
 510                 }
 511         } else {
 512                 locatorOut, wroteReplicas, err = kc.PutHR(locatorIn, req.Body, expectLength)
 513         }
 514
 515         // Tell the client how many successful PUTs we accomplished
 516         resp.Header().Set(keepclient.X_Keep_Replicas_Stored, fmt.Sprintf("%d", wroteReplicas))
 517
 518         switch err.(type) {
 519         case nil:
 520                 status = http.StatusOK
 521                 _, err = io.WriteString(resp, locatorOut)
 522
 523         case keepclient.OversizeBlockError:
 524                 // Too much data
 525                 status = http.StatusRequestEntityTooLarge
 526
 527         case keepclient.InsufficientReplicasError:
 528                 if wroteReplicas > 0 {
 529                         // At least one write is considered success.  The
 530                         // client can decide if getting less than the number of
 531                         // replications it asked for is a fatal error.
 532                         status = http.StatusOK
 533                         _, err = io.WriteString(resp, locatorOut)
 534                 } else {
 535                         status = http.StatusServiceUnavailable
 536                 }
 537
 538         default:
 539                 status = http.StatusBadGateway
 540         }
 541 }
 542
 543 // ServeHTTP implementation for IndexHandler
 544 // Supports only GET requests for /index/{prefix:[0-9a-f]{0,32}}
 545 // For each keep server found in LocalRoots:
 546 //   Invokes GetIndex using keepclient
 547 //   Expects "complete" response (terminating with blank new line)
 548 //   Aborts on any errors
 549 // Concatenates responses from all those keep servers and returns
 550 func (h *proxyHandler) Index(resp http.ResponseWriter, req *http.Request) {
 551         SetCorsHeaders(resp)
 552
 553         prefix := mux.Vars(req)["prefix"]
 554         var err error
 555         var status int
 556
 557         defer func() {
 558                 if status != http.StatusOK {
 559                         http.Error(resp, err.Error(), status)
 560                 }
 561         }()
 562
 563         kc := h.makeKeepClient(req)
 564         ok, token := CheckAuthorizationHeader(kc, h.ApiTokenCache, req)
 565         if !ok {
 566                 status, err = http.StatusForbidden, BadAuthorizationHeader
 567                 return
 568         }
 569
 570         // Copy ArvadosClient struct and use the client's API token
 571         arvclient := *kc.Arvados
 572         arvclient.ApiToken = token
 573         kc.Arvados = &arvclient
 574
 575         // Only GET method is supported
 576         if req.Method != "GET" {
 577                 status, err = http.StatusNotImplemented, MethodNotSupported
 578                 return
 579         }
 580
 581         // Get index from all LocalRoots and write to resp
 582         var reader io.Reader
 583         for uuid := range kc.LocalRoots() {
 584                 reader, err = kc.GetIndex(uuid, prefix)
 585                 if err != nil {
 586                         status = http.StatusBadGateway
 587                         return
 588                 }
 589
 590                 _, err = io.Copy(resp, reader)
 591                 if err != nil {
 592                         status = http.StatusBadGateway
 593                         return
 594                 }
 595         }
 596
 597         // Got index from all the keep servers and wrote to resp
 598         status = http.StatusOK
 599         resp.Write([]byte("\n"))
 600 }
 601
 602 func (h *proxyHandler) makeKeepClient(req *http.Request) *keepclient.KeepClient {
 603         kc := *h.KeepClient
 604         kc.HTTPClient = &proxyClient{
 605                 client: &http.Client{
 606                         Timeout:   h.timeout,
 607                         Transport: h.transport,
 608                 },
 609                 proto: req.Proto,
 610         }
 611         return &kc
 612 }