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         "github.com/coreos/go-systemd/daemon"
  30         "github.com/ghodss/yaml"
  31         "github.com/gorilla/mux"
  32 )
  33
  34 var version = "dev"
  35
  36 type Config struct {
  37         Client          arvados.Client
  38         Listen          string
  39         DisableGet      bool
  40         DisablePut      bool
  41         DefaultReplicas int
  42         Timeout         arvados.Duration
  43         PIDFile         string
  44         Debug           bool
  45         ManagementToken string
  46 }
  47
  48 func DefaultConfig() *Config {
  49         return &Config{
  50                 Listen:  ":25107",
  51                 Timeout: arvados.Duration(15 * time.Second),
  52         }
  53 }
  54
  55 var (
  56         listener net.Listener
  57         router   http.Handler
  58 )
  59
  60 func main() {
  61         cfg := DefaultConfig()
  62
  63         flagset := flag.NewFlagSet("keepproxy", flag.ExitOnError)
  64         flagset.Usage = usage
  65
  66         const deprecated = " (DEPRECATED -- use config file instead)"
  67         flagset.StringVar(&cfg.Listen, "listen", cfg.Listen, "Local port to listen on."+deprecated)
  68         flagset.BoolVar(&cfg.DisableGet, "no-get", cfg.DisableGet, "Disable GET operations."+deprecated)
  69         flagset.BoolVar(&cfg.DisablePut, "no-put", cfg.DisablePut, "Disable PUT operations."+deprecated)
  70         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)
  71         flagset.StringVar(&cfg.PIDFile, "pid", cfg.PIDFile, "Path to write pid file."+deprecated)
  72         timeoutSeconds := flagset.Int("timeout", int(time.Duration(cfg.Timeout)/time.Second), "Timeout (in seconds) on requests to internal Keep services."+deprecated)
  73         flagset.StringVar(&cfg.ManagementToken, "management-token", cfg.ManagementToken, "Authorization token to be included in all health check requests.")
  74
  75         var cfgPath string
  76         const defaultCfgPath = "/etc/arvados/keepproxy/keepproxy.yml"
  77         flagset.StringVar(&cfgPath, "config", defaultCfgPath, "Configuration file `path`")
  78         dumpConfig := flagset.Bool("dump-config", false, "write current configuration to stdout and exit")
  79         getVersion := flagset.Bool("version", false, "Print version information and exit.")
  80         flagset.Parse(os.Args[1:])
  81
  82         // Print version information if requested
  83         if *getVersion {
  84                 fmt.Printf("Version: %s\n", version)
  85                 os.Exit(0)
  86         }
  87
  88         err := config.LoadFile(cfg, cfgPath)
  89         if err != nil {
  90                 h := os.Getenv("ARVADOS_API_HOST")
  91                 t := os.Getenv("ARVADOS_API_TOKEN")
  92                 if h == "" || t == "" || !os.IsNotExist(err) || cfgPath != defaultCfgPath {
  93                         log.Fatal(err)
  94                 }
  95                 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.")
  96                 cfg.Client.APIHost = h
  97                 cfg.Client.AuthToken = t
  98                 if regexp.MustCompile("^(?i:1|yes|true)$").MatchString(os.Getenv("ARVADOS_API_HOST_INSECURE")) {
  99                         cfg.Client.Insecure = true
 100                 }
 101                 if y, err := yaml.Marshal(cfg); err == nil && !*dumpConfig {
 102                         log.Print("Current configuration:\n", string(y))
 103                 }
 104                 cfg.Timeout = arvados.Duration(time.Duration(*timeoutSeconds) * time.Second)
 105         }
 106
 107         if *dumpConfig {
 108                 log.Fatal(config.DumpAndExit(cfg))
 109         }
 110
 111         log.Printf("keepproxy %q started", version)
 112
 113         arv, err := arvadosclient.New(&cfg.Client)
 114         if err != nil {
 115                 log.Fatalf("Error setting up arvados client %s", err.Error())
 116         }
 117
 118         if cfg.Debug {
 119                 keepclient.DebugPrintf = log.Printf
 120         }
 121         kc, err := keepclient.MakeKeepClient(arv)
 122         if err != nil {
 123                 log.Fatalf("Error setting up keep client %s", err.Error())
 124         }
 125         keepclient.RefreshServiceDiscoveryOnSIGHUP()
 126
 127         if cfg.PIDFile != "" {
 128                 f, err := os.Create(cfg.PIDFile)
 129                 if err != nil {
 130                         log.Fatal(err)
 131                 }
 132                 defer f.Close()
 133                 err = syscall.Flock(int(f.Fd()), syscall.LOCK_EX|syscall.LOCK_NB)
 134                 if err != nil {
 135                         log.Fatalf("flock(%s): %s", cfg.PIDFile, err)
 136                 }
 137                 defer os.Remove(cfg.PIDFile)
 138                 err = f.Truncate(0)
 139                 if err != nil {
 140                         log.Fatalf("truncate(%s): %s", cfg.PIDFile, err)
 141                 }
 142                 _, err = fmt.Fprint(f, os.Getpid())
 143                 if err != nil {
 144                         log.Fatalf("write(%s): %s", cfg.PIDFile, err)
 145                 }
 146                 err = f.Sync()
 147                 if err != nil {
 148                         log.Fatal("sync(%s): %s", cfg.PIDFile, err)
 149                 }
 150         }
 151
 152         if cfg.DefaultReplicas > 0 {
 153                 kc.Want_replicas = cfg.DefaultReplicas
 154         }
 155
 156         listener, err = net.Listen("tcp", cfg.Listen)
 157         if err != nil {
 158                 log.Fatalf("listen(%s): %s", cfg.Listen, err)
 159         }
 160         if _, err := daemon.SdNotify(false, "READY=1"); err != nil {
 161                 log.Printf("Error notifying init daemon: %v", err)
 162         }
 163         log.Println("Listening at", listener.Addr())
 164
 165         // Shut down the server gracefully (by closing the listener)
 166         // if SIGTERM is received.
 167         term := make(chan os.Signal, 1)
 168         go func(sig <-chan os.Signal) {
 169                 s := <-sig
 170                 log.Println("caught signal:", s)
 171                 listener.Close()
 172         }(term)
 173         signal.Notify(term, syscall.SIGTERM)
 174         signal.Notify(term, syscall.SIGINT)
 175
 176         // Start serving requests.
 177         router = MakeRESTRouter(!cfg.DisableGet, !cfg.DisablePut, kc, time.Duration(cfg.Timeout), cfg.ManagementToken)
 178         http.Serve(listener, router)
 179
 180         log.Println("shutting down")
 181 }
 182
 183 type ApiTokenCache struct {
 184         tokens     map[string]int64
 185         lock       sync.Mutex
 186         expireTime int64
 187 }
 188
 189 // Cache the token and set an expire time.  If we already have an expire time
 190 // on the token, it is not updated.
 191 func (this *ApiTokenCache) RememberToken(token string) {
 192         this.lock.Lock()
 193         defer this.lock.Unlock()
 194
 195         now := time.Now().Unix()
 196         if this.tokens[token] == 0 {
 197                 this.tokens[token] = now + this.expireTime
 198         }
 199 }
 200
 201 // Check if the cached token is known and still believed to be valid.
 202 func (this *ApiTokenCache) RecallToken(token string) bool {
 203         this.lock.Lock()
 204         defer this.lock.Unlock()
 205
 206         now := time.Now().Unix()
 207         if this.tokens[token] == 0 {
 208                 // Unknown token
 209                 return false
 210         } else if now < this.tokens[token] {
 211                 // Token is known and still valid
 212                 return true
 213         } else {
 214                 // Token is expired
 215                 this.tokens[token] = 0
 216                 return false
 217         }
 218 }
 219
 220 func GetRemoteAddress(req *http.Request) string {
 221         if xff := req.Header.Get("X-Forwarded-For"); xff != "" {
 222                 return xff + "," + req.RemoteAddr
 223         }
 224         return req.RemoteAddr
 225 }
 226
 227 func CheckAuthorizationHeader(kc *keepclient.KeepClient, cache *ApiTokenCache, req *http.Request) (pass bool, tok string) {
 228         var auth string
 229         if auth = req.Header.Get("Authorization"); auth == "" {
 230                 return false, ""
 231         }
 232
 233         _, err := fmt.Sscanf(auth, "OAuth2 %s", &tok)
 234         if err != nil {
 235                 // Scanning error
 236                 return false, ""
 237         }
 238
 239         if cache.RecallToken(tok) {
 240                 // Valid in the cache, short circuit
 241                 return true, tok
 242         }
 243
 244         arv := *kc.Arvados
 245         arv.ApiToken = tok
 246         if err := arv.Call("HEAD", "users", "", "current", nil, nil); err != nil {
 247                 log.Printf("%s: CheckAuthorizationHeader error: %v", GetRemoteAddress(req), err)
 248                 return false, ""
 249         }
 250
 251         // Success!  Update cache
 252         cache.RememberToken(tok)
 253
 254         return true, tok
 255 }
 256
 257 type proxyHandler struct {
 258         http.Handler
 259         *keepclient.KeepClient
 260         *ApiTokenCache
 261         timeout   time.Duration
 262         transport *http.Transport
 263 }
 264
 265 // MakeRESTRouter returns an http.Handler that passes GET and PUT
 266 // requests to the appropriate handlers.
 267 func MakeRESTRouter(enable_get bool, enable_put bool, kc *keepclient.KeepClient, timeout time.Duration, mgmtToken string) http.Handler {
 268         rest := mux.NewRouter()
 269
 270         transport := *(http.DefaultTransport.(*http.Transport))
 271         transport.DialContext = (&net.Dialer{
 272                 Timeout:   keepclient.DefaultConnectTimeout,
 273                 KeepAlive: keepclient.DefaultKeepAlive,
 274                 DualStack: true,
 275         }).DialContext
 276         transport.TLSClientConfig = arvadosclient.MakeTLSConfig(kc.Arvados.ApiInsecure)
 277         transport.TLSHandshakeTimeout = keepclient.DefaultTLSHandshakeTimeout
 278
 279         h := &proxyHandler{
 280                 Handler:    rest,
 281                 KeepClient: kc,
 282                 timeout:    timeout,
 283                 transport:  &transport,
 284                 ApiTokenCache: &ApiTokenCache{
 285                         tokens:     make(map[string]int64),
 286                         expireTime: 300,
 287                 },
 288         }
 289
 290         if enable_get {
 291                 rest.HandleFunc(`/{locator:[0-9a-f]{32}\+.*}`, h.Get).Methods("GET", "HEAD")
 292                 rest.HandleFunc(`/{locator:[0-9a-f]{32}}`, h.Get).Methods("GET", "HEAD")
 293
 294                 // List all blocks
 295                 rest.HandleFunc(`/index`, h.Index).Methods("GET")
 296
 297                 // List blocks whose hash has the given prefix
 298                 rest.HandleFunc(`/index/{prefix:[0-9a-f]{0,32}}`, h.Index).Methods("GET")
 299         }
 300
 301         if enable_put {
 302                 rest.HandleFunc(`/{locator:[0-9a-f]{32}\+.*}`, h.Put).Methods("PUT")
 303                 rest.HandleFunc(`/{locator:[0-9a-f]{32}}`, h.Put).Methods("PUT")
 304                 rest.HandleFunc(`/`, h.Put).Methods("POST")
 305                 rest.HandleFunc(`/{any}`, h.Options).Methods("OPTIONS")
 306                 rest.HandleFunc(`/`, h.Options).Methods("OPTIONS")
 307         }
 308
 309         rest.Handle("/_health/{check}", &health.Handler{
 310                 Token:  mgmtToken,
 311                 Prefix: "/_health/",
 312         }).Methods("GET")
 313
 314         rest.NotFoundHandler = InvalidPathHandler{}
 315         return h
 316 }
 317
 318 var errLoopDetected = errors.New("loop detected")
 319
 320 func (*proxyHandler) checkLoop(resp http.ResponseWriter, req *http.Request) error {
 321         if via := req.Header.Get("Via"); strings.Index(via, " "+viaAlias) >= 0 {
 322                 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)
 323                 http.Error(resp, errLoopDetected.Error(), http.StatusInternalServerError)
 324                 return errLoopDetected
 325         }
 326         return nil
 327 }
 328
 329 func SetCorsHeaders(resp http.ResponseWriter) {
 330         resp.Header().Set("Access-Control-Allow-Methods", "GET, HEAD, POST, PUT, OPTIONS")
 331         resp.Header().Set("Access-Control-Allow-Origin", "*")
 332         resp.Header().Set("Access-Control-Allow-Headers", "Authorization, Content-Length, Content-Type, X-Keep-Desired-Replicas")
 333         resp.Header().Set("Access-Control-Max-Age", "86486400")
 334 }
 335
 336 type InvalidPathHandler struct{}
 337
 338 func (InvalidPathHandler) ServeHTTP(resp http.ResponseWriter, req *http.Request) {
 339         log.Printf("%s: %s %s unroutable", GetRemoteAddress(req), req.Method, req.URL.Path)
 340         http.Error(resp, "Bad request", http.StatusBadRequest)
 341 }
 342
 343 func (h *proxyHandler) Options(resp http.ResponseWriter, req *http.Request) {
 344         log.Printf("%s: %s %s", GetRemoteAddress(req), req.Method, req.URL.Path)
 345         SetCorsHeaders(resp)
 346 }
 347
 348 var BadAuthorizationHeader = errors.New("Missing or invalid Authorization header")
 349 var ContentLengthMismatch = errors.New("Actual length != expected content length")
 350 var MethodNotSupported = errors.New("Method not supported")
 351
 352 var removeHint, _ = regexp.Compile("\\+K@[a-z0-9]{5}(\\+|$)")
 353
 354 func (h *proxyHandler) Get(resp http.ResponseWriter, req *http.Request) {
 355         if err := h.checkLoop(resp, req); err != nil {
 356                 return
 357         }
 358         SetCorsHeaders(resp)
 359         resp.Header().Set("Via", req.Proto+" "+viaAlias)
 360
 361         locator := mux.Vars(req)["locator"]
 362         var err error
 363         var status int
 364         var expectLength, responseLength int64
 365         var proxiedURI = "-"
 366
 367         defer func() {
 368                 log.Println(GetRemoteAddress(req), req.Method, req.URL.Path, status, expectLength, responseLength, proxiedURI, err)
 369                 if status != http.StatusOK {
 370                         http.Error(resp, err.Error(), status)
 371                 }
 372         }()
 373
 374         kc := h.makeKeepClient(req)
 375
 376         var pass bool
 377         var tok string
 378         if pass, tok = CheckAuthorizationHeader(kc, h.ApiTokenCache, req); !pass {
 379                 status, err = http.StatusForbidden, BadAuthorizationHeader
 380                 return
 381         }
 382
 383         // Copy ArvadosClient struct and use the client's API token
 384         arvclient := *kc.Arvados
 385         arvclient.ApiToken = tok
 386         kc.Arvados = &arvclient
 387
 388         var reader io.ReadCloser
 389
 390         locator = removeHint.ReplaceAllString(locator, "$1")
 391
 392         switch req.Method {
 393         case "HEAD":
 394                 expectLength, proxiedURI, err = kc.Ask(locator)
 395         case "GET":
 396                 reader, expectLength, proxiedURI, err = kc.Get(locator)
 397                 if reader != nil {
 398                         defer reader.Close()
 399                 }
 400         default:
 401                 status, err = http.StatusNotImplemented, MethodNotSupported
 402                 return
 403         }
 404
 405         if expectLength == -1 {
 406                 log.Println("Warning:", GetRemoteAddress(req), req.Method, proxiedURI, "Content-Length not provided")
 407         }
 408
 409         switch respErr := err.(type) {
 410         case nil:
 411                 status = http.StatusOK
 412                 resp.Header().Set("Content-Length", fmt.Sprint(expectLength))
 413                 switch req.Method {
 414                 case "HEAD":
 415                         responseLength = 0
 416                 case "GET":
 417                         responseLength, err = io.Copy(resp, reader)
 418                         if err == nil && expectLength > -1 && responseLength != expectLength {
 419                                 err = ContentLengthMismatch
 420                         }
 421                 }
 422         case keepclient.Error:
 423                 if respErr == keepclient.BlockNotFound {
 424                         status = http.StatusNotFound
 425                 } else if respErr.Temporary() {
 426                         status = http.StatusBadGateway
 427                 } else {
 428                         status = 422
 429                 }
 430         default:
 431                 status = http.StatusInternalServerError
 432         }
 433 }
 434
 435 var LengthRequiredError = errors.New(http.StatusText(http.StatusLengthRequired))
 436 var LengthMismatchError = errors.New("Locator size hint does not match Content-Length header")
 437
 438 func (h *proxyHandler) Put(resp http.ResponseWriter, req *http.Request) {
 439         if err := h.checkLoop(resp, req); err != nil {
 440                 return
 441         }
 442         SetCorsHeaders(resp)
 443         resp.Header().Set("Via", "HTTP/1.1 "+viaAlias)
 444
 445         kc := h.makeKeepClient(req)
 446
 447         var err error
 448         var expectLength int64
 449         var status = http.StatusInternalServerError
 450         var wroteReplicas int
 451         var locatorOut string = "-"
 452
 453         defer func() {
 454                 log.Println(GetRemoteAddress(req), req.Method, req.URL.Path, status, expectLength, kc.Want_replicas, wroteReplicas, locatorOut, err)
 455                 if status != http.StatusOK {
 456                         http.Error(resp, err.Error(), status)
 457                 }
 458         }()
 459
 460         locatorIn := mux.Vars(req)["locator"]
 461
 462         _, err = fmt.Sscanf(req.Header.Get("Content-Length"), "%d", &expectLength)
 463         if err != nil || expectLength < 0 {
 464                 err = LengthRequiredError
 465                 status = http.StatusLengthRequired
 466                 return
 467         }
 468
 469         if locatorIn != "" {
 470                 var loc *keepclient.Locator
 471                 if loc, err = keepclient.MakeLocator(locatorIn); err != nil {
 472                         status = http.StatusBadRequest
 473                         return
 474                 } else if loc.Size > 0 && int64(loc.Size) != expectLength {
 475                         err = LengthMismatchError
 476                         status = http.StatusBadRequest
 477                         return
 478                 }
 479         }
 480
 481         var pass bool
 482         var tok string
 483         if pass, tok = CheckAuthorizationHeader(kc, h.ApiTokenCache, req); !pass {
 484                 err = BadAuthorizationHeader
 485                 status = http.StatusForbidden
 486                 return
 487         }
 488
 489         // Copy ArvadosClient struct and use the client's API token
 490         arvclient := *kc.Arvados
 491         arvclient.ApiToken = tok
 492         kc.Arvados = &arvclient
 493
 494         // Check if the client specified the number of replicas
 495         if req.Header.Get("X-Keep-Desired-Replicas") != "" {
 496                 var r int
 497                 _, err := fmt.Sscanf(req.Header.Get(keepclient.X_Keep_Desired_Replicas), "%d", &r)
 498                 if err == nil {
 499                         kc.Want_replicas = r
 500                 }
 501         }
 502
 503         // Now try to put the block through
 504         if locatorIn == "" {
 505                 if bytes, err := ioutil.ReadAll(req.Body); err != nil {
 506                         err = errors.New(fmt.Sprintf("Error reading request body: %s", err))
 507                         status = http.StatusInternalServerError
 508                         return
 509                 } else {
 510                         locatorOut, wroteReplicas, err = kc.PutB(bytes)
 511                 }
 512         } else {
 513                 locatorOut, wroteReplicas, err = kc.PutHR(locatorIn, req.Body, expectLength)
 514         }
 515
 516         // Tell the client how many successful PUTs we accomplished
 517         resp.Header().Set(keepclient.X_Keep_Replicas_Stored, fmt.Sprintf("%d", wroteReplicas))
 518
 519         switch err.(type) {
 520         case nil:
 521                 status = http.StatusOK
 522                 _, err = io.WriteString(resp, locatorOut)
 523
 524         case keepclient.OversizeBlockError:
 525                 // Too much data
 526                 status = http.StatusRequestEntityTooLarge
 527
 528         case keepclient.InsufficientReplicasError:
 529                 if wroteReplicas > 0 {
 530                         // At least one write is considered success.  The
 531                         // client can decide if getting less than the number of
 532                         // replications it asked for is a fatal error.
 533                         status = http.StatusOK
 534                         _, err = io.WriteString(resp, locatorOut)
 535                 } else {
 536                         status = http.StatusServiceUnavailable
 537                 }
 538
 539         default:
 540                 status = http.StatusBadGateway
 541         }
 542 }
 543
 544 // ServeHTTP implementation for IndexHandler
 545 // Supports only GET requests for /index/{prefix:[0-9a-f]{0,32}}
 546 // For each keep server found in LocalRoots:
 547 //   Invokes GetIndex using keepclient
 548 //   Expects "complete" response (terminating with blank new line)
 549 //   Aborts on any errors
 550 // Concatenates responses from all those keep servers and returns
 551 func (h *proxyHandler) Index(resp http.ResponseWriter, req *http.Request) {
 552         SetCorsHeaders(resp)
 553
 554         prefix := mux.Vars(req)["prefix"]
 555         var err error
 556         var status int
 557
 558         defer func() {
 559                 if status != http.StatusOK {
 560                         http.Error(resp, err.Error(), status)
 561                 }
 562         }()
 563
 564         kc := h.makeKeepClient(req)
 565         ok, token := CheckAuthorizationHeader(kc, h.ApiTokenCache, req)
 566         if !ok {
 567                 status, err = http.StatusForbidden, BadAuthorizationHeader
 568                 return
 569         }
 570
 571         // Copy ArvadosClient struct and use the client's API token
 572         arvclient := *kc.Arvados
 573         arvclient.ApiToken = token
 574         kc.Arvados = &arvclient
 575
 576         // Only GET method is supported
 577         if req.Method != "GET" {
 578                 status, err = http.StatusNotImplemented, MethodNotSupported
 579                 return
 580         }
 581
 582         // Get index from all LocalRoots and write to resp
 583         var reader io.Reader
 584         for uuid := range kc.LocalRoots() {
 585                 reader, err = kc.GetIndex(uuid, prefix)
 586                 if err != nil {
 587                         status = http.StatusBadGateway
 588                         return
 589                 }
 590
 591                 _, err = io.Copy(resp, reader)
 592                 if err != nil {
 593                         status = http.StatusBadGateway
 594                         return
 595                 }
 596         }
 597
 598         // Got index from all the keep servers and wrote to resp
 599         status = http.StatusOK
 600         resp.Write([]byte("\n"))
 601 }
 602
 603 func (h *proxyHandler) makeKeepClient(req *http.Request) *keepclient.KeepClient {
 604         kc := *h.KeepClient
 605         kc.HTTPClient = &proxyClient{
 606                 client: &http.Client{
 607                         Timeout:   h.timeout,
 608                         Transport: h.transport,
 609                 },
 610                 proto: req.Proto,
 611         }
 612         return &kc
 613 }