services/keepproxy/keepproxy.go

   1 package main
   2
   3 import (
   4         "errors"
   5         "flag"
   6         "fmt"
   7         "io"
   8         "io/ioutil"
   9         "log"
  10         "net"
  11         "net/http"
  12         "os"
  13         "os/signal"
  14         "regexp"
  15         "strings"
  16         "sync"
  17         "syscall"
  18         "time"
  19
  20         "git.curoverse.com/arvados.git/sdk/go/arvados"
  21         "git.curoverse.com/arvados.git/sdk/go/arvadosclient"
  22         "git.curoverse.com/arvados.git/sdk/go/config"
  23         "git.curoverse.com/arvados.git/sdk/go/keepclient"
  24         "github.com/coreos/go-systemd/daemon"
  25         "github.com/ghodss/yaml"
  26         "github.com/gorilla/mux"
  27 )
  28
  29 type Config struct {
  30         Client          arvados.Client
  31         Listen          string
  32         DisableGet      bool
  33         DisablePut      bool
  34         DefaultReplicas int
  35         Timeout         arvados.Duration
  36         PIDFile         string
  37         Debug           bool
  38 }
  39
  40 func DefaultConfig() *Config {
  41         return &Config{
  42                 Listen:  ":25107",
  43                 Timeout: arvados.Duration(15 * time.Second),
  44         }
  45 }
  46
  47 var (
  48         listener net.Listener
  49         router   http.Handler
  50 )
  51
  52 func main() {
  53         cfg := DefaultConfig()
  54
  55         flagset := flag.NewFlagSet("keepproxy", flag.ExitOnError)
  56         flagset.Usage = usage
  57
  58         const deprecated = " (DEPRECATED -- use config file instead)"
  59         flagset.StringVar(&cfg.Listen, "listen", cfg.Listen, "Local port to listen on."+deprecated)
  60         flagset.BoolVar(&cfg.DisableGet, "no-get", cfg.DisableGet, "Disable GET operations."+deprecated)
  61         flagset.BoolVar(&cfg.DisablePut, "no-put", cfg.DisablePut, "Disable PUT operations."+deprecated)
  62         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)
  63         flagset.StringVar(&cfg.PIDFile, "pid", cfg.PIDFile, "Path to write pid file."+deprecated)
  64         timeoutSeconds := flagset.Int("timeout", int(time.Duration(cfg.Timeout)/time.Second), "Timeout (in seconds) on requests to internal Keep services."+deprecated)
  65
  66         var cfgPath string
  67         const defaultCfgPath = "/etc/arvados/keepproxy/keepproxy.yml"
  68         flagset.StringVar(&cfgPath, "config", defaultCfgPath, "Configuration file `path`")
  69         dumpConfig := flagset.Bool("dump-config", false, "write current configuration to stdout and exit")
  70         flagset.Parse(os.Args[1:])
  71
  72         err := config.LoadFile(cfg, cfgPath)
  73         if err != nil {
  74                 h := os.Getenv("ARVADOS_API_HOST")
  75                 t := os.Getenv("ARVADOS_API_TOKEN")
  76                 if h == "" || t == "" || !os.IsNotExist(err) || cfgPath != defaultCfgPath {
  77                         log.Fatal(err)
  78                 }
  79                 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.")
  80                 cfg.Client.APIHost = h
  81                 cfg.Client.AuthToken = t
  82                 if regexp.MustCompile("^(?i:1|yes|true)$").MatchString(os.Getenv("ARVADOS_API_HOST_INSECURE")) {
  83                         cfg.Client.Insecure = true
  84                 }
  85                 if y, err := yaml.Marshal(cfg); err == nil && !*dumpConfig {
  86                         log.Print("Current configuration:\n", string(y))
  87                 }
  88                 cfg.Timeout = arvados.Duration(time.Duration(*timeoutSeconds) * time.Second)
  89         }
  90
  91         if *dumpConfig {
  92                 log.Fatal(config.DumpAndExit(cfg))
  93         }
  94
  95         arv, err := arvadosclient.New(&cfg.Client)
  96         if err != nil {
  97                 log.Fatalf("Error setting up arvados client %s", err.Error())
  98         }
  99
 100         if cfg.Debug {
 101                 keepclient.DebugPrintf = log.Printf
 102         }
 103         kc, err := keepclient.MakeKeepClient(arv)
 104         if err != nil {
 105                 log.Fatalf("Error setting up keep client %s", err.Error())
 106         }
 107
 108         if cfg.PIDFile != "" {
 109                 f, err := os.Create(cfg.PIDFile)
 110                 if err != nil {
 111                         log.Fatal(err)
 112                 }
 113                 defer f.Close()
 114                 err = syscall.Flock(int(f.Fd()), syscall.LOCK_EX|syscall.LOCK_NB)
 115                 if err != nil {
 116                         log.Fatalf("flock(%s): %s", cfg.PIDFile, err)
 117                 }
 118                 defer os.Remove(cfg.PIDFile)
 119                 err = f.Truncate(0)
 120                 if err != nil {
 121                         log.Fatalf("truncate(%s): %s", cfg.PIDFile, err)
 122                 }
 123                 _, err = fmt.Fprint(f, os.Getpid())
 124                 if err != nil {
 125                         log.Fatalf("write(%s): %s", cfg.PIDFile, err)
 126                 }
 127                 err = f.Sync()
 128                 if err != nil {
 129                         log.Fatal("sync(%s): %s", cfg.PIDFile, err)
 130                 }
 131         }
 132
 133         if cfg.DefaultReplicas > 0 {
 134                 kc.Want_replicas = cfg.DefaultReplicas
 135         }
 136
 137         listener, err = net.Listen("tcp", cfg.Listen)
 138         if err != nil {
 139                 log.Fatalf("listen(%s): %s", cfg.Listen, err)
 140         }
 141         if _, err := daemon.SdNotify(false, "READY=1"); err != nil {
 142                 log.Printf("Error notifying init daemon: %v", err)
 143         }
 144         log.Println("Listening at", listener.Addr())
 145
 146         // Shut down the server gracefully (by closing the listener)
 147         // if SIGTERM is received.
 148         term := make(chan os.Signal, 1)
 149         go func(sig <-chan os.Signal) {
 150                 s := <-sig
 151                 log.Println("caught signal:", s)
 152                 listener.Close()
 153         }(term)
 154         signal.Notify(term, syscall.SIGTERM)
 155         signal.Notify(term, syscall.SIGINT)
 156
 157         // Start serving requests.
 158         router = MakeRESTRouter(!cfg.DisableGet, !cfg.DisablePut, kc, time.Duration(cfg.Timeout))
 159         http.Serve(listener, router)
 160
 161         log.Println("shutting down")
 162 }
 163
 164 type ApiTokenCache struct {
 165         tokens     map[string]int64
 166         lock       sync.Mutex
 167         expireTime int64
 168 }
 169
 170 // Cache the token and set an expire time.  If we already have an expire time
 171 // on the token, it is not updated.
 172 func (this *ApiTokenCache) RememberToken(token string) {
 173         this.lock.Lock()
 174         defer this.lock.Unlock()
 175
 176         now := time.Now().Unix()
 177         if this.tokens[token] == 0 {
 178                 this.tokens[token] = now + this.expireTime
 179         }
 180 }
 181
 182 // Check if the cached token is known and still believed to be valid.
 183 func (this *ApiTokenCache) RecallToken(token string) bool {
 184         this.lock.Lock()
 185         defer this.lock.Unlock()
 186
 187         now := time.Now().Unix()
 188         if this.tokens[token] == 0 {
 189                 // Unknown token
 190                 return false
 191         } else if now < this.tokens[token] {
 192                 // Token is known and still valid
 193                 return true
 194         } else {
 195                 // Token is expired
 196                 this.tokens[token] = 0
 197                 return false
 198         }
 199 }
 200
 201 func GetRemoteAddress(req *http.Request) string {
 202         if xff := req.Header.Get("X-Forwarded-For"); xff != "" {
 203                 return xff + "," + req.RemoteAddr
 204         }
 205         return req.RemoteAddr
 206 }
 207
 208 func CheckAuthorizationHeader(kc *keepclient.KeepClient, cache *ApiTokenCache, req *http.Request) (pass bool, tok string) {
 209         var auth string
 210         if auth = req.Header.Get("Authorization"); auth == "" {
 211                 return false, ""
 212         }
 213
 214         _, err := fmt.Sscanf(auth, "OAuth2 %s", &tok)
 215         if err != nil {
 216                 // Scanning error
 217                 return false, ""
 218         }
 219
 220         if cache.RecallToken(tok) {
 221                 // Valid in the cache, short circuit
 222                 return true, tok
 223         }
 224
 225         arv := *kc.Arvados
 226         arv.ApiToken = tok
 227         if err := arv.Call("HEAD", "users", "", "current", nil, nil); err != nil {
 228                 log.Printf("%s: CheckAuthorizationHeader error: %v", GetRemoteAddress(req), err)
 229                 return false, ""
 230         }
 231
 232         // Success!  Update cache
 233         cache.RememberToken(tok)
 234
 235         return true, tok
 236 }
 237
 238 type proxyHandler struct {
 239         http.Handler
 240         *keepclient.KeepClient
 241         *ApiTokenCache
 242         timeout   time.Duration
 243         transport *http.Transport
 244 }
 245
 246 // MakeRESTRouter returns an http.Handler that passes GET and PUT
 247 // requests to the appropriate handlers.
 248 func MakeRESTRouter(enable_get bool, enable_put bool, kc *keepclient.KeepClient, timeout time.Duration) http.Handler {
 249         rest := mux.NewRouter()
 250
 251         transport := *(http.DefaultTransport.(*http.Transport))
 252         transport.DialContext = (&net.Dialer{
 253                 Timeout:   keepclient.DefaultConnectTimeout,
 254                 KeepAlive: keepclient.DefaultKeepAlive,
 255                 DualStack: true,
 256         }).DialContext
 257         transport.TLSClientConfig = arvadosclient.MakeTLSConfig(kc.Arvados.ApiInsecure)
 258         transport.TLSHandshakeTimeout = keepclient.DefaultTLSHandshakeTimeout
 259
 260         h := &proxyHandler{
 261                 Handler:    rest,
 262                 KeepClient: kc,
 263                 timeout:    timeout,
 264                 transport:  &transport,
 265                 ApiTokenCache: &ApiTokenCache{
 266                         tokens:     make(map[string]int64),
 267                         expireTime: 300,
 268                 },
 269         }
 270
 271         if enable_get {
 272                 rest.HandleFunc(`/{locator:[0-9a-f]{32}\+.*}`, h.Get).Methods("GET", "HEAD")
 273                 rest.HandleFunc(`/{locator:[0-9a-f]{32}}`, h.Get).Methods("GET", "HEAD")
 274
 275                 // List all blocks
 276                 rest.HandleFunc(`/index`, h.Index).Methods("GET")
 277
 278                 // List blocks whose hash has the given prefix
 279                 rest.HandleFunc(`/index/{prefix:[0-9a-f]{0,32}}`, h.Index).Methods("GET")
 280         }
 281
 282         if enable_put {
 283                 rest.HandleFunc(`/{locator:[0-9a-f]{32}\+.*}`, h.Put).Methods("PUT")
 284                 rest.HandleFunc(`/{locator:[0-9a-f]{32}}`, h.Put).Methods("PUT")
 285                 rest.HandleFunc(`/`, h.Put).Methods("POST")
 286                 rest.HandleFunc(`/{any}`, h.Options).Methods("OPTIONS")
 287                 rest.HandleFunc(`/`, h.Options).Methods("OPTIONS")
 288         }
 289
 290         rest.NotFoundHandler = InvalidPathHandler{}
 291         return h
 292 }
 293
 294 var errLoopDetected = errors.New("loop detected")
 295
 296 func (*proxyHandler) checkLoop(resp http.ResponseWriter, req *http.Request) error {
 297         if via := req.Header.Get("Via"); strings.Index(via, " "+viaAlias) >= 0 {
 298                 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)
 299                 http.Error(resp, errLoopDetected.Error(), http.StatusInternalServerError)
 300                 return errLoopDetected
 301         }
 302         return nil
 303 }
 304
 305 func SetCorsHeaders(resp http.ResponseWriter) {
 306         resp.Header().Set("Access-Control-Allow-Methods", "GET, HEAD, POST, PUT, OPTIONS")
 307         resp.Header().Set("Access-Control-Allow-Origin", "*")
 308         resp.Header().Set("Access-Control-Allow-Headers", "Authorization, Content-Length, Content-Type, X-Keep-Desired-Replicas")
 309         resp.Header().Set("Access-Control-Max-Age", "86486400")
 310 }
 311
 312 type InvalidPathHandler struct{}
 313
 314 func (InvalidPathHandler) ServeHTTP(resp http.ResponseWriter, req *http.Request) {
 315         log.Printf("%s: %s %s unroutable", GetRemoteAddress(req), req.Method, req.URL.Path)
 316         http.Error(resp, "Bad request", http.StatusBadRequest)
 317 }
 318
 319 func (h *proxyHandler) Options(resp http.ResponseWriter, req *http.Request) {
 320         log.Printf("%s: %s %s", GetRemoteAddress(req), req.Method, req.URL.Path)
 321         SetCorsHeaders(resp)
 322 }
 323
 324 var BadAuthorizationHeader = errors.New("Missing or invalid Authorization header")
 325 var ContentLengthMismatch = errors.New("Actual length != expected content length")
 326 var MethodNotSupported = errors.New("Method not supported")
 327
 328 var removeHint, _ = regexp.Compile("\\+K@[a-z0-9]{5}(\\+|$)")
 329
 330 func (h *proxyHandler) Get(resp http.ResponseWriter, req *http.Request) {
 331         if err := h.checkLoop(resp, req); err != nil {
 332                 return
 333         }
 334         SetCorsHeaders(resp)
 335         resp.Header().Set("Via", req.Proto+" "+viaAlias)
 336
 337         locator := mux.Vars(req)["locator"]
 338         var err error
 339         var status int
 340         var expectLength, responseLength int64
 341         var proxiedURI = "-"
 342
 343         defer func() {
 344                 log.Println(GetRemoteAddress(req), req.Method, req.URL.Path, status, expectLength, responseLength, proxiedURI, err)
 345                 if status != http.StatusOK {
 346                         http.Error(resp, err.Error(), status)
 347                 }
 348         }()
 349
 350         kc := h.makeKeepClient(req)
 351
 352         var pass bool
 353         var tok string
 354         if pass, tok = CheckAuthorizationHeader(kc, h.ApiTokenCache, req); !pass {
 355                 status, err = http.StatusForbidden, BadAuthorizationHeader
 356                 return
 357         }
 358
 359         // Copy ArvadosClient struct and use the client's API token
 360         arvclient := *kc.Arvados
 361         arvclient.ApiToken = tok
 362         kc.Arvados = &arvclient
 363
 364         var reader io.ReadCloser
 365
 366         locator = removeHint.ReplaceAllString(locator, "$1")
 367
 368         switch req.Method {
 369         case "HEAD":
 370                 expectLength, proxiedURI, err = kc.Ask(locator)
 371         case "GET":
 372                 reader, expectLength, proxiedURI, err = kc.Get(locator)
 373                 if reader != nil {
 374                         defer reader.Close()
 375                 }
 376         default:
 377                 status, err = http.StatusNotImplemented, MethodNotSupported
 378                 return
 379         }
 380
 381         if expectLength == -1 {
 382                 log.Println("Warning:", GetRemoteAddress(req), req.Method, proxiedURI, "Content-Length not provided")
 383         }
 384
 385         switch respErr := err.(type) {
 386         case nil:
 387                 status = http.StatusOK
 388                 resp.Header().Set("Content-Length", fmt.Sprint(expectLength))
 389                 switch req.Method {
 390                 case "HEAD":
 391                         responseLength = 0
 392                 case "GET":
 393                         responseLength, err = io.Copy(resp, reader)
 394                         if err == nil && expectLength > -1 && responseLength != expectLength {
 395                                 err = ContentLengthMismatch
 396                         }
 397                 }
 398         case keepclient.Error:
 399                 if respErr == keepclient.BlockNotFound {
 400                         status = http.StatusNotFound
 401                 } else if respErr.Temporary() {
 402                         status = http.StatusBadGateway
 403                 } else {
 404                         status = 422
 405                 }
 406         default:
 407                 status = http.StatusInternalServerError
 408         }
 409 }
 410
 411 var LengthRequiredError = errors.New(http.StatusText(http.StatusLengthRequired))
 412 var LengthMismatchError = errors.New("Locator size hint does not match Content-Length header")
 413
 414 func (h *proxyHandler) Put(resp http.ResponseWriter, req *http.Request) {
 415         if err := h.checkLoop(resp, req); err != nil {
 416                 return
 417         }
 418         SetCorsHeaders(resp)
 419         resp.Header().Set("Via", "HTTP/1.1 "+viaAlias)
 420
 421         kc := h.makeKeepClient(req)
 422
 423         var err error
 424         var expectLength int64
 425         var status = http.StatusInternalServerError
 426         var wroteReplicas int
 427         var locatorOut string = "-"
 428
 429         defer func() {
 430                 log.Println(GetRemoteAddress(req), req.Method, req.URL.Path, status, expectLength, kc.Want_replicas, wroteReplicas, locatorOut, err)
 431                 if status != http.StatusOK {
 432                         http.Error(resp, err.Error(), status)
 433                 }
 434         }()
 435
 436         locatorIn := mux.Vars(req)["locator"]
 437
 438         _, err = fmt.Sscanf(req.Header.Get("Content-Length"), "%d", &expectLength)
 439         if err != nil || expectLength < 0 {
 440                 err = LengthRequiredError
 441                 status = http.StatusLengthRequired
 442                 return
 443         }
 444
 445         if locatorIn != "" {
 446                 var loc *keepclient.Locator
 447                 if loc, err = keepclient.MakeLocator(locatorIn); err != nil {
 448                         status = http.StatusBadRequest
 449                         return
 450                 } else if loc.Size > 0 && int64(loc.Size) != expectLength {
 451                         err = LengthMismatchError
 452                         status = http.StatusBadRequest
 453                         return
 454                 }
 455         }
 456
 457         var pass bool
 458         var tok string
 459         if pass, tok = CheckAuthorizationHeader(kc, h.ApiTokenCache, req); !pass {
 460                 err = BadAuthorizationHeader
 461                 status = http.StatusForbidden
 462                 return
 463         }
 464
 465         // Copy ArvadosClient struct and use the client's API token
 466         arvclient := *kc.Arvados
 467         arvclient.ApiToken = tok
 468         kc.Arvados = &arvclient
 469
 470         // Check if the client specified the number of replicas
 471         if req.Header.Get("X-Keep-Desired-Replicas") != "" {
 472                 var r int
 473                 _, err := fmt.Sscanf(req.Header.Get(keepclient.X_Keep_Desired_Replicas), "%d", &r)
 474                 if err == nil {
 475                         kc.Want_replicas = r
 476                 }
 477         }
 478
 479         // Now try to put the block through
 480         if locatorIn == "" {
 481                 if bytes, err := ioutil.ReadAll(req.Body); err != nil {
 482                         err = errors.New(fmt.Sprintf("Error reading request body: %s", err))
 483                         status = http.StatusInternalServerError
 484                         return
 485                 } else {
 486                         locatorOut, wroteReplicas, err = kc.PutB(bytes)
 487                 }
 488         } else {
 489                 locatorOut, wroteReplicas, err = kc.PutHR(locatorIn, req.Body, expectLength)
 490         }
 491
 492         // Tell the client how many successful PUTs we accomplished
 493         resp.Header().Set(keepclient.X_Keep_Replicas_Stored, fmt.Sprintf("%d", wroteReplicas))
 494
 495         switch err.(type) {
 496         case nil:
 497                 status = http.StatusOK
 498                 _, err = io.WriteString(resp, locatorOut)
 499
 500         case keepclient.OversizeBlockError:
 501                 // Too much data
 502                 status = http.StatusRequestEntityTooLarge
 503
 504         case keepclient.InsufficientReplicasError:
 505                 if wroteReplicas > 0 {
 506                         // At least one write is considered success.  The
 507                         // client can decide if getting less than the number of
 508                         // replications it asked for is a fatal error.
 509                         status = http.StatusOK
 510                         _, err = io.WriteString(resp, locatorOut)
 511                 } else {
 512                         status = http.StatusServiceUnavailable
 513                 }
 514
 515         default:
 516                 status = http.StatusBadGateway
 517         }
 518 }
 519
 520 // ServeHTTP implementation for IndexHandler
 521 // Supports only GET requests for /index/{prefix:[0-9a-f]{0,32}}
 522 // For each keep server found in LocalRoots:
 523 //   Invokes GetIndex using keepclient
 524 //   Expects "complete" response (terminating with blank new line)
 525 //   Aborts on any errors
 526 // Concatenates responses from all those keep servers and returns
 527 func (h *proxyHandler) Index(resp http.ResponseWriter, req *http.Request) {
 528         SetCorsHeaders(resp)
 529
 530         prefix := mux.Vars(req)["prefix"]
 531         var err error
 532         var status int
 533
 534         defer func() {
 535                 if status != http.StatusOK {
 536                         http.Error(resp, err.Error(), status)
 537                 }
 538         }()
 539
 540         kc := h.makeKeepClient(req)
 541         ok, token := CheckAuthorizationHeader(kc, h.ApiTokenCache, req)
 542         if !ok {
 543                 status, err = http.StatusForbidden, BadAuthorizationHeader
 544                 return
 545         }
 546
 547         // Copy ArvadosClient struct and use the client's API token
 548         arvclient := *kc.Arvados
 549         arvclient.ApiToken = token
 550         kc.Arvados = &arvclient
 551
 552         // Only GET method is supported
 553         if req.Method != "GET" {
 554                 status, err = http.StatusNotImplemented, MethodNotSupported
 555                 return
 556         }
 557
 558         // Get index from all LocalRoots and write to resp
 559         var reader io.Reader
 560         for uuid := range kc.LocalRoots() {
 561                 reader, err = kc.GetIndex(uuid, prefix)
 562                 if err != nil {
 563                         status = http.StatusBadGateway
 564                         return
 565                 }
 566
 567                 _, err = io.Copy(resp, reader)
 568                 if err != nil {
 569                         status = http.StatusBadGateway
 570                         return
 571                 }
 572         }
 573
 574         // Got index from all the keep servers and wrote to resp
 575         status = http.StatusOK
 576         resp.Write([]byte("\n"))
 577 }
 578
 579 func (h *proxyHandler) makeKeepClient(req *http.Request) *keepclient.KeepClient {
 580         kc := *h.KeepClient
 581         kc.HTTPClient = &proxyClient{
 582                 client: &http.Client{
 583                         Timeout:   h.timeout,
 584                         Transport: h.transport,
 585                 },
 586                 proto: req.Proto,
 587         }
 588         return &kc
 589 }