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