services/keepproxy/keepproxy.go

   1 // Copyright (C) The Arvados Authors. All rights reserved.
   2 //
   3 // SPDX-License-Identifier: AGPL-3.0
   4
   5 package keepproxy
   6
   7 import (
   8         "context"
   9         "errors"
  10         "fmt"
  11         "io"
  12         "io/ioutil"
  13         "net"
  14         "net/http"
  15         "regexp"
  16         "strings"
  17         "time"
  18
  19         "git.arvados.org/arvados.git/lib/service"
  20         "git.arvados.org/arvados.git/sdk/go/arvados"
  21         "git.arvados.org/arvados.git/sdk/go/arvadosclient"
  22         "git.arvados.org/arvados.git/sdk/go/ctxlog"
  23         "git.arvados.org/arvados.git/sdk/go/health"
  24         "git.arvados.org/arvados.git/sdk/go/httpserver"
  25         "git.arvados.org/arvados.git/sdk/go/keepclient"
  26         "github.com/gorilla/mux"
  27         lru "github.com/hashicorp/golang-lru"
  28         "github.com/prometheus/client_golang/prometheus"
  29         "github.com/sirupsen/logrus"
  30 )
  31
  32 const rfc3339NanoFixed = "2006-01-02T15:04:05.000000000Z07:00"
  33
  34 var Command = service.Command(arvados.ServiceNameKeepproxy, newHandlerOrErrorHandler)
  35
  36 func newHandlerOrErrorHandler(ctx context.Context, cluster *arvados.Cluster, token string, reg *prometheus.Registry) service.Handler {
  37         client, err := arvados.NewClientFromConfig(cluster)
  38         if err != nil {
  39                 return service.ErrorHandler(ctx, cluster, fmt.Errorf("Error setting up arvados client: %w", err))
  40         }
  41         arv, err := arvadosclient.New(client)
  42         if err != nil {
  43                 return service.ErrorHandler(ctx, cluster, fmt.Errorf("Error setting up arvados client: %w", err))
  44         }
  45         kc, err := keepclient.MakeKeepClient(arv)
  46         if err != nil {
  47                 return service.ErrorHandler(ctx, cluster, fmt.Errorf("Error setting up keep client: %w", err))
  48         }
  49         keepclient.RefreshServiceDiscoveryOnSIGHUP()
  50         router, err := newHandler(ctx, kc, time.Duration(keepclient.DefaultProxyRequestTimeout), cluster)
  51         if err != nil {
  52                 return service.ErrorHandler(ctx, cluster, err)
  53         }
  54         return router
  55 }
  56
  57 type tokenCacheEntry struct {
  58         expire int64
  59         user   *arvados.User
  60 }
  61
  62 type apiTokenCache struct {
  63         tokens     *lru.TwoQueueCache
  64         expireTime int64
  65 }
  66
  67 // RememberToken caches the token and set an expire time.  If the
  68 // token is already in the cache, it is not updated.
  69 func (cache *apiTokenCache) RememberToken(token string, user *arvados.User) {
  70         now := time.Now().Unix()
  71         _, ok := cache.tokens.Get(token)
  72         if !ok {
  73                 cache.tokens.Add(token, tokenCacheEntry{
  74                         expire: now + cache.expireTime,
  75                         user:   user,
  76                 })
  77         }
  78 }
  79
  80 // RecallToken checks if the cached token is known and still believed to be
  81 // valid.
  82 func (cache *apiTokenCache) RecallToken(token string) (bool, *arvados.User) {
  83         val, ok := cache.tokens.Get(token)
  84         if !ok {
  85                 return false, nil
  86         }
  87
  88         cacheEntry := val.(tokenCacheEntry)
  89         now := time.Now().Unix()
  90         if now < cacheEntry.expire {
  91                 // Token is known and still valid
  92                 return true, cacheEntry.user
  93         } else {
  94                 // Token is expired
  95                 cache.tokens.Remove(token)
  96                 return false, nil
  97         }
  98 }
  99
 100 func (h *proxyHandler) Done() <-chan struct{} {
 101         return nil
 102 }
 103
 104 func (h *proxyHandler) CheckHealth() error {
 105         return nil
 106 }
 107
 108 func (h *proxyHandler) checkAuthorizationHeader(req *http.Request) (pass bool, tok string, user *arvados.User) {
 109         parts := strings.SplitN(req.Header.Get("Authorization"), " ", 2)
 110         if len(parts) < 2 || !(parts[0] == "OAuth2" || parts[0] == "Bearer") || len(parts[1]) == 0 {
 111                 return false, "", nil
 112         }
 113         tok = parts[1]
 114
 115         // Tokens are validated differently depending on what kind of
 116         // operation is being performed. For example, tokens in
 117         // collection-sharing links permit GET requests, but not
 118         // PUT requests.
 119         var op string
 120         if req.Method == "GET" || req.Method == "HEAD" {
 121                 op = "read"
 122         } else {
 123                 op = "write"
 124         }
 125
 126         if ok, user := h.apiTokenCache.RecallToken(op + ":" + tok); ok {
 127                 // Valid in the cache, short circuit
 128                 return true, tok, user
 129         }
 130
 131         var err error
 132         arv := *h.KeepClient.Arvados
 133         arv.ApiToken = tok
 134         arv.RequestID = req.Header.Get("X-Request-Id")
 135         user = &arvados.User{}
 136         userCurrentError := arv.Call("GET", "users", "", "current", nil, user)
 137         err = userCurrentError
 138         if err != nil && op == "read" {
 139                 apiError, ok := err.(arvadosclient.APIServerError)
 140                 if ok && apiError.HttpStatusCode == http.StatusForbidden {
 141                         // If it was a scoped "sharing" token it will
 142                         // return 403 instead of 401 for the current
 143                         // user check.  If it is a download operation
 144                         // and they have permission to read the
 145                         // keep_services table, we can allow it.
 146                         err = arv.Call("HEAD", "keep_services", "", "accessible", nil, nil)
 147                 }
 148         }
 149         if err != nil {
 150                 ctxlog.FromContext(req.Context()).WithError(err).Info("checkAuthorizationHeader error")
 151                 return false, "", nil
 152         }
 153
 154         if userCurrentError == nil && user.IsAdmin {
 155                 // checking userCurrentError is probably redundant,
 156                 // IsAdmin would be false anyway. But can't hurt.
 157                 if op == "read" && !h.cluster.Collections.KeepproxyPermission.Admin.Download {
 158                         return false, "", nil
 159                 }
 160                 if op == "write" && !h.cluster.Collections.KeepproxyPermission.Admin.Upload {
 161                         return false, "", nil
 162                 }
 163         } else {
 164                 if op == "read" && !h.cluster.Collections.KeepproxyPermission.User.Download {
 165                         return false, "", nil
 166                 }
 167                 if op == "write" && !h.cluster.Collections.KeepproxyPermission.User.Upload {
 168                         return false, "", nil
 169                 }
 170         }
 171
 172         // Success!  Update cache
 173         h.apiTokenCache.RememberToken(op+":"+tok, user)
 174
 175         return true, tok, user
 176 }
 177
 178 // We need to make a private copy of the default http transport early
 179 // in initialization, then make copies of our private copy later. It
 180 // won't be safe to copy http.DefaultTransport itself later, because
 181 // its private mutexes might have already been used. (Without this,
 182 // the test suite sometimes panics "concurrent map writes" in
 183 // net/http.(*Transport).removeIdleConnLocked().)
 184 var defaultTransport = *(http.DefaultTransport.(*http.Transport))
 185
 186 type proxyHandler struct {
 187         http.Handler
 188         *keepclient.KeepClient
 189         *apiTokenCache
 190         timeout   time.Duration
 191         transport *http.Transport
 192         cluster   *arvados.Cluster
 193 }
 194
 195 func newHandler(ctx context.Context, kc *keepclient.KeepClient, timeout time.Duration, cluster *arvados.Cluster) (service.Handler, error) {
 196         rest := mux.NewRouter()
 197
 198         transport := defaultTransport
 199         transport.DialContext = (&net.Dialer{
 200                 Timeout:   keepclient.DefaultConnectTimeout,
 201                 KeepAlive: keepclient.DefaultKeepAlive,
 202                 DualStack: true,
 203         }).DialContext
 204         transport.TLSClientConfig = arvadosclient.MakeTLSConfig(kc.Arvados.ApiInsecure)
 205         transport.TLSHandshakeTimeout = keepclient.DefaultTLSHandshakeTimeout
 206
 207         cacheQ, err := lru.New2Q(500)
 208         if err != nil {
 209                 return nil, fmt.Errorf("Error from lru.New2Q: %v", err)
 210         }
 211
 212         h := &proxyHandler{
 213                 Handler:    rest,
 214                 KeepClient: kc,
 215                 timeout:    timeout,
 216                 transport:  &transport,
 217                 apiTokenCache: &apiTokenCache{
 218                         tokens:     cacheQ,
 219                         expireTime: 300,
 220                 },
 221                 cluster: cluster,
 222         }
 223
 224         rest.HandleFunc(`/{locator:[0-9a-f]{32}\+.*}`, h.Get).Methods("GET", "HEAD")
 225         rest.HandleFunc(`/{locator:[0-9a-f]{32}}`, h.Get).Methods("GET", "HEAD")
 226
 227         // List all blocks
 228         rest.HandleFunc(`/index`, h.Index).Methods("GET")
 229
 230         // List blocks whose hash has the given prefix
 231         rest.HandleFunc(`/index/{prefix:[0-9a-f]{0,32}}`, h.Index).Methods("GET")
 232
 233         rest.HandleFunc(`/{locator:[0-9a-f]{32}\+.*}`, h.Put).Methods("PUT")
 234         rest.HandleFunc(`/{locator:[0-9a-f]{32}}`, h.Put).Methods("PUT")
 235         rest.HandleFunc(`/`, h.Put).Methods("POST")
 236         rest.HandleFunc(`/{any}`, h.Options).Methods("OPTIONS")
 237         rest.HandleFunc(`/`, h.Options).Methods("OPTIONS")
 238
 239         rest.Handle("/_health/{check}", &health.Handler{
 240                 Token:  cluster.ManagementToken,
 241                 Prefix: "/_health/",
 242         }).Methods("GET")
 243
 244         rest.NotFoundHandler = invalidPathHandler{}
 245         return h, nil
 246 }
 247
 248 var errLoopDetected = errors.New("loop detected")
 249
 250 func (h *proxyHandler) checkLoop(resp http.ResponseWriter, req *http.Request) error {
 251         if via := req.Header.Get("Via"); strings.Index(via, " "+viaAlias) >= 0 {
 252                 ctxlog.FromContext(req.Context()).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)
 253                 http.Error(resp, errLoopDetected.Error(), http.StatusInternalServerError)
 254                 return errLoopDetected
 255         }
 256         return nil
 257 }
 258
 259 func setCORSHeaders(resp http.ResponseWriter) {
 260         resp.Header().Set("Access-Control-Allow-Methods", "GET, HEAD, POST, PUT, OPTIONS")
 261         resp.Header().Set("Access-Control-Allow-Origin", "*")
 262         resp.Header().Set("Access-Control-Allow-Headers", "Authorization, Content-Length, Content-Type, X-Keep-Desired-Replicas")
 263         resp.Header().Set("Access-Control-Max-Age", "86486400")
 264 }
 265
 266 type invalidPathHandler struct{}
 267
 268 func (invalidPathHandler) ServeHTTP(resp http.ResponseWriter, req *http.Request) {
 269         http.Error(resp, "Bad request", http.StatusBadRequest)
 270 }
 271
 272 func (h *proxyHandler) Options(resp http.ResponseWriter, req *http.Request) {
 273         setCORSHeaders(resp)
 274 }
 275
 276 var errBadAuthorizationHeader = errors.New("Missing or invalid Authorization header, or method not allowed")
 277 var errContentLengthMismatch = errors.New("Actual length != expected content length")
 278 var errMethodNotSupported = errors.New("Method not supported")
 279
 280 var removeHint, _ = regexp.Compile("\\+K@[a-z0-9]{5}(\\+|$)")
 281
 282 func (h *proxyHandler) Get(resp http.ResponseWriter, req *http.Request) {
 283         if err := h.checkLoop(resp, req); err != nil {
 284                 return
 285         }
 286         setCORSHeaders(resp)
 287         resp.Header().Set("Via", req.Proto+" "+viaAlias)
 288
 289         locator := mux.Vars(req)["locator"]
 290         var err error
 291         var status int
 292         var expectLength, responseLength int64
 293         var proxiedURI = "-"
 294
 295         logger := ctxlog.FromContext(req.Context())
 296         defer func() {
 297                 httpserver.SetResponseLogFields(req.Context(), logrus.Fields{
 298                         "locator":        locator,
 299                         "expectLength":   expectLength,
 300                         "responseLength": responseLength,
 301                         "proxiedURI":     proxiedURI,
 302                         "err":            err,
 303                 })
 304                 if status != http.StatusOK {
 305                         http.Error(resp, err.Error(), status)
 306                 }
 307         }()
 308
 309         kc := h.makeKeepClient(req)
 310
 311         var pass bool
 312         var tok string
 313         var user *arvados.User
 314         if pass, tok, user = h.checkAuthorizationHeader(req); !pass {
 315                 status, err = http.StatusForbidden, errBadAuthorizationHeader
 316                 return
 317         }
 318         httpserver.SetResponseLogFields(req.Context(), logrus.Fields{
 319                 "userUUID":     user.UUID,
 320                 "userFullName": user.FullName,
 321         })
 322
 323         // Copy ArvadosClient struct and use the client's API token
 324         arvclient := *kc.Arvados
 325         arvclient.ApiToken = tok
 326         kc.Arvados = &arvclient
 327
 328         var reader io.ReadCloser
 329
 330         locator = removeHint.ReplaceAllString(locator, "$1")
 331
 332         switch req.Method {
 333         case "HEAD":
 334                 expectLength, proxiedURI, err = kc.Ask(locator)
 335         case "GET":
 336                 reader, expectLength, proxiedURI, err = kc.Get(locator)
 337                 if reader != nil {
 338                         defer reader.Close()
 339                 }
 340         default:
 341                 status, err = http.StatusNotImplemented, errMethodNotSupported
 342                 return
 343         }
 344
 345         if expectLength == -1 {
 346                 logger.Warn("Content-Length not provided")
 347         }
 348
 349         switch respErr := err.(type) {
 350         case nil:
 351                 status = http.StatusOK
 352                 resp.Header().Set("Content-Length", fmt.Sprint(expectLength))
 353                 switch req.Method {
 354                 case "HEAD":
 355                         responseLength = 0
 356                 case "GET":
 357                         responseLength, err = io.Copy(resp, reader)
 358                         if err == nil && expectLength > -1 && responseLength != expectLength {
 359                                 err = errContentLengthMismatch
 360                         }
 361                 }
 362         case keepclient.Error:
 363                 if respErr == keepclient.BlockNotFound {
 364                         status = http.StatusNotFound
 365                 } else if respErr.Temporary() {
 366                         status = http.StatusBadGateway
 367                 } else {
 368                         status = 422
 369                 }
 370         default:
 371                 status = http.StatusInternalServerError
 372         }
 373 }
 374
 375 var errLengthRequired = errors.New(http.StatusText(http.StatusLengthRequired))
 376 var errLengthMismatch = errors.New("Locator size hint does not match Content-Length header")
 377
 378 func (h *proxyHandler) Put(resp http.ResponseWriter, req *http.Request) {
 379         if err := h.checkLoop(resp, req); err != nil {
 380                 return
 381         }
 382         setCORSHeaders(resp)
 383         resp.Header().Set("Via", "HTTP/1.1 "+viaAlias)
 384
 385         kc := h.makeKeepClient(req)
 386
 387         var err error
 388         var expectLength int64
 389         var status = http.StatusInternalServerError
 390         var wroteReplicas int
 391         var locatorOut string = "-"
 392
 393         defer func() {
 394                 httpserver.SetResponseLogFields(req.Context(), logrus.Fields{
 395                         "expectLength":  expectLength,
 396                         "wantReplicas":  kc.Want_replicas,
 397                         "wroteReplicas": wroteReplicas,
 398                         "locator":       strings.SplitN(locatorOut, "+A", 2)[0],
 399                         "err":           err,
 400                 })
 401                 if status != http.StatusOK {
 402                         http.Error(resp, err.Error(), status)
 403                 }
 404         }()
 405
 406         locatorIn := mux.Vars(req)["locator"]
 407
 408         // Check if the client specified storage classes
 409         if req.Header.Get("X-Keep-Storage-Classes") != "" {
 410                 var scl []string
 411                 for _, sc := range strings.Split(req.Header.Get("X-Keep-Storage-Classes"), ",") {
 412                         scl = append(scl, strings.Trim(sc, " "))
 413                 }
 414                 kc.SetStorageClasses(scl)
 415         }
 416
 417         _, err = fmt.Sscanf(req.Header.Get("Content-Length"), "%d", &expectLength)
 418         if err != nil || expectLength < 0 {
 419                 err = errLengthRequired
 420                 status = http.StatusLengthRequired
 421                 return
 422         }
 423
 424         if locatorIn != "" {
 425                 var loc *keepclient.Locator
 426                 if loc, err = keepclient.MakeLocator(locatorIn); err != nil {
 427                         status = http.StatusBadRequest
 428                         return
 429                 } else if loc.Size > 0 && int64(loc.Size) != expectLength {
 430                         err = errLengthMismatch
 431                         status = http.StatusBadRequest
 432                         return
 433                 }
 434         }
 435
 436         var pass bool
 437         var tok string
 438         var user *arvados.User
 439         if pass, tok, user = h.checkAuthorizationHeader(req); !pass {
 440                 err = errBadAuthorizationHeader
 441                 status = http.StatusForbidden
 442                 return
 443         }
 444         httpserver.SetResponseLogFields(req.Context(), logrus.Fields{
 445                 "userUUID":     user.UUID,
 446                 "userFullName": user.FullName,
 447         })
 448
 449         // Copy ArvadosClient struct and use the client's API token
 450         arvclient := *kc.Arvados
 451         arvclient.ApiToken = tok
 452         kc.Arvados = &arvclient
 453
 454         // Check if the client specified the number of replicas
 455         if desiredReplicas := req.Header.Get(keepclient.XKeepDesiredReplicas); desiredReplicas != "" {
 456                 var r int
 457                 _, err := fmt.Sscanf(desiredReplicas, "%d", &r)
 458                 if err == nil {
 459                         kc.Want_replicas = r
 460                 }
 461         }
 462
 463         // Now try to put the block through
 464         if locatorIn == "" {
 465                 bytes, err2 := ioutil.ReadAll(req.Body)
 466                 if err2 != nil {
 467                         err = fmt.Errorf("Error reading request body: %s", err2)
 468                         status = http.StatusInternalServerError
 469                         return
 470                 }
 471                 locatorOut, wroteReplicas, err = kc.PutB(bytes)
 472         } else {
 473                 locatorOut, wroteReplicas, err = kc.PutHR(locatorIn, req.Body, expectLength)
 474         }
 475
 476         // Tell the client how many successful PUTs we accomplished
 477         resp.Header().Set(keepclient.XKeepReplicasStored, fmt.Sprintf("%d", wroteReplicas))
 478
 479         switch err.(type) {
 480         case nil:
 481                 status = http.StatusOK
 482                 if len(kc.StorageClasses) > 0 {
 483                         // A successful PUT request with storage classes means that all
 484                         // storage classes were fulfilled, so the client will get a
 485                         // confirmation via the X-Storage-Classes-Confirmed header.
 486                         hdr := ""
 487                         isFirst := true
 488                         for _, sc := range kc.StorageClasses {
 489                                 if isFirst {
 490                                         hdr = fmt.Sprintf("%s=%d", sc, wroteReplicas)
 491                                         isFirst = false
 492                                 } else {
 493                                         hdr += fmt.Sprintf(", %s=%d", sc, wroteReplicas)
 494                                 }
 495                         }
 496                         resp.Header().Set(keepclient.XKeepStorageClassesConfirmed, hdr)
 497                 }
 498                 _, err = io.WriteString(resp, locatorOut)
 499         case keepclient.OversizeBlockError:
 500                 // Too much data
 501                 status = http.StatusRequestEntityTooLarge
 502         case keepclient.InsufficientReplicasError:
 503                 status = http.StatusServiceUnavailable
 504         default:
 505                 status = http.StatusBadGateway
 506         }
 507 }
 508
 509 // ServeHTTP implementation for IndexHandler
 510 // Supports only GET requests for /index/{prefix:[0-9a-f]{0,32}}
 511 // For each keep server found in LocalRoots:
 512 //   Invokes GetIndex using keepclient
 513 //   Expects "complete" response (terminating with blank new line)
 514 //   Aborts on any errors
 515 // Concatenates responses from all those keep servers and returns
 516 func (h *proxyHandler) Index(resp http.ResponseWriter, req *http.Request) {
 517         setCORSHeaders(resp)
 518
 519         prefix := mux.Vars(req)["prefix"]
 520         var err error
 521         var status int
 522
 523         defer func() {
 524                 if status != http.StatusOK {
 525                         http.Error(resp, err.Error(), status)
 526                 }
 527         }()
 528
 529         kc := h.makeKeepClient(req)
 530         ok, token, _ := h.checkAuthorizationHeader(req)
 531         if !ok {
 532                 status, err = http.StatusForbidden, errBadAuthorizationHeader
 533                 return
 534         }
 535
 536         // Copy ArvadosClient struct and use the client's API token
 537         arvclient := *kc.Arvados
 538         arvclient.ApiToken = token
 539         kc.Arvados = &arvclient
 540
 541         // Only GET method is supported
 542         if req.Method != "GET" {
 543                 status, err = http.StatusNotImplemented, errMethodNotSupported
 544                 return
 545         }
 546
 547         // Get index from all LocalRoots and write to resp
 548         var reader io.Reader
 549         for uuid := range kc.LocalRoots() {
 550                 reader, err = kc.GetIndex(uuid, prefix)
 551                 if err != nil {
 552                         status = http.StatusBadGateway
 553                         return
 554                 }
 555
 556                 _, err = io.Copy(resp, reader)
 557                 if err != nil {
 558                         status = http.StatusBadGateway
 559                         return
 560                 }
 561         }
 562
 563         // Got index from all the keep servers and wrote to resp
 564         status = http.StatusOK
 565         resp.Write([]byte("\n"))
 566 }
 567
 568 func (h *proxyHandler) makeKeepClient(req *http.Request) *keepclient.KeepClient {
 569         kc := *h.KeepClient
 570         kc.RequestID = req.Header.Get("X-Request-Id")
 571         kc.HTTPClient = &proxyClient{
 572                 client: &http.Client{
 573                         Timeout:   h.timeout,
 574                         Transport: h.transport,
 575                 },
 576                 proto: req.Proto,
 577         }
 578         return &kc
 579 }