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 can't copy the default http transport because http.Transport has
 179 // a mutex field, so we make our own using the values of the exported
 180 // fields.
 181 var defaultTransport = http.Transport{
 182         Proxy:                 http.DefaultTransport.(*http.Transport).Proxy,
 183         DialContext:           http.DefaultTransport.(*http.Transport).DialContext,
 184         ForceAttemptHTTP2:     http.DefaultTransport.(*http.Transport).ForceAttemptHTTP2,
 185         MaxIdleConns:          http.DefaultTransport.(*http.Transport).MaxIdleConns,
 186         IdleConnTimeout:       http.DefaultTransport.(*http.Transport).IdleConnTimeout,
 187         TLSHandshakeTimeout:   http.DefaultTransport.(*http.Transport).TLSHandshakeTimeout,
 188         ExpectContinueTimeout: http.DefaultTransport.(*http.Transport).ExpectContinueTimeout,
 189 }
 190
 191 type proxyHandler struct {
 192         http.Handler
 193         *keepclient.KeepClient
 194         *apiTokenCache
 195         timeout   time.Duration
 196         transport *http.Transport
 197         cluster   *arvados.Cluster
 198 }
 199
 200 func newHandler(ctx context.Context, kc *keepclient.KeepClient, timeout time.Duration, cluster *arvados.Cluster) (service.Handler, error) {
 201         rest := mux.NewRouter()
 202
 203         // We can't copy the default http transport because
 204         // http.Transport has a mutex field, so we copy the fields
 205         // that we know have non-zero values in http.DefaultTransport.
 206         transport := &http.Transport{
 207                 Proxy:                 http.DefaultTransport.(*http.Transport).Proxy,
 208                 ForceAttemptHTTP2:     http.DefaultTransport.(*http.Transport).ForceAttemptHTTP2,
 209                 MaxIdleConns:          http.DefaultTransport.(*http.Transport).MaxIdleConns,
 210                 IdleConnTimeout:       http.DefaultTransport.(*http.Transport).IdleConnTimeout,
 211                 ExpectContinueTimeout: http.DefaultTransport.(*http.Transport).ExpectContinueTimeout,
 212                 DialContext: (&net.Dialer{
 213                         Timeout:   keepclient.DefaultConnectTimeout,
 214                         KeepAlive: keepclient.DefaultKeepAlive,
 215                         DualStack: true,
 216                 }).DialContext,
 217                 TLSClientConfig:     arvadosclient.MakeTLSConfig(kc.Arvados.ApiInsecure),
 218                 TLSHandshakeTimeout: keepclient.DefaultTLSHandshakeTimeout,
 219         }
 220
 221         cacheQ, err := lru.New2Q(500)
 222         if err != nil {
 223                 return nil, fmt.Errorf("Error from lru.New2Q: %v", err)
 224         }
 225
 226         h := &proxyHandler{
 227                 Handler:    rest,
 228                 KeepClient: kc,
 229                 timeout:    timeout,
 230                 transport:  transport,
 231                 apiTokenCache: &apiTokenCache{
 232                         tokens:     cacheQ,
 233                         expireTime: 300,
 234                 },
 235                 cluster: cluster,
 236         }
 237
 238         rest.HandleFunc(`/{locator:[0-9a-f]{32}\+.*}`, h.Get).Methods("GET", "HEAD")
 239         rest.HandleFunc(`/{locator:[0-9a-f]{32}}`, h.Get).Methods("GET", "HEAD")
 240
 241         // List all blocks
 242         rest.HandleFunc(`/index`, h.Index).Methods("GET")
 243
 244         // List blocks whose hash has the given prefix
 245         rest.HandleFunc(`/index/{prefix:[0-9a-f]{0,32}}`, h.Index).Methods("GET")
 246
 247         rest.HandleFunc(`/{locator:[0-9a-f]{32}\+.*}`, h.Put).Methods("PUT")
 248         rest.HandleFunc(`/{locator:[0-9a-f]{32}}`, h.Put).Methods("PUT")
 249         rest.HandleFunc(`/`, h.Put).Methods("POST")
 250         rest.HandleFunc(`/{any}`, h.Options).Methods("OPTIONS")
 251         rest.HandleFunc(`/`, h.Options).Methods("OPTIONS")
 252
 253         rest.Handle("/_health/{check}", &health.Handler{
 254                 Token:  cluster.ManagementToken,
 255                 Prefix: "/_health/",
 256         }).Methods("GET")
 257
 258         rest.NotFoundHandler = invalidPathHandler{}
 259         return h, nil
 260 }
 261
 262 var errLoopDetected = errors.New("loop detected")
 263
 264 func (h *proxyHandler) checkLoop(resp http.ResponseWriter, req *http.Request) error {
 265         if via := req.Header.Get("Via"); strings.Index(via, " "+viaAlias) >= 0 {
 266                 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)
 267                 http.Error(resp, errLoopDetected.Error(), http.StatusInternalServerError)
 268                 return errLoopDetected
 269         }
 270         return nil
 271 }
 272
 273 func setCORSHeaders(resp http.ResponseWriter) {
 274         resp.Header().Set("Access-Control-Allow-Methods", "GET, HEAD, POST, PUT, OPTIONS")
 275         resp.Header().Set("Access-Control-Allow-Origin", "*")
 276         resp.Header().Set("Access-Control-Allow-Headers", "Authorization, Content-Length, Content-Type, X-Keep-Desired-Replicas")
 277         resp.Header().Set("Access-Control-Max-Age", "86486400")
 278 }
 279
 280 type invalidPathHandler struct{}
 281
 282 func (invalidPathHandler) ServeHTTP(resp http.ResponseWriter, req *http.Request) {
 283         http.Error(resp, "Bad request", http.StatusBadRequest)
 284 }
 285
 286 func (h *proxyHandler) Options(resp http.ResponseWriter, req *http.Request) {
 287         setCORSHeaders(resp)
 288 }
 289
 290 var errBadAuthorizationHeader = errors.New("Missing or invalid Authorization header, or method not allowed")
 291 var errContentLengthMismatch = errors.New("Actual length != expected content length")
 292 var errMethodNotSupported = errors.New("Method not supported")
 293
 294 var removeHint, _ = regexp.Compile("\\+K@[a-z0-9]{5}(\\+|$)")
 295
 296 func (h *proxyHandler) Get(resp http.ResponseWriter, req *http.Request) {
 297         if err := h.checkLoop(resp, req); err != nil {
 298                 return
 299         }
 300         setCORSHeaders(resp)
 301         resp.Header().Set("Via", req.Proto+" "+viaAlias)
 302
 303         locator := mux.Vars(req)["locator"]
 304         var err error
 305         var status int
 306         var expectLength, responseLength int64
 307         var proxiedURI = "-"
 308
 309         logger := ctxlog.FromContext(req.Context())
 310         defer func() {
 311                 httpserver.SetResponseLogFields(req.Context(), logrus.Fields{
 312                         "locator":        locator,
 313                         "expectLength":   expectLength,
 314                         "responseLength": responseLength,
 315                         "proxiedURI":     proxiedURI,
 316                         "err":            err,
 317                 })
 318                 if status != http.StatusOK {
 319                         http.Error(resp, err.Error(), status)
 320                 }
 321         }()
 322
 323         kc := h.makeKeepClient(req)
 324
 325         var pass bool
 326         var tok string
 327         var user *arvados.User
 328         if pass, tok, user = h.checkAuthorizationHeader(req); !pass {
 329                 status, err = http.StatusForbidden, errBadAuthorizationHeader
 330                 return
 331         }
 332         httpserver.SetResponseLogFields(req.Context(), logrus.Fields{
 333                 "userUUID":     user.UUID,
 334                 "userFullName": user.FullName,
 335         })
 336
 337         // Copy ArvadosClient struct and use the client's API token
 338         arvclient := *kc.Arvados
 339         arvclient.ApiToken = tok
 340         kc.Arvados = &arvclient
 341
 342         var reader io.ReadCloser
 343
 344         locator = removeHint.ReplaceAllString(locator, "$1")
 345
 346         switch req.Method {
 347         case "HEAD":
 348                 expectLength, proxiedURI, err = kc.Ask(locator)
 349         case "GET":
 350                 reader, expectLength, proxiedURI, err = kc.Get(locator)
 351                 if reader != nil {
 352                         defer reader.Close()
 353                 }
 354         default:
 355                 status, err = http.StatusNotImplemented, errMethodNotSupported
 356                 return
 357         }
 358
 359         if expectLength == -1 {
 360                 logger.Warn("Content-Length not provided")
 361         }
 362
 363         switch respErr := err.(type) {
 364         case nil:
 365                 status = http.StatusOK
 366                 resp.Header().Set("Content-Length", fmt.Sprint(expectLength))
 367                 switch req.Method {
 368                 case "HEAD":
 369                         responseLength = 0
 370                 case "GET":
 371                         responseLength, err = io.Copy(resp, reader)
 372                         if err == nil && expectLength > -1 && responseLength != expectLength {
 373                                 err = errContentLengthMismatch
 374                         }
 375                 }
 376         case keepclient.Error:
 377                 if respErr == keepclient.BlockNotFound {
 378                         status = http.StatusNotFound
 379                 } else if respErr.Temporary() {
 380                         status = http.StatusBadGateway
 381                 } else {
 382                         status = 422
 383                 }
 384         default:
 385                 status = http.StatusInternalServerError
 386         }
 387 }
 388
 389 var errLengthRequired = errors.New(http.StatusText(http.StatusLengthRequired))
 390 var errLengthMismatch = errors.New("Locator size hint does not match Content-Length header")
 391
 392 func (h *proxyHandler) Put(resp http.ResponseWriter, req *http.Request) {
 393         if err := h.checkLoop(resp, req); err != nil {
 394                 return
 395         }
 396         setCORSHeaders(resp)
 397         resp.Header().Set("Via", "HTTP/1.1 "+viaAlias)
 398
 399         kc := h.makeKeepClient(req)
 400
 401         var err error
 402         var expectLength int64
 403         var status = http.StatusInternalServerError
 404         var wroteReplicas int
 405         var locatorOut string = "-"
 406
 407         defer func() {
 408                 httpserver.SetResponseLogFields(req.Context(), logrus.Fields{
 409                         "expectLength":  expectLength,
 410                         "wantReplicas":  kc.Want_replicas,
 411                         "wroteReplicas": wroteReplicas,
 412                         "locator":       strings.SplitN(locatorOut, "+A", 2)[0],
 413                         "err":           err,
 414                 })
 415                 if status != http.StatusOK {
 416                         http.Error(resp, err.Error(), status)
 417                 }
 418         }()
 419
 420         locatorIn := mux.Vars(req)["locator"]
 421
 422         // Check if the client specified storage classes
 423         if req.Header.Get("X-Keep-Storage-Classes") != "" {
 424                 var scl []string
 425                 for _, sc := range strings.Split(req.Header.Get("X-Keep-Storage-Classes"), ",") {
 426                         scl = append(scl, strings.Trim(sc, " "))
 427                 }
 428                 kc.SetStorageClasses(scl)
 429         }
 430
 431         _, err = fmt.Sscanf(req.Header.Get("Content-Length"), "%d", &expectLength)
 432         if err != nil || expectLength < 0 {
 433                 err = errLengthRequired
 434                 status = http.StatusLengthRequired
 435                 return
 436         }
 437
 438         if locatorIn != "" {
 439                 var loc *keepclient.Locator
 440                 if loc, err = keepclient.MakeLocator(locatorIn); err != nil {
 441                         status = http.StatusBadRequest
 442                         return
 443                 } else if loc.Size > 0 && int64(loc.Size) != expectLength {
 444                         err = errLengthMismatch
 445                         status = http.StatusBadRequest
 446                         return
 447                 }
 448         }
 449
 450         var pass bool
 451         var tok string
 452         var user *arvados.User
 453         if pass, tok, user = h.checkAuthorizationHeader(req); !pass {
 454                 err = errBadAuthorizationHeader
 455                 status = http.StatusForbidden
 456                 return
 457         }
 458         httpserver.SetResponseLogFields(req.Context(), logrus.Fields{
 459                 "userUUID":     user.UUID,
 460                 "userFullName": user.FullName,
 461         })
 462
 463         // Copy ArvadosClient struct and use the client's API token
 464         arvclient := *kc.Arvados
 465         arvclient.ApiToken = tok
 466         kc.Arvados = &arvclient
 467
 468         // Check if the client specified the number of replicas
 469         if desiredReplicas := req.Header.Get(keepclient.XKeepDesiredReplicas); desiredReplicas != "" {
 470                 var r int
 471                 _, err := fmt.Sscanf(desiredReplicas, "%d", &r)
 472                 if err == nil {
 473                         kc.Want_replicas = r
 474                 }
 475         }
 476
 477         // Now try to put the block through
 478         if locatorIn == "" {
 479                 bytes, err2 := ioutil.ReadAll(req.Body)
 480                 if err2 != nil {
 481                         err = fmt.Errorf("Error reading request body: %s", err2)
 482                         status = http.StatusInternalServerError
 483                         return
 484                 }
 485                 locatorOut, wroteReplicas, err = kc.PutB(bytes)
 486         } else {
 487                 locatorOut, wroteReplicas, err = kc.PutHR(locatorIn, req.Body, expectLength)
 488         }
 489
 490         // Tell the client how many successful PUTs we accomplished
 491         resp.Header().Set(keepclient.XKeepReplicasStored, fmt.Sprintf("%d", wroteReplicas))
 492
 493         switch err.(type) {
 494         case nil:
 495                 status = http.StatusOK
 496                 if len(kc.StorageClasses) > 0 {
 497                         // A successful PUT request with storage classes means that all
 498                         // storage classes were fulfilled, so the client will get a
 499                         // confirmation via the X-Storage-Classes-Confirmed header.
 500                         hdr := ""
 501                         isFirst := true
 502                         for _, sc := range kc.StorageClasses {
 503                                 if isFirst {
 504                                         hdr = fmt.Sprintf("%s=%d", sc, wroteReplicas)
 505                                         isFirst = false
 506                                 } else {
 507                                         hdr += fmt.Sprintf(", %s=%d", sc, wroteReplicas)
 508                                 }
 509                         }
 510                         resp.Header().Set(keepclient.XKeepStorageClassesConfirmed, hdr)
 511                 }
 512                 _, err = io.WriteString(resp, locatorOut)
 513         case keepclient.OversizeBlockError:
 514                 // Too much data
 515                 status = http.StatusRequestEntityTooLarge
 516         case keepclient.InsufficientReplicasError:
 517                 status = http.StatusServiceUnavailable
 518         default:
 519                 status = http.StatusBadGateway
 520         }
 521 }
 522
 523 // ServeHTTP implementation for IndexHandler
 524 // Supports only GET requests for /index/{prefix:[0-9a-f]{0,32}}
 525 // For each keep server found in LocalRoots:
 526 // - Invokes GetIndex using keepclient
 527 // - Expects "complete" response (terminating with blank new line)
 528 // - Aborts on any errors
 529 // Concatenates responses from all those keep servers and returns
 530 func (h *proxyHandler) Index(resp http.ResponseWriter, req *http.Request) {
 531         setCORSHeaders(resp)
 532
 533         prefix := mux.Vars(req)["prefix"]
 534         var err error
 535         var status int
 536
 537         defer func() {
 538                 if status != http.StatusOK {
 539                         http.Error(resp, err.Error(), status)
 540                 }
 541         }()
 542
 543         kc := h.makeKeepClient(req)
 544         ok, token, _ := h.checkAuthorizationHeader(req)
 545         if !ok {
 546                 status, err = http.StatusForbidden, errBadAuthorizationHeader
 547                 return
 548         }
 549
 550         // Copy ArvadosClient struct and use the client's API token
 551         arvclient := *kc.Arvados
 552         arvclient.ApiToken = token
 553         kc.Arvados = &arvclient
 554
 555         // Only GET method is supported
 556         if req.Method != "GET" {
 557                 status, err = http.StatusNotImplemented, errMethodNotSupported
 558                 return
 559         }
 560
 561         // Get index from all LocalRoots and write to resp
 562         var reader io.Reader
 563         for uuid := range kc.LocalRoots() {
 564                 reader, err = kc.GetIndex(uuid, prefix)
 565                 if err != nil {
 566                         status = http.StatusBadGateway
 567                         return
 568                 }
 569
 570                 _, err = io.Copy(resp, reader)
 571                 if err != nil {
 572                         status = http.StatusBadGateway
 573                         return
 574                 }
 575         }
 576
 577         // Got index from all the keep servers and wrote to resp
 578         status = http.StatusOK
 579         resp.Write([]byte("\n"))
 580 }
 581
 582 func (h *proxyHandler) makeKeepClient(req *http.Request) *keepclient.KeepClient {
 583         kc := h.KeepClient.Clone()
 584         kc.RequestID = req.Header.Get("X-Request-Id")
 585         kc.HTTPClient = &proxyClient{
 586                 client: &http.Client{
 587                         Timeout:   h.timeout,
 588                         Transport: h.transport,
 589                 },
 590                 proto: req.Proto,
 591         }
 592         return kc
 593 }