lib/controller/federation.go

   1 // Copyright (C) The Arvados Authors. All rights reserved.
   2 //
   3 // SPDX-License-Identifier: AGPL-3.0
   4
   5 package controller
   6
   7 import (
   8         "bufio"
   9         "bytes"
  10         "context"
  11         "database/sql"
  12         "encoding/json"
  13         "fmt"
  14         "io/ioutil"
  15         "log"
  16         "net/http"
  17         "net/url"
  18         "regexp"
  19         "strings"
  20         "sync"
  21
  22         "git.curoverse.com/arvados.git/sdk/go/arvados"
  23         "git.curoverse.com/arvados.git/sdk/go/auth"
  24         "git.curoverse.com/arvados.git/sdk/go/httpserver"
  25         "git.curoverse.com/arvados.git/sdk/go/keepclient"
  26 )
  27
  28 var wfRe = regexp.MustCompile(`^/arvados/v1/workflows/([0-9a-z]{5})-[^/]+$`)
  29 var collectionRe = regexp.MustCompile(`^/arvados/v1/collections/([0-9a-z]{5})-[^/]+$`)
  30 var collectionByPDHRe = regexp.MustCompile(`^/arvados/v1/collections/([0-9a-fA-F]{32}\+[0-9]+)+$`)
  31
  32 type genericFederatedRequestHandler struct {
  33         next    http.Handler
  34         handler *Handler
  35 }
  36
  37 type collectionFederatedRequestHandler struct {
  38         next    http.Handler
  39         handler *Handler
  40 }
  41
  42 func (h *Handler) remoteClusterRequest(remoteID string, w http.ResponseWriter, req *http.Request, filter ResponseFilter) {
  43         remote, ok := h.Cluster.RemoteClusters[remoteID]
  44         if !ok {
  45                 httpserver.Error(w, "no proxy available for cluster "+remoteID, http.StatusNotFound)
  46                 return
  47         }
  48         scheme := remote.Scheme
  49         if scheme == "" {
  50                 scheme = "https"
  51         }
  52         err := h.saltAuthToken(req, remoteID)
  53         if err != nil {
  54                 httpserver.Error(w, err.Error(), http.StatusBadRequest)
  55                 return
  56         }
  57         urlOut := &url.URL{
  58                 Scheme:   scheme,
  59                 Host:     remote.Host,
  60                 Path:     req.URL.Path,
  61                 RawPath:  req.URL.RawPath,
  62                 RawQuery: req.URL.RawQuery,
  63         }
  64         client := h.secureClient
  65         if remote.Insecure {
  66                 client = h.insecureClient
  67         }
  68         log.Printf("Remote cluster request to %v %v", remoteID, urlOut)
  69         h.proxy.Do(w, req, urlOut, client, filter)
  70 }
  71
  72 func (h *genericFederatedRequestHandler) ServeHTTP(w http.ResponseWriter, req *http.Request) {
  73         m := wfRe.FindStringSubmatch(req.URL.Path)
  74         if len(m) < 2 || m[1] == h.handler.Cluster.ClusterID {
  75                 h.next.ServeHTTP(w, req)
  76                 return
  77         }
  78         h.handler.remoteClusterRequest(m[1], w, req, nil)
  79 }
  80
  81 type rewriteSignaturesClusterId string
  82
  83 func (clusterId rewriteSignaturesClusterId) rewriteSignatures(resp *http.Response, requestError error) (newResponse *http.Response, err error) {
  84         if requestError != nil {
  85                 return resp, requestError
  86         }
  87
  88         if resp.StatusCode != 200 {
  89                 return resp, nil
  90         }
  91
  92         originalBody := resp.Body
  93         defer originalBody.Close()
  94
  95         var col arvados.Collection
  96         err = json.NewDecoder(resp.Body).Decode(&col)
  97         if err != nil {
  98                 return nil, err
  99         }
 100
 101         // rewriting signatures will make manifest text 5-10% bigger so calculate
 102         // capacity accordingly
 103         updatedManifest := bytes.NewBuffer(make([]byte, 0, int(float64(len(col.ManifestText))*1.1)))
 104
 105         scanner := bufio.NewScanner(strings.NewReader(col.ManifestText))
 106         scanner.Buffer(make([]byte, 1048576), len(col.ManifestText))
 107         for scanner.Scan() {
 108                 line := scanner.Text()
 109                 tokens := strings.Split(line, " ")
 110                 if len(tokens) < 3 {
 111                         return nil, fmt.Errorf("Invalid stream (<3 tokens): %q", line)
 112                 }
 113
 114                 updatedManifest.WriteString(tokens[0])
 115                 for _, token := range tokens[1:] {
 116                         updatedManifest.WriteString(" ")
 117                         m := keepclient.SignedLocatorRe.FindStringSubmatch(token)
 118                         if m != nil {
 119                                 // Rewrite the block signature to be a remote signature
 120                                 fmt.Fprintf(updatedManifest, "%s%s%s+R%s-%s%s", m[1], m[2], m[3], clusterId, m[5][2:], m[8])
 121                         } else {
 122                                 updatedManifest.WriteString(token)
 123                         }
 124
 125                 }
 126                 updatedManifest.WriteString("\n")
 127         }
 128
 129         col.ManifestText = updatedManifest.String()
 130
 131         newbody, err := json.Marshal(col)
 132         if err != nil {
 133                 return nil, err
 134         }
 135
 136         buf := bytes.NewBuffer(newbody)
 137         resp.Body = ioutil.NopCloser(buf)
 138         resp.ContentLength = int64(buf.Len())
 139         resp.Header.Set("Content-Length", fmt.Sprintf("%v", buf.Len()))
 140
 141         return resp, nil
 142 }
 143
 144 type searchLocalClusterForPDH struct {
 145         sentResponse bool
 146 }
 147
 148 func (s *searchLocalClusterForPDH) filterLocalClusterResponse(resp *http.Response, requestError error) (newResponse *http.Response, err error) {
 149         if requestError != nil {
 150                 return resp, requestError
 151         }
 152
 153         if resp.StatusCode == 404 {
 154                 // Suppress returning this result, because we want to
 155                 // search the federation.
 156                 s.sentResponse = false
 157                 return nil, nil
 158         }
 159         s.sentResponse = true
 160         return resp, nil
 161 }
 162
 163 type searchRemoteClusterForPDH struct {
 164         remoteID      string
 165         mtx           *sync.Mutex
 166         sentResponse  *bool
 167         sharedContext *context.Context
 168         cancelFunc    func()
 169         errors        *[]string
 170         statusCode    *int
 171 }
 172
 173 func (s *searchRemoteClusterForPDH) filterRemoteClusterResponse(resp *http.Response, requestError error) (newResponse *http.Response, err error) {
 174         s.mtx.Lock()
 175         defer s.mtx.Unlock()
 176
 177         if *s.sentResponse {
 178                 // Another request already returned a response
 179                 return nil, nil
 180         }
 181
 182         if requestError != nil {
 183                 *s.errors = append(*s.errors, fmt.Sprintf("Request error contacting %q: %v", s.remoteID, requestError))
 184                 // Record the error and suppress response
 185                 return nil, nil
 186         }
 187
 188         if resp.StatusCode != 200 {
 189                 // Suppress returning unsuccessful result.  Maybe
 190                 // another request will find it.
 191                 // TODO collect and return error responses.
 192                 *s.errors = append(*s.errors, fmt.Sprintf("Response from %q: %v", s.remoteID, resp.Status))
 193                 if resp.StatusCode == 404 && (*s.statusCode == 0 || *s.statusCode == 404) {
 194                         // Only return 404 if every response is 404
 195                         *s.statusCode = http.StatusNotFound
 196                 } else {
 197                         // Got a non-404 error response, convert into BadGateway
 198                         *s.statusCode = http.StatusBadGateway
 199                 }
 200                 return nil, nil
 201         }
 202
 203         s.mtx.Unlock()
 204
 205         // This reads the response body.  We don't want to hold the
 206         // lock while doing this because other remote requests could
 207         // also have made it to this point, and we want don't want a
 208         // slow response holding the lock to block a faster response
 209         // that is waiting on the lock.
 210         newResponse, err = rewriteSignaturesClusterId(s.remoteID).rewriteSignatures(resp, nil)
 211
 212         s.mtx.Lock()
 213
 214         if *s.sentResponse {
 215                 // Another request already returned a response
 216                 return nil, nil
 217         }
 218
 219         if err != nil {
 220                 // Suppress returning unsuccessful result.  Maybe
 221                 // another request will be successful.
 222                 *s.errors = append(*s.errors, fmt.Sprintf("Error parsing response from %q: %v", s.remoteID, err))
 223                 return nil, nil
 224         }
 225
 226         // We have a successful response.  Suppress/cancel all the
 227         // other requests/responses.
 228         *s.sentResponse = true
 229         s.cancelFunc()
 230
 231         return newResponse, nil
 232 }
 233
 234 func (h *collectionFederatedRequestHandler) ServeHTTP(w http.ResponseWriter, req *http.Request) {
 235         m := collectionByPDHRe.FindStringSubmatch(req.URL.Path)
 236         if len(m) == 2 && len(h.handler.Cluster.RemoteClusters) > 0 {
 237                 bearer := req.Header.Get("Authorization")
 238                 if strings.HasPrefix(bearer, "Bearer v2/") &&
 239                         len(bearer) > 10 &&
 240                         bearer[10:15] != h.handler.Cluster.ClusterID {
 241                         // Salted token from another cluster, just
 242                         // fall back to query local cluster only.
 243                         h.next.ServeHTTP(w, req)
 244                         return
 245                 }
 246
 247                 urlOut, insecure, err := findRailsAPI(h.handler.Cluster, h.handler.NodeProfile)
 248                 if err != nil {
 249                         httpserver.Error(w, err.Error(), http.StatusInternalServerError)
 250                         return
 251                 }
 252
 253                 urlOut = &url.URL{
 254                         Scheme:   urlOut.Scheme,
 255                         Host:     urlOut.Host,
 256                         Path:     req.URL.Path,
 257                         RawPath:  req.URL.RawPath,
 258                         RawQuery: req.URL.RawQuery,
 259                 }
 260                 client := h.handler.secureClient
 261                 if insecure {
 262                         client = h.handler.insecureClient
 263                 }
 264                 sf := &searchLocalClusterForPDH{}
 265                 h.handler.proxy.Do(w, req, urlOut, client, sf.filterLocalClusterResponse)
 266                 if sf.sentResponse {
 267                         // a response was sent, nothing more to do
 268                         return
 269                 }
 270
 271                 sharedContext, cancelFunc := context.WithCancel(req.Context())
 272                 defer cancelFunc()
 273                 req = req.WithContext(sharedContext)
 274
 275                 // Create a goroutine that will contact each cluster
 276                 // in the RemoteClusters map.  The first one to return
 277                 // a valid result gets returned to the client.  When
 278                 // that happens, all other outstanding requests are
 279                 // cancelled or suppressed.
 280                 sentResponse := false
 281                 mtx := sync.Mutex{}
 282                 wg := sync.WaitGroup{}
 283                 var errors []string
 284                 var errorCode int = 0
 285                 for remoteID := range h.handler.Cluster.RemoteClusters {
 286                         search := &searchRemoteClusterForPDH{remoteID, &mtx, &sentResponse,
 287                                 &sharedContext, cancelFunc, &errors, &errorCode}
 288                         wg.Add(1)
 289                         go func() {
 290                                 h.handler.remoteClusterRequest(search.remoteID, w, req, search.filterRemoteClusterResponse)
 291                                 wg.Done()
 292                         }()
 293                 }
 294                 wg.Wait()
 295                 if sentResponse {
 296                         return
 297                 }
 298
 299                 if errorCode == 0 {
 300                         errorCode = http.StatusBadGateway
 301                 }
 302
 303                 // No successful responses, so return an error
 304                 httpserver.Errors(w, errors, errorCode)
 305                 return
 306         }
 307
 308         m = collectionRe.FindStringSubmatch(req.URL.Path)
 309         if len(m) < 2 || m[1] == h.handler.Cluster.ClusterID {
 310                 h.next.ServeHTTP(w, req)
 311                 return
 312         }
 313         h.handler.remoteClusterRequest(m[1], w, req,
 314                 rewriteSignaturesClusterId(m[1]).rewriteSignatures)
 315 }
 316
 317 func (h *Handler) setupProxyRemoteCluster(next http.Handler) http.Handler {
 318         mux := http.NewServeMux()
 319         mux.Handle("/arvados/v1/workflows", next)
 320         mux.Handle("/arvados/v1/workflows/", &genericFederatedRequestHandler{next, h})
 321         mux.Handle("/arvados/v1/collections", next)
 322         mux.Handle("/arvados/v1/collections/", &collectionFederatedRequestHandler{next, h})
 323         mux.Handle("/", next)
 324
 325         return mux
 326 }
 327
 328 type CurrentUser struct {
 329         Authorization arvados.APIClientAuthorization
 330         UUID          string
 331 }
 332
 333 func (h *Handler) validateAPItoken(req *http.Request, user *CurrentUser) error {
 334         db, err := h.db(req)
 335         if err != nil {
 336                 return err
 337         }
 338         return db.QueryRowContext(req.Context(), `SELECT api_client_authorizations.uuid, users.uuid FROM api_client_authorizations JOIN users on api_client_authorizations.user_id=users.id WHERE api_token=$1 AND (expires_at IS NULL OR expires_at > current_timestamp) LIMIT 1`, user.Authorization.APIToken).Scan(&user.Authorization.UUID, &user.UUID)
 339 }
 340
 341 // Extract the auth token supplied in req, and replace it with a
 342 // salted token for the remote cluster.
 343 func (h *Handler) saltAuthToken(req *http.Request, remote string) error {
 344         creds := auth.NewCredentials()
 345         creds.LoadTokensFromHTTPRequest(req)
 346         if len(creds.Tokens) == 0 && req.Header.Get("Content-Type") == "application/x-www-form-encoded" {
 347                 // Override ParseForm's 10MiB limit by ensuring
 348                 // req.Body is a *http.maxBytesReader.
 349                 req.Body = http.MaxBytesReader(nil, req.Body, 1<<28) // 256MiB. TODO: use MaxRequestSize from discovery doc or config.
 350                 if err := creds.LoadTokensFromHTTPRequestBody(req); err != nil {
 351                         return err
 352                 }
 353                 // Replace req.Body with a buffer that re-encodes the
 354                 // form without api_token, in case we end up
 355                 // forwarding the request.
 356                 if req.PostForm != nil {
 357                         req.PostForm.Del("api_token")
 358                 }
 359                 req.Body = ioutil.NopCloser(bytes.NewBufferString(req.PostForm.Encode()))
 360         }
 361         if len(creds.Tokens) == 0 {
 362                 return nil
 363         }
 364         token, err := auth.SaltToken(creds.Tokens[0], remote)
 365         if err == auth.ErrObsoleteToken {
 366                 // If the token exists in our own database, salt it
 367                 // for the remote. Otherwise, assume it was issued by
 368                 // the remote, and pass it through unmodified.
 369                 currentUser := CurrentUser{Authorization: arvados.APIClientAuthorization{APIToken: creds.Tokens[0]}}
 370                 err = h.validateAPItoken(req, &currentUser)
 371                 if err == sql.ErrNoRows {
 372                         // Not ours; pass through unmodified.
 373                         token = currentUser.Authorization.APIToken
 374                 } else if err != nil {
 375                         return err
 376                 } else {
 377                         // Found; make V2 version and salt it.
 378                         token, err = auth.SaltToken(currentUser.Authorization.TokenV2(), remote)
 379                         if err != nil {
 380                                 return err
 381                         }
 382                 }
 383         } else if err != nil {
 384                 return err
 385         }
 386         req.Header.Set("Authorization", "Bearer "+token)
 387
 388         // Remove api_token=... from the the query string, in case we
 389         // end up forwarding the request.
 390         if values, err := url.ParseQuery(req.URL.RawQuery); err != nil {
 391                 return err
 392         } else if _, ok := values["api_token"]; ok {
 393                 delete(values, "api_token")
 394                 req.URL.RawQuery = values.Encode()
 395         }
 396         return nil
 397 }