services/keepproxy/keepproxy.go

   1 package main
   2
   3 import (
   4         "errors"
   5         "flag"
   6         "fmt"
   7         "git.curoverse.com/arvados.git/sdk/go/arvadosclient"
   8         "git.curoverse.com/arvados.git/sdk/go/keepclient"
   9         "github.com/gorilla/mux"
  10         "io"
  11         "io/ioutil"
  12         "log"
  13         "net"
  14         "net/http"
  15         "os"
  16         "os/signal"
  17         "reflect"
  18         "regexp"
  19         "sync"
  20         "syscall"
  21         "time"
  22 )
  23
  24 // Default TCP address on which to listen for requests.
  25 // Initialized by the -listen flag.
  26 const DEFAULT_ADDR = ":25107"
  27
  28 var listener net.Listener
  29
  30 func main() {
  31         var (
  32                 listen           string
  33                 no_get           bool
  34                 no_put           bool
  35                 default_replicas int
  36                 timeout          int64
  37                 pidfile          string
  38         )
  39
  40         flagset := flag.NewFlagSet("default", flag.ExitOnError)
  41
  42         flagset.StringVar(
  43                 &listen,
  44                 "listen",
  45                 DEFAULT_ADDR,
  46                 "Interface on which to listen for requests, in the format "+
  47                         "ipaddr:port. e.g. -listen=10.0.1.24:8000. Use -listen=:port "+
  48                         "to listen on all network interfaces.")
  49
  50         flagset.BoolVar(
  51                 &no_get,
  52                 "no-get",
  53                 false,
  54                 "If set, disable GET operations")
  55
  56         flagset.BoolVar(
  57                 &no_put,
  58                 "no-put",
  59                 false,
  60                 "If set, disable PUT operations")
  61
  62         flagset.IntVar(
  63                 &default_replicas,
  64                 "default-replicas",
  65                 2,
  66                 "Default number of replicas to write if not specified by the client.")
  67
  68         flagset.Int64Var(
  69                 &timeout,
  70                 "timeout",
  71                 15,
  72                 "Timeout on requests to internal Keep services (default 15 seconds)")
  73
  74         flagset.StringVar(
  75                 &pidfile,
  76                 "pid",
  77                 "",
  78                 "Path to write pid file")
  79
  80         flagset.Parse(os.Args[1:])
  81
  82         arv, err := arvadosclient.MakeArvadosClient()
  83         if err != nil {
  84                 log.Fatalf("Error setting up arvados client %s", err.Error())
  85         }
  86
  87         kc, err := keepclient.MakeKeepClient(&arv)
  88         if err != nil {
  89                 log.Fatalf("Error setting up keep client %s", err.Error())
  90         }
  91
  92         if pidfile != "" {
  93                 f, err := os.Create(pidfile)
  94                 if err != nil {
  95                         log.Fatalf("Error writing pid file (%s): %s", pidfile, err.Error())
  96                 }
  97                 fmt.Fprint(f, os.Getpid())
  98                 f.Close()
  99                 defer os.Remove(pidfile)
 100         }
 101
 102         kc.Want_replicas = default_replicas
 103
 104         kc.Client.Timeout = time.Duration(timeout) * time.Second
 105
 106         listener, err = net.Listen("tcp", listen)
 107         if err != nil {
 108                 log.Fatalf("Could not listen on %v", listen)
 109         }
 110
 111         go RefreshServicesList(kc)
 112
 113         // Shut down the server gracefully (by closing the listener)
 114         // if SIGTERM is received.
 115         term := make(chan os.Signal, 1)
 116         go func(sig <-chan os.Signal) {
 117                 s := <-sig
 118                 log.Println("caught signal:", s)
 119                 listener.Close()
 120         }(term)
 121         signal.Notify(term, syscall.SIGTERM)
 122         signal.Notify(term, syscall.SIGINT)
 123
 124         log.Printf("Arvados Keep proxy started listening on %v", listener.Addr())
 125
 126         // Start listening for requests.
 127         http.Serve(listener, MakeRESTRouter(!no_get, !no_put, kc))
 128
 129         log.Println("shutting down")
 130 }
 131
 132 type ApiTokenCache struct {
 133         tokens     map[string]int64
 134         lock       sync.Mutex
 135         expireTime int64
 136 }
 137
 138 // Refresh the keep service list every five minutes.
 139 func RefreshServicesList(kc *keepclient.KeepClient) {
 140         var previousRoots = []map[string]string{}
 141         var delay time.Duration = 0
 142         for {
 143                 time.Sleep(delay * time.Second)
 144                 delay = 300
 145                 if err := kc.DiscoverKeepServers(); err != nil {
 146                         log.Println("Error retrieving services list:", err)
 147                         delay = 3
 148                         continue
 149                 }
 150                 newRoots := []map[string]string{kc.LocalRoots(), kc.GatewayRoots()}
 151                 if !reflect.DeepEqual(previousRoots, newRoots) {
 152                         log.Printf("Updated services list: locals %v gateways %v", newRoots[0], newRoots[1])
 153                 }
 154                 if len(newRoots[0]) == 0 {
 155                         log.Print("WARNING: No local services. Retrying in 3 seconds.")
 156                         delay = 3
 157                 }
 158                 previousRoots = newRoots
 159         }
 160 }
 161
 162 // Cache the token and set an expire time.  If we already have an expire time
 163 // on the token, it is not updated.
 164 func (this *ApiTokenCache) RememberToken(token string) {
 165         this.lock.Lock()
 166         defer this.lock.Unlock()
 167
 168         now := time.Now().Unix()
 169         if this.tokens[token] == 0 {
 170                 this.tokens[token] = now + this.expireTime
 171         }
 172 }
 173
 174 // Check if the cached token is known and still believed to be valid.
 175 func (this *ApiTokenCache) RecallToken(token string) bool {
 176         this.lock.Lock()
 177         defer this.lock.Unlock()
 178
 179         now := time.Now().Unix()
 180         if this.tokens[token] == 0 {
 181                 // Unknown token
 182                 return false
 183         } else if now < this.tokens[token] {
 184                 // Token is known and still valid
 185                 return true
 186         } else {
 187                 // Token is expired
 188                 this.tokens[token] = 0
 189                 return false
 190         }
 191 }
 192
 193 func GetRemoteAddress(req *http.Request) string {
 194         if realip := req.Header.Get("X-Real-IP"); realip != "" {
 195                 if forwarded := req.Header.Get("X-Forwarded-For"); forwarded != realip {
 196                         return fmt.Sprintf("%s (X-Forwarded-For %s)", realip, forwarded)
 197                 } else {
 198                         return realip
 199                 }
 200         }
 201         return req.RemoteAddr
 202 }
 203
 204 func CheckAuthorizationHeader(kc keepclient.KeepClient, cache *ApiTokenCache, req *http.Request) (pass bool, tok string) {
 205         var auth string
 206         if auth = req.Header.Get("Authorization"); auth == "" {
 207                 return false, ""
 208         }
 209
 210         _, err := fmt.Sscanf(auth, "OAuth2 %s", &tok)
 211         if err != nil {
 212                 // Scanning error
 213                 return false, ""
 214         }
 215
 216         if cache.RecallToken(tok) {
 217                 // Valid in the cache, short circut
 218                 return true, tok
 219         }
 220
 221         arv := *kc.Arvados
 222         arv.ApiToken = tok
 223         if err := arv.Call("HEAD", "users", "", "current", nil, nil); err != nil {
 224                 log.Printf("%s: CheckAuthorizationHeader error: %v", GetRemoteAddress(req), err)
 225                 return false, ""
 226         }
 227
 228         // Success!  Update cache
 229         cache.RememberToken(tok)
 230
 231         return true, tok
 232 }
 233
 234 type GetBlockHandler struct {
 235         *keepclient.KeepClient
 236         *ApiTokenCache
 237 }
 238
 239 type PutBlockHandler struct {
 240         *keepclient.KeepClient
 241         *ApiTokenCache
 242 }
 243
 244 type InvalidPathHandler struct{}
 245
 246 type OptionsHandler struct{}
 247
 248 // MakeRESTRouter
 249 //     Returns a mux.Router that passes GET and PUT requests to the
 250 //     appropriate handlers.
 251 //
 252 func MakeRESTRouter(
 253         enable_get bool,
 254         enable_put bool,
 255         kc *keepclient.KeepClient) *mux.Router {
 256
 257         t := &ApiTokenCache{tokens: make(map[string]int64), expireTime: 300}
 258
 259         rest := mux.NewRouter()
 260
 261         if enable_get {
 262                 rest.Handle(`/{locator:[0-9a-f]{32}\+.*}`,
 263                         GetBlockHandler{kc, t}).Methods("GET", "HEAD")
 264                 rest.Handle(`/{locator:[0-9a-f]{32}}`, GetBlockHandler{kc, t}).Methods("GET", "HEAD")
 265         }
 266
 267         if enable_put {
 268                 rest.Handle(`/{locator:[0-9a-f]{32}\+.*}`, PutBlockHandler{kc, t}).Methods("PUT")
 269                 rest.Handle(`/{locator:[0-9a-f]{32}}`, PutBlockHandler{kc, t}).Methods("PUT")
 270                 rest.Handle(`/`, PutBlockHandler{kc, t}).Methods("POST")
 271                 rest.Handle(`/{any}`, OptionsHandler{}).Methods("OPTIONS")
 272                 rest.Handle(`/`, OptionsHandler{}).Methods("OPTIONS")
 273         }
 274
 275         rest.NotFoundHandler = InvalidPathHandler{}
 276
 277         return rest
 278 }
 279
 280 func SetCorsHeaders(resp http.ResponseWriter) {
 281         resp.Header().Set("Access-Control-Allow-Methods", "GET, HEAD, POST, PUT, OPTIONS")
 282         resp.Header().Set("Access-Control-Allow-Origin", "*")
 283         resp.Header().Set("Access-Control-Allow-Headers", "Authorization, Content-Length, Content-Type, X-Keep-Desired-Replicas")
 284         resp.Header().Set("Access-Control-Max-Age", "86486400")
 285 }
 286
 287 func (this InvalidPathHandler) ServeHTTP(resp http.ResponseWriter, req *http.Request) {
 288         log.Printf("%s: %s %s unroutable", GetRemoteAddress(req), req.Method, req.URL.Path)
 289         http.Error(resp, "Bad request", http.StatusBadRequest)
 290 }
 291
 292 func (this OptionsHandler) ServeHTTP(resp http.ResponseWriter, req *http.Request) {
 293         log.Printf("%s: %s %s", GetRemoteAddress(req), req.Method, req.URL.Path)
 294         SetCorsHeaders(resp)
 295 }
 296
 297 var BadAuthorizationHeader = errors.New("Missing or invalid Authorization header")
 298 var ContentLengthMismatch = errors.New("Actual length != expected content length")
 299 var MethodNotSupported = errors.New("Method not supported")
 300
 301 var removeHint, _ = regexp.Compile("\\+K@[a-z0-9]{5}(\\+|$)")
 302
 303 func (this GetBlockHandler) ServeHTTP(resp http.ResponseWriter, req *http.Request) {
 304         SetCorsHeaders(resp)
 305
 306         locator := mux.Vars(req)["locator"]
 307         var err error
 308         var status int
 309         var expectLength, responseLength int64
 310         var proxiedURI = "-"
 311
 312         defer func() {
 313                 log.Println(GetRemoteAddress(req), req.Method, req.URL.Path, status, expectLength, responseLength, proxiedURI, err)
 314                 if status != http.StatusOK {
 315                         http.Error(resp, err.Error(), status)
 316                 }
 317         }()
 318
 319         kc := *this.KeepClient
 320
 321         var pass bool
 322         var tok string
 323         if pass, tok = CheckAuthorizationHeader(kc, this.ApiTokenCache, req); !pass {
 324                 status, err = http.StatusForbidden, BadAuthorizationHeader
 325                 return
 326         }
 327
 328         // Copy ArvadosClient struct and use the client's API token
 329         arvclient := *kc.Arvados
 330         arvclient.ApiToken = tok
 331         kc.Arvados = &arvclient
 332
 333         var reader io.ReadCloser
 334
 335         locator = removeHint.ReplaceAllString(locator, "$1")
 336
 337         switch req.Method {
 338         case "HEAD":
 339                 expectLength, proxiedURI, err = kc.Ask(locator)
 340         case "GET":
 341                 reader, expectLength, proxiedURI, err = kc.Get(locator)
 342                 if reader != nil {
 343                         defer reader.Close()
 344                 }
 345         default:
 346                 status, err = http.StatusNotImplemented, MethodNotSupported
 347                 return
 348         }
 349
 350         if expectLength == -1 {
 351                 log.Println("Warning:", GetRemoteAddress(req), req.Method, proxiedURI, "Content-Length not provided")
 352         }
 353
 354         switch err {
 355         case nil:
 356                 status = http.StatusOK
 357                 resp.Header().Set("Content-Length", fmt.Sprint(expectLength))
 358                 switch req.Method {
 359                 case "HEAD":
 360                         responseLength = 0
 361                 case "GET":
 362                         responseLength, err = io.Copy(resp, reader)
 363                         if err == nil && expectLength > -1 && responseLength != expectLength {
 364                                 err = ContentLengthMismatch
 365                         }
 366                 }
 367         case keepclient.BlockNotFound:
 368                 status = http.StatusNotFound
 369         default:
 370                 status = http.StatusBadGateway
 371         }
 372 }
 373
 374 var LengthRequiredError = errors.New(http.StatusText(http.StatusLengthRequired))
 375 var LengthMismatchError = errors.New("Locator size hint does not match Content-Length header")
 376
 377 func (this PutBlockHandler) ServeHTTP(resp http.ResponseWriter, req *http.Request) {
 378         SetCorsHeaders(resp)
 379
 380         kc := *this.KeepClient
 381         var err error
 382         var expectLength int64 = -1
 383         var status = http.StatusInternalServerError
 384         var wroteReplicas int
 385         var locatorOut string = "-"
 386
 387         defer func() {
 388                 log.Println(GetRemoteAddress(req), req.Method, req.URL.Path, status, expectLength, kc.Want_replicas, wroteReplicas, locatorOut, err)
 389                 if status != http.StatusOK {
 390                         http.Error(resp, err.Error(), status)
 391                 }
 392         }()
 393
 394         locatorIn := mux.Vars(req)["locator"]
 395
 396         if req.Header.Get("Content-Length") != "" {
 397                 _, err := fmt.Sscanf(req.Header.Get("Content-Length"), "%d", &expectLength)
 398                 if err != nil {
 399                         resp.Header().Set("Content-Length", fmt.Sprintf("%d", expectLength))
 400                 }
 401
 402         }
 403
 404         if expectLength < 0 {
 405                 err = LengthRequiredError
 406                 status = http.StatusLengthRequired
 407                 return
 408         }
 409
 410         if locatorIn != "" {
 411                 var loc *keepclient.Locator
 412                 if loc, err = keepclient.MakeLocator(locatorIn); err != nil {
 413                         status = http.StatusBadRequest
 414                         return
 415                 } else if loc.Size > 0 && int64(loc.Size) != expectLength {
 416                         err = LengthMismatchError
 417                         status = http.StatusBadRequest
 418                         return
 419                 }
 420         }
 421
 422         var pass bool
 423         var tok string
 424         if pass, tok = CheckAuthorizationHeader(kc, this.ApiTokenCache, req); !pass {
 425                 err = BadAuthorizationHeader
 426                 status = http.StatusForbidden
 427                 return
 428         }
 429
 430         // Copy ArvadosClient struct and use the client's API token
 431         arvclient := *kc.Arvados
 432         arvclient.ApiToken = tok
 433         kc.Arvados = &arvclient
 434
 435         // Check if the client specified the number of replicas
 436         if req.Header.Get("X-Keep-Desired-Replicas") != "" {
 437                 var r int
 438                 _, err := fmt.Sscanf(req.Header.Get(keepclient.X_Keep_Desired_Replicas), "%d", &r)
 439                 if err != nil {
 440                         kc.Want_replicas = r
 441                 }
 442         }
 443
 444         // Now try to put the block through
 445         if locatorIn == "" {
 446                 if bytes, err := ioutil.ReadAll(req.Body); err != nil {
 447                         err = errors.New(fmt.Sprintf("Error reading request body: %s", err))
 448                         status = http.StatusInternalServerError
 449                         return
 450                 } else {
 451                         locatorOut, wroteReplicas, err = kc.PutB(bytes)
 452                 }
 453         } else {
 454                 locatorOut, wroteReplicas, err = kc.PutHR(locatorIn, req.Body, expectLength)
 455         }
 456
 457         // Tell the client how many successful PUTs we accomplished
 458         resp.Header().Set(keepclient.X_Keep_Replicas_Stored, fmt.Sprintf("%d", wroteReplicas))
 459
 460         switch err {
 461         case nil:
 462                 status = http.StatusOK
 463                 _, err = io.WriteString(resp, locatorOut)
 464
 465         case keepclient.OversizeBlockError:
 466                 // Too much data
 467                 status = http.StatusRequestEntityTooLarge
 468
 469         case keepclient.InsufficientReplicasError:
 470                 if wroteReplicas > 0 {
 471                         // At least one write is considered success.  The
 472                         // client can decide if getting less than the number of
 473                         // replications it asked for is a fatal error.
 474                         status = http.StatusOK
 475                         _, err = io.WriteString(resp, locatorOut)
 476                 } else {
 477                         status = http.StatusServiceUnavailable
 478                 }
 479
 480         default:
 481                 status = http.StatusBadGateway
 482         }
 483 }