gocheese.go

   1 /*
   2 GoCheese -- Python private package repository and caching proxy
   3 Copyright (C) 2019 Sergey Matveev <stargrave@stargrave.org>
   4               2019 Elena Balakhonova <balakhonova_e@riseup.net>
   5
   6 This program is free software: you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation, version 3 of the License.
   9
  10 This program is distributed in the hope that it will be useful,
  11 but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 GNU General Public License for more details.
  14
  15 You should have received a copy of the GNU General Public License
  16 along with this program.  If not, see <http://www.gnu.org/licenses/>.
  17 */
  18
  19 // Python private package repository and caching proxy
  20 package main
  21
  22 import (
  23         "bytes"
  24         "context"
  25         "crypto/sha256"
  26         "encoding/hex"
  27         "flag"
  28         "fmt"
  29         "io"
  30         "io/ioutil"
  31         "log"
  32         "net"
  33         "net/http"
  34         "net/url"
  35         "os"
  36         "os/signal"
  37         "path/filepath"
  38         "regexp"
  39         "runtime"
  40         "strings"
  41         "syscall"
  42         "time"
  43
  44         "golang.org/x/net/netutil"
  45 )
  46
  47 const (
  48         HTMLBegin = `<!DOCTYPE html>
  49 <html>
  50   <head>
  51     <title>Links for %s</title>
  52   </head>
  53   <body>
  54 `
  55         HTMLEnd      = "  </body>\n</html>\n"
  56         HTMLElement  = "    <a href=\"%s\"%s>%s</a><br/>\n"
  57         SHA256Prefix = "sha256="
  58         SHA256Ext    = ".sha256"
  59         InternalFlag = ".internal"
  60         GPGSigExt    = ".asc"
  61         GPGSigAttr   = " data-gpg-sig=true"
  62
  63         Warranty = `This program is free software: you can redistribute it and/or modify
  64 it under the terms of the GNU General Public License as published by
  65 the Free Software Foundation, version 3 of the License.
  66
  67 This program is distributed in the hope that it will be useful,
  68 but WITHOUT ANY WARRANTY; without even the implied warranty of
  69 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  70 GNU General Public License for more details.
  71
  72 You should have received a copy of the GNU General Public License
  73 along with this program.  If not, see <http://www.gnu.org/licenses/>.`
  74 )
  75
  76 var (
  77         pkgPyPI        = regexp.MustCompile(`^.*<a href="([^"]+)"[^>]*>(.+)</a><br/>.*$`)
  78         Version string = "UNKNOWN"
  79
  80         root             = flag.String("root", "./packages", "Path to packages directory")
  81         bind             = flag.String("bind", "[::]:8080", "Address to bind to")
  82         tlsCert          = flag.String("tls-cert", "", "Path to TLS X.509 certificate")
  83         tlsKey           = flag.String("tls-key", "", "Path to TLS X.509 private key")
  84         norefreshURLPath = flag.String("norefresh", "/norefresh/", "Non-refreshing URL path")
  85         refreshURLPath   = flag.String("refresh", "/simple/", "Auto-refreshing URL path")
  86         gpgUpdateURLPath = flag.String("gpgupdate", "/gpgupdate/", "GPG forceful refreshing URL path")
  87         pypiURL          = flag.String("pypi", "https://pypi.org/simple/", "Upstream PyPI URL")
  88         passwdPath       = flag.String("passwd", "passwd", "Path to file with authenticators")
  89         passwdCheck      = flag.Bool("passwd-check", false, "Test the -passwd file for syntax errors and exit")
  90         fsck             = flag.Bool("fsck", false, "Check integrity of all packages")
  91         maxClients       = flag.Int("maxclients", 128, "Maximal amount of simultaneous clients")
  92         version          = flag.Bool("version", false, "Print version information")
  93         warranty         = flag.Bool("warranty", false, "Print warranty information")
  94
  95         killed bool
  96
  97         normalizationRe *regexp.Regexp = regexp.MustCompilePOSIX("[-_.]+")
  98 )
  99
 100 func mkdirForPkg(w http.ResponseWriter, r *http.Request, dir string) bool {
 101         path := filepath.Join(*root, dir)
 102         if _, err := os.Stat(path); os.IsNotExist(err) {
 103                 if err = os.Mkdir(path, os.FileMode(0777)); err != nil {
 104                         http.Error(w, err.Error(), http.StatusInternalServerError)
 105                         return false
 106                 }
 107                 log.Println(r.RemoteAddr, "mkdir", dir)
 108         }
 109         return true
 110 }
 111
 112 func refreshDir(
 113         w http.ResponseWriter,
 114         r *http.Request,
 115         dir,
 116         filenameGet string,
 117         gpgUpdate bool,
 118 ) bool {
 119         if _, err := os.Stat(filepath.Join(*root, dir, InternalFlag)); err == nil {
 120                 return true
 121         }
 122         resp, err := http.Get(*pypiURL + dir + "/")
 123         if err != nil {
 124                 http.Error(w, err.Error(), http.StatusBadGateway)
 125                 return false
 126         }
 127         body, err := ioutil.ReadAll(resp.Body)
 128         resp.Body.Close()
 129         if err != nil {
 130                 http.Error(w, err.Error(), http.StatusBadGateway)
 131                 return false
 132         }
 133         if !mkdirForPkg(w, r, dir) {
 134                 return false
 135         }
 136         dirPath := filepath.Join(*root, dir)
 137         var submatches []string
 138         var uri string
 139         var filename string
 140         var path string
 141         var pkgURL *url.URL
 142         var digest []byte
 143         for _, lineRaw := range bytes.Split(body, []byte("\n")) {
 144                 submatches = pkgPyPI.FindStringSubmatch(string(lineRaw))
 145                 if len(submatches) == 0 {
 146                         continue
 147                 }
 148                 uri = submatches[1]
 149                 filename = submatches[2]
 150                 if pkgURL, err = url.Parse(uri); err != nil {
 151                         http.Error(w, err.Error(), http.StatusInternalServerError)
 152                         return false
 153                 }
 154                 if !strings.HasPrefix(pkgURL.Fragment, SHA256Prefix) {
 155                         log.Println(r.RemoteAddr, "pypi", filename, "no SHA256 digest provided")
 156                         http.Error(w, "no SHA256 digest provided", http.StatusBadGateway)
 157                         return false
 158                 }
 159                 digest, err = hex.DecodeString(strings.TrimPrefix(pkgURL.Fragment, SHA256Prefix))
 160                 if err != nil {
 161                         http.Error(w, err.Error(), http.StatusBadGateway)
 162                         return false
 163                 }
 164                 pkgURL.Fragment = ""
 165                 uri = pkgURL.String()
 166                 if pkgURL.Host == "" {
 167                         uri = *pypiURL + strings.TrimPrefix(uri, "/")
 168                 }
 169                 path = filepath.Join(dirPath, filename)
 170                 if filename == filenameGet {
 171                         if killed {
 172                                 // Skip heavy remote call, when shutting down
 173                                 http.Error(w, "shutting down", http.StatusInternalServerError)
 174                                 return false
 175                         }
 176                         log.Println(r.RemoteAddr, "pypi download", filename)
 177                         resp, err = http.Get(uri)
 178                         if err != nil {
 179                                 http.Error(w, err.Error(), http.StatusBadGateway)
 180                                 return false
 181                         }
 182                         defer resp.Body.Close()
 183                         hasher := sha256.New()
 184                         dst, err := TempFile(dirPath)
 185                         if err != nil {
 186                                 http.Error(w, err.Error(), http.StatusInternalServerError)
 187                                 return false
 188                         }
 189                         wr := io.MultiWriter(hasher, dst)
 190                         if _, err = io.Copy(wr, resp.Body); err != nil {
 191                                 os.Remove(dst.Name())
 192                                 dst.Close()
 193                                 http.Error(w, err.Error(), http.StatusInternalServerError)
 194                                 return false
 195                         }
 196                         if bytes.Compare(hasher.Sum(nil), digest) != 0 {
 197                                 log.Println(r.RemoteAddr, "pypi", filename, "digest mismatch")
 198                                 os.Remove(dst.Name())
 199                                 dst.Close()
 200                                 http.Error(w, err.Error(), http.StatusBadGateway)
 201                                 return false
 202                         }
 203                         if err = dst.Sync(); err != nil {
 204                                 os.Remove(dst.Name())
 205                                 dst.Close()
 206                                 http.Error(w, err.Error(), http.StatusInternalServerError)
 207                                 return false
 208                         }
 209                         dst.Close()
 210                         if err = os.Rename(dst.Name(), path); err != nil {
 211                                 http.Error(w, err.Error(), http.StatusInternalServerError)
 212                                 return false
 213                         }
 214                         if err = DirSync(dirPath); err != nil {
 215                                 http.Error(w, err.Error(), http.StatusInternalServerError)
 216                                 return false
 217                         }
 218                 }
 219                 if filename == filenameGet || gpgUpdate {
 220                         if _, err = os.Stat(path); err != nil {
 221                                 goto GPGSigSkip
 222                         }
 223                         resp, err := http.Get(uri + GPGSigExt)
 224                         if err != nil {
 225                                 goto GPGSigSkip
 226                         }
 227                         if resp.StatusCode != http.StatusOK {
 228                                 resp.Body.Close()
 229                                 goto GPGSigSkip
 230                         }
 231                         sig, err := ioutil.ReadAll(resp.Body)
 232                         resp.Body.Close()
 233                         if err != nil {
 234                                 goto GPGSigSkip
 235                         }
 236                         if err = WriteFileSync(dirPath, path+GPGSigExt, sig); err != nil {
 237                                 http.Error(w, err.Error(), http.StatusInternalServerError)
 238                                 return false
 239                         }
 240                         log.Println(r.RemoteAddr, "pypi downloaded signature", filename)
 241                 }
 242         GPGSigSkip:
 243                 path = path + SHA256Ext
 244                 _, err = os.Stat(path)
 245                 if err == nil {
 246                         continue
 247                 }
 248                 if !os.IsNotExist(err) {
 249                         http.Error(w, err.Error(), http.StatusInternalServerError)
 250                         return false
 251                 }
 252                 log.Println(r.RemoteAddr, "pypi touch", filename)
 253                 if err = WriteFileSync(dirPath, path, digest); err != nil {
 254                         http.Error(w, err.Error(), http.StatusInternalServerError)
 255                         return false
 256                 }
 257         }
 258         return true
 259 }
 260
 261 func listRoot(w http.ResponseWriter, r *http.Request) {
 262         files, err := ioutil.ReadDir(*root)
 263         if err != nil {
 264                 http.Error(w, err.Error(), http.StatusInternalServerError)
 265                 return
 266         }
 267         var result bytes.Buffer
 268         result.WriteString(fmt.Sprintf(HTMLBegin, "root"))
 269         for _, file := range files {
 270                 if file.Mode().IsDir() {
 271                         result.WriteString(fmt.Sprintf(
 272                                 HTMLElement,
 273                                 *refreshURLPath+file.Name()+"/",
 274                                 file.Name(),
 275                         ))
 276                 }
 277         }
 278         result.WriteString(HTMLEnd)
 279         w.Write(result.Bytes())
 280 }
 281
 282 func listDir(
 283         w http.ResponseWriter,
 284         r *http.Request,
 285         dir string,
 286         autorefresh,
 287         gpgUpdate bool,
 288 ) {
 289         dirPath := filepath.Join(*root, dir)
 290         if autorefresh {
 291                 if !refreshDir(w, r, dir, "", gpgUpdate) {
 292                         return
 293                 }
 294         } else if _, err := os.Stat(dirPath); os.IsNotExist(err) && !refreshDir(w, r, dir, "", false) {
 295                 return
 296         }
 297         files, err := ioutil.ReadDir(dirPath)
 298         if err != nil {
 299                 http.Error(w, err.Error(), http.StatusInternalServerError)
 300                 return
 301         }
 302         var result bytes.Buffer
 303         result.WriteString(fmt.Sprintf(HTMLBegin, dir))
 304         var data []byte
 305         var gpgSigAttr string
 306         var filenameClean string
 307         for _, file := range files {
 308                 if !strings.HasSuffix(file.Name(), SHA256Ext) {
 309                         continue
 310                 }
 311                 if killed {
 312                         // Skip expensive I/O when shutting down
 313                         http.Error(w, "shutting down", http.StatusInternalServerError)
 314                         return
 315                 }
 316                 data, err = ioutil.ReadFile(filepath.Join(dirPath, file.Name()))
 317                 if err != nil {
 318                         http.Error(w, err.Error(), http.StatusInternalServerError)
 319                         return
 320                 }
 321                 filenameClean = strings.TrimSuffix(file.Name(), SHA256Ext)
 322                 if _, err = os.Stat(filepath.Join(dirPath, filenameClean+GPGSigExt)); os.IsNotExist(err) {
 323                         gpgSigAttr = ""
 324                 } else {
 325                         gpgSigAttr = GPGSigAttr
 326                 }
 327                 result.WriteString(fmt.Sprintf(
 328                         HTMLElement,
 329                         strings.Join([]string{
 330                                 *refreshURLPath, dir, "/",
 331                                 filenameClean, "#", SHA256Prefix, hex.EncodeToString(data),
 332                         }, ""),
 333                         gpgSigAttr,
 334                         filenameClean,
 335                 ))
 336         }
 337         result.WriteString(HTMLEnd)
 338         w.Write(result.Bytes())
 339 }
 340
 341 func servePkg(w http.ResponseWriter, r *http.Request, dir, filename string) {
 342         log.Println(r.RemoteAddr, "get", filename)
 343         path := filepath.Join(*root, dir, filename)
 344         if _, err := os.Stat(path); os.IsNotExist(err) {
 345                 if !refreshDir(w, r, dir, filename, false) {
 346                         return
 347                 }
 348         }
 349         http.ServeFile(w, r, path)
 350 }
 351
 352 func serveUpload(w http.ResponseWriter, r *http.Request) {
 353         // Authentication
 354         username, password, ok := r.BasicAuth()
 355         if !ok {
 356                 log.Println(r.RemoteAddr, "unauthenticated", username)
 357                 http.Error(w, "unauthenticated", http.StatusUnauthorized)
 358                 return
 359         }
 360         auther, ok := passwords[username]
 361         if !ok || !auther.Auth(password) {
 362                 log.Println(r.RemoteAddr, "unauthenticated", username)
 363                 http.Error(w, "unauthenticated", http.StatusUnauthorized)
 364                 return
 365         }
 366
 367         // Form parsing
 368         var err error
 369         if err = r.ParseMultipartForm(1 << 20); err != nil {
 370                 http.Error(w, err.Error(), http.StatusBadRequest)
 371                 return
 372         }
 373         pkgNames, exists := r.MultipartForm.Value["name"]
 374         if !exists || len(pkgNames) != 1 {
 375                 http.Error(w, "single name is expected in request", http.StatusBadRequest)
 376                 return
 377         }
 378         dir := normalizationRe.ReplaceAllString(pkgNames[0], "-")
 379         dirPath := filepath.Join(*root, dir)
 380         var digestExpected []byte
 381         if digestExpectedHex, exists := r.MultipartForm.Value["sha256_digest"]; exists {
 382                 digestExpected, err = hex.DecodeString(digestExpectedHex[0])
 383                 if err != nil {
 384                         http.Error(w, "bad sha256_digest: "+err.Error(), http.StatusBadRequest)
 385                         return
 386                 }
 387         }
 388         gpgSigsExpected := make(map[string]struct{})
 389
 390         // Checking is it internal package
 391         if _, err = os.Stat(filepath.Join(dirPath, InternalFlag)); err != nil {
 392                 log.Println(r.RemoteAddr, "non-internal package", dir)
 393                 http.Error(w, "unknown internal package", http.StatusUnauthorized)
 394                 return
 395         }
 396
 397         for _, file := range r.MultipartForm.File["content"] {
 398                 filename := file.Filename
 399                 gpgSigsExpected[filename+GPGSigExt] = struct{}{}
 400                 log.Println(r.RemoteAddr, "put", filename, "by", username)
 401                 path := filepath.Join(dirPath, filename)
 402                 if _, err = os.Stat(path); err == nil {
 403                         log.Println(r.RemoteAddr, "already exists", filename)
 404                         http.Error(w, "already exists", http.StatusBadRequest)
 405                         return
 406                 }
 407                 if !mkdirForPkg(w, r, dir) {
 408                         return
 409                 }
 410                 src, err := file.Open()
 411                 defer src.Close()
 412                 if err != nil {
 413                         http.Error(w, err.Error(), http.StatusInternalServerError)
 414                         return
 415                 }
 416                 dst, err := TempFile(dirPath)
 417                 if err != nil {
 418                         http.Error(w, err.Error(), http.StatusInternalServerError)
 419                         return
 420                 }
 421                 hasher := sha256.New()
 422                 wr := io.MultiWriter(hasher, dst)
 423                 if _, err = io.Copy(wr, src); err != nil {
 424                         os.Remove(dst.Name())
 425                         dst.Close()
 426                         http.Error(w, err.Error(), http.StatusInternalServerError)
 427                         return
 428                 }
 429                 if err = dst.Sync(); err != nil {
 430                         os.Remove(dst.Name())
 431                         dst.Close()
 432                         http.Error(w, err.Error(), http.StatusInternalServerError)
 433                         return
 434                 }
 435                 dst.Close()
 436                 digest := hasher.Sum(nil)
 437                 if digestExpected != nil {
 438                         if bytes.Compare(digestExpected, digest) == 0 {
 439                                 log.Println(r.RemoteAddr, filename, "good checksum received")
 440                         } else {
 441                                 log.Println(r.RemoteAddr, filename, "bad checksum received")
 442                                 http.Error(w, "bad checksum", http.StatusBadRequest)
 443                                 os.Remove(dst.Name())
 444                                 return
 445                         }
 446                 }
 447                 if err = os.Rename(dst.Name(), path); err != nil {
 448                         http.Error(w, err.Error(), http.StatusInternalServerError)
 449                         return
 450                 }
 451                 if err = DirSync(dirPath); err != nil {
 452                         http.Error(w, err.Error(), http.StatusInternalServerError)
 453                         return
 454                 }
 455                 if err = WriteFileSync(dirPath, path+SHA256Ext, digest); err != nil {
 456                         http.Error(w, err.Error(), http.StatusInternalServerError)
 457                         return
 458                 }
 459         }
 460         for _, file := range r.MultipartForm.File["gpg_signature"] {
 461                 filename := file.Filename
 462                 if _, exists := gpgSigsExpected[filename]; !exists {
 463                         http.Error(w, "unexpected GPG signature filename", http.StatusBadRequest)
 464                         return
 465                 }
 466                 delete(gpgSigsExpected, filename)
 467                 log.Println(r.RemoteAddr, "put", filename, "by", username)
 468                 path := filepath.Join(dirPath, filename)
 469                 if _, err = os.Stat(path); err == nil {
 470                         log.Println(r.RemoteAddr, "already exists", filename)
 471                         http.Error(w, "already exists", http.StatusBadRequest)
 472                         return
 473                 }
 474                 src, err := file.Open()
 475                 if err != nil {
 476                         http.Error(w, err.Error(), http.StatusInternalServerError)
 477                         return
 478                 }
 479                 sig, err := ioutil.ReadAll(src)
 480                 src.Close()
 481                 if err != nil {
 482                         http.Error(w, err.Error(), http.StatusInternalServerError)
 483                         return
 484                 }
 485                 if err = WriteFileSync(dirPath, path, sig); err != nil {
 486                         http.Error(w, err.Error(), http.StatusInternalServerError)
 487                         return
 488                 }
 489         }
 490 }
 491
 492 func handler(w http.ResponseWriter, r *http.Request) {
 493         switch r.Method {
 494         case "GET":
 495                 var path string
 496                 var autorefresh bool
 497                 var gpgUpdate bool
 498                 if strings.HasPrefix(r.URL.Path, *norefreshURLPath) {
 499                         path = strings.TrimPrefix(r.URL.Path, *norefreshURLPath)
 500                 } else if strings.HasPrefix(r.URL.Path, *refreshURLPath) {
 501                         path = strings.TrimPrefix(r.URL.Path, *refreshURLPath)
 502                         autorefresh = true
 503                 } else if strings.HasPrefix(r.URL.Path, *gpgUpdateURLPath) {
 504                         path = strings.TrimPrefix(r.URL.Path, *gpgUpdateURLPath)
 505                         autorefresh = true
 506                         gpgUpdate = true
 507                 } else {
 508                         http.Error(w, "unknown action", http.StatusBadRequest)
 509                         return
 510                 }
 511                 parts := strings.Split(strings.TrimSuffix(path, "/"), "/")
 512                 if len(parts) > 2 {
 513                         http.Error(w, "invalid path", http.StatusBadRequest)
 514                         return
 515                 }
 516                 if len(parts) == 1 {
 517                         if parts[0] == "" {
 518                                 listRoot(w, r)
 519                         } else {
 520                                 listDir(w, r, parts[0], autorefresh, gpgUpdate)
 521                         }
 522                 } else {
 523                         servePkg(w, r, parts[0], parts[1])
 524                 }
 525         case "POST":
 526                 serveUpload(w, r)
 527         default:
 528                 http.Error(w, "unknown action", http.StatusBadRequest)
 529         }
 530 }
 531
 532 func goodIntegrity() bool {
 533         dirs, err := ioutil.ReadDir(*root)
 534         if err != nil {
 535                 log.Fatal(err)
 536         }
 537         hasher := sha256.New()
 538         digest := make([]byte, sha256.Size)
 539         isGood := true
 540         var data []byte
 541         var pkgName string
 542         for _, dir := range dirs {
 543                 files, err := ioutil.ReadDir(filepath.Join(*root, dir.Name()))
 544                 if err != nil {
 545                         log.Fatal(err)
 546                 }
 547                 for _, file := range files {
 548                         if !strings.HasSuffix(file.Name(), SHA256Ext) {
 549                                 continue
 550                         }
 551                         pkgName = strings.TrimSuffix(file.Name(), SHA256Ext)
 552                         data, err = ioutil.ReadFile(filepath.Join(*root, dir.Name(), pkgName))
 553                         if err != nil {
 554                                 if os.IsNotExist(err) {
 555                                         continue
 556                                 }
 557                                 log.Fatal(err)
 558                         }
 559                         hasher.Write(data)
 560                         data, err = ioutil.ReadFile(filepath.Join(*root, dir.Name(), file.Name()))
 561                         if err != nil {
 562                                 log.Fatal(err)
 563                         }
 564                         if bytes.Compare(hasher.Sum(digest[:0]), data) == 0 {
 565                                 fmt.Println(pkgName, "GOOD")
 566                         } else {
 567                                 isGood = false
 568                                 fmt.Println(pkgName, "BAD")
 569                         }
 570                         hasher.Reset()
 571                 }
 572         }
 573         return isGood
 574 }
 575
 576 func main() {
 577         flag.Parse()
 578         if *warranty {
 579                 fmt.Println(Warranty)
 580                 return
 581         }
 582         if *version {
 583                 fmt.Println("GoCheese version " + Version + " built with " + runtime.Version())
 584                 return
 585         }
 586         if *fsck {
 587                 if !goodIntegrity() {
 588                         os.Exit(1)
 589                 }
 590                 return
 591         }
 592         if *passwdCheck {
 593                 refreshPasswd()
 594                 return
 595         }
 596         if (*tlsCert != "" && *tlsKey == "") || (*tlsCert == "" && *tlsKey != "") {
 597                 log.Fatalln("Both -tls-cert and -tls-key are required")
 598         }
 599         refreshPasswd()
 600         log.Println("root:", *root, "bind:", *bind)
 601
 602         ln, err := net.Listen("tcp", *bind)
 603         if err != nil {
 604                 log.Fatal(err)
 605         }
 606         ln = netutil.LimitListener(ln, *maxClients)
 607         server := &http.Server{
 608                 ReadTimeout:  time.Minute,
 609                 WriteTimeout: time.Minute,
 610         }
 611         http.HandleFunc(*norefreshURLPath, handler)
 612         http.HandleFunc(*refreshURLPath, handler)
 613         http.HandleFunc(*gpgUpdateURLPath, handler)
 614
 615         needsRefreshPasswd := make(chan os.Signal, 0)
 616         needsShutdown := make(chan os.Signal, 0)
 617         exitErr := make(chan error, 0)
 618         signal.Notify(needsRefreshPasswd, syscall.SIGHUP)
 619         signal.Notify(needsShutdown, syscall.SIGTERM, syscall.SIGINT)
 620         go func() {
 621                 for range needsRefreshPasswd {
 622                         log.Println("Refreshing passwords")
 623                         refreshPasswd()
 624                 }
 625         }()
 626         go func(s *http.Server) {
 627                 <-needsShutdown
 628                 killed = true
 629                 log.Println("Shutting down")
 630                 ctx, cancel := context.WithTimeout(context.TODO(), time.Minute)
 631                 exitErr <- s.Shutdown(ctx)
 632                 cancel()
 633         }(server)
 634
 635         if *tlsCert == "" {
 636                 err = server.Serve(ln)
 637         } else {
 638                 err = server.ServeTLS(ln, *tlsCert, *tlsKey)
 639         }
 640         if err != http.ErrServerClosed {
 641                 log.Fatal(err)
 642         }
 643         if err := <-exitErr; err != nil {
 644                 log.Fatal(err)
 645         }
 646 }