main.go

   1 /*
   2  * Copyright (C) 2017 "IoT.bzh"
   3  * Author Sebastien Douheret <sebastien@iot.bzh>
   4  *
   5  * Licensed under the Apache License, Version 2.0 (the "License");
   6  * you may not use this file except in compliance with the License.
   7  * You may obtain a copy of the License at
   8  *
   9  *   http://www.apache.org/licenses/LICENSE-2.0
  10  *
  11  * Unless required by applicable law or agreed to in writing, software
  12  * distributed under the License is distributed on an "AS IS" BASIS,
  13  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  14  * See the License for the specific language governing permissions and
  15  * limitations under the License.
  16  *
  17  *
  18  * xds-gdb: a wrapper on gdb tool for X(cross) Development System.
  19  */
  20
  21 package main
  22
  23 import (
  24         "bufio"
  25         "fmt"
  26         "io/ioutil"
  27         "os"
  28         "os/signal"
  29         "os/user"
  30         "syscall"
  31         "time"
  32
  33         "strings"
  34
  35         "path"
  36
  37         "github.com/Sirupsen/logrus"
  38         "github.com/codegangsta/cli"
  39         common "github.com/iotbzh/xds-common/golib"
  40         "github.com/joho/godotenv"
  41 )
  42
  43 var appAuthors = []cli.Author{
  44         cli.Author{Name: "Sebastien Douheret", Email: "sebastien@iot.bzh"},
  45 }
  46
  47 // AppName name of this application
  48 var AppName = "xds-gdb"
  49
  50 // AppVersion Version of this application
  51 // (set by Makefile)
  52 var AppVersion = "?.?.?"
  53
  54 // AppSubVersion is the git tag id added to version string
  55 // Should be set by compilation -ldflags "-X main.AppSubVersion=xxx"
  56 // (set by Makefile)
  57 var AppSubVersion = "unknown-dev"
  58
  59 // Create logger
  60 var log = logrus.New()
  61 var logFileInitial = "/tmp/xds-gdb.log"
  62
  63 // Application details
  64 const (
  65         appCopyright    = "Copyright (C) 2017 IoT.bzh - Apache-2.0"
  66         defaultLogLevel = "warning"
  67 )
  68
  69 // Exit events
  70 type exitResult struct {
  71         error error
  72         code  int
  73 }
  74
  75 // EnvVar - Environment variables used by application
  76 type EnvVar struct {
  77         Name        string
  78         Usage       string
  79         Destination *string
  80 }
  81
  82 // exitError terminates this program with the specified error
  83 func exitError(code syscall.Errno, f string, a ...interface{}) {
  84         err := fmt.Sprintf(f, a...)
  85         fmt.Fprintf(os.Stderr, err+"\n")
  86         log.Debugf("Exit: code=%v, err=%s", code, err)
  87
  88         os.Exit(int(code))
  89 }
  90
  91 // main
  92 func main() {
  93         var agentURL, serverURL string
  94         var prjID, rPath, logLevel, logFile, sdkid, confFile, gdbNative string
  95         var listProject bool
  96         var err error
  97
  98         // Init Logger and set temporary file and level for the 1st part
  99         // IOW while XDS_LOGLEVEL and XDS_LOGFILE options are not parsed
 100         logFile = logFileInitial
 101         fdL, err := os.OpenFile(logFileInitial, os.O_CREATE|os.O_TRUNC|os.O_WRONLY, 0666)
 102         if err != nil {
 103                 msgErr := fmt.Sprintf("Cannot create log file %s", logFileInitial)
 104                 exitError(syscall.EPERM, msgErr)
 105         }
 106         log.Formatter = &logrus.TextFormatter{}
 107         log.Out = fdL
 108         log.Level = logrus.DebugLevel
 109
 110         agentURL = "localhost:8000"
 111         logLevel = defaultLogLevel
 112
 113         // Create a new App instance
 114         app := cli.NewApp()
 115         app.Name = AppName
 116         app.Usage = "wrapper on gdb for X(cross) Development System."
 117         app.Version = AppVersion + " (" + AppSubVersion + ")"
 118         app.Authors = appAuthors
 119         app.Copyright = appCopyright
 120         app.Metadata = make(map[string]interface{})
 121         app.Metadata["version"] = AppVersion
 122         app.Metadata["git-tag"] = AppSubVersion
 123         app.Metadata["logger"] = log
 124
 125         app.Flags = []cli.Flag{
 126                 cli.BoolFlag{
 127                         Name:        "list, ls",
 128                         Usage:       "list existing xds projects",
 129                         Destination: &listProject,
 130                 },
 131         }
 132
 133         appEnvVars := []EnvVar{
 134                 EnvVar{
 135                         Name:        "XDS_CONFIG",
 136                         Usage:       "env config file to source on startup",
 137                         Destination: &confFile,
 138                 },
 139                 EnvVar{
 140                         Name:        "XDS_LOGLEVEL",
 141                         Usage:       "logging level (supported levels: panic, fatal, error, warn, info, debug)",
 142                         Destination: &logLevel,
 143                 },
 144                 EnvVar{
 145                         Name:        "XDS_LOGFILE",
 146                         Usage:       "logging file (default: " + logFileInitial + ")",
 147                         Destination: &logFile,
 148                 },
 149                 EnvVar{
 150                         Name:        "XDS_NATIVE_GDB",
 151                         Usage:       "use native gdb instead of remote XDS server",
 152                         Destination: &gdbNative,
 153                 },
 154                 EnvVar{
 155                         Name:        "XDS_PROJECT_ID",
 156                         Usage:       "project ID you want to build (mandatory variable)",
 157                         Destination: &prjID,
 158                 },
 159                 EnvVar{
 160                         Name:        "XDS_RPATH",
 161                         Usage:       "relative path into project",
 162                         Destination: &rPath,
 163                 },
 164                 EnvVar{
 165                         Name:        "XDS_SDK_ID",
 166                         Usage:       "Cross Sdk ID to use to build project",
 167                         Destination: &sdkid,
 168                 },
 169                 EnvVar{
 170                         Name:        "XDS_AGENT_URL",
 171                         Usage:       "local XDS agent url",
 172                         Destination: &agentURL,
 173                 },
 174                 EnvVar{
 175                         Name:        "XDS_SERVER_URL",
 176                         Usage:       "overwrite remote XDS server url (default value set in xds-agent-config.json file)",
 177                         Destination: &serverURL,
 178                 },
 179         }
 180
 181         // Process gdb arguments
 182         log.Debugf("xds-gdb started with args: %v", os.Args)
 183         args := make([]string, len(os.Args))
 184         args[0] = os.Args[0]
 185         gdbArgs := make([]string, len(os.Args))
 186
 187         // Split xds-xxx options from gdb options
 188         copy(gdbArgs, os.Args[1:])
 189         for idx, a := range os.Args[1:] {
 190                 // Specific case to print help or version of xds-gdb
 191                 switch a {
 192                 case "--help", "-h", "--version", "-v", "--list", "-ls":
 193                         args[1] = a
 194                         goto endloop
 195                 case "--":
 196                         // Detect skip option (IOW '--') to split arguments
 197                         copy(args, os.Args[0:idx+1])
 198                         copy(gdbArgs, os.Args[idx+2:])
 199                         goto endloop
 200                 }
 201         }
 202 endloop:
 203
 204         // Parse gdb arguments to detect:
 205         //  --tty option: used for inferior/ tty of debugged program
 206         //  -x/--command option: XDS env vars may be set within gdb command file
 207         clientPty := ""
 208         gdbCmdFile := ""
 209         for idx, a := range gdbArgs {
 210                 switch {
 211                 case strings.HasPrefix(a, "--tty="):
 212                         clientPty = a[len("--tty="):]
 213                         gdbArgs[idx] = ""
 214
 215                 case a == "--tty":
 216                 case strings.HasPrefix(a, "-tty"):
 217                         clientPty = gdbArgs[idx+1]
 218                         gdbArgs[idx] = ""
 219                         gdbArgs[idx+1] = ""
 220
 221                 case strings.HasPrefix(a, "--command="):
 222                         gdbCmdFile = a[len("--command="):]
 223
 224                 case a == "--command":
 225                 case strings.HasPrefix(a, "-x"):
 226                         gdbCmdFile = gdbArgs[idx+1]
 227                 }
 228         }
 229
 230         // Source config env file
 231         // (we cannot use confFile var because env variables setting is just after)
 232         envMap, confFile, err := loadConfigEnvFile(os.Getenv("XDS_CONFIG"), gdbCmdFile)
 233         log.Infof("Load env config: envMap=%v, confFile=%v, err=%v", envMap, confFile, err)
 234
 235         // Only rise an error when args is not set (IOW when --help or --version is not set)
 236         if len(args) == 1 {
 237                 if err != nil {
 238                         exitError(syscall.ENOENT, err.Error())
 239                 }
 240         }
 241
 242         // Managed env vars and create help
 243         dynDesc := "\nENVIRONMENT VARIABLES:"
 244         for _, ev := range appEnvVars {
 245                 dynDesc += fmt.Sprintf("\n %s \t\t %s", ev.Name, ev.Usage)
 246                 if evVal, evExist := os.LookupEnv(ev.Name); evExist && ev.Destination != nil {
 247                         *ev.Destination = evVal
 248                 }
 249         }
 250         app.Description = "gdb wrapper for X(cross) Development System\n"
 251         app.Description += "\n"
 252         app.Description += " Two debugging models are supported:\n"
 253         app.Description += "  - xds remote debugging requiring an XDS server and allowing cross debug\n"
 254         app.Description += "  - native debugging\n"
 255         app.Description += " By default xds remote debug is used and you need to define XDS_NATIVE_GDB to\n"
 256         app.Description += " use native gdb debug mode instead.\n"
 257         app.Description += "\n"
 258         app.Description += " xds-gdb configuration (see variables list below) can be set using:\n"
 259         app.Description += "  - a config file (XDS_CONFIG)\n"
 260         app.Description += "  - or environment variables\n"
 261         app.Description += "  - or by setting variables within gdb ini file (commented line including :XDS-ENV: tag)\n"
 262         app.Description += "    Example of gdb ini file where we define project and sdk ID:\n"
 263         app.Description += "     # :XDS-ENV: XDS_PROJECT_ID=IW7B4EE-DBY4Z74_myProject\n"
 264         app.Description += "     # :XDS-ENV: XDS_SDK_ID=poky-agl_aarch64_3.99.1+snapshot\n"
 265         app.Description += "\n"
 266         app.Description += dynDesc + "\n"
 267
 268         // only one action
 269         app.Action = func(ctx *cli.Context) error {
 270                 var err error
 271                 curDir, _ := os.Getwd()
 272
 273                 // Build env variables
 274                 env := []string{}
 275                 for k, v := range envMap {
 276                         env = append(env, k+"="+v)
 277                 }
 278
 279                 // Now set logger level and log file to correct/env var settings
 280                 if log.Level, err = logrus.ParseLevel(logLevel); err != nil {
 281                         msg := fmt.Sprintf("Invalid log level : \"%v\"\n", logLevel)
 282                         return cli.NewExitError(msg, int(syscall.EINVAL))
 283                 }
 284                 log.Infof("Switch log level to %s", logLevel)
 285
 286                 if logFile != logFileInitial {
 287                         log.Infof("Switch logging to log file %s", logFile)
 288
 289                         fdL, err := os.OpenFile(logFile, os.O_CREATE|os.O_TRUNC|os.O_WRONLY, 0666)
 290                         if err != nil {
 291                                 msgErr := fmt.Sprintf("Cannot create log file %s", logFile)
 292                                 return cli.NewExitError(msgErr, int(syscall.EPERM))
 293                         }
 294                         defer fdL.Close()
 295                         log.Out = fdL
 296                 }
 297
 298                 // Create cross or native gdb interface
 299                 var gdb IGDB
 300                 if gdbNative != "" {
 301                         gdb = NewGdbNative(log, gdbArgs, env)
 302                 } else {
 303                         gdb = NewGdbXds(log, gdbArgs, env)
 304                         gdb.SetConfig("agentURL", agentURL)
 305                         gdb.SetConfig("serverURL", serverURL)
 306                         gdb.SetConfig("prjID", prjID)
 307                         gdb.SetConfig("sdkID", sdkid)
 308                         gdb.SetConfig("rPath", rPath)
 309                         gdb.SetConfig("listProject", listProject)
 310                 }
 311
 312                 // Log useful info
 313                 log.Infof("Original arguments: %v", os.Args)
 314                 log.Infof("Current directory : %v", curDir)
 315                 log.Infof("Use confFile      : '%s'", confFile)
 316                 log.Infof("Execute           : /exec %v %v", gdb.Cmd(), gdb.Args())
 317
 318                 // Properly report invalid init file error
 319                 gdbCommandFileError := ""
 320                 for i, a := range gdbArgs {
 321                         if a == "-x" {
 322                                 gdbCommandFileError = gdbArgs[i+1] + ": No such file or directory."
 323                                 break
 324                         } else if strings.HasPrefix(a, "--command=") {
 325                                 gdbCommandFileError = strings.TrimLeft(a, "--command=") + ": No such file or directory."
 326                                 break
 327                         }
 328                 }
 329                 log.Infof("Add detection of error: <%s>", gdbCommandFileError)
 330
 331                 // Init gdb subprocess management
 332                 if code, err := gdb.Init(); err != nil {
 333                         return cli.NewExitError(err.Error(), code)
 334                 }
 335
 336                 exitChan := make(chan exitResult, 1)
 337
 338                 gdb.OnError(func(err error) {
 339                         fmt.Println("ERROR: ", err.Error())
 340                 })
 341
 342                 gdb.OnDisconnect(func(err error) {
 343                         fmt.Println("Disconnection: ", err.Error())
 344                         exitChan <- exitResult{err, int(syscall.ESHUTDOWN)}
 345                 })
 346
 347                 gdb.Read(func(timestamp, stdout, stderr string) {
 348                         if stdout != "" {
 349                                 fmt.Printf("%s", stdout)
 350                                 log.Debugf("Recv OUT: <%s>", stdout)
 351                         }
 352                         if stderr != "" {
 353                                 fmt.Fprintf(os.Stderr, "%s", stderr)
 354                                 log.Debugf("Recv ERR: <%s>", stderr)
 355                         }
 356
 357                         // Correctly report error about init file
 358                         if gdbCommandFileError != "" && strings.Contains(stdout, gdbCommandFileError) {
 359                                 fmt.Fprintf(os.Stderr, "ERROR: "+gdbCommandFileError)
 360                                 log.Errorf("ERROR: " + gdbCommandFileError)
 361                                 if err := gdb.SendSignal(syscall.SIGTERM); err != nil {
 362                                         log.Errorf("Error while sending signal: %s", err.Error())
 363                                 }
 364                                 exitChan <- exitResult{err, int(syscall.ENOENT)}
 365                         }
 366                 })
 367
 368                 gdb.OnExit(func(code int, err error) {
 369                         exitChan <- exitResult{err, code}
 370                 })
 371
 372                 // Handle client tty / pts
 373                 if clientPty != "" {
 374                         log.Infoln("Client tty detected: %v", clientPty)
 375
 376                         cpFd, err := os.OpenFile(clientPty, os.O_RDWR, 0)
 377                         if err != nil {
 378                                 return cli.NewExitError(err.Error(), int(syscall.EPERM))
 379                         }
 380                         defer cpFd.Close()
 381
 382                         // client tty stdin
 383                         /* XXX TODO - implement stdin to send data to debugged program
 384                         go func() {
 385                                 reader := bufio.NewReader(cpFd)
 386                                 sc := bufio.NewScanner(reader)
 387                                 for sc.Scan() {
 388                                         data := sc.Text()
 389                                         iosk.Emit(xaapiv1.ExecInferiorInEvent, data+"\n")
 390                                         log.Debugf("Inferior IN: <%v>", data)
 391                                 }
 392                                 if sc.Err() != nil {
 393                                         log.Warnf("Inferior Stdin scanner exit, close stdin (err=%v)", sc.Err())
 394                                 }
 395                         }()
 396                         */
 397
 398                         // client tty stdout
 399                         gdb.InferiorRead(func(timestamp, stdout, stderr string) {
 400                                 if stdout != "" {
 401                                         fmt.Fprintf(cpFd, "%s", stdout)
 402                                         log.Debugf("Inferior OUT: <%s>", stdout)
 403                                 }
 404                                 if stderr != "" {
 405                                         fmt.Fprintf(cpFd, "%s", stderr)
 406                                         log.Debugf("Inferior ERR: <%s>", stderr)
 407                                 }
 408                         })
 409                 }
 410
 411                 // Allow to overwrite some gdb commands
 412                 var overwriteMap = make(map[string]string)
 413                 if overEnv, exist := os.LookupEnv("XDS_OVERWRITE_COMMANDS"); exist {
 414                         overEnvS := strings.TrimSpace(overEnv)
 415                         if len(overEnvS) > 0 {
 416                                 // Extract overwrite commands from env variable
 417                                 for _, def := range strings.Split(overEnvS, ",") {
 418                                         if kv := strings.Split(def, ":"); len(kv) == 2 {
 419                                                 overwriteMap[strings.TrimSpace(kv[0])] = strings.TrimSpace(kv[1])
 420                                         } else {
 421                                                 return cli.NewExitError(
 422                                                         fmt.Errorf("Invalid definition in XDS_OVERWRITE_COMMANDS (%s)", def),
 423                                                         int(syscall.EINVAL))
 424                                         }
 425                                 }
 426                         }
 427                 } else {
 428                         overwriteMap["-exec-run"] = "-exec-continue"
 429                         overwriteMap["-file-exec-and-symbols"] = "-file-exec-file"
 430                 }
 431                 log.Debugf("overwriteMap = %v", overwriteMap)
 432
 433                 // Send stdin though WS
 434                 go func() {
 435                         paranoia := 600
 436                         reader := bufio.NewReader(os.Stdin)
 437
 438                         // Enable workaround to correctly close connection
 439                         // except if XDS_GDBSERVER_EXIT_NOFIX is defined
 440                         _, gdbExitNoFix := os.LookupEnv("XDS_GDBSERVER_EXIT_NOFIX")
 441
 442                         for {
 443                                 sc := bufio.NewScanner(reader)
 444                                 for sc.Scan() {
 445                                         command := sc.Text()
 446
 447                                         // overwrite some commands
 448                                         for key, value := range overwriteMap {
 449                                                 if strings.Contains(command, key) {
 450                                                         command = strings.Replace(command, key, value, 1)
 451                                                         log.Debugf("OVERWRITE %s -> %s", key, value)
 452                                                 }
 453                                         }
 454
 455                                         // Send SIGINT to stop debugged process execution before sending -gdb-exit command
 456                                         if !gdbExitNoFix && strings.Contains(command, "-gdb-exit") {
 457                                                 log.Infof("Detection of -gdb-exit, exiting...")
 458                                                 if err := gdb.SendSignal(syscall.SIGINT); err != nil {
 459                                                         log.Errorf("Error while sending signal SIGINT : %s", err.Error())
 460                                                 }
 461                                                 time.Sleep(time.Millisecond * 200)
 462                                         }
 463
 464                                         gdb.Write(command + "\n")
 465                                         log.Debugf("Send: <%v>", command)
 466                                 }
 467                                 log.Infof("Stdin scanner exit, close stdin (err=%v)", sc.Err())
 468
 469                                 // CTRL-D exited scanner, so send it explicitly
 470                                 gdb.Write("\x04")
 471                                 time.Sleep(time.Millisecond * 100)
 472
 473                                 if paranoia--; paranoia <= 0 {
 474                                         msg := "Abnormal loop detected on stdin"
 475                                         log.Errorf("Abnormal loop detected on stdin")
 476                                         gdb.SendSignal(syscall.SIGTERM)
 477                                         exitChan <- exitResult{fmt.Errorf(msg), int(syscall.ELOOP)}
 478                                 }
 479                         }
 480                 }()
 481
 482                 // Handling all Signals
 483                 sigs := make(chan os.Signal, 1)
 484                 signal.Notify(sigs)
 485
 486                 go func() {
 487                         for {
 488                                 sig := <-sigs
 489
 490                                 if isIgnoredSignal(sig) {
 491                                         return
 492                                 }
 493
 494                                 if err := gdb.SendSignal(sig); err != nil {
 495                                         log.Errorf("Error while sending signal %v : %s", sig, err.Error())
 496                                 }
 497                         }
 498                 }()
 499
 500                 // Start gdb
 501                 if code, err := gdb.Start(clientPty != ""); err != nil {
 502                         return cli.NewExitError(err.Error(), code)
 503                 }
 504
 505                 // Wait exit
 506                 select {
 507                 case res := <-exitChan:
 508                         errStr := ""
 509                         if res.code == 0 {
 510                                 log.Infoln("Exit successfully")
 511                         }
 512                         if res.error != nil {
 513                                 log.Infoln("Exit with ERROR: ", res.error.Error())
 514                                 errStr = res.error.Error()
 515                         }
 516                         return cli.NewExitError(errStr, res.code)
 517                 }
 518         }
 519
 520         app.Run(args)
 521 }
 522
 523 // loadConfigEnvFile
 524 func loadConfigEnvFile(confFile, gdbCmdFile string) (map[string]string, string, error) {
 525         var err error
 526         envMap := make(map[string]string)
 527
 528         // 1- if no confFile set, use setting from gdb command file is option
 529         //    --command/-x is set
 530         if confFile == "" && gdbCmdFile != "" {
 531                 log.Infof("Try extract config from gdbCmdFile: %s", gdbCmdFile)
 532                 confFile, err = extractEnvFromCmdFile(gdbCmdFile)
 533                 if confFile != "" {
 534                         defer os.Remove(confFile)
 535                 }
 536                 if err != nil {
 537                         log.Infof("Extraction from gdbCmdFile failed: %v", err.Error())
 538                 }
 539         }
 540         // 2- search xds-gdb.env file in various locations
 541         if confFile == "" {
 542                 curDir, _ := os.Getwd()
 543                 if u, err := user.Current(); err == nil {
 544                         xdsEnvFile := "xds-gdb.env"
 545                         for _, d := range []string{
 546                                 path.Join(curDir),
 547                                 path.Join(curDir, ".."),
 548                                 path.Join(curDir, "target"),
 549                                 path.Join(u.HomeDir, ".config", "xds"),
 550                         } {
 551                                 cf := path.Join(d, xdsEnvFile)
 552                                 log.Infof("Search config in %s", cf)
 553                                 if common.Exists(cf) {
 554                                         confFile = cf
 555                                         break
 556                                 }
 557                         }
 558                 }
 559         }
 560
 561         if confFile == "" {
 562                 log.Infof("NO valid conf file found!")
 563                 return envMap, "", nil
 564         }
 565
 566         if !common.Exists(confFile) {
 567                 return envMap, confFile, fmt.Errorf("Error no env config file not found")
 568         }
 569         if err = godotenv.Load(confFile); err != nil {
 570                 return envMap, confFile, fmt.Errorf("Error loading env config file " + confFile)
 571         }
 572         if envMap, err = godotenv.Read(confFile); err != nil {
 573                 return envMap, confFile, fmt.Errorf("Error reading env config file " + confFile)
 574         }
 575
 576         return envMap, confFile, nil
 577 }
 578
 579 /*
 580  extractEnvFromCmdFile: extract xds-gdb env variable from gdb command file
 581   All commented lines (#) in gdb command file that start with ':XDS-ENV:' prefix
 582   will be considered as XDS env commands. For example the 3 syntaxes below
 583   are supported:
 584   # :XDS-ENV: XDS_PROJECT_ID=4021617e-ced0-11e7-acd2-3c970e49ad9b
 585   #:XDS-ENV:XDS_SDK_ID=06c0e95a-e215-3a5a-b373-f677c0dabd3b
 586   # :XDS-ENV:  export XDS_AGENT_URL=localhost:8800
 587 */
 588 func extractEnvFromCmdFile(cmdFile string) (string, error) {
 589         if !common.Exists(cmdFile) {
 590                 return "", nil
 591         }
 592         cFd, err := os.Open(cmdFile)
 593         if err != nil {
 594                 return "", fmt.Errorf("Cannot open %s : %s", cmdFile, err.Error())
 595         }
 596         defer cFd.Close()
 597
 598         var lines []string
 599         scanner := bufio.NewScanner(cFd)
 600         for scanner.Scan() {
 601                 lines = append(lines, scanner.Text())
 602         }
 603         if err = scanner.Err(); err != nil {
 604                 return "", fmt.Errorf("Cannot parse %s : %s", cmdFile, err.Error())
 605         }
 606
 607         envFile, err := ioutil.TempFile("", "xds-gdb_env.ini")
 608         if err != nil {
 609                 return "", fmt.Errorf("Error while creating temporary env file: %s", err.Error())
 610         }
 611         envFileName := envFile.Name()
 612         defer envFile.Close()
 613
 614         envFound := false
 615         for _, ln := range lines {
 616                 ln = strings.TrimSpace(ln)
 617                 if strings.HasPrefix(ln, "#") && strings.Contains(ln, ":XDS-ENV:") {
 618                         env := strings.SplitAfterN(ln, ":XDS-ENV:", 2)
 619                         if len(env) == 2 {
 620                                 envFound = true
 621                                 if _, err := envFile.WriteString(strings.TrimSpace(env[1]) + "\n"); err != nil {
 622                                         return "", fmt.Errorf("Error write into temporary env file: %s", err.Error())
 623                                 }
 624                         } else {
 625                                 log.Warnf("Error while decoding line %s", ln)
 626                         }
 627                 }
 628         }
 629
 630         if !envFound {
 631                 ff := envFileName
 632                 defer os.Remove(ff)
 633                 envFileName = ""
 634
 635         }
 636
 637         return envFileName, nil
 638 }