lib/dispatchcloud/test/stub_driver.go

   1 // Copyright (C) The Arvados Authors. All rights reserved.
   2 //
   3 // SPDX-License-Identifier: AGPL-3.0
   4
   5 package test
   6
   7 import (
   8         "crypto/rand"
   9         "encoding/json"
  10         "errors"
  11         "fmt"
  12         "io"
  13         "io/ioutil"
  14         math_rand "math/rand"
  15         "regexp"
  16         "strings"
  17         "sync"
  18         "time"
  19
  20         "git.arvados.org/arvados.git/lib/cloud"
  21         "git.arvados.org/arvados.git/sdk/go/arvados"
  22         "github.com/sirupsen/logrus"
  23         "golang.org/x/crypto/ssh"
  24 )
  25
  26 // A StubDriver implements cloud.Driver by setting up local SSH
  27 // servers that do fake command executions.
  28 type StubDriver struct {
  29         HostKey        ssh.Signer
  30         AuthorizedKeys []ssh.PublicKey
  31
  32         // SetupVM, if set, is called upon creation of each new
  33         // StubVM. This is the caller's opportunity to customize the
  34         // VM's error rate and other behaviors.
  35         SetupVM func(*StubVM)
  36
  37         // Bugf, if set, is called if a bug is detected in the caller
  38         // or stub. Typically set to (*check.C)Errorf. If unset,
  39         // logger.Warnf is called instead.
  40         Bugf func(string, ...interface{})
  41
  42         // StubVM's fake crunch-run uses this Queue to read and update
  43         // container state.
  44         Queue *Queue
  45
  46         // Frequency of artificially introduced errors on calls to
  47         // Destroy. 0=always succeed, 1=always fail.
  48         ErrorRateDestroy float64
  49
  50         // If Create() or Instances() is called too frequently, return
  51         // rate-limiting errors.
  52         MinTimeBetweenCreateCalls    time.Duration
  53         MinTimeBetweenInstancesCalls time.Duration
  54
  55         // If true, Create and Destroy calls block until Release() is
  56         // called.
  57         HoldCloudOps bool
  58
  59         instanceSets []*StubInstanceSet
  60         holdCloudOps chan bool
  61 }
  62
  63 // InstanceSet returns a new *StubInstanceSet.
  64 func (sd *StubDriver) InstanceSet(params json.RawMessage, id cloud.InstanceSetID, _ cloud.SharedResourceTags, logger logrus.FieldLogger) (cloud.InstanceSet, error) {
  65         if sd.holdCloudOps == nil {
  66                 sd.holdCloudOps = make(chan bool)
  67         }
  68         sis := StubInstanceSet{
  69                 driver:  sd,
  70                 logger:  logger,
  71                 servers: map[cloud.InstanceID]*StubVM{},
  72         }
  73         sd.instanceSets = append(sd.instanceSets, &sis)
  74
  75         var err error
  76         if params != nil {
  77                 err = json.Unmarshal(params, &sis)
  78         }
  79         return &sis, err
  80 }
  81
  82 // InstanceSets returns all instances that have been created by the
  83 // driver. This can be used to test a component that uses the driver
  84 // but doesn't expose the InstanceSets it has created.
  85 func (sd *StubDriver) InstanceSets() []*StubInstanceSet {
  86         return sd.instanceSets
  87 }
  88
  89 // ReleaseCloudOps releases n pending Create/Destroy calls. If there
  90 // are fewer than n blocked calls pending, it waits for the rest to
  91 // arrive.
  92 func (sd *StubDriver) ReleaseCloudOps(n int) {
  93         for i := 0; i < n; i++ {
  94                 <-sd.holdCloudOps
  95         }
  96 }
  97
  98 type StubInstanceSet struct {
  99         driver  *StubDriver
 100         logger  logrus.FieldLogger
 101         servers map[cloud.InstanceID]*StubVM
 102         mtx     sync.RWMutex
 103         stopped bool
 104
 105         allowCreateCall    time.Time
 106         allowInstancesCall time.Time
 107         lastInstanceID     int
 108 }
 109
 110 func (sis *StubInstanceSet) Create(it arvados.InstanceType, image cloud.ImageID, tags cloud.InstanceTags, cmd cloud.InitCommand, authKey ssh.PublicKey) (cloud.Instance, error) {
 111         if sis.driver.HoldCloudOps {
 112                 sis.driver.holdCloudOps <- true
 113         }
 114         sis.mtx.Lock()
 115         defer sis.mtx.Unlock()
 116         if sis.stopped {
 117                 return nil, errors.New("StubInstanceSet: Create called after Stop")
 118         }
 119         if sis.allowCreateCall.After(time.Now()) {
 120                 return nil, RateLimitError{sis.allowCreateCall}
 121         }
 122         sis.allowCreateCall = time.Now().Add(sis.driver.MinTimeBetweenCreateCalls)
 123         ak := sis.driver.AuthorizedKeys
 124         if authKey != nil {
 125                 ak = append([]ssh.PublicKey{authKey}, ak...)
 126         }
 127         sis.lastInstanceID++
 128         svm := &StubVM{
 129                 sis:          sis,
 130                 id:           cloud.InstanceID(fmt.Sprintf("inst%d,%s", sis.lastInstanceID, it.ProviderType)),
 131                 tags:         copyTags(tags),
 132                 providerType: it.ProviderType,
 133                 initCommand:  cmd,
 134                 running:      map[string]int64{},
 135                 killing:      map[string]bool{},
 136         }
 137         svm.SSHService = SSHService{
 138                 HostKey:        sis.driver.HostKey,
 139                 AuthorizedUser: "root",
 140                 AuthorizedKeys: ak,
 141                 Exec:           svm.Exec,
 142         }
 143         if setup := sis.driver.SetupVM; setup != nil {
 144                 setup(svm)
 145         }
 146         sis.servers[svm.id] = svm
 147         return svm.Instance(), nil
 148 }
 149
 150 func (sis *StubInstanceSet) Instances(cloud.InstanceTags) ([]cloud.Instance, error) {
 151         sis.mtx.RLock()
 152         defer sis.mtx.RUnlock()
 153         if sis.allowInstancesCall.After(time.Now()) {
 154                 return nil, RateLimitError{sis.allowInstancesCall}
 155         }
 156         sis.allowInstancesCall = time.Now().Add(sis.driver.MinTimeBetweenInstancesCalls)
 157         var r []cloud.Instance
 158         for _, ss := range sis.servers {
 159                 r = append(r, ss.Instance())
 160         }
 161         return r, nil
 162 }
 163
 164 func (sis *StubInstanceSet) Stop() {
 165         sis.mtx.Lock()
 166         defer sis.mtx.Unlock()
 167         if sis.stopped {
 168                 panic("Stop called twice")
 169         }
 170         sis.stopped = true
 171 }
 172
 173 type RateLimitError struct{ Retry time.Time }
 174
 175 func (e RateLimitError) Error() string            { return fmt.Sprintf("rate limited until %s", e.Retry) }
 176 func (e RateLimitError) EarliestRetry() time.Time { return e.Retry }
 177
 178 // StubVM is a fake server that runs an SSH service. It represents a
 179 // VM running in a fake cloud.
 180 //
 181 // Note this is distinct from a stubInstance, which is a snapshot of
 182 // the VM's metadata. Like a VM in a real cloud, a StubVM keeps
 183 // running (and might change IP addresses, shut down, etc.)  without
 184 // updating any stubInstances that have been returned to callers.
 185 type StubVM struct {
 186         Boot                  time.Time
 187         Broken                time.Time
 188         ReportBroken          time.Time
 189         CrunchRunMissing      bool
 190         CrunchRunCrashRate    float64
 191         CrunchRunDetachDelay  time.Duration
 192         ExecuteContainer      func(arvados.Container) int
 193         CrashRunningContainer func(arvados.Container)
 194
 195         sis          *StubInstanceSet
 196         id           cloud.InstanceID
 197         tags         cloud.InstanceTags
 198         initCommand  cloud.InitCommand
 199         providerType string
 200         SSHService   SSHService
 201         running      map[string]int64
 202         killing      map[string]bool
 203         lastPID      int64
 204         sync.Mutex
 205 }
 206
 207 func (svm *StubVM) Instance() stubInstance {
 208         svm.Lock()
 209         defer svm.Unlock()
 210         return stubInstance{
 211                 svm:  svm,
 212                 addr: svm.SSHService.Address(),
 213                 // We deliberately return a cached/stale copy of the
 214                 // real tags here, so that (Instance)Tags() sometimes
 215                 // returns old data after a call to
 216                 // (Instance)SetTags().  This is permitted by the
 217                 // driver interface, and this might help remind
 218                 // callers that they need to tolerate it.
 219                 tags: copyTags(svm.tags),
 220         }
 221 }
 222
 223 func (svm *StubVM) Exec(env map[string]string, command string, stdin io.Reader, stdout, stderr io.Writer) uint32 {
 224         stdinData, err := ioutil.ReadAll(stdin)
 225         if err != nil {
 226                 fmt.Fprintf(stderr, "error reading stdin: %s\n", err)
 227                 return 1
 228         }
 229         queue := svm.sis.driver.Queue
 230         uuid := regexp.MustCompile(`.{5}-dz642-.{15}`).FindString(command)
 231         if eta := svm.Boot.Sub(time.Now()); eta > 0 {
 232                 fmt.Fprintf(stderr, "stub is booting, ETA %s\n", eta)
 233                 return 1
 234         }
 235         if !svm.Broken.IsZero() && svm.Broken.Before(time.Now()) {
 236                 fmt.Fprintf(stderr, "cannot fork\n")
 237                 return 2
 238         }
 239         if svm.CrunchRunMissing && strings.Contains(command, "crunch-run") {
 240                 fmt.Fprint(stderr, "crunch-run: command not found\n")
 241                 return 1
 242         }
 243         if strings.HasPrefix(command, "crunch-run --detach --stdin-env ") {
 244                 var stdinKV map[string]string
 245                 err := json.Unmarshal(stdinData, &stdinKV)
 246                 if err != nil {
 247                         fmt.Fprintf(stderr, "unmarshal stdin: %s (stdin was: %q)\n", err, stdinData)
 248                         return 1
 249                 }
 250                 for _, name := range []string{"ARVADOS_API_HOST", "ARVADOS_API_TOKEN"} {
 251                         if stdinKV[name] == "" {
 252                                 fmt.Fprintf(stderr, "%s env var missing from stdin %q\n", name, stdinData)
 253                                 return 1
 254                         }
 255                 }
 256                 svm.Lock()
 257                 svm.lastPID++
 258                 pid := svm.lastPID
 259                 svm.running[uuid] = pid
 260                 svm.Unlock()
 261                 time.Sleep(svm.CrunchRunDetachDelay)
 262                 fmt.Fprintf(stderr, "starting %s\n", uuid)
 263                 logger := svm.sis.logger.WithFields(logrus.Fields{
 264                         "Instance":      svm.id,
 265                         "ContainerUUID": uuid,
 266                         "PID":           pid,
 267                 })
 268                 logger.Printf("[test] starting crunch-run stub")
 269                 go func() {
 270                         var ctr arvados.Container
 271                         var started, completed bool
 272                         defer func() {
 273                                 logger.Print("[test] exiting crunch-run stub")
 274                                 svm.Lock()
 275                                 defer svm.Unlock()
 276                                 if svm.running[uuid] != pid {
 277                                         bugf := svm.sis.driver.Bugf
 278                                         if bugf == nil {
 279                                                 bugf = logger.Warnf
 280                                         }
 281                                         bugf("[test] StubDriver bug or caller bug: pid %d exiting, running[%s]==%d", pid, uuid, svm.running[uuid])
 282                                 } else {
 283                                         delete(svm.running, uuid)
 284                                 }
 285                                 if !completed {
 286                                         logger.WithField("State", ctr.State).Print("[test] crashing crunch-run stub")
 287                                         if started && svm.CrashRunningContainer != nil {
 288                                                 svm.CrashRunningContainer(ctr)
 289                                         }
 290                                 }
 291                         }()
 292
 293                         crashluck := math_rand.Float64()
 294                         wantCrash := crashluck < svm.CrunchRunCrashRate
 295                         wantCrashEarly := crashluck < svm.CrunchRunCrashRate/2
 296
 297                         ctr, ok := queue.Get(uuid)
 298                         if !ok {
 299                                 logger.Print("[test] container not in queue")
 300                                 return
 301                         }
 302
 303                         time.Sleep(time.Duration(math_rand.Float64()*20) * time.Millisecond)
 304
 305                         svm.Lock()
 306                         killed := svm.killing[uuid]
 307                         svm.Unlock()
 308                         if killed || wantCrashEarly {
 309                                 return
 310                         }
 311
 312                         ctr.State = arvados.ContainerStateRunning
 313                         started = queue.Notify(ctr)
 314                         if !started {
 315                                 ctr, _ = queue.Get(uuid)
 316                                 logger.Print("[test] erroring out because state=Running update was rejected")
 317                                 return
 318                         }
 319
 320                         if wantCrash {
 321                                 logger.WithField("State", ctr.State).Print("[test] crashing crunch-run stub")
 322                                 return
 323                         }
 324                         if svm.ExecuteContainer != nil {
 325                                 ctr.ExitCode = svm.ExecuteContainer(ctr)
 326                         }
 327                         logger.WithField("ExitCode", ctr.ExitCode).Print("[test] completing container")
 328                         ctr.State = arvados.ContainerStateComplete
 329                         completed = queue.Notify(ctr)
 330                 }()
 331                 return 0
 332         }
 333         if command == "crunch-run --list" {
 334                 svm.Lock()
 335                 defer svm.Unlock()
 336                 for uuid := range svm.running {
 337                         fmt.Fprintf(stdout, "%s\n", uuid)
 338                 }
 339                 if !svm.ReportBroken.IsZero() && svm.ReportBroken.Before(time.Now()) {
 340                         fmt.Fprintln(stdout, "broken")
 341                 }
 342                 return 0
 343         }
 344         if strings.HasPrefix(command, "crunch-run --kill ") {
 345                 svm.Lock()
 346                 _, running := svm.running[uuid]
 347                 if running {
 348                         svm.killing[uuid] = true
 349                         svm.Unlock()
 350                         time.Sleep(time.Duration(math_rand.Float64()*2) * time.Millisecond)
 351                         svm.Lock()
 352                         _, running = svm.running[uuid]
 353                 }
 354                 svm.Unlock()
 355                 if running {
 356                         fmt.Fprintf(stderr, "%s: container is running\n", uuid)
 357                         return 1
 358                 }
 359                 fmt.Fprintf(stderr, "%s: container is not running\n", uuid)
 360                 return 0
 361         }
 362         if command == "true" {
 363                 return 0
 364         }
 365         fmt.Fprintf(stderr, "%q: command not found", command)
 366         return 1
 367 }
 368
 369 type stubInstance struct {
 370         svm  *StubVM
 371         addr string
 372         tags cloud.InstanceTags
 373 }
 374
 375 func (si stubInstance) ID() cloud.InstanceID {
 376         return si.svm.id
 377 }
 378
 379 func (si stubInstance) Address() string {
 380         return si.addr
 381 }
 382
 383 func (si stubInstance) RemoteUser() string {
 384         return si.svm.SSHService.AuthorizedUser
 385 }
 386
 387 func (si stubInstance) Destroy() error {
 388         sis := si.svm.sis
 389         if sis.driver.HoldCloudOps {
 390                 sis.driver.holdCloudOps <- true
 391         }
 392         if math_rand.Float64() < si.svm.sis.driver.ErrorRateDestroy {
 393                 return errors.New("instance could not be destroyed")
 394         }
 395         si.svm.SSHService.Close()
 396         sis.mtx.Lock()
 397         defer sis.mtx.Unlock()
 398         delete(sis.servers, si.svm.id)
 399         return nil
 400 }
 401
 402 func (si stubInstance) ProviderType() string {
 403         return si.svm.providerType
 404 }
 405
 406 func (si stubInstance) SetTags(tags cloud.InstanceTags) error {
 407         tags = copyTags(tags)
 408         svm := si.svm
 409         go func() {
 410                 svm.Lock()
 411                 defer svm.Unlock()
 412                 svm.tags = tags
 413         }()
 414         return nil
 415 }
 416
 417 func (si stubInstance) Tags() cloud.InstanceTags {
 418         // Return a copy to ensure a caller can't change our saved
 419         // tags just by writing to the returned map.
 420         return copyTags(si.tags)
 421 }
 422
 423 func (si stubInstance) String() string {
 424         return string(si.svm.id)
 425 }
 426
 427 func (si stubInstance) VerifyHostKey(key ssh.PublicKey, client *ssh.Client) error {
 428         buf := make([]byte, 512)
 429         _, err := io.ReadFull(rand.Reader, buf)
 430         if err != nil {
 431                 return err
 432         }
 433         sig, err := si.svm.sis.driver.HostKey.Sign(rand.Reader, buf)
 434         if err != nil {
 435                 return err
 436         }
 437         return key.Verify(buf, sig)
 438 }
 439
 440 func copyTags(src cloud.InstanceTags) cloud.InstanceTags {
 441         dst := cloud.InstanceTags{}
 442         for k, v := range src {
 443                 dst[k] = v
 444         }
 445         return dst
 446 }