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         "errors"
  10         "fmt"
  11         "io"
  12         math_rand "math/rand"
  13         "regexp"
  14         "strings"
  15         "sync"
  16         "time"
  17
  18         "git.curoverse.com/arvados.git/lib/cloud"
  19         "git.curoverse.com/arvados.git/sdk/go/arvados"
  20         "github.com/mitchellh/mapstructure"
  21         "github.com/sirupsen/logrus"
  22         "golang.org/x/crypto/ssh"
  23 )
  24
  25 // A StubDriver implements cloud.Driver by setting up local SSH
  26 // servers that do fake command executions.
  27 type StubDriver struct {
  28         HostKey        ssh.Signer
  29         AuthorizedKeys []ssh.PublicKey
  30
  31         // SetupVM, if set, is called upon creation of each new
  32         // StubVM. This is the caller's opportunity to customize the
  33         // VM's error rate and other behaviors.
  34         SetupVM func(*StubVM)
  35
  36         // StubVM's fake crunch-run uses this Queue to read and update
  37         // container state.
  38         Queue *Queue
  39
  40         // Frequency of artificially introduced errors on calls to
  41         // Destroy. 0=always succeed, 1=always fail.
  42         ErrorRateDestroy float64
  43
  44         // If Create() or Instances() is called too frequently, return
  45         // rate-limiting errors.
  46         MinTimeBetweenCreateCalls    time.Duration
  47         MinTimeBetweenInstancesCalls time.Duration
  48
  49         instanceSets []*StubInstanceSet
  50 }
  51
  52 // InstanceSet returns a new *StubInstanceSet.
  53 func (sd *StubDriver) InstanceSet(params map[string]interface{}, id cloud.InstanceSetID, logger logrus.FieldLogger) (cloud.InstanceSet, error) {
  54         sis := StubInstanceSet{
  55                 driver:  sd,
  56                 servers: map[cloud.InstanceID]*StubVM{},
  57         }
  58         sd.instanceSets = append(sd.instanceSets, &sis)
  59         return &sis, mapstructure.Decode(params, &sis)
  60 }
  61
  62 // InstanceSets returns all instances that have been created by the
  63 // driver. This can be used to test a component that uses the driver
  64 // but doesn't expose the InstanceSets it has created.
  65 func (sd *StubDriver) InstanceSets() []*StubInstanceSet {
  66         return sd.instanceSets
  67 }
  68
  69 type StubInstanceSet struct {
  70         driver  *StubDriver
  71         servers map[cloud.InstanceID]*StubVM
  72         mtx     sync.RWMutex
  73         stopped bool
  74
  75         allowCreateCall    time.Time
  76         allowInstancesCall time.Time
  77 }
  78
  79 func (sis *StubInstanceSet) Create(it arvados.InstanceType, image cloud.ImageID, tags cloud.InstanceTags, authKey ssh.PublicKey) (cloud.Instance, error) {
  80         sis.mtx.Lock()
  81         defer sis.mtx.Unlock()
  82         if sis.stopped {
  83                 return nil, errors.New("StubInstanceSet: Create called after Stop")
  84         }
  85         if sis.allowCreateCall.After(time.Now()) {
  86                 return nil, RateLimitError{sis.allowCreateCall}
  87         } else {
  88                 sis.allowCreateCall = time.Now().Add(sis.driver.MinTimeBetweenCreateCalls)
  89         }
  90
  91         ak := sis.driver.AuthorizedKeys
  92         if authKey != nil {
  93                 ak = append([]ssh.PublicKey{authKey}, ak...)
  94         }
  95         svm := &StubVM{
  96                 sis:          sis,
  97                 id:           cloud.InstanceID(fmt.Sprintf("stub-%s-%x", it.ProviderType, math_rand.Int63())),
  98                 tags:         copyTags(tags),
  99                 providerType: it.ProviderType,
 100         }
 101         svm.SSHService = SSHService{
 102                 HostKey:        sis.driver.HostKey,
 103                 AuthorizedKeys: ak,
 104                 Exec:           svm.Exec,
 105         }
 106         if setup := sis.driver.SetupVM; setup != nil {
 107                 setup(svm)
 108         }
 109         sis.servers[svm.id] = svm
 110         return svm.Instance(), nil
 111 }
 112
 113 func (sis *StubInstanceSet) Instances(cloud.InstanceTags) ([]cloud.Instance, error) {
 114         sis.mtx.RLock()
 115         defer sis.mtx.RUnlock()
 116         if sis.allowInstancesCall.After(time.Now()) {
 117                 return nil, RateLimitError{sis.allowInstancesCall}
 118         } else {
 119                 sis.allowInstancesCall = time.Now().Add(sis.driver.MinTimeBetweenInstancesCalls)
 120         }
 121         var r []cloud.Instance
 122         for _, ss := range sis.servers {
 123                 r = append(r, ss.Instance())
 124         }
 125         return r, nil
 126 }
 127
 128 func (sis *StubInstanceSet) Stop() {
 129         sis.mtx.Lock()
 130         defer sis.mtx.Unlock()
 131         if sis.stopped {
 132                 panic("Stop called twice")
 133         }
 134         sis.stopped = true
 135 }
 136
 137 type RateLimitError struct{ Retry time.Time }
 138
 139 func (e RateLimitError) Error() string            { return fmt.Sprintf("rate limited until %s", e.Retry) }
 140 func (e RateLimitError) EarliestRetry() time.Time { return e.Retry }
 141
 142 // StubVM is a fake server that runs an SSH service. It represents a
 143 // VM running in a fake cloud.
 144 //
 145 // Note this is distinct from a stubInstance, which is a snapshot of
 146 // the VM's metadata. Like a VM in a real cloud, a StubVM keeps
 147 // running (and might change IP addresses, shut down, etc.)  without
 148 // updating any stubInstances that have been returned to callers.
 149 type StubVM struct {
 150         Boot                 time.Time
 151         Broken               time.Time
 152         CrunchRunMissing     bool
 153         CrunchRunCrashRate   float64
 154         CrunchRunDetachDelay time.Duration
 155         ExecuteContainer     func(arvados.Container) int
 156
 157         sis          *StubInstanceSet
 158         id           cloud.InstanceID
 159         tags         cloud.InstanceTags
 160         providerType string
 161         SSHService   SSHService
 162         running      map[string]bool
 163         sync.Mutex
 164 }
 165
 166 func (svm *StubVM) Instance() stubInstance {
 167         svm.Lock()
 168         defer svm.Unlock()
 169         return stubInstance{
 170                 svm:  svm,
 171                 addr: svm.SSHService.Address(),
 172                 // We deliberately return a cached/stale copy of the
 173                 // real tags here, so that (Instance)Tags() sometimes
 174                 // returns old data after a call to
 175                 // (Instance)SetTags().  This is permitted by the
 176                 // driver interface, and this might help remind
 177                 // callers that they need to tolerate it.
 178                 tags: copyTags(svm.tags),
 179         }
 180 }
 181
 182 func (svm *StubVM) Exec(env map[string]string, command string, stdin io.Reader, stdout, stderr io.Writer) uint32 {
 183         queue := svm.sis.driver.Queue
 184         uuid := regexp.MustCompile(`.{5}-dz642-.{15}`).FindString(command)
 185         if eta := svm.Boot.Sub(time.Now()); eta > 0 {
 186                 fmt.Fprintf(stderr, "stub is booting, ETA %s\n", eta)
 187                 return 1
 188         }
 189         if !svm.Broken.IsZero() && svm.Broken.Before(time.Now()) {
 190                 fmt.Fprintf(stderr, "cannot fork\n")
 191                 return 2
 192         }
 193         if svm.CrunchRunMissing && strings.Contains(command, "crunch-run") {
 194                 fmt.Fprint(stderr, "crunch-run: command not found\n")
 195                 return 1
 196         }
 197         if strings.HasPrefix(command, "crunch-run --detach ") {
 198                 for _, name := range []string{"ARVADOS_API_HOST", "ARVADOS_API_TOKEN"} {
 199                         if env[name] == "" {
 200                                 fmt.Fprintf(stderr, "%s missing from environment %q\n", name, env)
 201                                 return 1
 202                         }
 203                 }
 204                 svm.Lock()
 205                 if svm.running == nil {
 206                         svm.running = map[string]bool{}
 207                 }
 208                 svm.running[uuid] = true
 209                 svm.Unlock()
 210                 time.Sleep(svm.CrunchRunDetachDelay)
 211                 fmt.Fprintf(stderr, "starting %s\n", uuid)
 212                 logger := logrus.WithFields(logrus.Fields{
 213                         "Instance":      svm.id,
 214                         "ContainerUUID": uuid,
 215                 })
 216                 logger.Printf("[test] starting crunch-run stub")
 217                 go func() {
 218                         crashluck := math_rand.Float64()
 219                         ctr, ok := queue.Get(uuid)
 220                         if !ok {
 221                                 logger.Print("[test] container not in queue")
 222                                 return
 223                         }
 224                         if crashluck > svm.CrunchRunCrashRate/2 {
 225                                 time.Sleep(time.Duration(math_rand.Float64()*20) * time.Millisecond)
 226                                 ctr.State = arvados.ContainerStateRunning
 227                                 queue.Notify(ctr)
 228                         }
 229
 230                         time.Sleep(time.Duration(math_rand.Float64()*20) * time.Millisecond)
 231                         svm.Lock()
 232                         _, running := svm.running[uuid]
 233                         svm.Unlock()
 234                         if !running {
 235                                 logger.Print("[test] container was killed")
 236                                 return
 237                         }
 238                         if svm.ExecuteContainer != nil {
 239                                 ctr.ExitCode = svm.ExecuteContainer(ctr)
 240                         }
 241                         // TODO: Check whether the stub instance has
 242                         // been destroyed, and if so, don't call
 243                         // queue.Notify. Then "container finished
 244                         // twice" can be classified as a bug.
 245                         if crashluck < svm.CrunchRunCrashRate {
 246                                 logger.Print("[test] crashing crunch-run stub")
 247                         } else {
 248                                 ctr.State = arvados.ContainerStateComplete
 249                                 queue.Notify(ctr)
 250                         }
 251                         logger.Print("[test] exiting crunch-run stub")
 252                         svm.Lock()
 253                         defer svm.Unlock()
 254                         delete(svm.running, uuid)
 255                 }()
 256                 return 0
 257         }
 258         if command == "crunch-run --list" {
 259                 svm.Lock()
 260                 defer svm.Unlock()
 261                 for uuid := range svm.running {
 262                         fmt.Fprintf(stdout, "%s\n", uuid)
 263                 }
 264                 return 0
 265         }
 266         if strings.HasPrefix(command, "crunch-run --kill ") {
 267                 svm.Lock()
 268                 defer svm.Unlock()
 269                 if svm.running[uuid] {
 270                         delete(svm.running, uuid)
 271                 } else {
 272                         fmt.Fprintf(stderr, "%s: container is not running\n", uuid)
 273                 }
 274                 return 0
 275         }
 276         if command == "true" {
 277                 return 0
 278         }
 279         fmt.Fprintf(stderr, "%q: command not found", command)
 280         return 1
 281 }
 282
 283 type stubInstance struct {
 284         svm  *StubVM
 285         addr string
 286         tags cloud.InstanceTags
 287 }
 288
 289 func (si stubInstance) ID() cloud.InstanceID {
 290         return si.svm.id
 291 }
 292
 293 func (si stubInstance) Address() string {
 294         return si.addr
 295 }
 296
 297 func (si stubInstance) Destroy() error {
 298         if math_rand.Float64() < si.svm.sis.driver.ErrorRateDestroy {
 299                 return errors.New("instance could not be destroyed")
 300         }
 301         si.svm.SSHService.Close()
 302         sis := si.svm.sis
 303         sis.mtx.Lock()
 304         defer sis.mtx.Unlock()
 305         delete(sis.servers, si.svm.id)
 306         return nil
 307 }
 308
 309 func (si stubInstance) ProviderType() string {
 310         return si.svm.providerType
 311 }
 312
 313 func (si stubInstance) SetTags(tags cloud.InstanceTags) error {
 314         tags = copyTags(tags)
 315         svm := si.svm
 316         go func() {
 317                 svm.Lock()
 318                 defer svm.Unlock()
 319                 svm.tags = tags
 320         }()
 321         return nil
 322 }
 323
 324 func (si stubInstance) Tags() cloud.InstanceTags {
 325         return si.tags
 326 }
 327
 328 func (si stubInstance) String() string {
 329         return string(si.svm.id)
 330 }
 331
 332 func (si stubInstance) VerifyHostKey(key ssh.PublicKey, client *ssh.Client) error {
 333         buf := make([]byte, 512)
 334         _, err := io.ReadFull(rand.Reader, buf)
 335         if err != nil {
 336                 return err
 337         }
 338         sig, err := si.svm.sis.driver.HostKey.Sign(rand.Reader, buf)
 339         if err != nil {
 340                 return err
 341         }
 342         return key.Verify(buf, sig)
 343 }
 344
 345 func copyTags(src cloud.InstanceTags) cloud.InstanceTags {
 346         dst := cloud.InstanceTags{}
 347         for k, v := range src {
 348                 dst[k] = v
 349         }
 350         return dst
 351 }