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