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