lib/cloud/azure.go

   1 // Copyright (C) The Arvados Authors. All rights reserved.
   2 //
   3 // SPDX-License-Identifier: AGPL-3.0
   4
   5 package cloud
   6
   7 import (
   8         "context"
   9         "encoding/base64"
  10         "fmt"
  11         "net/http"
  12         "regexp"
  13         "strconv"
  14         "strings"
  15         "sync"
  16         "time"
  17
  18         "git.curoverse.com/arvados.git/sdk/go/arvados"
  19         "github.com/Azure/azure-sdk-for-go/services/compute/mgmt/2018-06-01/compute"
  20         "github.com/Azure/azure-sdk-for-go/services/network/mgmt/2018-06-01/network"
  21         storageacct "github.com/Azure/azure-sdk-for-go/services/storage/mgmt/2018-02-01/storage"
  22         "github.com/Azure/azure-sdk-for-go/storage"
  23         "github.com/Azure/go-autorest/autorest"
  24         "github.com/Azure/go-autorest/autorest/azure"
  25         "github.com/Azure/go-autorest/autorest/azure/auth"
  26         "github.com/Azure/go-autorest/autorest/to"
  27         "github.com/jmcvetta/randutil"
  28         "github.com/mitchellh/mapstructure"
  29         "github.com/sirupsen/logrus"
  30         "golang.org/x/crypto/ssh"
  31 )
  32
  33 type AzureInstanceSetConfig struct {
  34         SubscriptionID               string  `mapstructure:"subscription_id"`
  35         ClientID                     string  `mapstructure:"key"`
  36         ClientSecret                 string  `mapstructure:"secret"`
  37         TenantID                     string  `mapstructure:"tenant_id"`
  38         CloudEnv                     string  `mapstructure:"cloud_environment"`
  39         ResourceGroup                string  `mapstructure:"resource_group"`
  40         Location                     string  `mapstructure:"region"`
  41         Network                      string  `mapstructure:"network"`
  42         Subnet                       string  `mapstructure:"subnet"`
  43         StorageAccount               string  `mapstructure:"storage_account"`
  44         BlobContainer                string  `mapstructure:"blob_container"`
  45         Image                        string  `mapstructure:"image"`
  46         DeleteDanglingResourcesAfter float64 `mapstructure:"delete_dangling_resources_after"`
  47 }
  48
  49 type VirtualMachinesClientWrapper interface {
  50         CreateOrUpdate(ctx context.Context,
  51                 resourceGroupName string,
  52                 VMName string,
  53                 parameters compute.VirtualMachine) (result compute.VirtualMachine, err error)
  54         Delete(ctx context.Context, resourceGroupName string, VMName string) (result *http.Response, err error)
  55         ListComplete(ctx context.Context, resourceGroupName string) (result compute.VirtualMachineListResultIterator, err error)
  56 }
  57
  58 type VirtualMachinesClientImpl struct {
  59         inner compute.VirtualMachinesClient
  60 }
  61
  62 func (cl *VirtualMachinesClientImpl) CreateOrUpdate(ctx context.Context,
  63         resourceGroupName string,
  64         VMName string,
  65         parameters compute.VirtualMachine) (result compute.VirtualMachine, err error) {
  66
  67         future, err := cl.inner.CreateOrUpdate(ctx, resourceGroupName, VMName, parameters)
  68         if err != nil {
  69                 return compute.VirtualMachine{}, WrapAzureError(err)
  70         }
  71         future.WaitForCompletionRef(ctx, cl.inner.Client)
  72         r, err := future.Result(cl.inner)
  73         return r, WrapAzureError(err)
  74 }
  75
  76 func (cl *VirtualMachinesClientImpl) Delete(ctx context.Context, resourceGroupName string, VMName string) (result *http.Response, err error) {
  77         future, err := cl.inner.Delete(ctx, resourceGroupName, VMName)
  78         if err != nil {
  79                 return nil, WrapAzureError(err)
  80         }
  81         err = future.WaitForCompletionRef(ctx, cl.inner.Client)
  82         return future.Response(), WrapAzureError(err)
  83 }
  84
  85 func (cl *VirtualMachinesClientImpl) ListComplete(ctx context.Context, resourceGroupName string) (result compute.VirtualMachineListResultIterator, err error) {
  86         r, err := cl.inner.ListComplete(ctx, resourceGroupName)
  87         return r, WrapAzureError(err)
  88 }
  89
  90 type InterfacesClientWrapper interface {
  91         CreateOrUpdate(ctx context.Context,
  92                 resourceGroupName string,
  93                 networkInterfaceName string,
  94                 parameters network.Interface) (result network.Interface, err error)
  95         Delete(ctx context.Context, resourceGroupName string, networkInterfaceName string) (result *http.Response, err error)
  96         ListComplete(ctx context.Context, resourceGroupName string) (result network.InterfaceListResultIterator, err error)
  97 }
  98
  99 type InterfacesClientImpl struct {
 100         inner network.InterfacesClient
 101 }
 102
 103 func (cl *InterfacesClientImpl) Delete(ctx context.Context, resourceGroupName string, VMName string) (result *http.Response, err error) {
 104         future, err := cl.inner.Delete(ctx, resourceGroupName, VMName)
 105         if err != nil {
 106                 return nil, WrapAzureError(err)
 107         }
 108         err = future.WaitForCompletionRef(ctx, cl.inner.Client)
 109         return future.Response(), WrapAzureError(err)
 110 }
 111
 112 func (cl *InterfacesClientImpl) CreateOrUpdate(ctx context.Context,
 113         resourceGroupName string,
 114         networkInterfaceName string,
 115         parameters network.Interface) (result network.Interface, err error) {
 116
 117         future, err := cl.inner.CreateOrUpdate(ctx, resourceGroupName, networkInterfaceName, parameters)
 118         if err != nil {
 119                 return network.Interface{}, WrapAzureError(err)
 120         }
 121         future.WaitForCompletionRef(ctx, cl.inner.Client)
 122         r, err := future.Result(cl.inner)
 123         return r, WrapAzureError(err)
 124 }
 125
 126 func (cl *InterfacesClientImpl) ListComplete(ctx context.Context, resourceGroupName string) (result network.InterfaceListResultIterator, err error) {
 127         r, err := cl.inner.ListComplete(ctx, resourceGroupName)
 128         return r, WrapAzureError(err)
 129 }
 130
 131 var quotaRe = regexp.MustCompile(`(?i:exceed|quota|limit)`)
 132
 133 type AzureRateLimitError struct {
 134         azure.RequestError
 135         earliestRetry time.Time
 136 }
 137
 138 func (ar *AzureRateLimitError) EarliestRetry() time.Time {
 139         return ar.earliestRetry
 140 }
 141
 142 type AzureQuotaError struct {
 143         azure.RequestError
 144 }
 145
 146 func (ar *AzureQuotaError) IsQuotaError() bool {
 147         return true
 148 }
 149
 150 func WrapAzureError(err error) error {
 151         de, ok := err.(autorest.DetailedError)
 152         if !ok {
 153                 return err
 154         }
 155         rq, ok := de.Original.(*azure.RequestError)
 156         if !ok {
 157                 return err
 158         }
 159         if rq.Response == nil {
 160                 return err
 161         }
 162         if rq.Response.StatusCode == 429 || len(rq.Response.Header["Retry-After"]) >= 1 {
 163                 // API throttling
 164                 ra := rq.Response.Header["Retry-After"][0]
 165                 earliestRetry, parseErr := http.ParseTime(ra)
 166                 if parseErr != nil {
 167                         // Could not parse as a timestamp, must be number of seconds
 168                         dur, parseErr := strconv.ParseInt(ra, 10, 64)
 169                         if parseErr != nil {
 170                                 earliestRetry = time.Now().Add(time.Duration(dur) * time.Second)
 171                         }
 172                 }
 173                 if parseErr != nil {
 174                         // Couldn't make sense of retry-after,
 175                         // so set retry to 20 seconds
 176                         earliestRetry = time.Now().Add(20 * time.Second)
 177                 }
 178                 return &AzureRateLimitError{*rq, earliestRetry}
 179         }
 180         if rq.ServiceError == nil {
 181                 return err
 182         }
 183         if quotaRe.FindString(rq.ServiceError.Code) != "" || quotaRe.FindString(rq.ServiceError.Message) != "" {
 184                 return &AzureQuotaError{*rq}
 185         }
 186         return err
 187 }
 188
 189 type AzureInstanceSet struct {
 190         azconfig          AzureInstanceSetConfig
 191         vmClient          VirtualMachinesClientWrapper
 192         netClient         InterfacesClientWrapper
 193         storageAcctClient storageacct.AccountsClient
 194         azureEnv          azure.Environment
 195         interfaces        map[string]network.Interface
 196         dispatcherID      string
 197         namePrefix        string
 198         ctx               context.Context
 199         stopFunc          context.CancelFunc
 200         stopWg            sync.WaitGroup
 201         deleteNIC         chan string
 202         deleteBlob        chan storage.Blob
 203         logger            logrus.FieldLogger
 204 }
 205
 206 func NewAzureInstanceSet(config map[string]interface{}, dispatcherID InstanceSetID, logger logrus.FieldLogger) (prv InstanceSet, err error) {
 207         azcfg := AzureInstanceSetConfig{}
 208         if err = mapstructure.Decode(config, &azcfg); err != nil {
 209                 return nil, err
 210         }
 211         ap := AzureInstanceSet{logger: logger}
 212         err = ap.setup(azcfg, string(dispatcherID))
 213         if err != nil {
 214                 return nil, err
 215         }
 216         return &ap, nil
 217 }
 218
 219 func (az *AzureInstanceSet) setup(azcfg AzureInstanceSetConfig, dispatcherID string) (err error) {
 220         az.azconfig = azcfg
 221         vmClient := compute.NewVirtualMachinesClient(az.azconfig.SubscriptionID)
 222         netClient := network.NewInterfacesClient(az.azconfig.SubscriptionID)
 223         storageAcctClient := storageacct.NewAccountsClient(az.azconfig.SubscriptionID)
 224
 225         az.azureEnv, err = azure.EnvironmentFromName(az.azconfig.CloudEnv)
 226         if err != nil {
 227                 return err
 228         }
 229
 230         authorizer, err := auth.ClientCredentialsConfig{
 231                 ClientID:     az.azconfig.ClientID,
 232                 ClientSecret: az.azconfig.ClientSecret,
 233                 TenantID:     az.azconfig.TenantID,
 234                 Resource:     az.azureEnv.ResourceManagerEndpoint,
 235                 AADEndpoint:  az.azureEnv.ActiveDirectoryEndpoint,
 236         }.Authorizer()
 237         if err != nil {
 238                 return err
 239         }
 240
 241         vmClient.Authorizer = authorizer
 242         netClient.Authorizer = authorizer
 243         storageAcctClient.Authorizer = authorizer
 244
 245         az.vmClient = &VirtualMachinesClientImpl{vmClient}
 246         az.netClient = &InterfacesClientImpl{netClient}
 247         az.storageAcctClient = storageAcctClient
 248
 249         az.dispatcherID = dispatcherID
 250         az.namePrefix = fmt.Sprintf("compute-%s-", az.dispatcherID)
 251
 252         az.ctx, az.stopFunc = context.WithCancel(context.Background())
 253         go func() {
 254                 tk := time.NewTicker(5 * time.Minute)
 255                 for {
 256                         select {
 257                         case <-az.ctx.Done():
 258                                 return
 259                         case <-tk.C:
 260                                 az.ManageBlobs()
 261                         }
 262                 }
 263         }()
 264
 265         az.deleteNIC = make(chan string)
 266         az.deleteBlob = make(chan storage.Blob)
 267
 268         for i := 0; i < 4; i += 1 {
 269                 go func() {
 270                         for {
 271                                 nicname, ok := <-az.deleteNIC
 272                                 if !ok {
 273                                         return
 274                                 }
 275                                 _, delerr := az.netClient.Delete(context.Background(), az.azconfig.ResourceGroup, nicname)
 276                                 if delerr != nil {
 277                                         az.logger.WithError(delerr).Warnf("Error deleting %v", nicname)
 278                                 } else {
 279                                         az.logger.Printf("Deleted NIC %v", nicname)
 280                                 }
 281                         }
 282                 }()
 283                 go func() {
 284                         for {
 285                                 blob, ok := <-az.deleteBlob
 286                                 if !ok {
 287                                         return
 288                                 }
 289                                 err := blob.Delete(nil)
 290                                 if err != nil {
 291                                         az.logger.WithError(err).Warnf("Error deleting %v", blob.Name)
 292                                 } else {
 293                                         az.logger.Printf("Deleted blob %v", blob.Name)
 294                                 }
 295                         }
 296                 }()
 297         }
 298
 299         return nil
 300 }
 301
 302 func (az *AzureInstanceSet) Create(
 303         instanceType arvados.InstanceType,
 304         imageId ImageID,
 305         newTags InstanceTags,
 306         publicKey ssh.PublicKey) (Instance, error) {
 307
 308         az.stopWg.Add(1)
 309         defer az.stopWg.Done()
 310
 311         if len(newTags["node-token"]) == 0 {
 312                 return nil, fmt.Errorf("Must provide tag 'node-token'")
 313         }
 314
 315         name, err := randutil.String(15, "abcdefghijklmnopqrstuvwxyz0123456789")
 316         if err != nil {
 317                 return nil, err
 318         }
 319
 320         name = az.namePrefix + name
 321
 322         timestamp := time.Now().Format(time.RFC3339Nano)
 323
 324         tags := make(map[string]*string)
 325         tags["created-at"] = &timestamp
 326         for k, v := range newTags {
 327                 newstr := v
 328                 tags["dispatch-"+k] = &newstr
 329         }
 330
 331         tags["dispatch-instance-type"] = &instanceType.Name
 332
 333         nicParameters := network.Interface{
 334                 Location: &az.azconfig.Location,
 335                 Tags:     tags,
 336                 InterfacePropertiesFormat: &network.InterfacePropertiesFormat{
 337                         IPConfigurations: &[]network.InterfaceIPConfiguration{
 338                                 network.InterfaceIPConfiguration{
 339                                         Name: to.StringPtr("ip1"),
 340                                         InterfaceIPConfigurationPropertiesFormat: &network.InterfaceIPConfigurationPropertiesFormat{
 341                                                 Subnet: &network.Subnet{
 342                                                         ID: to.StringPtr(fmt.Sprintf("/subscriptions/%s/resourceGroups/%s/providers"+
 343                                                                 "/Microsoft.Network/virtualnetworks/%s/subnets/%s",
 344                                                                 az.azconfig.SubscriptionID,
 345                                                                 az.azconfig.ResourceGroup,
 346                                                                 az.azconfig.Network,
 347                                                                 az.azconfig.Subnet)),
 348                                                 },
 349                                                 PrivateIPAllocationMethod: network.Dynamic,
 350                                         },
 351                                 },
 352                         },
 353                 },
 354         }
 355         nic, err := az.netClient.CreateOrUpdate(az.ctx, az.azconfig.ResourceGroup, name+"-nic", nicParameters)
 356         if err != nil {
 357                 return nil, WrapAzureError(err)
 358         }
 359
 360         instance_vhd := fmt.Sprintf("https://%s.blob.%s/%s/%s-os.vhd",
 361                 az.azconfig.StorageAccount,
 362                 az.azureEnv.StorageEndpointSuffix,
 363                 az.azconfig.BlobContainer,
 364                 name)
 365
 366         customData := base64.StdEncoding.EncodeToString([]byte(fmt.Sprintf(`#!/bin/sh
 367 echo '%s-%s' > /home/crunch/node-token`, name, newTags["node-token"])))
 368
 369         vmParameters := compute.VirtualMachine{
 370                 Location: &az.azconfig.Location,
 371                 Tags:     tags,
 372                 VirtualMachineProperties: &compute.VirtualMachineProperties{
 373                         HardwareProfile: &compute.HardwareProfile{
 374                                 VMSize: compute.VirtualMachineSizeTypes(instanceType.ProviderType),
 375                         },
 376                         StorageProfile: &compute.StorageProfile{
 377                                 OsDisk: &compute.OSDisk{
 378                                         OsType:       compute.Linux,
 379                                         Name:         to.StringPtr(name + "-os"),
 380                                         CreateOption: compute.FromImage,
 381                                         Image: &compute.VirtualHardDisk{
 382                                                 URI: to.StringPtr(string(imageId)),
 383                                         },
 384                                         Vhd: &compute.VirtualHardDisk{
 385                                                 URI: &instance_vhd,
 386                                         },
 387                                 },
 388                         },
 389                         NetworkProfile: &compute.NetworkProfile{
 390                                 NetworkInterfaces: &[]compute.NetworkInterfaceReference{
 391                                         compute.NetworkInterfaceReference{
 392                                                 ID: nic.ID,
 393                                                 NetworkInterfaceReferenceProperties: &compute.NetworkInterfaceReferenceProperties{
 394                                                         Primary: to.BoolPtr(true),
 395                                                 },
 396                                         },
 397                                 },
 398                         },
 399                         OsProfile: &compute.OSProfile{
 400                                 ComputerName:  &name,
 401                                 AdminUsername: to.StringPtr("crunch"),
 402                                 LinuxConfiguration: &compute.LinuxConfiguration{
 403                                         DisablePasswordAuthentication: to.BoolPtr(true),
 404                                         SSH: &compute.SSHConfiguration{
 405                                                 PublicKeys: &[]compute.SSHPublicKey{
 406                                                         compute.SSHPublicKey{
 407                                                                 Path:    to.StringPtr("/home/crunch/.ssh/authorized_keys"),
 408                                                                 KeyData: to.StringPtr(string(ssh.MarshalAuthorizedKey(publicKey))),
 409                                                         },
 410                                                 },
 411                                         },
 412                                 },
 413                                 CustomData: &customData,
 414                         },
 415                 },
 416         }
 417
 418         vm, err := az.vmClient.CreateOrUpdate(az.ctx, az.azconfig.ResourceGroup, name, vmParameters)
 419         if err != nil {
 420                 return nil, WrapAzureError(err)
 421         }
 422
 423         return &AzureInstance{
 424                 provider: az,
 425                 nic:      nic,
 426                 vm:       vm,
 427         }, nil
 428 }
 429
 430 func (az *AzureInstanceSet) Instances(InstanceTags) ([]Instance, error) {
 431         az.stopWg.Add(1)
 432         defer az.stopWg.Done()
 433
 434         interfaces, err := az.ManageNics()
 435         if err != nil {
 436                 return nil, err
 437         }
 438
 439         result, err := az.vmClient.ListComplete(az.ctx, az.azconfig.ResourceGroup)
 440         if err != nil {
 441                 return nil, WrapAzureError(err)
 442         }
 443
 444         instances := make([]Instance, 0)
 445
 446         for ; result.NotDone(); err = result.Next() {
 447                 if err != nil {
 448                         return nil, WrapAzureError(err)
 449                 }
 450                 if strings.HasPrefix(*result.Value().Name, az.namePrefix) {
 451                         instances = append(instances, &AzureInstance{
 452                                 provider: az,
 453                                 vm:       result.Value(),
 454                                 nic:      interfaces[*(*result.Value().NetworkProfile.NetworkInterfaces)[0].ID]})
 455                 }
 456         }
 457         return instances, nil
 458 }
 459
 460 // ManageNics returns a list of Azure network interface resources.
 461 // Also performs garbage collection of NICs which have "namePrefix", are
 462 // not associated with a virtual machine and have a "create-at" time
 463 // more than DeleteDanglingResourcesAfter (to prevent racing and
 464 // deleting newly created NICs) in the past are deleted.
 465 func (az *AzureInstanceSet) ManageNics() (map[string]network.Interface, error) {
 466         az.stopWg.Add(1)
 467         defer az.stopWg.Done()
 468
 469         result, err := az.netClient.ListComplete(az.ctx, az.azconfig.ResourceGroup)
 470         if err != nil {
 471                 return nil, WrapAzureError(err)
 472         }
 473
 474         interfaces := make(map[string]network.Interface)
 475
 476         timestamp := time.Now()
 477         for ; result.NotDone(); err = result.Next() {
 478                 if err != nil {
 479                         az.logger.WithError(err).Warnf("Error listing nics")
 480                         return interfaces, nil
 481                 }
 482                 if strings.HasPrefix(*result.Value().Name, az.namePrefix) {
 483                         if result.Value().VirtualMachine != nil {
 484                                 interfaces[*result.Value().ID] = result.Value()
 485                         } else {
 486                                 if result.Value().Tags["created-at"] != nil {
 487                                         created_at, err := time.Parse(time.RFC3339Nano, *result.Value().Tags["created-at"])
 488                                         if err == nil {
 489                                                 if timestamp.Sub(created_at).Seconds() > az.azconfig.DeleteDanglingResourcesAfter {
 490                                                         az.logger.Printf("Will delete %v because it is older than %v s", *result.Value().Name, az.azconfig.DeleteDanglingResourcesAfter)
 491                                                         az.deleteNIC <- *result.Value().Name
 492                                                 }
 493                                         }
 494                                 }
 495                         }
 496                 }
 497         }
 498         return interfaces, nil
 499 }
 500
 501 // ManageBlobs garbage collects blobs (VM disk images) in the
 502 // configured storage account container.  It will delete blobs which
 503 // have "namePrefix", are "available" (which means they are not
 504 // leased to a VM) and haven't been modified for
 505 // DeleteDanglingResourcesAfter seconds.
 506 func (az *AzureInstanceSet) ManageBlobs() {
 507         az.stopWg.Add(1)
 508         defer az.stopWg.Done()
 509
 510         result, err := az.storageAcctClient.ListKeys(az.ctx, az.azconfig.ResourceGroup, az.azconfig.StorageAccount)
 511         if err != nil {
 512                 az.logger.WithError(err).Warn("Couldn't get account keys")
 513                 return
 514         }
 515
 516         key1 := *(*result.Keys)[0].Value
 517         client, err := storage.NewBasicClientOnSovereignCloud(az.azconfig.StorageAccount, key1, az.azureEnv)
 518         if err != nil {
 519                 az.logger.WithError(err).Warn("Couldn't make client")
 520                 return
 521         }
 522
 523         blobsvc := client.GetBlobService()
 524         blobcont := blobsvc.GetContainerReference(az.azconfig.BlobContainer)
 525
 526         page := storage.ListBlobsParameters{Prefix: az.namePrefix}
 527         timestamp := time.Now()
 528
 529         for {
 530                 response, err := blobcont.ListBlobs(page)
 531                 if err != nil {
 532                         az.logger.WithError(err).Warn("Error listing blobs")
 533                         return
 534                 }
 535                 for _, b := range response.Blobs {
 536                         age := timestamp.Sub(time.Time(b.Properties.LastModified))
 537                         if b.Properties.BlobType == storage.BlobTypePage &&
 538                                 b.Properties.LeaseState == "available" &&
 539                                 b.Properties.LeaseStatus == "unlocked" &&
 540                                 age.Seconds() > az.azconfig.DeleteDanglingResourcesAfter {
 541
 542                                 az.logger.Printf("Blob %v is unlocked and not modified for %v seconds, will delete", b.Name, age.Seconds())
 543                                 az.deleteBlob <- b
 544                         }
 545                 }
 546                 if response.NextMarker != "" {
 547                         page.Marker = response.NextMarker
 548                 } else {
 549                         break
 550                 }
 551         }
 552 }
 553
 554 func (az *AzureInstanceSet) Stop() {
 555         az.stopFunc()
 556         az.stopWg.Wait()
 557         close(az.deleteNIC)
 558         close(az.deleteBlob)
 559 }
 560
 561 type AzureInstance struct {
 562         provider *AzureInstanceSet
 563         nic      network.Interface
 564         vm       compute.VirtualMachine
 565 }
 566
 567 func (ai *AzureInstance) ID() InstanceID {
 568         return InstanceID(*ai.vm.ID)
 569 }
 570
 571 func (ai *AzureInstance) String() string {
 572         return *ai.vm.Name
 573 }
 574
 575 func (ai *AzureInstance) ProviderType() string {
 576         return string(ai.vm.VirtualMachineProperties.HardwareProfile.VMSize)
 577 }
 578
 579 func (ai *AzureInstance) SetTags(newTags InstanceTags) error {
 580         ai.provider.stopWg.Add(1)
 581         defer ai.provider.stopWg.Done()
 582
 583         tags := make(map[string]*string)
 584
 585         for k, v := range ai.vm.Tags {
 586                 if !strings.HasPrefix(k, "dispatch-") {
 587                         tags[k] = v
 588                 }
 589         }
 590         for k, v := range newTags {
 591                 newstr := v
 592                 tags["dispatch-"+k] = &newstr
 593         }
 594
 595         vmParameters := compute.VirtualMachine{
 596                 Location: &ai.provider.azconfig.Location,
 597                 Tags:     tags,
 598         }
 599         vm, err := ai.provider.vmClient.CreateOrUpdate(ai.provider.ctx, ai.provider.azconfig.ResourceGroup, *ai.vm.Name, vmParameters)
 600         if err != nil {
 601                 return WrapAzureError(err)
 602         }
 603         ai.vm = vm
 604
 605         return nil
 606 }
 607
 608 func (ai *AzureInstance) Tags() InstanceTags {
 609         tags := make(map[string]string)
 610
 611         for k, v := range ai.vm.Tags {
 612                 if strings.HasPrefix(k, "dispatch-") {
 613                         tags[k[9:]] = *v
 614                 }
 615         }
 616
 617         return tags
 618 }
 619
 620 func (ai *AzureInstance) Destroy() error {
 621         ai.provider.stopWg.Add(1)
 622         defer ai.provider.stopWg.Done()
 623
 624         _, err := ai.provider.vmClient.Delete(ai.provider.ctx, ai.provider.azconfig.ResourceGroup, *ai.vm.Name)
 625         return WrapAzureError(err)
 626 }
 627
 628 func (ai *AzureInstance) Address() string {
 629         return *(*ai.nic.IPConfigurations)[0].PrivateIPAddress
 630 }
 631
 632 func (ai *AzureInstance) VerifyHostKey(receivedKey ssh.PublicKey, client *ssh.Client) error {
 633         ai.provider.stopWg.Add(1)
 634         defer ai.provider.stopWg.Done()
 635
 636         remoteFingerprint := ssh.FingerprintSHA256(receivedKey)
 637
 638         tags := ai.Tags()
 639
 640         tg := tags["ssh-pubkey-fingerprint"]
 641         if tg != "" {
 642                 if remoteFingerprint == tg {
 643                         return nil
 644                 } else {
 645                         return fmt.Errorf("Key fingerprint did not match, expected %q got %q", tg, remoteFingerprint)
 646                 }
 647         }
 648
 649         nodetokenTag := tags["node-token"]
 650         if nodetokenTag == "" {
 651                 return fmt.Errorf("Missing node token tag")
 652         }
 653
 654         sess, err := client.NewSession()
 655         if err != nil {
 656                 return err
 657         }
 658
 659         nodetokenbytes, err := sess.Output("cat /home/crunch/node-token")
 660         if err != nil {
 661                 return err
 662         }
 663
 664         nodetoken := strings.TrimSpace(string(nodetokenbytes))
 665
 666         expectedToken := fmt.Sprintf("%s-%s", *ai.vm.Name, nodetokenTag)
 667
 668         if strings.TrimSpace(nodetoken) != expectedToken {
 669                 return fmt.Errorf("Node token did not match, expected %q got %q", expectedToken, nodetoken)
 670         }
 671
 672         sess, err = client.NewSession()
 673         if err != nil {
 674                 return err
 675         }
 676
 677         keyfingerprintbytes, err := sess.Output("ssh-keygen -E sha256 -l -f /etc/ssh/ssh_host_rsa_key.pub")
 678         if err != nil {
 679                 return err
 680         }
 681
 682         sp := strings.Split(string(keyfingerprintbytes), " ")
 683
 684         if remoteFingerprint != sp[1] {
 685                 return fmt.Errorf("Key fingerprint did not match, expected %q got %q", sp[1], remoteFingerprint)
 686         }
 687
 688         tags["ssh-pubkey-fingerprint"] = sp[1]
 689         delete(tags, "node-token")
 690         ai.SetTags(tags)
 691         return nil
 692 }