github.com/andresvia/terraform@v0.6.15-0.20160412045437-d51c75946785/builtin/providers/aws/resource_aws_autoscaling_group.go (about)

     1  package aws
     2  
     3  import (
     4  	"fmt"
     5  	"log"
     6  	"strings"
     7  	"time"
     8  
     9  	"github.com/hashicorp/terraform/helper/resource"
    10  	"github.com/hashicorp/terraform/helper/schema"
    11  
    12  	"github.com/aws/aws-sdk-go/aws"
    13  	"github.com/aws/aws-sdk-go/aws/awserr"
    14  	"github.com/aws/aws-sdk-go/service/autoscaling"
    15  	"github.com/aws/aws-sdk-go/service/elb"
    16  )
    17  
    18  func resourceAwsAutoscalingGroup() *schema.Resource {
    19  	return &schema.Resource{
    20  		Create: resourceAwsAutoscalingGroupCreate,
    21  		Read:   resourceAwsAutoscalingGroupRead,
    22  		Update: resourceAwsAutoscalingGroupUpdate,
    23  		Delete: resourceAwsAutoscalingGroupDelete,
    24  
    25  		Schema: map[string]*schema.Schema{
    26  			"name": &schema.Schema{
    27  				Type:     schema.TypeString,
    28  				Optional: true,
    29  				Computed: true,
    30  				ForceNew: true,
    31  				ValidateFunc: func(v interface{}, k string) (ws []string, errors []error) {
    32  					// https://github.com/boto/botocore/blob/9f322b1/botocore/data/autoscaling/2011-01-01/service-2.json#L1862-L1873
    33  					value := v.(string)
    34  					if len(value) > 255 {
    35  						errors = append(errors, fmt.Errorf(
    36  							"%q cannot be longer than 255 characters", k))
    37  					}
    38  					return
    39  				},
    40  			},
    41  
    42  			"launch_configuration": &schema.Schema{
    43  				Type:     schema.TypeString,
    44  				Required: true,
    45  			},
    46  
    47  			"desired_capacity": &schema.Schema{
    48  				Type:     schema.TypeInt,
    49  				Optional: true,
    50  				Computed: true,
    51  			},
    52  
    53  			"min_elb_capacity": &schema.Schema{
    54  				Type:     schema.TypeInt,
    55  				Optional: true,
    56  			},
    57  
    58  			"min_size": &schema.Schema{
    59  				Type:     schema.TypeInt,
    60  				Required: true,
    61  			},
    62  
    63  			"max_size": &schema.Schema{
    64  				Type:     schema.TypeInt,
    65  				Required: true,
    66  			},
    67  
    68  			"default_cooldown": &schema.Schema{
    69  				Type:     schema.TypeInt,
    70  				Optional: true,
    71  				Computed: true,
    72  			},
    73  
    74  			"force_delete": &schema.Schema{
    75  				Type:     schema.TypeBool,
    76  				Optional: true,
    77  				Default:  false,
    78  			},
    79  
    80  			"health_check_grace_period": &schema.Schema{
    81  				Type:     schema.TypeInt,
    82  				Optional: true,
    83  				Default:  300,
    84  			},
    85  
    86  			"health_check_type": &schema.Schema{
    87  				Type:     schema.TypeString,
    88  				Optional: true,
    89  				Computed: true,
    90  			},
    91  
    92  			"availability_zones": &schema.Schema{
    93  				Type:     schema.TypeSet,
    94  				Optional: true,
    95  				Computed: true,
    96  				Elem:     &schema.Schema{Type: schema.TypeString},
    97  				Set:      schema.HashString,
    98  			},
    99  
   100  			"placement_group": &schema.Schema{
   101  				Type:     schema.TypeString,
   102  				Optional: true,
   103  			},
   104  
   105  			"load_balancers": &schema.Schema{
   106  				Type:     schema.TypeSet,
   107  				Optional: true,
   108  				Elem:     &schema.Schema{Type: schema.TypeString},
   109  				Set:      schema.HashString,
   110  			},
   111  
   112  			"vpc_zone_identifier": &schema.Schema{
   113  				Type:     schema.TypeSet,
   114  				Optional: true,
   115  				Computed: true,
   116  				Elem:     &schema.Schema{Type: schema.TypeString},
   117  				Set:      schema.HashString,
   118  			},
   119  
   120  			"termination_policies": &schema.Schema{
   121  				Type:     schema.TypeList,
   122  				Optional: true,
   123  				Elem:     &schema.Schema{Type: schema.TypeString},
   124  			},
   125  
   126  			"wait_for_capacity_timeout": &schema.Schema{
   127  				Type:     schema.TypeString,
   128  				Optional: true,
   129  				Default:  "10m",
   130  				ValidateFunc: func(v interface{}, k string) (ws []string, errors []error) {
   131  					value := v.(string)
   132  					duration, err := time.ParseDuration(value)
   133  					if err != nil {
   134  						errors = append(errors, fmt.Errorf(
   135  							"%q cannot be parsed as a duration: %s", k, err))
   136  					}
   137  					if duration < 0 {
   138  						errors = append(errors, fmt.Errorf(
   139  							"%q must be greater than zero", k))
   140  					}
   141  					return
   142  				},
   143  			},
   144  
   145  			"wait_for_elb_capacity": &schema.Schema{
   146  				Type:     schema.TypeInt,
   147  				Optional: true,
   148  			},
   149  
   150  			"enabled_metrics": &schema.Schema{
   151  				Type:     schema.TypeSet,
   152  				Optional: true,
   153  				Elem:     &schema.Schema{Type: schema.TypeString},
   154  				Set:      schema.HashString,
   155  			},
   156  
   157  			"metrics_granularity": &schema.Schema{
   158  				Type:     schema.TypeString,
   159  				Optional: true,
   160  				Default:  "1Minute",
   161  			},
   162  
   163  			"tag": autoscalingTagsSchema(),
   164  		},
   165  	}
   166  }
   167  
   168  func resourceAwsAutoscalingGroupCreate(d *schema.ResourceData, meta interface{}) error {
   169  	conn := meta.(*AWSClient).autoscalingconn
   170  
   171  	var autoScalingGroupOpts autoscaling.CreateAutoScalingGroupInput
   172  
   173  	var asgName string
   174  	if v, ok := d.GetOk("name"); ok {
   175  		asgName = v.(string)
   176  	} else {
   177  		asgName = resource.PrefixedUniqueId("tf-asg-")
   178  		d.Set("name", asgName)
   179  	}
   180  
   181  	autoScalingGroupOpts.AutoScalingGroupName = aws.String(asgName)
   182  	autoScalingGroupOpts.LaunchConfigurationName = aws.String(d.Get("launch_configuration").(string))
   183  	autoScalingGroupOpts.MinSize = aws.Int64(int64(d.Get("min_size").(int)))
   184  	autoScalingGroupOpts.MaxSize = aws.Int64(int64(d.Get("max_size").(int)))
   185  
   186  	// Availability Zones are optional if VPC Zone Identifer(s) are specified
   187  	if v, ok := d.GetOk("availability_zones"); ok && v.(*schema.Set).Len() > 0 {
   188  		autoScalingGroupOpts.AvailabilityZones = expandStringList(v.(*schema.Set).List())
   189  	}
   190  
   191  	if v, ok := d.GetOk("tag"); ok {
   192  		autoScalingGroupOpts.Tags = autoscalingTagsFromMap(
   193  			setToMapByKey(v.(*schema.Set), "key"), d.Get("name").(string))
   194  	}
   195  
   196  	if v, ok := d.GetOk("default_cooldown"); ok {
   197  		autoScalingGroupOpts.DefaultCooldown = aws.Int64(int64(v.(int)))
   198  	}
   199  
   200  	if v, ok := d.GetOk("health_check_type"); ok && v.(string) != "" {
   201  		autoScalingGroupOpts.HealthCheckType = aws.String(v.(string))
   202  	}
   203  
   204  	if v, ok := d.GetOk("desired_capacity"); ok {
   205  		autoScalingGroupOpts.DesiredCapacity = aws.Int64(int64(v.(int)))
   206  	}
   207  
   208  	if v, ok := d.GetOk("health_check_grace_period"); ok {
   209  		autoScalingGroupOpts.HealthCheckGracePeriod = aws.Int64(int64(v.(int)))
   210  	}
   211  
   212  	if v, ok := d.GetOk("placement_group"); ok {
   213  		autoScalingGroupOpts.PlacementGroup = aws.String(v.(string))
   214  	}
   215  
   216  	if v, ok := d.GetOk("load_balancers"); ok && v.(*schema.Set).Len() > 0 {
   217  		autoScalingGroupOpts.LoadBalancerNames = expandStringList(
   218  			v.(*schema.Set).List())
   219  	}
   220  
   221  	if v, ok := d.GetOk("vpc_zone_identifier"); ok && v.(*schema.Set).Len() > 0 {
   222  		autoScalingGroupOpts.VPCZoneIdentifier = expandVpcZoneIdentifiers(v.(*schema.Set).List())
   223  	}
   224  
   225  	if v, ok := d.GetOk("termination_policies"); ok && len(v.([]interface{})) > 0 {
   226  		autoScalingGroupOpts.TerminationPolicies = expandStringList(v.([]interface{}))
   227  	}
   228  
   229  	log.Printf("[DEBUG] AutoScaling Group create configuration: %#v", autoScalingGroupOpts)
   230  	_, err := conn.CreateAutoScalingGroup(&autoScalingGroupOpts)
   231  	if err != nil {
   232  		return fmt.Errorf("Error creating Autoscaling Group: %s", err)
   233  	}
   234  
   235  	d.SetId(d.Get("name").(string))
   236  	log.Printf("[INFO] AutoScaling Group ID: %s", d.Id())
   237  
   238  	if err := waitForASGCapacity(d, meta, capacitySatifiedCreate); err != nil {
   239  		return err
   240  	}
   241  
   242  	if _, ok := d.GetOk("enabled_metrics"); ok {
   243  		metricsErr := enableASGMetricsCollection(d, conn)
   244  		if metricsErr != nil {
   245  			return metricsErr
   246  		}
   247  	}
   248  
   249  	return resourceAwsAutoscalingGroupRead(d, meta)
   250  }
   251  
   252  func resourceAwsAutoscalingGroupRead(d *schema.ResourceData, meta interface{}) error {
   253  	conn := meta.(*AWSClient).autoscalingconn
   254  
   255  	g, err := getAwsAutoscalingGroup(d.Id(), conn)
   256  	if err != nil {
   257  		return err
   258  	}
   259  	if g == nil {
   260  		log.Printf("[INFO] Autoscaling Group %q not found", d.Id())
   261  		d.SetId("")
   262  		return nil
   263  	}
   264  
   265  	d.Set("availability_zones", flattenStringList(g.AvailabilityZones))
   266  	d.Set("default_cooldown", g.DefaultCooldown)
   267  	d.Set("desired_capacity", g.DesiredCapacity)
   268  	d.Set("health_check_grace_period", g.HealthCheckGracePeriod)
   269  	d.Set("health_check_type", g.HealthCheckType)
   270  	d.Set("launch_configuration", g.LaunchConfigurationName)
   271  	d.Set("load_balancers", flattenStringList(g.LoadBalancerNames))
   272  	d.Set("min_size", g.MinSize)
   273  	d.Set("max_size", g.MaxSize)
   274  	d.Set("placement_group", g.PlacementGroup)
   275  	d.Set("name", g.AutoScalingGroupName)
   276  	d.Set("tag", g.Tags)
   277  	d.Set("vpc_zone_identifier", strings.Split(*g.VPCZoneIdentifier, ","))
   278  
   279  	// If no termination polices are explicitly configured and the upstream state
   280  	// is only using the "Default" policy, clear the state to make it consistent
   281  	// with the default AWS create API behavior.
   282  	_, ok := d.GetOk("termination_policies")
   283  	if !ok && len(g.TerminationPolicies) == 1 && *g.TerminationPolicies[0] == "Default" {
   284  		d.Set("termination_policies", []interface{}{})
   285  	} else {
   286  		d.Set("termination_policies", flattenStringList(g.TerminationPolicies))
   287  	}
   288  
   289  	if g.EnabledMetrics != nil {
   290  		if err := d.Set("enabled_metrics", flattenAsgEnabledMetrics(g.EnabledMetrics)); err != nil {
   291  			log.Printf("[WARN] Error setting metrics for (%s): %s", d.Id(), err)
   292  		}
   293  		d.Set("metrics_granularity", g.EnabledMetrics[0].Granularity)
   294  	}
   295  
   296  	return nil
   297  }
   298  
   299  func resourceAwsAutoscalingGroupUpdate(d *schema.ResourceData, meta interface{}) error {
   300  	conn := meta.(*AWSClient).autoscalingconn
   301  	shouldWaitForCapacity := false
   302  
   303  	opts := autoscaling.UpdateAutoScalingGroupInput{
   304  		AutoScalingGroupName: aws.String(d.Id()),
   305  	}
   306  
   307  	if d.HasChange("default_cooldown") {
   308  		opts.DefaultCooldown = aws.Int64(int64(d.Get("default_cooldown").(int)))
   309  	}
   310  
   311  	if d.HasChange("desired_capacity") {
   312  		opts.DesiredCapacity = aws.Int64(int64(d.Get("desired_capacity").(int)))
   313  		shouldWaitForCapacity = true
   314  	}
   315  
   316  	if d.HasChange("launch_configuration") {
   317  		opts.LaunchConfigurationName = aws.String(d.Get("launch_configuration").(string))
   318  	}
   319  
   320  	if d.HasChange("min_size") {
   321  		opts.MinSize = aws.Int64(int64(d.Get("min_size").(int)))
   322  		shouldWaitForCapacity = true
   323  	}
   324  
   325  	if d.HasChange("max_size") {
   326  		opts.MaxSize = aws.Int64(int64(d.Get("max_size").(int)))
   327  	}
   328  
   329  	if d.HasChange("health_check_grace_period") {
   330  		opts.HealthCheckGracePeriod = aws.Int64(int64(d.Get("health_check_grace_period").(int)))
   331  	}
   332  
   333  	if d.HasChange("health_check_type") {
   334  		opts.HealthCheckGracePeriod = aws.Int64(int64(d.Get("health_check_grace_period").(int)))
   335  		opts.HealthCheckType = aws.String(d.Get("health_check_type").(string))
   336  	}
   337  
   338  	if d.HasChange("vpc_zone_identifier") {
   339  		opts.VPCZoneIdentifier = expandVpcZoneIdentifiers(d.Get("vpc_zone_identifier").(*schema.Set).List())
   340  	}
   341  
   342  	if d.HasChange("availability_zones") {
   343  		if v, ok := d.GetOk("availability_zones"); ok && v.(*schema.Set).Len() > 0 {
   344  			opts.AvailabilityZones = expandStringList(v.(*schema.Set).List())
   345  		}
   346  	}
   347  
   348  	if d.HasChange("placement_group") {
   349  		opts.PlacementGroup = aws.String(d.Get("placement_group").(string))
   350  	}
   351  
   352  	if d.HasChange("termination_policies") {
   353  		// If the termination policy is set to null, we need to explicitly set
   354  		// it back to "Default", or the API won't reset it for us.
   355  		if v, ok := d.GetOk("termination_policies"); ok && len(v.([]interface{})) > 0 {
   356  			opts.TerminationPolicies = expandStringList(v.([]interface{}))
   357  		} else {
   358  			log.Printf("[DEBUG] Explictly setting null termination policy to 'Default'")
   359  			opts.TerminationPolicies = aws.StringSlice([]string{"Default"})
   360  		}
   361  	}
   362  
   363  	if err := setAutoscalingTags(conn, d); err != nil {
   364  		return err
   365  	} else {
   366  		d.SetPartial("tag")
   367  	}
   368  
   369  	log.Printf("[DEBUG] AutoScaling Group update configuration: %#v", opts)
   370  	_, err := conn.UpdateAutoScalingGroup(&opts)
   371  	if err != nil {
   372  		d.Partial(true)
   373  		return fmt.Errorf("Error updating Autoscaling group: %s", err)
   374  	}
   375  
   376  	if d.HasChange("load_balancers") {
   377  
   378  		o, n := d.GetChange("load_balancers")
   379  		if o == nil {
   380  			o = new(schema.Set)
   381  		}
   382  		if n == nil {
   383  			n = new(schema.Set)
   384  		}
   385  
   386  		os := o.(*schema.Set)
   387  		ns := n.(*schema.Set)
   388  		remove := expandStringList(os.Difference(ns).List())
   389  		add := expandStringList(ns.Difference(os).List())
   390  
   391  		if len(remove) > 0 {
   392  			_, err := conn.DetachLoadBalancers(&autoscaling.DetachLoadBalancersInput{
   393  				AutoScalingGroupName: aws.String(d.Id()),
   394  				LoadBalancerNames:    remove,
   395  			})
   396  			if err != nil {
   397  				return fmt.Errorf("[WARN] Error updating Load Balancers for AutoScaling Group (%s), error: %s", d.Id(), err)
   398  			}
   399  		}
   400  
   401  		if len(add) > 0 {
   402  			_, err := conn.AttachLoadBalancers(&autoscaling.AttachLoadBalancersInput{
   403  				AutoScalingGroupName: aws.String(d.Id()),
   404  				LoadBalancerNames:    add,
   405  			})
   406  			if err != nil {
   407  				return fmt.Errorf("[WARN] Error updating Load Balancers for AutoScaling Group (%s), error: %s", d.Id(), err)
   408  			}
   409  		}
   410  	}
   411  
   412  	if shouldWaitForCapacity {
   413  		waitForASGCapacity(d, meta, capacitySatifiedUpdate)
   414  	}
   415  
   416  	if d.HasChange("enabled_metrics") {
   417  		updateASGMetricsCollection(d, conn)
   418  	}
   419  
   420  	return resourceAwsAutoscalingGroupRead(d, meta)
   421  }
   422  
   423  func resourceAwsAutoscalingGroupDelete(d *schema.ResourceData, meta interface{}) error {
   424  	conn := meta.(*AWSClient).autoscalingconn
   425  
   426  	// Read the autoscaling group first. If it doesn't exist, we're done.
   427  	// We need the group in order to check if there are instances attached.
   428  	// If so, we need to remove those first.
   429  	g, err := getAwsAutoscalingGroup(d.Id(), conn)
   430  	if err != nil {
   431  		return err
   432  	}
   433  	if g == nil {
   434  		log.Printf("[INFO] Autoscaling Group %q not found", d.Id())
   435  		d.SetId("")
   436  		return nil
   437  	}
   438  	if len(g.Instances) > 0 || *g.DesiredCapacity > 0 {
   439  		if err := resourceAwsAutoscalingGroupDrain(d, meta); err != nil {
   440  			return err
   441  		}
   442  	}
   443  
   444  	log.Printf("[DEBUG] AutoScaling Group destroy: %v", d.Id())
   445  	deleteopts := autoscaling.DeleteAutoScalingGroupInput{
   446  		AutoScalingGroupName: aws.String(d.Id()),
   447  		ForceDelete:          aws.Bool(d.Get("force_delete").(bool)),
   448  	}
   449  
   450  	// We retry the delete operation to handle InUse/InProgress errors coming
   451  	// from scaling operations. We should be able to sneak in a delete in between
   452  	// scaling operations within 5m.
   453  	err = resource.Retry(5*time.Minute, func() *resource.RetryError {
   454  		if _, err := conn.DeleteAutoScalingGroup(&deleteopts); err != nil {
   455  			if awserr, ok := err.(awserr.Error); ok {
   456  				switch awserr.Code() {
   457  				case "InvalidGroup.NotFound":
   458  					// Already gone? Sure!
   459  					return nil
   460  				case "ResourceInUse", "ScalingActivityInProgress":
   461  					// These are retryable
   462  					return resource.RetryableError(awserr)
   463  				}
   464  			}
   465  			// Didn't recognize the error, so shouldn't retry.
   466  			return resource.NonRetryableError(err)
   467  		}
   468  		// Successful delete
   469  		return nil
   470  	})
   471  	if err != nil {
   472  		return err
   473  	}
   474  
   475  	return resource.Retry(5*time.Minute, func() *resource.RetryError {
   476  		if g, _ = getAwsAutoscalingGroup(d.Id(), conn); g != nil {
   477  			return resource.RetryableError(
   478  				fmt.Errorf("Auto Scaling Group still exists"))
   479  		}
   480  		return nil
   481  	})
   482  }
   483  
   484  func getAwsAutoscalingGroup(
   485  	asgName string,
   486  	conn *autoscaling.AutoScaling) (*autoscaling.Group, error) {
   487  
   488  	describeOpts := autoscaling.DescribeAutoScalingGroupsInput{
   489  		AutoScalingGroupNames: []*string{aws.String(asgName)},
   490  	}
   491  
   492  	log.Printf("[DEBUG] AutoScaling Group describe configuration: %#v", describeOpts)
   493  	describeGroups, err := conn.DescribeAutoScalingGroups(&describeOpts)
   494  	if err != nil {
   495  		autoscalingerr, ok := err.(awserr.Error)
   496  		if ok && autoscalingerr.Code() == "InvalidGroup.NotFound" {
   497  			return nil, nil
   498  		}
   499  
   500  		return nil, fmt.Errorf("Error retrieving AutoScaling groups: %s", err)
   501  	}
   502  
   503  	// Search for the autoscaling group
   504  	for idx, asc := range describeGroups.AutoScalingGroups {
   505  		if *asc.AutoScalingGroupName == asgName {
   506  			return describeGroups.AutoScalingGroups[idx], nil
   507  		}
   508  	}
   509  
   510  	return nil, nil
   511  }
   512  
   513  func resourceAwsAutoscalingGroupDrain(d *schema.ResourceData, meta interface{}) error {
   514  	conn := meta.(*AWSClient).autoscalingconn
   515  
   516  	if d.Get("force_delete").(bool) {
   517  		log.Printf("[DEBUG] Skipping ASG drain, force_delete was set.")
   518  		return nil
   519  	}
   520  
   521  	// First, set the capacity to zero so the group will drain
   522  	log.Printf("[DEBUG] Reducing autoscaling group capacity to zero")
   523  	opts := autoscaling.UpdateAutoScalingGroupInput{
   524  		AutoScalingGroupName: aws.String(d.Id()),
   525  		DesiredCapacity:      aws.Int64(0),
   526  		MinSize:              aws.Int64(0),
   527  		MaxSize:              aws.Int64(0),
   528  	}
   529  	if _, err := conn.UpdateAutoScalingGroup(&opts); err != nil {
   530  		return fmt.Errorf("Error setting capacity to zero to drain: %s", err)
   531  	}
   532  
   533  	// Next, wait for the autoscale group to drain
   534  	log.Printf("[DEBUG] Waiting for group to have zero instances")
   535  	return resource.Retry(10*time.Minute, func() *resource.RetryError {
   536  		g, err := getAwsAutoscalingGroup(d.Id(), conn)
   537  		if err != nil {
   538  			return resource.NonRetryableError(err)
   539  		}
   540  		if g == nil {
   541  			log.Printf("[INFO] Autoscaling Group %q not found", d.Id())
   542  			d.SetId("")
   543  			return nil
   544  		}
   545  
   546  		if len(g.Instances) == 0 {
   547  			return nil
   548  		}
   549  
   550  		return resource.RetryableError(
   551  			fmt.Errorf("group still has %d instances", len(g.Instances)))
   552  	})
   553  }
   554  
   555  func enableASGMetricsCollection(d *schema.ResourceData, conn *autoscaling.AutoScaling) error {
   556  	props := &autoscaling.EnableMetricsCollectionInput{
   557  		AutoScalingGroupName: aws.String(d.Id()),
   558  		Granularity:          aws.String(d.Get("metrics_granularity").(string)),
   559  		Metrics:              expandStringList(d.Get("enabled_metrics").(*schema.Set).List()),
   560  	}
   561  
   562  	log.Printf("[INFO] Enabling metrics collection for the ASG: %s", d.Id())
   563  	_, metricsErr := conn.EnableMetricsCollection(props)
   564  	if metricsErr != nil {
   565  		return metricsErr
   566  	}
   567  
   568  	return nil
   569  }
   570  
   571  func updateASGMetricsCollection(d *schema.ResourceData, conn *autoscaling.AutoScaling) error {
   572  
   573  	o, n := d.GetChange("enabled_metrics")
   574  	if o == nil {
   575  		o = new(schema.Set)
   576  	}
   577  	if n == nil {
   578  		n = new(schema.Set)
   579  	}
   580  
   581  	os := o.(*schema.Set)
   582  	ns := n.(*schema.Set)
   583  
   584  	disableMetrics := os.Difference(ns)
   585  	if disableMetrics.Len() != 0 {
   586  		props := &autoscaling.DisableMetricsCollectionInput{
   587  			AutoScalingGroupName: aws.String(d.Id()),
   588  			Metrics:              expandStringList(disableMetrics.List()),
   589  		}
   590  
   591  		_, err := conn.DisableMetricsCollection(props)
   592  		if err != nil {
   593  			return fmt.Errorf("Failure to Disable metrics collection types for ASG %s: %s", d.Id(), err)
   594  		}
   595  	}
   596  
   597  	enabledMetrics := ns.Difference(os)
   598  	if enabledMetrics.Len() != 0 {
   599  		props := &autoscaling.EnableMetricsCollectionInput{
   600  			AutoScalingGroupName: aws.String(d.Id()),
   601  			Metrics:              expandStringList(enabledMetrics.List()),
   602  		}
   603  
   604  		_, err := conn.EnableMetricsCollection(props)
   605  		if err != nil {
   606  			return fmt.Errorf("Failure to Enable metrics collection types for ASG %s: %s", d.Id(), err)
   607  		}
   608  	}
   609  
   610  	return nil
   611  }
   612  
   613  // Returns a mapping of the instance states of all the ELBs attached to the
   614  // provided ASG.
   615  //
   616  // Nested like: lbName -> instanceId -> instanceState
   617  func getLBInstanceStates(g *autoscaling.Group, meta interface{}) (map[string]map[string]string, error) {
   618  	lbInstanceStates := make(map[string]map[string]string)
   619  	elbconn := meta.(*AWSClient).elbconn
   620  
   621  	for _, lbName := range g.LoadBalancerNames {
   622  		lbInstanceStates[*lbName] = make(map[string]string)
   623  		opts := &elb.DescribeInstanceHealthInput{LoadBalancerName: lbName}
   624  		r, err := elbconn.DescribeInstanceHealth(opts)
   625  		if err != nil {
   626  			return nil, err
   627  		}
   628  		for _, is := range r.InstanceStates {
   629  			if is.InstanceId == nil || is.State == nil {
   630  				continue
   631  			}
   632  			lbInstanceStates[*lbName][*is.InstanceId] = *is.State
   633  		}
   634  	}
   635  
   636  	return lbInstanceStates, nil
   637  }
   638  
   639  func expandVpcZoneIdentifiers(list []interface{}) *string {
   640  	strs := make([]string, len(list))
   641  	for _, s := range list {
   642  		strs = append(strs, s.(string))
   643  	}
   644  	return aws.String(strings.Join(strs, ","))
   645  }