func resourceAwsInternetGatewayRead(d *schema.ResourceData, meta interface{}) error {
	conn := meta.(*AWSClient).ec2conn

	igRaw, _, err := IGStateRefreshFunc(conn, d.Id())()
	if err != nil {
		return err
	}
	if igRaw == nil {
		// Seems we have lost our internet gateway
		d.SetId("")
		return nil
	}

	ig := igRaw.(*ec2.InternetGateway)
	if len(ig.Attachments) == 0 {
		// Gateway exists but not attached to the VPC
		d.Set("vpc_id", "")
	} else {
		d.Set("vpc_id", ig.Attachments[0].VpcId)
	}

	d.Set("tags", tagsToMap(ig.Tags))

	return nil
}

// resourceAwsLambdaEventSourceMappingUpdate maps to:
// UpdateEventSourceMapping in the API / SDK
func resourceAwsLambdaEventSourceMappingUpdate(d *schema.ResourceData, meta interface{}) error {
	conn := meta.(*AWSClient).lambdaconn

	log.Printf("[DEBUG] Updating Lambda event source mapping: %s", d.Id())

	params := &lambda.UpdateEventSourceMappingInput{
		UUID:         aws.String(d.Id()),
		BatchSize:    aws.Int64(int64(d.Get("batch_size").(int))),
		FunctionName: aws.String(d.Get("function_name").(string)),
		Enabled:      aws.Bool(d.Get("enabled").(bool)),
	}

	err := resource.Retry(1*time.Minute, func() *resource.RetryError {
		_, err := conn.UpdateEventSourceMapping(params)
		if err != nil {
			if awserr, ok := err.(awserr.Error); ok {
				if awserr.Code() == "InvalidParameterValueException" {
					return resource.RetryableError(awserr)
				}
			}
			return resource.NonRetryableError(err)
		}
		return nil
	})

	if err != nil {
		return fmt.Errorf("Error updating Lambda event source mapping: %s", err)
	}

	return resourceAwsLambdaEventSourceMappingRead(d, meta)
}

func resourceAwsIamAccessKeyCreate(d *schema.ResourceData, meta interface{}) error {
	iamconn := meta.(*AWSClient).iamconn

	request := &iam.CreateAccessKeyInput{
		UserName: aws.String(d.Get("user").(string)),
	}

	createResp, err := iamconn.CreateAccessKey(request)
	if err != nil {
		return fmt.Errorf(
			"Error creating access key for user %s: %s",
			*request.UserName,
			err,
		)
	}

	if err := d.Set("secret", createResp.AccessKey.SecretAccessKey); err != nil {
		return err
	}
	return resourceAwsIamAccessKeyReadResult(d, &iam.AccessKeyMetadata{
		AccessKeyID: createResp.AccessKey.AccessKeyID,
		CreateDate:  createResp.AccessKey.CreateDate,
		Status:      createResp.AccessKey.Status,
		UserName:    createResp.AccessKey.UserName,
	})
}

func getVolumeAttachments(computeClient *gophercloud.ServiceClient, d *schema.ResourceData) error {
	var attachments []volumeattach.VolumeAttachment

	err := volumeattach.List(computeClient, d.Id()).EachPage(func(page pagination.Page) (bool, error) {
		actual, err := volumeattach.ExtractVolumeAttachments(page)
		if err != nil {
			return false, err
		}

		attachments = actual
		return true, nil
	})

	if err != nil {
		return err
	}

	vols := make([]map[string]interface{}, len(attachments))
	for i, attachment := range attachments {
		vols[i] = make(map[string]interface{})
		vols[i]["id"] = attachment.ID
		vols[i]["volume_id"] = attachment.VolumeID
		vols[i]["device"] = attachment.Device
	}
	log.Printf("[INFO] Volume attachments: %v", vols)
	d.Set("volume", vols)

	return nil
}

func getInstanceAccessAddresses(d *schema.ResourceData, networks []map[string]interface{}) (string, string) {
	var hostv4, hostv6 string

	// Start with a global floating IP
	floatingIP := d.Get("floating_ip").(string)
	if floatingIP != "" {
		hostv4 = floatingIP
	}

	// Loop through all networks and check for the following:
	// * If the network is set as an access network.
	// * If the network has a floating IP.
	// * If the network has a v4/v6 fixed IP.
	for _, n := range networks {
		if n["floating_ip"] != nil {
			hostv4 = n["floating_ip"].(string)
		} else {
			if hostv4 == "" && n["fixed_ip_v4"] != nil {
				hostv4 = n["fixed_ip_v4"].(string)
			}
		}

		if hostv6 == "" && n["fixed_ip_v6"] != nil {
			hostv6 = n["fixed_ip_v6"].(string)
		}

		if an, ok := n["access_network"].(bool); ok && an {
			break
		}
	}

	log.Printf("[DEBUG] OpenStack Instance Network Access Addresses: %s, %s", hostv4, hostv6)

	return hostv4, hostv6
}

func resourceComputeTargetPoolDelete(d *schema.ResourceData, meta interface{}) error {
	config := meta.(*Config)

	region, err := getRegion(d, config)
	if err != nil {
		return err
	}

	project, err := getProject(d, config)
	if err != nil {
		return err
	}

	// Delete the TargetPool
	op, err := config.clientCompute.TargetPools.Delete(
		project, region, d.Id()).Do()
	if err != nil {
		return fmt.Errorf("Error deleting TargetPool: %s", err)
	}

	err = computeOperationWaitRegion(config, op, region, "Deleting Target Pool")
	if err != nil {
		return err
	}
	d.SetId("")
	return nil
}

func resourceInstanceMetadataV2(d *schema.ResourceData) map[string]string {
	m := make(map[string]string)
	for key, val := range d.Get("metadata").(map[string]interface{}) {
		m[key] = val.(string)
	}
	return m
}

func resourceSqlDatabaseDelete(d *schema.ResourceData, meta interface{}) error {
	config := meta.(*Config)

	database_name := d.Get("name").(string)
	instance_name := d.Get("instance").(string)
	project := config.Project

	op, err := config.clientSqlAdmin.Databases.Delete(project, instance_name,
		database_name).Do()

	if err != nil {
		return fmt.Errorf("Error, failed to delete"+
			"database %s in instance %s: %s", database_name,
			instance_name, err)
	}

	err = sqladminOperationWait(config, op, "Delete Database")

	if err != nil {
		return fmt.Errorf("Error, failure waiting for deletion of %s "+
			"in %s: %s", database_name, instance_name, err)
	}

	return nil
}

// resourceAwsDbInstanceRetrieve fetches DBInstance information from the AWS
// API. It returns an error if there is a communication problem or unexpected
// error with AWS. When the DBInstance is not found, it returns no error and a
// nil pointer.
func resourceAwsDbInstanceRetrieve(
	d *schema.ResourceData, meta interface{}) (*rds.DBInstance, error) {
	conn := meta.(*AWSClient).rdsconn

	opts := rds.DescribeDBInstancesInput{
		DBInstanceIdentifier: aws.String(d.Id()),
	}

	log.Printf("[DEBUG] DB Instance describe configuration: %#v", opts)

	resp, err := conn.DescribeDBInstances(&opts)
	if err != nil {
		dbinstanceerr, ok := err.(awserr.Error)
		if ok && dbinstanceerr.Code() == "DBInstanceNotFound" {
			return nil, nil
		}
		return nil, fmt.Errorf("Error retrieving DB Instances: %s", err)
	}

	if len(resp.DBInstances) != 1 ||
		*resp.DBInstances[0].DBInstanceIdentifier != d.Id() {
		if err != nil {
			return nil, nil
		}
	}

	return resp.DBInstances[0], nil
}

func resourceAwsAutoscalingGroupDrain(d *schema.ResourceData, meta interface{}) error {
	conn := meta.(*AWSClient).autoscalingconn

	// First, set the capacity to zero so the group will drain
	log.Printf("[DEBUG] Reducing autoscaling group capacity to zero")
	opts := autoscaling.UpdateAutoScalingGroupInput{
		AutoScalingGroupName: aws.String(d.Id()),
		DesiredCapacity:      aws.Long(0),
		MinSize:              aws.Long(0),
		MaxSize:              aws.Long(0),
	}
	if _, err := conn.UpdateAutoScalingGroup(&opts); err != nil {
		return fmt.Errorf("Error setting capacity to zero to drain: %s", err)
	}

	// Next, wait for the autoscale group to drain
	log.Printf("[DEBUG] Waiting for group to have zero instances")
	return resource.Retry(10*time.Minute, func() error {
		g, err := getAwsAutoscalingGroup(d, meta)
		if err != nil {
			return resource.RetryError{Err: err}
		}
		if g == nil {
			return nil
		}

		if len(g.Instances) == 0 {
			return nil
		}

		return fmt.Errorf("group still has %d instances", len(g.Instances))
	})
}

func resourceSqlDatabaseCreate(d *schema.ResourceData, meta interface{}) error {
	config := meta.(*Config)

	database_name := d.Get("name").(string)
	instance_name := d.Get("instance").(string)
	project := config.Project

	db := &sqladmin.Database{
		Name:     database_name,
		Instance: instance_name,
	}

	op, err := config.clientSqlAdmin.Databases.Insert(project, instance_name,
		db).Do()

	if err != nil {
		return fmt.Errorf("Error, failed to insert "+
			"database %s into instance %s: %s", database_name,
			instance_name, err)
	}

	err = sqladminOperationWait(config, op, "Insert Database")

	if err != nil {
		return fmt.Errorf("Error, failure waiting for insertion of %s "+
			"into %s: %s", database_name, instance_name, err)
	}

	return resourceSqlDatabaseRead(d, meta)
}

func (lt *opsworksLayerType) SetVolumeConfigurations(d *schema.ResourceData, v []*opsworks.VolumeConfiguration) {
	newValue := make([]*map[string]interface{}, len(v))

	for i := 0; i < len(v); i++ {
		config := v[i]
		data := make(map[string]interface{})
		newValue[i] = &data

		if config.Iops != nil {
			data["iops"] = int(*config.Iops)
		} else {
			data["iops"] = 0
		}
		if config.MountPoint != nil {
			data["mount_point"] = *config.MountPoint
		}
		if config.NumberOfDisks != nil {
			data["number_of_disks"] = int(*config.NumberOfDisks)
		}
		if config.RaidLevel != nil {
			data["raid_level"] = strconv.Itoa(int(*config.RaidLevel))
		}
		if config.Size != nil {
			data["size"] = int(*config.Size)
		}
		if config.VolumeType != nil {
			data["type"] = *config.VolumeType
		}
	}

	d.Set("ebs_volume", newValue)
}

func (lt *opsworksLayerType) VolumeConfigurations(d *schema.ResourceData) []*opsworks.VolumeConfiguration {
	configuredVolumes := d.Get("ebs_volume").(*schema.Set).List()
	result := make([]*opsworks.VolumeConfiguration, len(configuredVolumes))

	for i := 0; i < len(configuredVolumes); i++ {
		volumeData := configuredVolumes[i].(map[string]interface{})

		result[i] = &opsworks.VolumeConfiguration{
			MountPoint:    aws.String(volumeData["mount_point"].(string)),
			NumberOfDisks: aws.Int64(int64(volumeData["number_of_disks"].(int))),
			Size:          aws.Int64(int64(volumeData["size"].(int))),
			VolumeType:    aws.String(volumeData["type"].(string)),
		}
		iops := int64(volumeData["iops"].(int))
		if iops != 0 {
			result[i].Iops = aws.Int64(iops)
		}

		raidLevelStr := volumeData["raid_level"].(string)
		if raidLevelStr != "" {
			raidLevel, err := strconv.Atoi(raidLevelStr)
			if err == nil {
				result[i].RaidLevel = aws.Int64(int64(raidLevel))
			}
		}
	}

	return result
}

func (lt *opsworksLayerType) AttributeMap(d *schema.ResourceData) map[string]*string {
	attrs := map[string]*string{}

	for key, def := range lt.Attributes {
		value := d.Get(key)
		switch def.Type {
		case schema.TypeString:
			strValue := value.(string)
			attrs[def.AttrName] = &strValue
		case schema.TypeInt:
			intValue := value.(int)
			strValue := strconv.Itoa(intValue)
			attrs[def.AttrName] = &strValue
		case schema.TypeBool:
			boolValue := value.(bool)
			if boolValue {
				attrs[def.AttrName] = &opsworksTrueString
			} else {
				attrs[def.AttrName] = &opsworksFalseString
			}
		default:
			// should never happen
			panic(fmt.Errorf("Unsupported OpsWorks layer attribute type"))
		}
	}

	return attrs
}

func expandAzureRmVirtualMachineDataDisk(d *schema.ResourceData) ([]compute.DataDisk, error) {
	disks := d.Get("storage_data_disk").([]interface{})
	data_disks := make([]compute.DataDisk, 0, len(disks))
	for _, disk_config := range disks {
		config := disk_config.(map[string]interface{})

		name := config["name"].(string)
		vhd := config["vhd_uri"].(string)
		createOption := config["create_option"].(string)
		lun := int32(config["lun"].(int))
		disk_size := int32(config["disk_size_gb"].(int))

		data_disk := compute.DataDisk{
			Name: &name,
			Vhd: &compute.VirtualHardDisk{
				URI: &vhd,
			},
			Lun:          &lun,
			DiskSizeGB:   &disk_size,
			CreateOption: compute.DiskCreateOptionTypes(createOption),
		}

		data_disks = append(data_disks, data_disk)
	}

	return data_disks, nil
}

func resourceAwsElasticacheClusterDelete(d *schema.ResourceData, meta interface{}) error {
	conn := meta.(*AWSClient).elasticacheconn

	req := &elasticache.DeleteCacheClusterInput{
		CacheClusterId: aws.String(d.Id()),
	}
	_, err := conn.DeleteCacheCluster(req)
	if err != nil {
		return err
	}

	log.Printf("[DEBUG] Waiting for deletion: %v", d.Id())
	stateConf := &resource.StateChangeConf{
		Pending:    []string{"creating", "available", "deleting", "incompatible-parameters", "incompatible-network", "restore-failed"},
		Target:     "",
		Refresh:    cacheClusterStateRefreshFunc(conn, d.Id(), "", []string{}),
		Timeout:    10 * time.Minute,
		Delay:      10 * time.Second,
		MinTimeout: 3 * time.Second,
	}

	_, sterr := stateConf.WaitForState()
	if sterr != nil {
		return fmt.Errorf("Error waiting for elasticache (%s) to delete: %s", d.Id(), sterr)
	}

	d.SetId("")

	return nil
}

func expandAzureRmVirtualMachineOsProfileLinuxConfig(d *schema.ResourceData) (*compute.LinuxConfiguration, error) {
	osProfilesLinuxConfig := d.Get("os_profile_linux_config").(*schema.Set).List()

	linuxConfig := osProfilesLinuxConfig[0].(map[string]interface{})
	disablePasswordAuth := linuxConfig["disable_password_authentication"].(bool)

	config := &compute.LinuxConfiguration{
		DisablePasswordAuthentication: &disablePasswordAuth,
	}

	linuxKeys := linuxConfig["ssh_keys"].([]interface{})
	sshPublicKeys := []compute.SSHPublicKey{}
	for _, key := range linuxKeys {

		sshKey, ok := key.(map[string]interface{})
		if !ok {
			continue
		}
		path := sshKey["path"].(string)
		keyData := sshKey["key_data"].(string)

		sshPublicKey := compute.SSHPublicKey{
			Path:    &path,
			KeyData: &keyData,
		}

		sshPublicKeys = append(sshPublicKeys, sshPublicKey)
	}

	config.SSH = &compute.SSHConfiguration{
		PublicKeys: &sshPublicKeys,
	}

	return config, nil
}

func websiteEndpoint(s3conn *s3.S3, d *schema.ResourceData) (*S3Website, error) {
	// If the bucket doesn't have a website configuration, return an empty
	// endpoint
	if _, ok := d.GetOk("website"); !ok {
		return nil, nil
	}

	bucket := d.Get("bucket").(string)

	// Lookup the region for this bucket
	location, err := s3conn.GetBucketLocation(
		&s3.GetBucketLocationInput{
			Bucket: aws.String(bucket),
		},
	)
	if err != nil {
		return nil, err
	}
	var region string
	if location.LocationConstraint != nil {
		region = *location.LocationConstraint
	}

	return WebsiteEndpoint(bucket, region), nil
}

func resourceAwsKinesisStreamDelete(d *schema.ResourceData, meta interface{}) error {
	conn := meta.(*AWSClient).kinesisconn
	sn := d.Get("name").(string)
	_, err := conn.DeleteStream(&kinesis.DeleteStreamInput{
		StreamName: aws.String(sn),
	})

	if err != nil {
		return err
	}

	stateConf := &resource.StateChangeConf{
		Pending:    []string{"DELETING"},
		Target:     "DESTROYED",
		Refresh:    streamStateRefreshFunc(conn, sn),
		Timeout:    5 * time.Minute,
		Delay:      10 * time.Second,
		MinTimeout: 3 * time.Second,
	}

	_, err = stateConf.WaitForState()
	if err != nil {
		return fmt.Errorf(
			"Error waiting for Stream (%s) to be destroyed: %s",
			sn, err)
	}

	d.SetId("")
	return nil
}

func resourceAwsS3BucketVersioningUpdate(s3conn *s3.S3, d *schema.ResourceData) error {
	v := d.Get("versioning").(*schema.Set).List()
	bucket := d.Get("bucket").(string)
	vc := &s3.VersioningConfiguration{}

	if len(v) > 0 {
		c := v[0].(map[string]interface{})

		if c["enabled"].(bool) {
			vc.Status = aws.String(s3.BucketVersioningStatusEnabled)
		} else {
			vc.Status = aws.String(s3.BucketVersioningStatusSuspended)
		}
	} else {
		vc.Status = aws.String(s3.BucketVersioningStatusSuspended)
	}

	i := &s3.PutBucketVersioningInput{
		Bucket:                  aws.String(bucket),
		VersioningConfiguration: vc,
	}
	log.Printf("[DEBUG] S3 put bucket versioning: %#v", i)

	_, err := s3conn.PutBucketVersioning(i)
	if err != nil {
		return fmt.Errorf("Error putting S3 versioning: %s", err)
	}

	return nil
}