github.com/ricardclau/terraform@v0.6.17-0.20160519222547-283e3ae6b5a9/builtin/providers/aws/resource_aws_redshift_cluster.go (about)

     1  package aws
     2  
     3  import (
     4  	"fmt"
     5  	"log"
     6  	"regexp"
     7  	"strings"
     8  	"time"
     9  
    10  	"github.com/aws/aws-sdk-go/aws"
    11  	"github.com/aws/aws-sdk-go/aws/awserr"
    12  	"github.com/aws/aws-sdk-go/service/redshift"
    13  	"github.com/hashicorp/terraform/helper/resource"
    14  	"github.com/hashicorp/terraform/helper/schema"
    15  )
    16  
    17  func resourceAwsRedshiftCluster() *schema.Resource {
    18  	return &schema.Resource{
    19  		Create: resourceAwsRedshiftClusterCreate,
    20  		Read:   resourceAwsRedshiftClusterRead,
    21  		Update: resourceAwsRedshiftClusterUpdate,
    22  		Delete: resourceAwsRedshiftClusterDelete,
    23  
    24  		Schema: map[string]*schema.Schema{
    25  			"database_name": &schema.Schema{
    26  				Type:         schema.TypeString,
    27  				Optional:     true,
    28  				Computed:     true,
    29  				ValidateFunc: validateRedshiftClusterDbName,
    30  			},
    31  
    32  			"cluster_identifier": &schema.Schema{
    33  				Type:         schema.TypeString,
    34  				Required:     true,
    35  				ForceNew:     true,
    36  				ValidateFunc: validateRedshiftClusterIdentifier,
    37  			},
    38  			"cluster_type": &schema.Schema{
    39  				Type:     schema.TypeString,
    40  				Optional: true,
    41  				Computed: true,
    42  			},
    43  
    44  			"node_type": &schema.Schema{
    45  				Type:     schema.TypeString,
    46  				Required: true,
    47  			},
    48  
    49  			"master_username": &schema.Schema{
    50  				Type:         schema.TypeString,
    51  				Required:     true,
    52  				ValidateFunc: validateRedshiftClusterMasterUsername,
    53  			},
    54  
    55  			"master_password": &schema.Schema{
    56  				Type:     schema.TypeString,
    57  				Required: true,
    58  			},
    59  
    60  			"cluster_security_groups": &schema.Schema{
    61  				Type:     schema.TypeSet,
    62  				Optional: true,
    63  				Computed: true,
    64  				Elem:     &schema.Schema{Type: schema.TypeString},
    65  				Set:      schema.HashString,
    66  			},
    67  
    68  			"vpc_security_group_ids": &schema.Schema{
    69  				Type:     schema.TypeSet,
    70  				Optional: true,
    71  				Computed: true,
    72  				Elem:     &schema.Schema{Type: schema.TypeString},
    73  				Set:      schema.HashString,
    74  			},
    75  
    76  			"cluster_subnet_group_name": &schema.Schema{
    77  				Type:     schema.TypeString,
    78  				Optional: true,
    79  				ForceNew: true,
    80  				Computed: true,
    81  			},
    82  
    83  			"availability_zone": &schema.Schema{
    84  				Type:     schema.TypeString,
    85  				Optional: true,
    86  				Computed: true,
    87  			},
    88  
    89  			"preferred_maintenance_window": &schema.Schema{
    90  				Type:     schema.TypeString,
    91  				Optional: true,
    92  				Computed: true,
    93  				StateFunc: func(val interface{}) string {
    94  					if val == nil {
    95  						return ""
    96  					}
    97  					return strings.ToLower(val.(string))
    98  				},
    99  			},
   100  
   101  			"cluster_parameter_group_name": &schema.Schema{
   102  				Type:     schema.TypeString,
   103  				Optional: true,
   104  				Computed: true,
   105  			},
   106  
   107  			"automated_snapshot_retention_period": &schema.Schema{
   108  				Type:     schema.TypeInt,
   109  				Optional: true,
   110  				Default:  1,
   111  				ValidateFunc: func(v interface{}, k string) (ws []string, es []error) {
   112  					value := v.(int)
   113  					if value > 35 {
   114  						es = append(es, fmt.Errorf(
   115  							"backup retention period cannot be more than 35 days"))
   116  					}
   117  					return
   118  				},
   119  			},
   120  
   121  			"port": &schema.Schema{
   122  				Type:     schema.TypeInt,
   123  				Optional: true,
   124  				Default:  5439,
   125  			},
   126  
   127  			"cluster_version": &schema.Schema{
   128  				Type:     schema.TypeString,
   129  				Optional: true,
   130  				Default:  "1.0",
   131  			},
   132  
   133  			"allow_version_upgrade": &schema.Schema{
   134  				Type:     schema.TypeBool,
   135  				Optional: true,
   136  				Default:  true,
   137  			},
   138  
   139  			"number_of_nodes": &schema.Schema{
   140  				Type:     schema.TypeInt,
   141  				Optional: true,
   142  				Default:  1,
   143  			},
   144  
   145  			"publicly_accessible": &schema.Schema{
   146  				Type:     schema.TypeBool,
   147  				Optional: true,
   148  				Default:  true,
   149  			},
   150  
   151  			"encrypted": &schema.Schema{
   152  				Type:     schema.TypeBool,
   153  				Optional: true,
   154  				Computed: true,
   155  			},
   156  
   157  			"kms_key_id": &schema.Schema{
   158  				Type:     schema.TypeString,
   159  				Optional: true,
   160  				Computed: true,
   161  				ForceNew: true,
   162  			},
   163  
   164  			"elastic_ip": &schema.Schema{
   165  				Type:     schema.TypeString,
   166  				Optional: true,
   167  			},
   168  
   169  			"final_snapshot_identifier": &schema.Schema{
   170  				Type:         schema.TypeString,
   171  				Optional:     true,
   172  				ValidateFunc: validateRedshiftClusterFinalSnapshotIdentifier,
   173  			},
   174  
   175  			"skip_final_snapshot": &schema.Schema{
   176  				Type:     schema.TypeBool,
   177  				Optional: true,
   178  				Default:  true,
   179  			},
   180  
   181  			"endpoint": &schema.Schema{
   182  				Type:     schema.TypeString,
   183  				Optional: true,
   184  				Computed: true,
   185  			},
   186  
   187  			"cluster_public_key": &schema.Schema{
   188  				Type:     schema.TypeString,
   189  				Optional: true,
   190  				Computed: true,
   191  			},
   192  
   193  			"cluster_revision_number": &schema.Schema{
   194  				Type:     schema.TypeString,
   195  				Optional: true,
   196  				Computed: true,
   197  			},
   198  		},
   199  	}
   200  }
   201  
   202  func resourceAwsRedshiftClusterCreate(d *schema.ResourceData, meta interface{}) error {
   203  	conn := meta.(*AWSClient).redshiftconn
   204  
   205  	log.Printf("[INFO] Building Redshift Cluster Options")
   206  	createOpts := &redshift.CreateClusterInput{
   207  		ClusterIdentifier:                aws.String(d.Get("cluster_identifier").(string)),
   208  		Port:                             aws.Int64(int64(d.Get("port").(int))),
   209  		MasterUserPassword:               aws.String(d.Get("master_password").(string)),
   210  		MasterUsername:                   aws.String(d.Get("master_username").(string)),
   211  		ClusterVersion:                   aws.String(d.Get("cluster_version").(string)),
   212  		NodeType:                         aws.String(d.Get("node_type").(string)),
   213  		DBName:                           aws.String(d.Get("database_name").(string)),
   214  		AllowVersionUpgrade:              aws.Bool(d.Get("allow_version_upgrade").(bool)),
   215  		PubliclyAccessible:               aws.Bool(d.Get("publicly_accessible").(bool)),
   216  		AutomatedSnapshotRetentionPeriod: aws.Int64(int64(d.Get("automated_snapshot_retention_period").(int))),
   217  	}
   218  
   219  	if v := d.Get("number_of_nodes").(int); v > 1 {
   220  		createOpts.ClusterType = aws.String("multi-node")
   221  		createOpts.NumberOfNodes = aws.Int64(int64(d.Get("number_of_nodes").(int)))
   222  	} else {
   223  		createOpts.ClusterType = aws.String("single-node")
   224  	}
   225  
   226  	if v := d.Get("cluster_security_groups").(*schema.Set); v.Len() > 0 {
   227  		createOpts.ClusterSecurityGroups = expandStringList(v.List())
   228  	}
   229  
   230  	if v := d.Get("vpc_security_group_ids").(*schema.Set); v.Len() > 0 {
   231  		createOpts.VpcSecurityGroupIds = expandStringList(v.List())
   232  	}
   233  
   234  	if v, ok := d.GetOk("cluster_subnet_group_name"); ok {
   235  		createOpts.ClusterSubnetGroupName = aws.String(v.(string))
   236  	}
   237  
   238  	if v, ok := d.GetOk("availability_zone"); ok {
   239  		createOpts.AvailabilityZone = aws.String(v.(string))
   240  	}
   241  
   242  	if v, ok := d.GetOk("preferred_maintenance_window"); ok {
   243  		createOpts.PreferredMaintenanceWindow = aws.String(v.(string))
   244  	}
   245  
   246  	if v, ok := d.GetOk("cluster_parameter_group_name"); ok {
   247  		createOpts.ClusterParameterGroupName = aws.String(v.(string))
   248  	}
   249  
   250  	if v, ok := d.GetOk("encrypted"); ok {
   251  		createOpts.Encrypted = aws.Bool(v.(bool))
   252  	}
   253  
   254  	if v, ok := d.GetOk("kms_key_id"); ok {
   255  		createOpts.KmsKeyId = aws.String(v.(string))
   256  	}
   257  
   258  	if v, ok := d.GetOk("elastic_ip"); ok {
   259  		createOpts.ElasticIp = aws.String(v.(string))
   260  	}
   261  
   262  	log.Printf("[DEBUG] Redshift Cluster create options: %s", createOpts)
   263  	resp, err := conn.CreateCluster(createOpts)
   264  	if err != nil {
   265  		log.Printf("[ERROR] Error creating Redshift Cluster: %s", err)
   266  		return err
   267  	}
   268  
   269  	log.Printf("[DEBUG]: Cluster create response: %s", resp)
   270  	d.SetId(*resp.Cluster.ClusterIdentifier)
   271  
   272  	stateConf := &resource.StateChangeConf{
   273  		Pending:    []string{"creating", "backing-up", "modifying"},
   274  		Target:     []string{"available"},
   275  		Refresh:    resourceAwsRedshiftClusterStateRefreshFunc(d, meta),
   276  		Timeout:    40 * time.Minute,
   277  		MinTimeout: 10 * time.Second,
   278  	}
   279  
   280  	_, err = stateConf.WaitForState()
   281  	if err != nil {
   282  		return fmt.Errorf("[WARN] Error waiting for Redshift Cluster state to be \"available\": %s", err)
   283  	}
   284  
   285  	return resourceAwsRedshiftClusterRead(d, meta)
   286  }
   287  
   288  func resourceAwsRedshiftClusterRead(d *schema.ResourceData, meta interface{}) error {
   289  	conn := meta.(*AWSClient).redshiftconn
   290  
   291  	log.Printf("[INFO] Reading Redshift Cluster Information: %s", d.Id())
   292  	resp, err := conn.DescribeClusters(&redshift.DescribeClustersInput{
   293  		ClusterIdentifier: aws.String(d.Id()),
   294  	})
   295  
   296  	if err != nil {
   297  		if awsErr, ok := err.(awserr.Error); ok {
   298  			if "ClusterNotFound" == awsErr.Code() {
   299  				d.SetId("")
   300  				log.Printf("[DEBUG] Redshift Cluster (%s) not found", d.Id())
   301  				return nil
   302  			}
   303  		}
   304  		log.Printf("[DEBUG] Error describing Redshift Cluster (%s)", d.Id())
   305  		return err
   306  	}
   307  
   308  	var rsc *redshift.Cluster
   309  	for _, c := range resp.Clusters {
   310  		if *c.ClusterIdentifier == d.Id() {
   311  			rsc = c
   312  		}
   313  	}
   314  
   315  	if rsc == nil {
   316  		log.Printf("[WARN] Redshift Cluster (%s) not found", d.Id())
   317  		d.SetId("")
   318  		return nil
   319  	}
   320  
   321  	d.Set("database_name", rsc.DBName)
   322  	d.Set("cluster_subnet_group_name", rsc.ClusterSubnetGroupName)
   323  	d.Set("availability_zone", rsc.AvailabilityZone)
   324  	d.Set("encrypted", rsc.Encrypted)
   325  	d.Set("kms_key_id", rsc.KmsKeyId)
   326  	d.Set("automated_snapshot_retention_period", rsc.AutomatedSnapshotRetentionPeriod)
   327  	d.Set("preferred_maintenance_window", rsc.PreferredMaintenanceWindow)
   328  	if rsc.Endpoint != nil && rsc.Endpoint.Address != nil {
   329  		endpoint := *rsc.Endpoint.Address
   330  		if rsc.Endpoint.Port != nil {
   331  			endpoint = fmt.Sprintf("%s:%d", endpoint, *rsc.Endpoint.Port)
   332  		}
   333  		d.Set("endpoint", endpoint)
   334  	}
   335  	d.Set("cluster_parameter_group_name", rsc.ClusterParameterGroups[0].ParameterGroupName)
   336  	if len(rsc.ClusterNodes) > 1 {
   337  		d.Set("cluster_type", "multi-node")
   338  	} else {
   339  		d.Set("cluster_type", "single-node")
   340  	}
   341  
   342  	var vpcg []string
   343  	for _, g := range rsc.VpcSecurityGroups {
   344  		vpcg = append(vpcg, *g.VpcSecurityGroupId)
   345  	}
   346  	if err := d.Set("vpc_security_group_ids", vpcg); err != nil {
   347  		return fmt.Errorf("[DEBUG] Error saving VPC Security Group IDs to state for Redshift Cluster (%s): %s", d.Id(), err)
   348  	}
   349  
   350  	var csg []string
   351  	for _, g := range rsc.ClusterSecurityGroups {
   352  		csg = append(csg, *g.ClusterSecurityGroupName)
   353  	}
   354  	if err := d.Set("cluster_security_groups", csg); err != nil {
   355  		return fmt.Errorf("[DEBUG] Error saving Cluster Security Group Names to state for Redshift Cluster (%s): %s", d.Id(), err)
   356  	}
   357  
   358  	d.Set("cluster_public_key", rsc.ClusterPublicKey)
   359  	d.Set("cluster_revision_number", rsc.ClusterRevisionNumber)
   360  
   361  	return nil
   362  }
   363  
   364  func resourceAwsRedshiftClusterUpdate(d *schema.ResourceData, meta interface{}) error {
   365  	conn := meta.(*AWSClient).redshiftconn
   366  
   367  	log.Printf("[INFO] Building Redshift Modify Cluster Options")
   368  	req := &redshift.ModifyClusterInput{
   369  		ClusterIdentifier: aws.String(d.Id()),
   370  	}
   371  
   372  	if d.HasChange("cluster_type") {
   373  		req.ClusterType = aws.String(d.Get("cluster_type").(string))
   374  	}
   375  
   376  	if d.HasChange("node_type") {
   377  		req.NodeType = aws.String(d.Get("node_type").(string))
   378  	}
   379  
   380  	if d.HasChange("number_of_nodes") {
   381  		if v := d.Get("number_of_nodes").(int); v > 1 {
   382  			req.ClusterType = aws.String("multi-node")
   383  			req.NumberOfNodes = aws.Int64(int64(d.Get("number_of_nodes").(int)))
   384  		} else {
   385  			req.ClusterType = aws.String("single-node")
   386  		}
   387  		req.NodeType = aws.String(d.Get("node_type").(string))
   388  	}
   389  
   390  	if d.HasChange("cluster_security_groups") {
   391  		req.ClusterSecurityGroups = expandStringList(d.Get("cluster_security_groups").(*schema.Set).List())
   392  	}
   393  
   394  	if d.HasChange("vpc_security_group_ips") {
   395  		req.VpcSecurityGroupIds = expandStringList(d.Get("vpc_security_group_ips").(*schema.Set).List())
   396  	}
   397  
   398  	if d.HasChange("master_password") {
   399  		req.MasterUserPassword = aws.String(d.Get("master_password").(string))
   400  	}
   401  
   402  	if d.HasChange("cluster_parameter_group_name") {
   403  		req.ClusterParameterGroupName = aws.String(d.Get("cluster_parameter_group_name").(string))
   404  	}
   405  
   406  	if d.HasChange("automated_snapshot_retention_period") {
   407  		req.AutomatedSnapshotRetentionPeriod = aws.Int64(int64(d.Get("automated_snapshot_retention_period").(int)))
   408  	}
   409  
   410  	if d.HasChange("preferred_maintenance_window") {
   411  		req.PreferredMaintenanceWindow = aws.String(d.Get("preferred_maintenance_window").(string))
   412  	}
   413  
   414  	if d.HasChange("cluster_version") {
   415  		req.ClusterVersion = aws.String(d.Get("cluster_version").(string))
   416  	}
   417  
   418  	if d.HasChange("allow_version_upgrade") {
   419  		req.AllowVersionUpgrade = aws.Bool(d.Get("allow_version_upgrade").(bool))
   420  	}
   421  
   422  	if d.HasChange("publicly_accessible") {
   423  		req.PubliclyAccessible = aws.Bool(d.Get("publicly_accessible").(bool))
   424  	}
   425  
   426  	log.Printf("[INFO] Modifying Redshift Cluster: %s", d.Id())
   427  	log.Printf("[DEBUG] Redshift Cluster Modify options: %s", req)
   428  	_, err := conn.ModifyCluster(req)
   429  	if err != nil {
   430  		return fmt.Errorf("[WARN] Error modifying Redshift Cluster (%s): %s", d.Id(), err)
   431  	}
   432  
   433  	stateConf := &resource.StateChangeConf{
   434  		Pending:    []string{"creating", "deleting", "rebooting", "resizing", "renaming", "modifying"},
   435  		Target:     []string{"available"},
   436  		Refresh:    resourceAwsRedshiftClusterStateRefreshFunc(d, meta),
   437  		Timeout:    40 * time.Minute,
   438  		MinTimeout: 10 * time.Second,
   439  	}
   440  
   441  	// Wait, catching any errors
   442  	_, err = stateConf.WaitForState()
   443  	if err != nil {
   444  		return fmt.Errorf("[WARN] Error Modifying Redshift Cluster (%s): %s", d.Id(), err)
   445  	}
   446  
   447  	return resourceAwsRedshiftClusterRead(d, meta)
   448  }
   449  
   450  func resourceAwsRedshiftClusterDelete(d *schema.ResourceData, meta interface{}) error {
   451  	conn := meta.(*AWSClient).redshiftconn
   452  	log.Printf("[DEBUG] Destroying Redshift Cluster (%s)", d.Id())
   453  
   454  	deleteOpts := redshift.DeleteClusterInput{
   455  		ClusterIdentifier: aws.String(d.Id()),
   456  	}
   457  
   458  	skipFinalSnapshot := d.Get("skip_final_snapshot").(bool)
   459  	deleteOpts.SkipFinalClusterSnapshot = aws.Bool(skipFinalSnapshot)
   460  
   461  	if !skipFinalSnapshot {
   462  		if name, present := d.GetOk("final_snapshot_identifier"); present {
   463  			deleteOpts.FinalClusterSnapshotIdentifier = aws.String(name.(string))
   464  		} else {
   465  			return fmt.Errorf("Redshift Cluster Instance FinalSnapshotIdentifier is required when a final snapshot is required")
   466  		}
   467  	}
   468  
   469  	log.Printf("[DEBUG] Redshift Cluster delete options: %s", deleteOpts)
   470  	_, err := conn.DeleteCluster(&deleteOpts)
   471  	if err != nil {
   472  		return fmt.Errorf("[ERROR] Error deleting Redshift Cluster (%s): %s", d.Id(), err)
   473  	}
   474  
   475  	stateConf := &resource.StateChangeConf{
   476  		Pending:    []string{"available", "creating", "deleting", "rebooting", "resizing", "renaming"},
   477  		Target:     []string{"destroyed"},
   478  		Refresh:    resourceAwsRedshiftClusterStateRefreshFunc(d, meta),
   479  		Timeout:    40 * time.Minute,
   480  		MinTimeout: 5 * time.Second,
   481  	}
   482  
   483  	// Wait, catching any errors
   484  	_, err = stateConf.WaitForState()
   485  	if err != nil {
   486  		return fmt.Errorf("[ERROR] Error deleting Redshift Cluster (%s): %s", d.Id(), err)
   487  	}
   488  
   489  	log.Printf("[INFO] Redshift Cluster %s successfully deleted", d.Id())
   490  
   491  	return nil
   492  }
   493  
   494  func resourceAwsRedshiftClusterStateRefreshFunc(d *schema.ResourceData, meta interface{}) resource.StateRefreshFunc {
   495  	return func() (interface{}, string, error) {
   496  		conn := meta.(*AWSClient).redshiftconn
   497  
   498  		log.Printf("[INFO] Reading Redshift Cluster Information: %s", d.Id())
   499  		resp, err := conn.DescribeClusters(&redshift.DescribeClustersInput{
   500  			ClusterIdentifier: aws.String(d.Id()),
   501  		})
   502  
   503  		if err != nil {
   504  			if awsErr, ok := err.(awserr.Error); ok {
   505  				if "ClusterNotFound" == awsErr.Code() {
   506  					return 42, "destroyed", nil
   507  				}
   508  			}
   509  			log.Printf("[WARN] Error on retrieving Redshift Cluster (%s) when waiting: %s", d.Id(), err)
   510  			return nil, "", err
   511  		}
   512  
   513  		var rsc *redshift.Cluster
   514  
   515  		for _, c := range resp.Clusters {
   516  			if *c.ClusterIdentifier == d.Id() {
   517  				rsc = c
   518  			}
   519  		}
   520  
   521  		if rsc == nil {
   522  			return 42, "destroyed", nil
   523  		}
   524  
   525  		if rsc.ClusterStatus != nil {
   526  			log.Printf("[DEBUG] Redshift Cluster status (%s): %s", d.Id(), *rsc.ClusterStatus)
   527  		}
   528  
   529  		return rsc, *rsc.ClusterStatus, nil
   530  	}
   531  }
   532  
   533  func validateRedshiftClusterIdentifier(v interface{}, k string) (ws []string, errors []error) {
   534  	value := v.(string)
   535  	if !regexp.MustCompile(`^[0-9a-z-]+$`).MatchString(value) {
   536  		errors = append(errors, fmt.Errorf(
   537  			"only lowercase alphanumeric characters and hyphens allowed in %q", k))
   538  	}
   539  	if !regexp.MustCompile(`^[a-z]`).MatchString(value) {
   540  		errors = append(errors, fmt.Errorf(
   541  			"first character of %q must be a letter", k))
   542  	}
   543  	if regexp.MustCompile(`--`).MatchString(value) {
   544  		errors = append(errors, fmt.Errorf(
   545  			"%q cannot contain two consecutive hyphens", k))
   546  	}
   547  	if regexp.MustCompile(`-$`).MatchString(value) {
   548  		errors = append(errors, fmt.Errorf(
   549  			"%q cannot end with a hyphen", k))
   550  	}
   551  	return
   552  }
   553  
   554  func validateRedshiftClusterDbName(v interface{}, k string) (ws []string, errors []error) {
   555  	value := v.(string)
   556  	if !regexp.MustCompile(`^[a-z]+$`).MatchString(value) {
   557  		errors = append(errors, fmt.Errorf(
   558  			"only lowercase letters characters allowed in %q", k))
   559  	}
   560  	if len(value) > 64 {
   561  		errors = append(errors, fmt.Errorf(
   562  			"%q cannot be longer than 64 characters: %q", k, value))
   563  	}
   564  	if value == "" {
   565  		errors = append(errors, fmt.Errorf(
   566  			"%q cannot be an empty string", k))
   567  	}
   568  
   569  	return
   570  }
   571  
   572  func validateRedshiftClusterFinalSnapshotIdentifier(v interface{}, k string) (ws []string, errors []error) {
   573  	value := v.(string)
   574  	if !regexp.MustCompile(`^[0-9A-Za-z-]+$`).MatchString(value) {
   575  		errors = append(errors, fmt.Errorf(
   576  			"only alphanumeric characters and hyphens allowed in %q", k))
   577  	}
   578  	if regexp.MustCompile(`--`).MatchString(value) {
   579  		errors = append(errors, fmt.Errorf("%q cannot contain two consecutive hyphens", k))
   580  	}
   581  	if regexp.MustCompile(`-$`).MatchString(value) {
   582  		errors = append(errors, fmt.Errorf("%q cannot end in a hyphen", k))
   583  	}
   584  	if len(value) > 255 {
   585  		errors = append(errors, fmt.Errorf("%q cannot be more than 255 characters", k))
   586  	}
   587  	return
   588  }
   589  
   590  func validateRedshiftClusterMasterUsername(v interface{}, k string) (ws []string, errors []error) {
   591  	value := v.(string)
   592  	if !regexp.MustCompile(`^\w+$`).MatchString(value) {
   593  		errors = append(errors, fmt.Errorf(
   594  			"only alphanumeric characters in %q", k))
   595  	}
   596  	if !regexp.MustCompile(`^[A-Za-z]`).MatchString(value) {
   597  		errors = append(errors, fmt.Errorf(
   598  			"first character of %q must be a letter", k))
   599  	}
   600  	if len(value) > 128 {
   601  		errors = append(errors, fmt.Errorf("%q cannot be more than 128 characters", k))
   602  	}
   603  	return
   604  }