» Resource: aws_rds_cluster_instance

Provides an RDS Cluster Instance Resource. A Cluster Instance Resource defines attributes that are specific to a single instance in a RDS Cluster, specifically running Amazon Aurora.

Unlike other RDS resources that support replication, with Amazon Aurora you do not designate a primary and subsequent replicas. Instead, you simply add RDS Instances and Aurora manages the replication. You can use the count meta-parameter to make multiple instances and join them all to the same RDS Cluster, or you may specify different Cluster Instance resources with various instance_class sizes.

For more information on Amazon Aurora, see Aurora on Amazon RDS in the Amazon RDS User Guide.

NOTE: Deletion Protection from the RDS service can only be enabled at the cluster level, not for individual cluster instances. You can still add the prevent_destroy lifecycle behavior to your Terraform resource configuration if you desire protection from accidental deletion.

» Example Usage

resource "aws_rds_cluster_instance" "cluster_instances" {
  count              = 2
  identifier         = "aurora-cluster-demo-${count.index}"
  cluster_identifier = "${aws_rds_cluster.default.id}"
  instance_class     = "db.r4.large"
}

resource "aws_rds_cluster" "default" {
  cluster_identifier = "aurora-cluster-demo"
  availability_zones = ["us-west-2a", "us-west-2b", "us-west-2c"]
  database_name      = "mydb"
  master_username    = "foo"
  master_password    = "barbut8chars"
}

» Argument Reference

For more detailed documentation about each argument, refer to the AWS official documentation.

The following arguments are supported:

identifier - (Optional, Forces new resource) The indentifier for the RDS instance, if omitted, Terraform will assign a random, unique identifier.
identifier_prefix - (Optional, Forces new resource) Creates a unique identifier beginning with the specified prefix. Conflicts with identifier.
cluster_identifier - (Required) The identifier of the aws_rds_cluster in which to launch this instance.
engine - (Optional) The name of the database engine to be used for the RDS instance. Defaults to aurora. Valid Values: aurora, aurora-mysql, aurora-postgresql. For information on the difference between the available Aurora MySQL engines see Comparison between Aurora MySQL 1 and Aurora MySQL 2 in the Amazon RDS User Guide.
engine_version - (Optional) The database engine version.
instance_class - (Required) The instance class to use. For details on CPU and memory, see Scaling Aurora DB Instances. Aurora uses db.* instance classes/types. Please see AWS Documentation for currently available instance classes and complete details.
publicly_accessible - (Optional) Bool to control if instance is publicly accessible. Default false. See the documentation on Creating DB Instances for more details on controlling this property.
db_subnet_group_name - (Required if publicly_accessible = false, Optional otherwise) A DB subnet group to associate with this DB instance. NOTE: This must match the db_subnet_group_name of the attached aws_rds_cluster.
db_parameter_group_name - (Optional) The name of the DB parameter group to associate with this instance.
apply_immediately - (Optional) Specifies whether any database modifications are applied immediately, or during the next maintenance window. Default isfalse.
monitoring_role_arn - (Optional) The ARN for the IAM role that permits RDS to send enhanced monitoring metrics to CloudWatch Logs. You can find more information on the AWS Documentation what IAM permissions are needed to allow Enhanced Monitoring for RDS Instances.
monitoring_interval - (Optional) The interval, in seconds, between points when Enhanced Monitoring metrics are collected for the DB instance. To disable collecting Enhanced Monitoring metrics, specify 0. The default is 0. Valid Values: 0, 1, 5, 10, 15, 30, 60.
promotion_tier - (Optional) Default 0. Failover Priority setting on instance level. The reader who has lower tier has higher priority to get promoter to writer.
availability_zone - (Optional, Computed) The EC2 Availability Zone that the DB instance is created in. See docs about the details.
preferred_backup_window - (Optional) The daily time range during which automated backups are created if automated backups are enabled. Eg: "04:00-09:00"
preferred_maintenance_window - (Optional) The window to perform maintenance in. Syntax: "ddd:hh24:mi-ddd:hh24:mi". Eg: "Mon:00:00-Mon:03:00".
auto_minor_version_upgrade - (Optional) Indicates that minor engine upgrades will be applied automatically to the DB instance during the maintenance window. Default true.
performance_insights_enabled - (Optional) Specifies whether Performance Insights is enabled or not.
performance_insights_kms_key_id - (Optional) The ARN for the KMS key to encrypt Performance Insights data. When specifying performance_insights_kms_key_id, performance_insights_enabled needs to be set to true.
copy_tags_to_snapshot – (Optional, boolean) Indicates whether to copy all of the user-defined tags from the DB instance to snapshots of the DB instance. Default false.
tags - (Optional) A mapping of tags to assign to the instance.

» Attributes Reference

In addition to all arguments above, the following attributes are exported:

arn - Amazon Resource Name (ARN) of cluster instance
cluster_identifier - The RDS Cluster Identifier
identifier - The Instance identifier
id - The Instance identifier
writer – Boolean indicating if this instance is writable. False indicates this instance is a read replica.
allocated_storage - The amount of allocated storage
availability_zone - The availability zone of the instance
endpoint - The DNS address for this instance. May not be writable
engine - The database engine
engine_version - The database engine version
database_name - The database name
port - The database port
status - The RDS instance status
storage_encrypted - Specifies whether the DB cluster is encrypted.
kms_key_id - The ARN for the KMS encryption key if one is set to the cluster.
dbi_resource_id - The region-unique, immutable identifier for the DB instance.
performance_insights_enabled - Specifies whether Performance Insights is enabled or not.
performance_insights_kms_key_id - The ARN for the KMS encryption key used by Performance Insights.

» Timeouts

aws_rds_cluster_instance provides the following Timeouts configuration options:

create - (Default 90 minutes) Used for Creating Instances, Replicas, and restoring from Snapshots
update - (Default 90 minutes) Used for Database modifications
delete - (Default 90 minutes) Used for destroying databases. This includes the time required to take snapshots

» Import

RDS Cluster Instances can be imported using the identifier, e.g.

$ terraform import aws_rds_cluster_instance.prod_instance_1 aurora-cluster-instance-1