Provides an RDS Cluster Resource. A Cluster Resource defines attributes that are applied to the entire cluster of RDS Cluster Instances. Use the RDS Cluster resource and RDS Cluster Instances to create and use Amazon Aurora, a MySQL-compatible database engine.

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

Changes to a RDS Cluster can occur when you manually change a parameter, such as port, and are reflected in the next maintenance window. Because of this, Terraform may report a difference in its planning phase because a modification has not yet taken place. You can use the apply_immediately flag to instruct the service to apply the change immediately (see documentation below).

~> Note: using apply_immediately can result in a brief downtime as the server reboots. See the AWS Docs on RDS Maintenance for more information.

Example Usage

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 = "bar"
  backup_retention_period = 5
  preferred_backup_window = "07:00-09:00"

~> NOTE: RDS Clusters resources that are created without any matching RDS Cluster Instances do not currently display in the AWS Console.

Argument Reference

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

The following arguments are supported:

  • cluster_identifier - (Required) The Cluster Identifier. Must be a lower case string.
  • database_name - (Optional) The name for your database of up to 8 alpha-numeric characters. If you do not provide a name, Amazon RDS will not create a database in the DB cluster you are creating
  • master_password - (Required unless a snapshot_identifier is provided) Password for the master DB user. Note that this may show up in logs, and it will be stored in the state file
  • master_username - (Required unless a snapshot_identifier is provided) Username for the master DB user
  • final_snapshot_identifier - (Optional) The name of your final DB snapshot when this DB cluster is deleted. If omitted, no final snapshot will be made.
  • skip_final_snapshot - (Optional) Determines whether a final DB snapshot is created before the DB cluster is deleted. If true is specified, no DB snapshot is created. If false is specified, a DB snapshot is created before the DB cluster is deleted, using the value from final_snapshot_identifier. Default is true.
  • availability_zones - (Optional) A list of EC2 Availability Zones that instances in the DB cluster can be created in
  • backup_retention_period - (Optional) The days to retain backups for. Default 1
  • preferred_backup_window - (Optional) The daily time range during which automated backups are created if automated backups are enabled using the BackupRetentionPeriod parameter. Default: A 30-minute window selected at random from an 8-hour block of time per region. e.g. 04:00-09:00
  • preferred_maintenance_window - (Optional) The weekly time range during which system maintenance can occur, in (UTC) e.g. wed:04:00-wed:04:30
  • port - (Optional) The port on which the DB accepts connections
  • vpc_security_group_ids - (Optional) List of VPC security groups to associate with the Cluster
  • snapshot_identifier - (Optional) Specifies whether or not to create this cluster from a snapshot. This correlates to the snapshot ID you'd find in the RDS console, e.g: rds:production-2015-06-26-06-05.
  • storage_encrypted - (Optional) Specifies whether the DB cluster is encrypted. The default is false if not specified.
  • apply_immediately - (Optional) Specifies whether any cluster modifications are applied immediately, or during the next maintenance window. Default is false. See Amazon RDS Documentation for more information.
  • db_subnet_group_name - (Optional) A DB subnet group to associate with this DB instance. NOTE: This must match the db_subnet_group_name specified on every aws_rds_cluster_instance in the cluster.
  • db_cluster_parameter_group_name - (Optional) A cluster parameter group to associate with the cluster.
  • kms_key_id - (Optional) The ARN for the KMS encryption key. When specifying kms_key_id, storage_encrypted needs to be set to true

Attributes Reference

The following attributes are exported:

  • id - The RDS Cluster Identifier
  • cluster_identifier - The RDS Cluster Identifier
  • cluster_members – List of RDS Instances that are a part of this cluster
  • allocated_storage - The amount of allocated storage
  • availability_zones - The availability zone of the instance
  • backup_retention_period - The backup retention period
  • preferred_backup_window - The backup window
  • preferred_maintenance_window - The maintenance window
  • endpoint - The DNS address of the RDS instance
  • engine - The database engine
  • engine_version - The database engine version
  • maintenance_window - The instance maintenance window
  • database_name - The database name
  • port - The database port
  • status - The RDS instance status
  • username - The master username for the database
  • storage_encrypted - Specifies whether the DB cluster is encrypted
  • preferred_backup_window - The daily time range during which the backups happen


RDS Clusters can be imported using the cluster_identifier, e.g.

$ terraform import aws_rds_cluster.aurora_cluster aurora-prod-cluster