tf-aws-aurora

AWS Aurora DB Cluster & Instance(s) Terraform Module.

Gives you:

• A DB subnet group
• An Aurora DB cluster
• An Aurora DB instance + 'n' number of additional instances
• Optionally RDS 'Enhanced Monitoring' + associated required IAM role/policy (by simply setting the monitoring_interval param to > 0
• Optionally sensible alarms to SNS (high CPU, high connections, slow replication)
• Optionally configure autoscaling for read replicas (MySQL clusters only)

Contributing

Ensure any variables you add have a type and a description. This README is generated with terraform-docs:

terraform-docs md . > README.md

Usage examples

It is recommended you always create a parameter group, even if it exactly matches the defaults. Changing the parameter group in use requires a restart of the DB cluster, modifying parameters within a group may not (depending on the parameter being altered)

Known issues

AWS doesn't automatically remove RDS instances created from autoscaling when you remove the autoscaling rules and this can cause issues when using Terraform to destroy the cluster. To work around this, you should make sure there are no automatically created RDS instances running before attempting to destroy a cluster.

Aurora 1.x (MySQL 5.6)

resource "aws_sns_topic" "db_alarms_56" { name = "aurora-db-alarms-56" }

module "aurora_db_56" { source = "../.." name = "test-aurora-db-56" envname = "test56" envtype = "test" subnets = ["${module.vpc.private_subnets}"] azs = ["${module.vpc.availability_zones}"] replica_count = "1" security_groups = ["${aws_security_group.allow_all.id}"] instance_type = "db.t2.medium" username = "root" password = "changeme" backup_retention_period = "5" final_snapshot_identifier = "final-db-snapshot-prod" storage_encrypted = "true" apply_immediately = "true" monitoring_interval = "10" cw_alarms = true cw_sns_topic = "${aws_sns_topic.db_alarms_56.id}" db_parameter_group_name = "${aws_db_parameter_group.aurora_db_56_parameter_group.id}" db_cluster_parameter_group_name = "${aws_rds_cluster_parameter_group.aurora_cluster_56_parameter_group.id}" }

resource "aws_db_parameter_group" "aurora_db_56_parameter_group" { name = "test-aurora-db-56-parameter-group" family = "aurora5.6" description = "test-aurora-db-56-parameter-group" }

resource "aws_rds_cluster_parameter_group" "aurora_cluster_56_parameter_group" { name = "test-aurora-56-cluster-parameter-group" family = "aurora5.6" description = "test-aurora-56-cluster-parameter-group" }

Aurora 2.x (MySQL 5.7)

resource "aws_sns_topic" "db_alarms" {
  name = "aurora-db-alarms"
}

module "aurora_db_57" {
  source                          = "../.."
  engine                          = "aurora-mysql"
  engine-version                  = "5.7.12"
  name                            = "test-aurora-db-57"
  envname                         = "test-57"
  envtype                         = "test"
  subnets                         = ["${module.vpc.private_subnets}"]
  azs                             = ["${module.vpc.availability_zones}"]
  replica_count                   = "1"
  security_groups                 = ["${aws_security_group.allow_all.id}"]
  instance_type                   = "db.t2.medium"
  username                        = "root"
  password                        = "changeme"
  backup_retention_period         = "5"
  final_snapshot_identifier       = "final-db-snapshot-prod"
  storage_encrypted               = "true"
  apply_immediately               = "true"
  monitoring_interval             = "10"
  cw_alarms                       = true
  cw_sns_topic                    = "${aws_sns_topic.db_alarms.id}"
  db_parameter_group_name         = "${aws_db_parameter_group.aurora_db_57_parameter_group.id}"
  db_cluster_parameter_group_name = "${aws_rds_cluster_parameter_group.aurora_57_cluster_parameter_group.id}"
}

resource "aws_db_parameter_group" "aurora_db_57_parameter_group" {
  name        = "test-aurora-db-57-parameter-group"
  family      = "aurora-mysql5.7"
  description = "test-aurora-db-57-parameter-group"
}

resource "aws_rds_cluster_parameter_group" "aurora_57_cluster_parameter_group" {
  name        = "test-aurora-57-cluster-parameter-group"
  family      = "aurora-mysql5.7"
  description = "test-aurora-57-cluster-parameter-group"
}

Aurora PostgreSQL

resource "aws_sns_topic" "db_alarms_postgres96" {
  name = "aurora-db-alarms-postgres96"
}

module "aurora_db_postgres96" {
  source                          = "../.."
  engine                          = "aurora-postgresql"
  engine-version                  = "9.6.3"
  name                            = "test-aurora-db-postgres96"
  envname                         = "test-pg96"
  envtype                         = "test"
  subnets                         = ["${module.vpc.private_subnets}"]
  azs                             = ["${module.vpc.availability_zones}"]
  replica_count                   = "1"
  security_groups                 = ["${aws_security_group.allow_all.id}"]
  instance_type                   = "db.r4.large"
  username                        = "root"
  password                        = "changeme"
  backup_retention_period         = "5"
  final_snapshot_identifier       = "final-db-snapshot-prod"
  storage_encrypted               = "true"
  apply_immediately               = "true"
  monitoring_interval             = "10"
  cw_alarms                       = true
  cw_sns_topic                    = "${aws_sns_topic.db_alarms_postgres96.id}"
  db_parameter_group_name         = "${aws_db_parameter_group.aurora_db_postgres96_parameter_group.id}"
  db_cluster_parameter_group_name = "${aws_rds_cluster_parameter_group.aurora_cluster_postgres96_parameter_group.id}"
}

resource "aws_db_parameter_group" "aurora_db_postgres96_parameter_group" {
  name        = "test-aurora-db-postgres96-parameter-group"
  family      = "aurora-postgresql9.6"
  description = "test-aurora-db-postgres96-parameter-group"
}

resource "aws_rds_cluster_parameter_group" "aurora_cluster_postgres96_parameter_group" {
  name        = "test-aurora-postgres96-cluster-parameter-group"
  family      = "aurora-postgresql9.6"
  description = "test-aurora-postgres96-cluster-parameter-group"
}

Inputs

Name	Description	Type	Default	Required
apply_immediately	Determines whether or not any DB modifications are applied immediately, or during the maintenance window	string	false	no
auto_minor_version_upgrade	Determines whether minor engine upgrades will be performed automatically in the maintenance window	string	true	no
azs	List of AZs to use	list	-	yes
backup_retention_period	How long to keep backups for (in days)	string	7	no
cw_alarms	Whether to enable CloudWatch alarms - requires cw_sns_topic is specified	string	false	no
cw_max_conns	Connection count beyond which to trigger a CloudWatch alarm	string	500	no
cw_max_cpu	CPU threshold above which to alarm	string	85	no
cw_max_replica_lag	Maximum Aurora replica lag in milliseconds above which to alarm	string	2000	no
cw_sns_topic	An SNS topic to publish CloudWatch alarms to	string	false	no
db_cluster_parameter_group_name	The name of a DB Cluster parameter group to use	string	default.aurora5.6	no
db_parameter_group_name	The name of a DB parameter group to use	string	default.aurora5.6	no
engine	Aurora database engine type, currently aurora, aurora-mysql or aurora-postgresql	string	aurora	no
engine-version	Aurora database engine version.	string	5.6.10a	no
envname	Environment name (eg,test, stage or prod)	string	-	yes
envtype	Environment type (eg,prod or nonprod)	string	-	yes
final_snapshot_identifier	The name to use when creating a final snapshot on cluster destroy, appends a random 8 digits to name to ensure it's unique too.	string	final	no
identifier_prefix	Prefix for cluster and instance identifier	string	``	no
instance_type	Instance type to use	string	db.t2.small	no
monitoring_interval	The interval (seconds) between points when Enhanced Monitoring metrics are collected	string	0	no
name	Name given to DB subnet group	string	-	yes
password	Master DB password	string	-	yes
port	The port on which to accept connections	string	3306	no
preferred_backup_window	When to perform DB backups	string	02:00-03:00	no
preferred_maintenance_window	When to perform DB maintenance	string	sun:05:00-sun:06:00	no
publicly_accessible	Whether the DB should have a public IP address	string	false	no
replica_count	Number of reader nodes to create. If replica_scale_enable is true, the value of replica_scale_min is used instead.	string	0	no
replica_scale_cpu	CPU usage to trigger autoscaling at	string	70	no
replica_scale_enabled	Whether to enable autoscaling for RDS Aurora (MySQL) read replicas	string	false	no
replica_scale_in_cooldown	Cooldown in seconds before allowing further scaling operations after a scale in	string	300	no
replica_scale_max	Maximum number of replicas to allow scaling for	string	0	no
replica_scale_min	Maximum number of replicas to allow scaling for	string	2	no
replica_scale_out_cooldown	Cooldown in seconds before allowing further scaling operations after a scale out	string	300	no
security_groups	VPC Security Group IDs	list	-	yes
skip_final_snapshot	Should a final snapshot be created on cluster destroy	string	false	no
snapshot_identifier	DB snapshot to create this database from	string	``	no
storage_encrypted	Specifies whether the underlying storage layer should be encrypted	string	true	no
subnets	List of subnet IDs to use	list	-	yes
username	Master DB username	string	root	no

Outputs

Name	Description
all_instance_endpoints_list	Comma separated list of all DB instance endpoints running in cluster
cluster_endpoint	The 'writer' endpoint for the cluster
reader_endpoint	A read-only endpoint for the Aurora cluster, automatically load-balanced across replicas