AWS Elasticache Cluster

ElastiCache is a fully managed in-memory data store and cache service. This component creates an elasticache cluster with encryption enabled. Read more

It creates:

• Elasticache replication group: Redis with Elasticache Cluster Mode Enabled.
• High Availability elasticache cluster with automatic failover and auto minor version upgrade
• Automatic backup and maintenance
• Encryption enabled at rest and transit by default

Architecture

Run-Book

Pre-requisites

IMPORTANT NOTE

1. Required version of Terraform is mentioned in versions.tf.
2. Go through variables.tf for understanding each terraform variable before running this component.

Resources needed before deploying this component

1. VPC with Private Subnets

AWS Accounts

Needs the following accounts:

1. Any AWS Account where Elasticache needs to be deployed

Getting Started

How to use this component in a blueprint

IMPORTANT: We periodically release versions for the components. Since, master branch may have on-going changes, best practice would be to use a released version in form of a tag (e.g. ?ref=x.y.z)

module "elasticache_cluster" {
  source         = "git::https://<YOUR_VCS_URL>/components/terraform-aws-elasticache.git?ref=v4.0.0"
  base_name         = "${var.base_name}--redis-"
  vpc_config        = {
    vpc_id = module.vpc.vpc_id
    private_subnets = [module.vpc.private_subnet_ids]
  }

  redis_cluster_config = {
    instance_type  = var.elasticache["instance_type"]
    node_count     = var.elasticache["node_count"]
    engine_version = "5.0.6"

  }

  auth_token     = var.elasticache["redis_auth_token"]
  multi_az_enabled = var.multi_az_enabled
}

Requirements

Name	Version
terraform	>= 1.0.0
aws	>= 5.0.0, < 6.0.0

Providers

Name	Version
aws	>= 5.0.0, < 6.0.0
null	n/a

Modules

Name	Source	Version
custom_elasticache_alarms	oozou/cloudwatch-alarm/aws	2.0.1

Resources

Name	Type
aws_cloudwatch_metric_alarm.redis_cpu_alarm	resource
aws_cloudwatch_metric_alarm.redis_memory_alarm	resource
aws_elasticache_replication_group.elasticache	resource
aws_elasticache_serverless_cache.elasticache	resource
aws_elasticache_subnet_group.elasticache	resource
aws_security_group.client	resource
aws_security_group.elasticache	resource
aws_security_group_rule.additional_cluster_ingress	resource
aws_security_group_rule.egress	resource
aws_security_group_rule.ingress	resource
null_resource.validate_config	resource
aws_subnet.subnets	data source

Inputs

Name	Description	Type	Default	Required
additional_cluster_security_group_ingress_rules	Additional ingress rule for cluster security group.	list(object({ from_port = number to_port = number protocol = string cidr_blocks = list(string) source_security_group_id = string description = string }))	[]	no
auth_token	Auth token for the Elasticache redis/valkey auth. Reference: https://docs.aws.amazon.com/AmazonElastiCache/latest/red-ug/auth.html	string	null	no
cache_type	Type of cache to create. Valid values: redis, valkey, redis-serverless, valkey-serverless	string	"redis"	no
custom_elasticache_alarms_configure	custom_elasticache_alarms_configure = { cpu_utilization_too_high = { metric_name = "EngineCPUUtilization" statistic = "Average" comparison_operator = ">=" threshold = "85" period = "300" evaluation_periods = "1" alarm_actions = [sns_topic_arn] ok_actions = [sns_topic_arn] } }	any	{}	no
default_alarm_actions	The list of actions to execute when this alarm transitions into an ALARM state from any other state. Each action is specified as an Amazon Resource Name (ARN).	list(string)	[]	no
default_ok_actions	The list of actions to execute when this alarm transitions into an OK state from any other state. Each action is specified as an Amazon Resource Name (ARN).	list(string)	[]	no
environment	Environment Variable used as a prefix	string	n/a	yes
is_enable_default_alarms	if enable the default alarms	bool	false	no
maintenance_window	Snapshot Retention Limit	string	"mon:00:00-mon:03:00"	no
multi_az_enabled	Specifies whether to enable Multi-AZ Support for the replication group (traditional clusters only)	bool	false	no
name	Name of the ElastiCache cluster to create	string	n/a	yes
prefix	The prefix name of customer to be displayed in AWS console and resource	string	n/a	yes
redis_cluster_config	Configuration for traditional redis/valkey cluster (not used for serverless)	object({ port = number instance_type = string engine_version = string node_count = number })	null	no
serverless_config	Configuration for serverless cache	object({ engine_version = string major_engine_version = optional(string) cache_usage_limits = optional(object({ data_storage = optional(object({ maximum = number unit = string })) ecpu_per_second = optional(object({ maximum = number })) })) daily_snapshot_time = optional(string) description = optional(string) kms_key_id = optional(string) snapshot_arns_to_restore = optional(list(string)) snapshot_retention_limit = optional(number) user_group_id = optional(string) })	null	no
serverless_security_group_ids	List of security group IDs for serverless cache (required for serverless caches)	list(string)	[]	no
snapshot_config	(optional) Snapshot config to retain and create backup	object({ snapshot_window = string snapshot_retention_limit = number })	{ "snapshot_retention_limit": 3, "snapshot_window": "03:00-05:00" }	no
tags	Custom tags which can be passed on to the AWS resources. They should be key value pairs having distinct keys.	map(string)	{}	no
vpc_config	VPC ID and private subnets for ElastiCache cluster	object({ vpc_id = string private_subnets = list(string) })	n/a	yes

Outputs

Name	Description
cache_engine	Cache engine (redis or valkey).
cache_host	Hostname of the cache endpoint (traditional cluster primary endpoint or serverless endpoint).
cache_port	Port of the cache endpoint.
cache_type	Type of cache created (redis, valkey, redis-serverless, valkey-serverless).
client_security_group_id	Security group id for the elasticache clients.
is_serverless	Whether the cache is serverless.
redis_host	Hostname of the redis/valkey host in the replication group (traditional clusters only).
replication_group_id	ID of the ElastiCache replication group (traditional clusters only).
security_group_id	Security group id for the elasticache.
serverless_cache_arn	ARN of the serverless cache (serverless caches only).
serverless_cache_name	Name of the serverless cache (serverless caches only).