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

Providers

Name	Version
aws	5.1.0

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_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
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 auth. Reference: https://docs.aws.amazon.com/AmazonElastiCache/latest/red-ug/auth.html	string	n/a	yes
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	bool	n/a	yes
name	Name of the ECS 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 redis cluster	object({ port = number instance_type = string engine_version = string node_count = number })	n/a	yes
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
client_security_group_id	Security group id for the elasticache clients.
redis_host	Hostname of the redis host in the replication group.
security_group_id	Security group id for the elasticache.