aws-terraform-elasticache

This module creates Elasticache-Memcached, Elasticache-Redis, or Elasticache-Redis Multi-Shard instances.

Basic Usage

module "elasticache_memcached" {
  source = "git@github.com:rackspace-infrastructure-automation/aws-terraform-elasticache.git?ref=v0.12.0"

  create_internal_zone_record = true
  curr_connections_threshold  = 500
  elasticache_engine_type     = "memcached14"
  evictions_threshold         = 10
  instance_class              = "cache.m4.large"
  internal_record_name        = "memcachedconfig"
  internal_zone_id            = module.internal_zone.internal_hosted_zone_id
  internal_zone_name          = module.internal_zone.internal_hosted_name
  name                        = "memc-${random_string.name_suffix.result}"
  security_groups             = [module.security_groups.elastic_cache_memcache_security_group_id]
  subnets                     = module.vpc.private_subnets

  tags = {
    MyTag1 = "MyValue1"
    MyTag2 = "MyValue2"
    MyTag3 = "MyValue3"
  }
}
*

Full working references are available at examples

Other TF Modules Used

Using aws-terraform-cloudwatch_alarm to create the following CloudWatch Alarms:

evictions_alarm
cpu_utilization_alarm
curr_connections_alarm
swap_usage_alarm

Terraform 0.12 upgrade

Several changes were required while adding terraform 0.12 compatibility. The following changes should be
made when upgrading from a previous release to version 0.12.0 or higher.

Module variables

The following module variables were updated to better meet current Rackspace style guides:

additional_tags -> tags
cluster_name -> name
cluster_name_version -> name_version
create_route53_record -> create_internal_zone_record
security_group_list -> security_groups

Requirements

Name	Version
terraform	>= 0.12
aws	>= 2.7.0

Providers

Name	Version
aws	>= 2.7.0
null	n/a

Modules

Name	Source	Version
cpu_utilization_alarm	git@github.com:rackspace-infrastructure-automation/aws-terraform-cloudwatch_alarm//?ref=v0.12.6
curr_connections_alarm	git@github.com:rackspace-infrastructure-automation/aws-terraform-cloudwatch_alarm//?ref=v0.12.6
evictions_alarm	git@github.com:rackspace-infrastructure-automation/aws-terraform-cloudwatch_alarm//?ref=v0.12.6
swap_usage_alarm	git@github.com:rackspace-infrastructure-automation/aws-terraform-cloudwatch_alarm//?ref=v0.12.6

Resources

Name
aws_elasticache_cluster
aws_elasticache_parameter_group
aws_elasticache_replication_group
aws_elasticache_subnet_group
aws_route53_record
null_data_source

Inputs

Name	Description	Type	Default	Required
at_rest_encrypted_disk	(redis, redis multi shard) Indicates whether to enable encryption at rest. ONLY AVAILABLE FOR REDIS 3.2.6, 4.0.10 AND 5.0.0. `true` or `false`.	`bool`	`false`	no
authentication_token	(redis, redis multi shard) The password used to access a password protected server. Can be specified only if `in_transit_encryption = true` and will be ignored otherwise	`string`	`""`	no
cache_cluster_port	(memcached, redis, redis multi shard) The port number on which each of the cache nodes will accept connections. Default for redis is 6379. Default for memcached is 11211	`string`	`""`	no
cluster_name	(memcached, redis, redis multi shard) Name of the Cluster. Will also be used to name other provisioned resources. If this value is empty, `name` and `name_version` will be used for backwards compatibility. Should not exceed 50 characters due to string length constraints. NOTICE: Cluster Name allows 50 characters MAX.	`string`	`""`	no
cpu_high_evaluations	(memcached, redis) The number of minutes CPU usage must remain above the specified threshold to generate an alarm.	`number`	`5`	no
cpu_high_threshold	(memcached, redis) The max CPU Usage % before generating an alarm.	`number`	`90`	no
create_internal_zone_record	(memcached, redis, redis multi shard) Specifies whether or not to create a route53 CNAME record for the configuration/primary endpoint. internal_zone_id, internal_zone_name, and internal_record_name must be provided if set to true. true or false.	`bool`	`false`	no
curr_connections_evaluations	(memcached, redis) The number of minutes current connections must remain above the specified threshold to generate an alarm.	`number`	`5`	no
curr_connections_threshold	(memcached, redis) The max number of current connections before generating an alarm. NOTE: If this variable is not set, the connections alarm will not be provisioned.	`string`	`""`	no
elasticache_engine_type	(memcached, redis, redis multi shard) The name of the cache engine to be used for this cluster. Valid values are: memcached14, memcached1510, memcached1516, redis28, redis2823, redis2822, redis2821, redis2819, redis286, redis32, redis326, redis3210, redis40, redis50, redis503, redis504, redis505, redis506	`string`	n/a	yes
environment	(memcached, redis, redis multi shard) Application environment for which this network is being created. Preferred value are Development, Integration, PreProduction, Production, QA, Staging, or Test	`string`	`"Development"`	no
evictions_evaluations	(memcached, redis) The number of minutes Evictions must remain above the specified threshold to generate an alarm.	`number`	`5`	no
evictions_threshold	(memcached, redis) The max evictions before generating an alarm. NOTE: If this variable is not set, the evictions alarm will not be provisioned.	`string`	`""`	no
failover_enabled	(redis) Enable Multi-AZ Failover. Failover is unsupported on the cache.t1.micro instance class. This is hardcoded as true for Redis multi-shard.	`bool`	`true`	no
in_transit_encryption	(redis, redis multi shard) Indicates whether to enable encryption in transit. Because there is some processing needed to encrypt and decrypt the data at the endpoints, enabling in-transit encryption can have some performance impact.ONLY AVAILABLE FOR REDIS 3.2.6, 4.0.10 and later. true or false	`bool`	`false`	no
instance_class	(memcached, redis, redis multi shard) The compute and memory capacity of the nodes within the ElastiCache cluster. Please see https://docs.aws.amazon.com/AmazonElastiCache/latest/mem-ug/CacheNodes.SupportedTypes.html for valid instance types.	`string`	n/a	yes
internal_record_name	(memcached, redis, redis multi shard) Record Name for the new Resource Record in the Internal Hosted Zone	`string`	`""`	no
internal_zone_id	(memcached, redis, redis multi shard) The Route53 Internal Hosted Zone ID	`string`	`""`	no
internal_zone_name	(memcached, redis, redis multi shard) LD for Internal Hosted Zone	`string`	`""`	no
name	DEPRECATED, MAY REMOVE IN A FUTURE VERSION, USE `cluster_name` AND `replication_group_name`!! (memcached, redis, redis multi shard) Name of Cluster. Will also be used to name other provisioned resources. If non empty cluster_name_version is being used, total length of cluster_name plus cluster_name_version should not exceed 19 due to string length constraints	`string`	`""`	no
name_version	DEPRECATED, MAY REMOVE IN A FUTURE VERSION, USE `cluster_name` AND `replication_group_name`!! (memcached, redis, redis multi shard) NOTE: This needs to increment on update with new snapshot. If non empty cluster_name_version is being used, total length of cluster_name plus cluster_name_version should not exceed 19 due to string length constraints	`string`	`"v00"`	no
notification_topic	(memcached, redis, redis multi shard) SNS Topic ARN to notify if there are any alarms	`string`	`""`	no
number_of_nodes	(memcached, redis) The number of cache nodes within the ElastiCache cluster. This number must be grearter or equal 2 to enable automatic failover.	`number`	`1`	no
number_of_read_replicas_per_shard	(redis multi shard) Number of read replicas per shard	`number`	`2`	no
number_of_shards	(redis multi shard) Number of shards	`number`	`2`	no
preferred_maintenance_window	(memcached, redis, redis multi shard) The weekly time range (in UTC) during which system maintenance can occur. Example: Sun:05:00-Sun:07:00	`string`	`"Sun:05:00-Sun:07:00"`	no
redis_multi_shard	(edis, redis multi shard) Is this a redis multi-shard instance? true or false	`bool`	`false`	no
replication_group_description	(redis, redis multi shard) Description of Replication Group	`string`	`"Elasticache"`	no
replication_group_name	(memcached, redis, redis multi shard) Name of the Cluster replication group ID, must be unique. If this value is empty, `name` and `name_version` will be used for backwards compatibility. Should not exceed 40 characters due to string length constraints. NOTICE: Group ID allows 40 characters MAX.	`string`	`""`	no
security_groups	(memcached, redis, redis multi shard) A list of EC2 security groups to assign to this resource.	`list(string)`	n/a	yes
snapshot_arn	(redis, redis multi shard) The S3 ARN of a snapshot to use for cluster creation. Proper access to the S3 file must be granted prior to building instance. See https://docs.aws.amazon.com/AmazonElastiCache/latest/UserGuide/backups-seeding-redis.html#backups-seeding-redis-grant-access for details. This parameter is ignored if a SnapshotName is provided.	`string`	`""`	no
snapshot_name	(redis, redis multi shard) The name of a snapshot to use for cluster creation. This property overrides any value assigned to SnapshotArn. Snapshots are unsupported on cache.t1.micro instance class.	`string`	`""`	no
snapshot_retention_limit	(redis, redis multi shard) The number of days for which automated backups are retained. Setting this parameter to a positive number enables backups. Setting this parameter to 0 disables automated backups. Snapshots are unsupported on cache.t1.micro instance class.	`number`	`7`	no
snapshot_window	(redis, redis multi shard) The daily time range (in UTC) during which ElastiCache will begin taking a daily snapshot of your node group. Snapshots are unsupported on cache.t1.micro instance class.	`string`	`"03:00-05:00"`	no
subnets	(memcached, redis, redis multi shard) List of subnets for use with this cache cluster	`list(string)`	n/a	yes
swap_usage_evaluations	(memcached) The number of minutes SwapUsage must remain above the specified threshold to generate an alarm	`number`	`5`	no
swap_usage_threshold	(memcached) The max SwapUsage before generating an alarm	`number`	`52428800`	no
tags	(memcached, redis, redis multi shard) Additional tags to be added to the Elasticache resources. Please see examples directory in this repo for examples.	`map(string)`	`{}`	no

Outputs

Name	Description
elasticache_endpoint	Elasticache endpoint address
elasticache_internal_r53_record	Internal Route 53 record FQDN for the Elasticache endpoint(s)