PBS TF ElastiCache Redis Standalone Module

Installation

Using the Repo Source

Use this URL for the source of the module. See the usage examples below for more details.

github.com/pbs/terraform-aws-elasticache-redis-standalone-module?ref=2.0.1

Alternative Installation Methods

More information can be found on these install methods and more in the documentation here.

Usage

Provisions an Elasticache Redis (or Valkey) cluster (with Cluster Mode Disabled).

ℹ️ Note the confusing terminology around Cluster Mode. The Cluster Mode setting is a Redis feature that allows data to be sharded among nodes in a cluster, and requires some additional configuration to connect with it correctly. A Redis cluster that does not have Cluster Mode enabled is a set of standalone Redis nodes that have a single primary node for reading and writing and replica nodes for reading.

By default, it will provision one writer and one reader node, but that can be adjusted by setting the nodes variable to a different value.

This module also assumes that connections are established through a private DNS record created in Route53. This makes it so that replacement of the ElastiCache cluster can be made in a fashion that is transparent to application configurations. This can be adjusted by setting create_dns to false.

Integrate this module like so:

module "redis" {
  source = "github.com/pbs/terraform-aws-elasticache-redis-standalone-module?ref=2.0.1"

  # Tagging Parameters
  organization = var.organization
  environment  = var.environment
  product      = var.product
  repo         = var.repo

  # Optional Parameters
}

Adding This Version of the Module

If this repo is added as a subtree, then the version of the module should be close to the version shown here:

2.0.1

Note, however that subtrees can be altered as desired within repositories.

Further documentation on usage can be found here.

Below is automatically generated documentation on this Terraform module using terraform-docs

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Requirements

Name	Version
terraform	>= 1.3.2
aws	>= 4.5.0

Providers

Name	Version
aws	5.24.0

Modules

No modules.

Resources

Name	Type
aws_elasticache_replication_group.replication_group	resource
aws_elasticache_subnet_group.subnet_group	resource
aws_route53_record.primary_endpoint	resource
aws_route53_record.reader_endpoint	resource
aws_security_group.sg	resource
aws_security_group_rule.egress	resource
aws_default_tags.common_tags	data source
aws_route53_zone.private_hosted_zone	data source
aws_subnets.private_subnets	data source
aws_vpc.vpc	data source

Inputs

Name	Description	Type	Default	Required
environment	Environment (sharedtools, dev, staging, qa, prod)	string	n/a	yes
organization	Organization using this module. Used to prefix tags so that they are easily identified as being from your organization	string	n/a	yes
product	Tag used to group resources according to product	string	n/a	yes
repo	Tag used to point to the repo using this module	string	n/a	yes
apply_immediately	Whether any database modifications are applied immediately, or during the next maintenance window.	bool	false	no
at_rest_encryption_enabled	Whether to enable encryption at rest. Because there is a performance hit to enabling this feature, the default is false. Consider setting to true if your application can tolerate it.	bool	false	no
auth_token	Password used to access a password protected server. Can be specified only if transit_encryption_enabled = true.	string	null	no
auto_minor_version_upgrade	Specifies whether minor version engine upgrades will be applied automatically to the underlying nodes during the maintenance window. Only supported for engine type "redis" and if the engine version is 6 or higher.	bool	true	no
automatic_failover_enabled	Specifies whether a read-only replica will be automatically promoted to read/write primary if the existing primary fails. If null, will be enabled if nodes > 1. If true, nodes must be greater than 1.	bool	null	no
cname	The value to use for the CNAME record if create_dns is true. The primary endpoint will be .<private_hosted_zone>, and the reader endpoint will be -ro.<private_hosted_zone>. If null, the name variable will be used instead.	string	null	no
create_dns	Whether to create DNS records for the primary and reader endpoints.	bool	true	no
data_tiering_enabled	Enables data tiering. Data tiering is only supported for replication groups using the r6gd node type. This parameter must be set to true when using r6gd nodes.	bool	false	no
dns_ttl	TTL for DNS records.	number	300	no
egress_cidr_blocks	List of CIDR blocks to assign to the egress rule of the security group. If null, egress_security_group_ids must be used.	list(string)	[ "10.0.0.0/8" ]	no
egress_source_sg_id	List of security group ID to assign to the egress rule of the security group. If null, egress_cidr_blocks must be used.	string	null	no
engine	The engine to use ('valkey' or 'redis')	string	"redis"	no
engine_version	Version number of the cache engine to be used. If not set, defaults to the latest version. See Describe Cache Engine Versions in the AWS Documentation for supported versions. When engine is redis and the version is 6 or higher, the major and minor version can be set, e.g., 6.2, or the minor version can be unspecified which will use the latest version at creation time, e.g., 6.x. Otherwise, specify the full version desired, e.g., 5.0.6.	string	null	no
final_snapshot_identifier	Name of your final cluster snapshot. If omitted, no final snapshot will be made.	string	null	no
global_replication_group_id	The ID of the global replication group to which this replication group should belong. If this parameter is specified, the replication group is added to the specified global replication group as a secondary replication group; otherwise, the replication group is not part of any global replication group. If global_replication_group_id is set, the num_node_groups parameter cannot be set.	string	null	no
kms_key_id	The ARN of the key that you wish to use if encrypting at rest. If not supplied, uses service managed encryption. Can be specified only if at_rest_encryption_enabled = true.	string	null	no
log_delivery_configurations	List of log delivery configurations. https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/elasticache_cluster#log-delivery-configuration	list(object({ destination = string destination_type = string log_format = string log_type = string }))	[]	no
maintenance_window	Specifies the weekly time range for when maintenance on the cluster is performed. The format is ddd:hh24:mi-ddd:hh24:mi (24H Clock UTC). The minimum maintenance window is a 60 minute period. Example: sun:05:00-sun:09:00.	string	"mon:07:00-mon:08:00"	no
multi_az_enabled	Whether to enable Multi-AZ. If Multi-AZ is enabled, the value of nodes must be at least 2.	bool	false	no
name	Name of the ElastiCache Redis instance. If null, will default to product.	string	null	no
node_type	ElastiCache node type	string	"cache.t3.micro"	no
nodes	Number of nodes (primary and replicas) this replication group will have. If Multi-AZ is enabled, the value of this parameter must be at least 2. Updates will occur before other modifications. Conflicts with num_node_groups, the deprecatednumber_cache_clusters, or the deprecated cluster_mode.	number	2	no
notification_topic_arn	ARN of an SNS topic to send ElastiCache notifications to. Example: arn:aws:sns:us-east-1:012345678999:my_sns_topic.	string	null	no
parameter_group_name	Name of the parameter group to be created.	string	null	no
port	The port number on which each of the cache nodes will accept connections. Cannot be provided with replication_group_id. Changing this value will re-create the resource.	number	6379	no
preferred_cache_cluster_azs	List of availability zones in which to create cluster.	list(string)	null	no
private_hosted_zone	Private hosted zone to create DNS records in. If null, create_dns must be set to false.	string	null	no
replication_group_description	Description of the replication group to be created. If null, one will be generated using the name of the nodes.	string	null	no
replication_group_id	Replication group identifier. This parameter is stored as a lowercase string. If null, the name of the nodes will be used.	string	null	no
security_group_ids	One or more VPC security groups associated with the nodes. If null, use the one provided by this module.	list(string)	null	no
sg_name	Name of the security group to be created. If null, will use the name of the nodes.	string	null	no
snapshot_arns	Single-element string list containing an Amazon Resource Name (ARN) of a Redis RDB snapshot file stored in Amazon S3. The object name cannot contain any commas. Changing snapshot_arns forces a new resource.	list(string)	null	no
snapshot_retention_limit	Number of days for which ElastiCache will retain automatic cluster snapshots before deleting them. For example, if you set SnapshotRetentionLimit to 5, then a snapshot that was taken today will be retained for 5 days before being deleted. If the value of SnapshotRetentionLimit is set to zero (0), backups are turned off. Please note that setting a snapshot_retention_limit is not supported on cache.t1.micro cache nodes.	number	null	no
snapshot_window	Daily time range (in UTC) during which ElastiCache will begin taking a daily snapshot of your nodes. Example: 05:00-09:00	string	null	no
subnet_data_lookup_filters	Values of the filter blocks in the aws_subnets data source used in this module. If null, one will be guessed using the resolved VPC and a Name filter of *-private-*. Ignored if subnets is populated.	map(any)	null	no
subnet_group_name	Name of the subnet group to be used for the cluster. Changing this value will re-create the resource. If null, will use the subnet group created by this module.	string	null	no
subnets	List of subnet IDs to create cluster nodes in. If null, a list will be generated by looking up subnets in the resolved VPC.	list(string)	null	no
tags	Extra tags	map(string)	{}	no
transit_encryption_enabled	Whether to enable encryption at rest. Because there is a performance hit to enabling this feature, the default is false. Consider setting to true if your application can tolerate it.	bool	false	no
use_prefix	Whether to use prefixes in the resource names. If false, will use a fully specified name for resources.	bool	true	no
user_group_ids	User Group ID to associate with the replication group. Only a maximum of one (1) user group ID is valid. NOTE: This argument is a set because the AWS specification allows for multiple IDs. However, in practice, AWS only allows a maximum size of one.	list(string)	null	no
vpc_data_lookup_tags	Value of the tags parameter in the aws_vpc data source used in this module. If null, a dynamic lookup based on environment will be used. Ignored if vpc_id is populated.	map(string)	null	no
vpc_id	VPC ID to create the nodes in. If null, one will be guessed based on vpc_data_lookup_tags.	string	null	no

Outputs

Name	Description
arn	The ARN of the ElastiCache replication group
engine_version_actual	Because ElastiCache pulls the latest minor or patch for a version, this attribute returns the running version of the cache engine.
member_clusters	Identifiers of all the nodes that are part of this replication group.
name	The name of the ElastiCache replication group
primary_endpoint_address	Address of the endpoint for the primary node in the replication group.
reader_endpoint_address	Address of the endpoint for the reader node in the replication group.
sg_ids	The security group ids
tags	The tags