AWS Elasticache Redis Terraform module

Terraform module which creates Elasticache resources on AWS

Root module calls these modules which can also be used separately to create independent resources:

cache_parameter_group - creates Elasticache parameter group
cache_subnet_group - creates Elasticache subnet group
cache_user - creates Elasticache user
cache_user_group - creates Elasticache user group

Usage

module "elasticache" {
  source = "osgurisdosre/elasticache/aws"

  create_cache         = true
  replication_group_id = "redis-app"
  description_redis    = "Redis App"
  node_type            = "cache.t2.micro"
  security_group_ids   = ["sg-0000000000000", "sg-111111111111111"]
  num_cache_clusters   = 3

  # Cache subnet group
  create_elasticache_subnet_group = true
  subnet_group_name               = "elasticache-subnets"
  subnet_ids                      = ["subnet-123456789", "subnet-987654321", "subnet-123321123"]

  # Cache parameter group
  create_elasticache_parameter_group = true
  parameters = [{
    name  = "activerehashing"
    value = "yes"
  }]

  # Cache user
  create_elasticache_user = true
  create_cache_password   = true

  user_name     = "userapp"
  user_id       = "userapp"
  access_string = "on ~* +@all"
  authentication_mode = [{
    type = "password"
  }]

  # Cache user group
  create_elasticache_user_group = true
  user_group_id                 = "app"
}

Serverless

module "elastic_serverlesss" {
  source = "osgurisdosre/elasticache/aws" 
  create_elasticache_serverless = true
  
  serverless_name    = "redis-serverless"
  description_serverless = "serverless"
  enabled_limits = true
  cache_usage_limits = {
    data_storage = {
      maximum = 1000
      unit    = "GB"
    }
    ecpu_per_second = {
     maximum = 1000
    }
  }
  daily_snapshot_time      = "09:00"
  kms_key_id               = aws_kms_key.test.arn
  major_engine_version     = "7"
  snapshot_retention_limit = 1
  security_group_ids       = ["sg-0000000000000", "sg-111111111111111"]
  subnet_ids               = ["subnet-123456789", "subnet-987654321", "subnet-123321123"]
  user_group_id            = module.user_group.elasticache_user_group_id
  tags = {
    "Environment" = "prd"
  }
}

Conditional creation

module "elasticache" {
  source                    = "osgurisdosre/documentdb/aws"
  
  # Disable creation of Elasticache
  create_cache                = false

  # Enable creation of a random password
  create_cache_password       = true

  # Enable creation of subnet group
  create_elasticache_subnet_group    = true
  
  # Enable creation of parameter group
  create_elasticache_parameter_group = true

  # Enable creation of user
  create_elasticache_user  = true

  # Enable creation of user group
  create_elasticache_user_group = true
  
  # Enable creation of serverless
  create_elasticache_serverless = true
 
  #Enable modification in cache_usage_limits
  enabled_limits = true
}

Examples

To-do:

Notes

This module does not create Elasticache security group. Use terraform-aws-security-group module for this.
By default, the variable create_db_password is set to true. Therefore, even if the user provides a password, it will not be read. The create_db_password variable should be set to false and the passwords variable should have a non-null value to be read and used.
By default, the create_elasticache_serverless variable is set false

Requirements

Name	Version
terraform	>= 1.4
aws	>= 5.40
random	>= 3.1

Providers

Name	Version
aws	>= 5.40
random	>= 3.1

Modules

Name	Source	Version
elasticache_parameter_group	./modules/cache_parameter_group	n/a
elasticache_subnet_group	./modules/cache_subnet_group	n/a
elasticache_user	./modules/cache_user	n/a
elasticache_user_group	./modules/cache_user_group	n/a

Resources

Name	Type
aws_elasticache_replication_group.this	resource
aws_elasticache_serverless_cache.this	resource
random_password.master_password	resource

Inputs

Name	Description	Type	Default	Required
access_string	Access permissions string used for this user.	`string`	`null`	no
apply_immediately	Specifies whether any modifications are applied immediately, or during the next maintenance window.	`bool`	`false`	no
at_rest_encryption_enabled	Whether to enable encryption at rest.	`bool`	`true`	no
auth_token	Password used to access a password protected server	`string`	`null`	no
authentication_mode	Denotes the user's authentication properties. Possible of type options are: password, no-password-required or iam.	list(object({ type = optional(string) passwords = optional(string) }))	[ { "passwords": null, "type": null } ]	no
auto_minor_version_upgrade	Specifies whether minor version engine upgrades will be applied automatically to the underlying	`bool`	`false`	no
automatic_failover_enabled	Specifies whether a read-only replica will be automatically promoted to read/write primary if the existing primary fails.	`bool`	`true`	no
cache_usage_limits	Sets the cache usage limits for storage and ElastiCache Processing Units for the cache.(data_storage,ecpu_per_second)	`any`	`{}`	no
create	Create the resource?	`bool`	`true`	no
create_cache	Create the elasticache Redis?	`bool`	`false`	no
create_cache_password	Create the password?	`bool`	`false`	no
create_elasticache_parameter_group	Create the parameter group?	`bool`	`false`	no
create_elasticache_replication_group	Create the replication group?	`bool`	`false`	no
create_elasticache_serverless	Create the elasticache Redis serverless?	`bool`	`false`	no
create_elasticache_subnet_group	Create the subnet group?	`bool`	`false`	no
create_elasticache_user	Create the user?	`bool`	`false`	no
create_elasticache_user_group	Create the user group?	`bool`	`false`	no
daily_snapshot_time	The daily time that snapshots will be created from the new serverless cache.(Only for the serverless module)	`string`	`"03:00"`	no
data_tiering_enabled	Enables data tiering	`bool`	`false`	no
description_parameter	The description of the ElastiCache parameter group.	`string`	`null`	no
description_redis	User-created description for the replication group. Must not be empty	`string`	`""`	no
description_serverless	User-created description for the serverless. Must not be empty	`string`	`""`	no
description_subnet	The Description of the ElastiCache Subnet Group.	`string`	`null`	no
enabled_limits	Enable customization of cache_usage_limits(Only for the serverless module)	`bool`	`false`	no
engine	Name of the cache engine to be used for the clusters in this replication group.	`string`	`"redis"`	no
engine_version	Version number of the cache engine to be used for the cache clusters in this replication group.	`string`	`"6.x"`	no
family	The family of the ElastiCache parameter group.	`string`	`"redis6.x"`	no
final_snapshot_identifier	The name of your final node group (shard) snapshot.	`string`	`null`	no
global_replication_group_id	The ID of the global replication group to which this replication group should belong.	`string`	`null`	no
kms_key_id	The ARN of the key that you wish to use if encrypting at rest.	`string`	`null`	no
log_delivery_configuration	block allows the streaming of Redis SLOWLOG or Redis Engine Log to CloudWatch Log	`list(map(string))`	`[]`	no
maintenance_window	Specifies the weekly time range for when maintenance on the cache cluster is performed.	`string`	`"sat:03:00-sat:06:00"`	no
major_engine_version	The version of the cache engine that will be used to create the serverless cache.(Only for the serverless module)	`string`	`"7"`	no
multi_az_enabled	Specifies whether to enable Multi-AZ Support for the replication group.	`bool`	`false`	no
node_type	Instance class to be used.	`string`	`null`	no
notification_topic_arn	ARN of an SNS topic to send ElastiCache notifications to	`string`	`null`	no
num_cache_clusters	Number of cache clusters (primary and replicas) this replication group will have.	`number`	`3`	no
num_node_groups	Number of node groups (shards) for this Redis replication group.	`number`	`null`	no
parameter_group_name	The name of the ElastiCache parameter group.	`string`	`null`	no
parameters	List of DB parameters to apply	`list(map(string))`	`[]`	no
password	Password for the user.	`list(string)`	`[]`	no
password_create	Password Create	`string`	`null`	no
port	Port number on which each of the cache nodes will accept connections.	`number`	`6379`	no
preferred_cache_cluster_azs	List of EC2 availability zones in which the replication group's cache clusters will be created.	`list(string)`	`null`	no
random_password_length	The length of the string desired.	`number`	`16`	no
replicas_per_node_group	Number of replica nodes in each node group.	`number`	`null`	no
replication_group_id	Replication group identifier. This parameter is stored as a lowercase string.	`string`	`null`	no
security_group_ids	One or more Amazon VPC security groups associated with this replication group.	`list(string)`	`[]`	no
security_group_names	List of cache security group names to associate with this replication group.	`list(string)`	`null`	no
serverless_name	Name Redis Serverless. This parameter is stored as a lowercase string.	`string`	`null`	no
snapshot_arns_to_restore	The list of ARN(s) of the snapshot that the new serverless cache will be created from(Only for the serverless module)	`list(string)`	`null`	no
snapshot_name	Name of a snapshot from which to restore data into the new node group.	`string`	`null`	no
snapshot_retention_limit	Number of days for which ElastiCache will retain automatic cache cluster snapshots before deleting them.	`number`	`7`	no
snapshot_window	Daily time range (in UTC) during which ElastiCache will begin taking a daily snapshot of your cache cluster.	`string`	`"00:00-02:00"`	no
subnet_group_name	The Name of the ElastiCache Subnet Group.	`string`	`null`	no
subnet_ids	The Subnet IDs of the ElastiCache Subnet Group.	`list(string)`	[ null ]	no
tags	A map of tags to add to all resources	`map(string)`	`{}`	no
transit_encryption_enabled	Whether to enable encryption in transit.	`bool`	`true`	no
user_group_id	The user group identifier.	`string`	`null`	no
user_group_ids	User Group ID to associate with the replication group.	`list(string)`	`null`	no
user_id	The ID of the user.	`string`	`null`	no
user_name	The username of the user.	`string`	`null`	no

Outputs

Name	Description
cache_instance_endpoint	The DNS address of the Primary Cache
cache_instance_password	The cache password (this password may be old, because Terraform doesn't track it after initial creation)
db_instance_endpoint_reader	The DNS address of the Reader Cache

Authors

Module is maintained by Emidio Neto, Leonardo Jardim and Yuri Azeredo

License

Apache 2 Licensed. See LICENSE for full details.

osgurisdosre/terraform-aws-elasticache