terraform-aws-elasticache-redis

Terraform module to provision an ElastiCache Redis Cluster

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Security & Compliance

Security scanning is graciously provided by Bridgecrew. Bridgecrew is the leading fully hosted, cloud-native solution providing continuous Terraform security and compliance.

Benchmark	Description
	Infrastructure Security Compliance
	Center for Internet Security, KUBERNETES Compliance
	Center for Internet Security, AWS Compliance
	Center for Internet Security, AZURE Compliance
	Payment Card Industry Data Security Standards Compliance
	National Institute of Standards and Technology Compliance
	Information Security Management System, ISO/IEC 27001 Compliance
	Service Organization Control 2 Compliance
	Center for Internet Security, GCP Compliance
	Health Insurance Portability and Accountability Compliance

Usage

IMPORTANT: We do not pin modules to versions in our examples because of the difficulty of keeping the versions in the documentation in sync with the latest released versions. We highly recommend that in your code you pin the version to the exact version you are using so that your infrastructure remains stable, and update versions in a systematic way so that they do not catch you by surprise.

Also, because of a bug in the Terraform registry (hashicorp/terraform#21417), the registry shows many of our inputs as required when in fact they are optional. The table below correctly indicates which inputs are required.

Disruptive changes introduced at version 0.41.0. If upgrading from an earlier version, see migration notes for details.

Note that this uses secure defaults. One of the ways this module can trip users up is with transit_encryption_enabled which is true by default. With this enabled, one does not simply redis-cli in without setting up an stunnel. Amazon provides good documentation on how to connect with it enabled. If this is not desired behavior, set transit_encryption_enabled=false.

This module creates, by default, a new security group for the Elasticache Redis Cluster. When a configuration change (for example, a different security group name) cannot be applied to the security group, Terraform will replace that security group with a new one with the new configuration. In order to allow Terraform to fully manage the security group, you should not place any other resources in (or associate any other resources with) the security group this module creates. Also, in order to keep things from breaking when this module replaces the security group, you should not reference the created security group anywhere else (such as in rules in other security groups). If you want to associate the cluster with a more stable security group that you can reference elsewhere, create that security group outside this module (perhaps with terraform-aws-security-group) and pass the security group ID in via associated_security_group_ids.

Note about zone_id: Previously, zone_id was a string. This caused problems (see #82). Now zone_id should be supplied as a list(string), either empty or with exactly 1 zone ID in order to avoid the problem.

For a complete example, see examples/complete.

For automated tests of the complete example using bats and Terratest (which tests and deploys the example on AWS), see test.

provider "aws" {
  region = var.region
}

module "this" {
  source  = "cloudposse/label/null"
  # Cloud Posse recommends pinning every module to a specific version
  # version = "x.x.x"
  namespace  = var.namespace
  stage      = var.stage
  name       = var.name
}

module "vpc" {
  source = "cloudposse/vpc/aws"
  # Cloud Posse recommends pinning every module to a specific version
  # version = "x.x.x"

  cidr_block = "172.16.0.0/16"

  context = module.this.context
}

module "subnets" {
  source = "cloudposse/dynamic-subnets/aws"
  # Cloud Posse recommends pinning every module to a specific version
  # version = "x.x.x"

  availability_zones   = var.availability_zones
  vpc_id               = module.vpc.vpc_id
  igw_id               = module.vpc.igw_id
  cidr_block           = module.vpc.vpc_cidr_block
  nat_gateway_enabled  = true
  nat_instance_enabled = false

  context = module.this.context
}

module "redis" {
  source = "cloudposse/elasticache-redis/aws"
  # Cloud Posse recommends pinning every module to a specific version
  # version = "x.x.x"

  availability_zones         = var.availability_zones
  zone_id                    = var.zone_id
  vpc_id                     = module.vpc.vpc_id
  allowed_security_group_ids = [module.vpc.vpc_default_security_group_id]
  subnets                    = module.subnets.private_subnet_ids
  cluster_size               = var.cluster_size
  instance_type              = var.instance_type
  apply_immediately          = true
  automatic_failover_enabled = false
  engine_version             = var.engine_version
  family                     = var.family
  at_rest_encryption_enabled = var.at_rest_encryption_enabled
  transit_encryption_enabled = var.transit_encryption_enabled

  parameter = [
    {
      name  = "notify-keyspace-events"
      value = "lK"
    }
  ]

  context = module.this.context
}

Examples

Review the complete example to see how to use this module.

Makefile Targets

Available targets:

  help                                Help screen
  help/all                            Display help for all targets
  help/short                          This help short screen
  lint                                Lint terraform code

Requirements

Name	Version
terraform	>= 0.14.0
aws	>= 4.18

Providers

Name	Version
aws	>= 4.18

Modules

Name	Source	Version
aws_security_group	cloudposse/security-group/aws	1.0.1
dns	cloudposse/route53-cluster-hostname/aws	0.12.2
this	cloudposse/label/null	0.25.0

Resources

Name	Type
aws_cloudwatch_metric_alarm.cache_cpu	resource
aws_cloudwatch_metric_alarm.cache_memory	resource
aws_elasticache_parameter_group.default	resource
aws_elasticache_replication_group.default	resource
aws_elasticache_subnet_group.default	resource

Inputs

Name	Description	Type	Default	Required
additional_security_group_rules	A list of Security Group rule objects to add to the created security group, in addition to the ones this module normally creates. (To suppress the module's rules, set `create_security_group` to false and supply your own security group via `associated_security_group_ids`.) The keys and values of the objects are fully compatible with the `aws_security_group_rule` resource, except for `security_group_id` which will be ignored, and the optional "key" which, if provided, must be unique and known at "plan" time. To get more info see https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/security_group_rule .	`list(any)`	`[]`	no
additional_tag_map	Additional key-value pairs to add to each map in `tags_as_list_of_maps`. Not added to `tags` or `id`. This is for some rare cases where resources want additional configuration of tags and therefore take a list of maps with tag key, value, and additional configuration.	`map(string)`	`{}`	no
alarm_actions	Alarm action list	`list(string)`	`[]`	no
alarm_cpu_threshold_percent	CPU threshold alarm level	`number`	`75`	no
alarm_memory_threshold_bytes	Ram threshold alarm level	`number`	`10000000`	no
allow_all_egress	If `true`, the created security group will allow egress on all ports and protocols to all IP address. If this is false and no egress rules are otherwise specified, then no egress will be allowed. Defaults to `true` unless the deprecated `egress_cidr_blocks` is provided and is not `["0.0.0.0/0"]`, in which case defaults to `false`.	`bool`	`null`	no
allowed_cidr_blocks	DEPRECATED: Use `additional_security_group_rules` instead. Historical description: List of CIDR blocks that are allowed ingress to the cluster's Security Group created in the module	`list(string)`	`[]`	no
allowed_security_group_ids	A list of IDs of Security Groups to allow access to the security group created by this module.	`list(string)`	`[]`	no
allowed_security_groups	DEPRECATED: Use `allowed_security_group_ids` instead.	`list(string)`	`[]`	no
apply_immediately	Apply changes immediately	`bool`	`true`	no
associated_security_group_ids	A list of IDs of Security Groups to associate the created resource with, in addition to the created security group. These security groups will not be modified and, if `create_security_group` is `false`, must provide all the required access.	`list(string)`	`[]`	no
at_rest_encryption_enabled	Enable encryption at rest	`bool`	`false`	no
attributes	ID element. Additional attributes (e.g. `workers` or `cluster`) to add to `id`, in the order they appear in the list. New attributes are appended to the end of the list. The elements of the list are joined by the `delimiter` and treated as a single ID element.	`list(string)`	`[]`	no
auth_token	Auth token for password protecting redis, `transit_encryption_enabled` must be set to `true`. Password must be longer than 16 chars	`string`	`null`	no
auto_minor_version_upgrade	Specifies whether minor version engine upgrades will be applied automatically to the underlying Cache Cluster instances during the maintenance window. Only supported if the engine version is 6 or higher.	`bool`	`null`	no
automatic_failover_enabled	Automatic failover (Not available for T1/T2 instances)	`bool`	`false`	no
availability_zones	Availability zone IDs	`list(string)`	`[]`	no
cloudwatch_metric_alarms_enabled	Boolean flag to enable/disable CloudWatch metrics alarms	`bool`	`false`	no
cluster_mode_enabled	Flag to enable/disable creation of a native redis cluster. `automatic_failover_enabled` must be set to `true`. Only 1 `cluster_mode` block is allowed	`bool`	`false`	no
cluster_mode_num_node_groups	Number of node groups (shards) for this Redis replication group. Changing this number will trigger an online resizing operation before other settings modifications	`number`	`0`	no
cluster_mode_replicas_per_node_group	Number of replica nodes in each node group. Valid values are 0 to 5. Changing this number will force a new resource	`number`	`0`	no
cluster_size	Number of nodes in cluster. Ignored when `cluster_mode_enabled` == `true`	`number`	`1`	no
context	Single object for setting entire context at once. See description of individual variables for details. Leave string and numeric variables as `null` to use default value. Individual variable settings (non-null) override settings in context object, except for attributes, tags, and additional_tag_map, which are merged.	`any`	{ "additional_tag_map": {}, "attributes": [], "delimiter": null, "descriptor_formats": {}, "enabled": true, "environment": null, "id_length_limit": null, "label_key_case": null, "label_order": [], "label_value_case": null, "labels_as_tags": [ "unset" ], "name": null, "namespace": null, "regex_replace_chars": null, "stage": null, "tags": {}, "tenant": null }	no
create_security_group	Set `true` to create and configure a new security group. If false, `associated_security_group_ids` must be provided.	`bool`	`true`	no
data_tiering_enabled	Enables data tiering. Data tiering is only supported for replication groups using the r6gd node type.	`bool`	`false`	no
delimiter	Delimiter to be used between ID elements. Defaults to `-` (hyphen). Set to `""` to use no delimiter at all.	`string`	`null`	no
description	Description of elasticache replication group	`string`	`null`	no
descriptor_formats	Describe additional descriptors to be output in the `descriptors` output map. Map of maps. Keys are names of descriptors. Values are maps of the form `{<br> format = string<br> labels = list(string)<br>}` (Type is `any` so the map values can later be enhanced to provide additional options.) `format` is a Terraform format string to be passed to the `format()` function. `labels` is a list of labels, in order, to pass to `format()` function. Label values will be normalized before being passed to `format()` so they will be identical to how they appear in `id`. Default is `{}` (`descriptors` output will be empty).	`any`	`{}`	no
dns_subdomain	The subdomain to use for the CNAME record. If not provided then the CNAME record will use var.name.	`string`	`""`	no
egress_cidr_blocks	DEPRECATED: Use `allow_all_egress` and `additional_security_group_rules` instead. Historical description: Outbound traffic address. Historical default: ["0.0.0.0/0"]	`list(any)`	`null`	no
elasticache_subnet_group_name	Subnet group name for the ElastiCache instance	`string`	`""`	no
enabled	Set to false to prevent the module from creating any resources	`bool`	`null`	no
engine_version	Redis engine version	`string`	`"4.0.10"`	no
environment	ID element. Usually used for region e.g. 'uw2', 'us-west-2', OR role 'prod', 'staging', 'dev', 'UAT'	`string`	`null`	no
existing_security_groups	DEPRECATED: Use `associated_security_group_ids` instead. Historical description: List of existing Security Group IDs to place the cluster into. Set `use_existing_security_groups` to `true` to enable using `existing_security_groups` as Security Groups for the cluster.	`list(string)`	`[]`	no
family	Redis family	`string`	`"redis4.0"`	no
final_snapshot_identifier	The name of your final node group (shard) snapshot. ElastiCache creates the snapshot from the primary node in the cluster. If omitted, no final snapshot will be made.	`string`	`null`	no
id_length_limit	Limit `id` to this many characters (minimum 6). Set to `0` for unlimited length. Set to `null` for keep the existing setting, which defaults to `0`. Does not affect `id_full`.	`number`	`null`	no
instance_type	Elastic cache instance type	`string`	`"cache.t2.micro"`	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. `at_rest_encryption_enabled` must be set to `true`	`string`	`null`	no
label_key_case	Controls the letter case of the `tags` keys (label names) for tags generated by this module. Does not affect keys of tags passed in via the `tags` input. Possible values: `lower`, `title`, `upper`. Default value: `title`.	`string`	`null`	no
label_order	The order in which the labels (ID elements) appear in the `id`. Defaults to ["namespace", "environment", "stage", "name", "attributes"]. You can omit any of the 6 labels ("tenant" is the 6th), but at least one must be present.	`list(string)`	`null`	no
label_value_case	Controls the letter case of ID elements (labels) as included in `id`, set as tag values, and output by this module individually. Does not affect values of tags passed in via the `tags` input. Possible values: `lower`, `title`, `upper` and `none` (no transformation). Set this to `title` and set `delimiter` to `""` to yield Pascal Case IDs. Default value: `lower`.	`string`	`null`	no
labels_as_tags	Set of labels (ID elements) to include as tags in the `tags` output. Default is to include all labels. Tags with empty values will not be included in the `tags` output. Set to `[]` to suppress all generated tags. Notes: The value of the `name` tag, if included, will be the `id`, not the `name`. Unlike other `null-label` inputs, the initial setting of `labels_as_tags` cannot be changed in later chained modules. Attempts to change it will be silently ignored.	`set(string)`	[ "default" ]	no
log_delivery_configuration	The log_delivery_configuration block allows the streaming of Redis SLOWLOG or Redis Engine Log to CloudWatch Logs or Kinesis Data Firehose. Max of 2 blocks.	`list(map(any))`	`[]`	no
maintenance_window	Maintenance window	`string`	`"wed:03:00-wed:04:00"`	no
multi_az_enabled	Multi AZ (Automatic Failover must also be enabled. If Cluster Mode is enabled, Multi AZ is on by default, and this setting is ignored)	`bool`	`false`	no
name	ID element. Usually the component or solution name, e.g. 'app' or 'jenkins'. This is the only ID element not also included as a `tag`. The "name" tag is set to the full `id` string. There is no tag with the value of the `name` input.	`string`	`null`	no
namespace	ID element. Usually an abbreviation of your organization name, e.g. 'eg' or 'cp', to help ensure generated IDs are globally unique	`string`	`null`	no
notification_topic_arn	Notification topic arn	`string`	`""`	no
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 Number (ARN)	`list(string)`	`[]`	no
parameter	A list of Redis parameters to apply. Note that parameters may differ from one Redis family to another	list(object({ name = string value = string }))	`[]`	no
parameter_group_description	Managed by Terraform	`string`	`null`	no
port	Redis port	`number`	`6379`	no
regex_replace_chars	Terraform regular expression (regex) string. Characters matching the regex will be removed from the ID elements. If not set, `"/[^a-zA-Z0-9-]/"` is used to remove all characters other than hyphens, letters and digits.	`string`	`null`	no
replication_group_id	Replication group ID with the following constraints: A name must contain from 1 to 20 alphanumeric characters or hyphens. The first character must be a letter. A name cannot end with a hyphen or contain two consecutive hyphens.	`string`	`""`	no
security_group_create_before_destroy	Set `true` to enable Terraform `create_before_destroy` behavior on the created security group. We only recommend setting this `false` if you are upgrading this module and need to keep the existing security group from being replaced. Note that changing this value will always cause the security group to be replaced.	`bool`	`true`	no
security_group_create_timeout	How long to wait for the security group to be created.	`string`	`"10m"`	no
security_group_delete_timeout	How long to retry on `DependencyViolation` errors during security group deletion.	`string`	`"15m"`	no
security_group_description	The description to assign to the created Security Group. Warning: Changing the description causes the security group to be replaced. Set this to `null` to maintain parity with releases <= `0.34.0`.	`string`	`"Security group for Elasticache Redis"`	no
security_group_name	The name to assign to the created security group. Must be unique within the VPC. If not provided, will be derived from the `null-label.context` passed in. If `create_before_destroy` is true, will be used as a name prefix.	`list(string)`	`[]`	no
snapshot_arns	A single-element string list containing an Amazon Resource Name (ARN) of a Redis RDB snapshot file stored in Amazon S3. Example: arn:aws:s3:::my_bucket/snapshot1.rdb	`list(string)`	`[]`	no
snapshot_name	The name of a snapshot from which to restore data into the new node group. Changing the snapshot_name forces a new resource.	`string`	`null`	no
snapshot_retention_limit	The number of days for which ElastiCache will retain automatic cache cluster snapshots before deleting them.	`number`	`0`	no
snapshot_window	The daily time range (in UTC) during which ElastiCache will begin taking a daily snapshot of your cache cluster.	`string`	`"06:30-07:30"`	no
stage	ID element. Usually used to indicate role, e.g. 'prod', 'staging', 'source', 'build', 'test', 'deploy', 'release'	`string`	`null`	no
subnets	Subnet IDs	`list(string)`	`[]`	no
tags	Additional tags (e.g. `{'BusinessUnit': 'XYZ'}`). Neither the tag keys nor the tag values will be modified by this module.	`map(string)`	`{}`	no
tenant	ID element _(Rarely used, not included by default)_. A customer identifier, indicating who this instance of a resource is for	`string`	`null`	no
transit_encryption_enabled	Set `true` to enable encryption in transit. Forced `true` if `var.auth_token` is set. If this is enabled, use the following guide to access redis.	`bool`	`true`	no
use_existing_security_groups	DEPRECATED: Use `create_security_group` instead. Historical description: Flag to enable/disable creation of Security Group in the module. Set to `true` to disable Security Group creation and provide a list of existing security Group IDs in `existing_security_groups` to place the cluster into. Historical default: `false`	`bool`	`null`	no
user_group_ids	User Group ID to associate with the replication group	`list(string)`	`null`	no
vpc_id	VPC ID	`string`	n/a	yes
zone_id	Route53 DNS Zone ID as list of string (0 or 1 items). If empty, no custom DNS name will be published. If the list contains a single Zone ID, a custom DNS name will be pulished in that zone. Can also be a plain string, but that use is DEPRECATED because of Terraform issues.	`any`	`[]`	no

Outputs

Name	Description
arn	Elasticache Replication Group ARN
cluster_enabled	Indicates if cluster mode is enabled
endpoint	Redis primary or configuration endpoint, whichever is appropriate for the given cluster mode
engine_version_actual	The running version of the cache engine
host	Redis hostname
id	Redis cluster ID
member_clusters	Redis cluster members
port	Redis port
reader_endpoint_address	The address of the endpoint for the reader node in the replication group, if the cluster mode is disabled.
security_group_id	The ID of the created security group
security_group_name	The name of the created security group

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Related Projects

Check out these related projects.

terraform-aws-security-group - Terraform module to provision an AWS Security Group.
terraform-null-label - Terraform module designed to generate consistent names and tags for resources. Use terraform-null-label to implement a strict naming convention.

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License

See LICENSE for full details.

Licensed to the Apache Software Foundation (ASF) under one
or more contributor license agreements.  See the NOTICE file
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regarding copyright ownership.  The ASF licenses this file
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Contributors

Erik Osterman	Igor Rodionov	Andriy Knysh	Daren Desjardins	Max Moon	Christopher Riley	RB

cloudposse/terraform-aws-elasticache-redis

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