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terraform-aws-elasticache-redis Latest Release Slack Community

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Cloud Posse

Terraform module to provision an ElastiCache Redis Cluster


This project is part of our comprehensive "SweetOps" approach towards DevOps.

It's 100% Open Source and licensed under the APACHE2.

We literally have hundreds of terraform modules that are Open Source and well-maintained. Check them out!

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.

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 >= 1.3
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_parameter_group Whether new parameter group should be created. Set to false if you want to use existing parameter group bool true 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
parameter_group_name Override the default parameter group name 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

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.

✨ Contributing

This project is under active development, and we encourage contributions from our community. Many thanks to our outstanding contributors:

🐛 Bug Reports & Feature Requests

Please use the issue tracker to report any bugs or file feature requests.

💻 Developing

If you are interested in being a contributor and want to get involved in developing this project or help out with our other projects, we would love to hear from you! Shoot us an email.

In general, PRs are welcome. We follow the typical "fork-and-pull" Git workflow.

  1. Fork the repo on GitHub
  2. Clone the project to your own machine
  3. Commit changes to your own branch
  4. Push your work back up to your fork
  5. Submit a Pull Request so that we can review your changes

NOTE: Be sure to merge the latest changes from "upstream" before making a pull request!

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About

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regarding copyright ownership.  The ASF licenses this file
to you under the Apache License, Version 2.0 (the
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