terraform-aws-modules / terraform-aws-memory-db

Terraform module to create AWS MemoryDB resources 🇺🇦

AWS MemoryDB Terraform module

Terraform module which creates AWS MemoryDB resources.

Usage

See examples directory for working examples to reference:

module "memory_db" {
  source = "terraform-aws-modules/memory-db/aws"

  # Cluster
  name        = "example"
  description = "Example MemoryDB cluster"

  engine_version             = "6.2"
  auto_minor_version_upgrade = true
  node_type                  = "db.t4g.small"
  num_shards                 = 2
  num_replicas_per_shard     = 2

  tls_enabled              = true
  security_group_ids       = ["sg-12345678"]
  maintenance_window       = "sun:23:00-mon:01:30"
  sns_topic_arn            = "arn:aws:sns:us-east-1:012345678910:example-topic"
  snapshot_retention_limit = 7
  snapshot_window          = "05:00-09:00"

  # Users
  users = {
    admin = {
      user_name     = "admin-user"
      access_string = "on ~* &* +@all"
      passwords     = ["YouShouldPickAStrongSecurePassword987!"]
      tags          = { User = "admin" }
    }
    readonly = {
      user_name     = "readonly-user"
      access_string = "on ~* &* -@all +@read"
      passwords     = ["YouShouldPickAStrongSecurePassword123!"]
      tags          = { User = "readonly" }
    }
  }

  # ACL
  acl_name = "example-acl"
  acl_tags = { Acl = "custom" }

  # Parameter group
  parameter_group_name        = "example-param-group"
  parameter_group_description = "Example MemoryDB parameter group"
  parameter_group_family      = "memorydb_redis6"
  parameter_group_parameters = [
    {
      name  = "activedefrag"
      value = "yes"
    }
  ]
  parameter_group_tags = {
    ParameterGroup = "custom"
  }

  # Subnet group
  subnet_group_name        = "example-subnet-group"
  subnet_group_description = "Example MemoryDB subnet group"
  subnet_ids               = ["subnet-1fe3d837", "subnet-129d66ab", "subnet-1211eef5"]
  subnet_group_tags = {
    SubnetGroup = "custom"
  }

  tags = {
    Terraform   = "true"
    Environment = "dev"
  }
}

Conditional Creation

The following values are provided to toggle on/off creation of the associated resources as desired:

module "memory_db" {
  source = "terraform-aws-modules/memory-db/aws"

  # Disable creation of cluster and all resources
  create = false

  # Disable creation of users
  create_users = false

  # Disable creation of ACL - an ACL will need to be provided
  create_acl = false
  acl_name   = "existing_acl"

  # Disable creation of parameter group - a parameter group will need to be provided
  create_parameter_group = false
  parameter_group_name   = "existing_parameter_group"

  # Disable creation of subnet group - a subnet group will need to be provided
  create_subnet_group = false
  subnet_group_name   = "existing_subnet_group"

  # ... omitted
}

Examples

Examples codified under the examples are intended to give users references for how to use the module(s) as well as testing/validating changes to the source code of the module. If contributing to the project, please be sure to make any appropriate updates to the relevant examples to allow maintainers to test your changes and to keep the examples up to date for users. Thank you!

• Complete

Requirements

Name	Version
terraform	>= 1.0
aws	>= 5.47

Providers

Name	Version
aws	>= 5.47

Modules

No modules.

Resources

Name	Type
aws_memorydb_acl.this	resource
aws_memorydb_cluster.this	resource
aws_memorydb_parameter_group.this	resource
aws_memorydb_subnet_group.this	resource
aws_memorydb_user.this	resource

Inputs

Name	Description	Type	Default	Required
acl_name	Name of ACL to be created if create_acl is true, otherwise its the name of an existing ACL to use if create_acl is false	string	null	no
acl_tags	Additional tags for the ACL created	map(string)	{}	no
acl_use_name_prefix	Determines whether acl_name is used as a prefix	bool	false	no
acl_user_names	List of externally created user names to associate with the ACL	list(string)	[]	no
auto_minor_version_upgrade	When set to true, the cluster will automatically receive minor engine version upgrades after launch. Defaults to true	bool	null	no
create	Determines whether resources will be created - affects all resources	bool	true	no
create_acl	Determines whether to create ACL specified	bool	true	no
create_parameter_group	Determines whether to create parameter group specified	bool	true	no
create_subnet_group	Determines whether to create subnet group specified	bool	true	no
create_users	Determines whether to create users specified	bool	true	no
data_tiering	Must be set to true when using a data tiering node type	bool	null	no
description	Description for the cluster. Defaults to Managed by Terraform	string	null	no
engine_version	Version number of the Redis engine to be used for the cluster. Downgrades are not supported	string	null	no
final_snapshot_name	Name of the final cluster snapshot to be created when this resource is deleted. If omitted, no final snapshot will be made	string	null	no
kms_key_arn	ARN of the KMS key used to encrypt the cluster at rest	string	null	no
maintenance_window	Specifies the weekly time range during which maintenance on the cluster is performed. It is specified as a range in the format ddd:hh24:mi-ddd:hh24:mi	string	null	no
name	Cluster name - also default name used on all resources if more specific resource names are not provided	string	""	no
node_type	The compute and memory capacity of the nodes in the cluster. See AWS documentation on supported node types as well as vertical scaling	string	null	no
num_replicas_per_shard	The number of replicas to apply to each shard, up to a maximum of 5. Defaults to 1 (i.e. 2 nodes per shard)	number	null	no
num_shards	The number of shards in the cluster. Defaults to 1	number	null	no
parameter_group_description	Description for the parameter group. Defaults to Managed by Terraform	string	null	no
parameter_group_family	The engine version that the parameter group can be used with	string	null	no
parameter_group_name	Name of parameter group to be created if create_parameter_group is true, otherwise its the name of an existing parameter group to use if create_parameter_group is false	string	null	no
parameter_group_parameters	A list of parameter maps to apply	list(map(string))	[]	no
parameter_group_tags	Additional tags for the parameter group created	map(string)	{}	no
parameter_group_use_name_prefix	Determines whether parameter_group_name is used as a prefix	bool	false	no
port	The port number on which each of the nodes accepts connections. Defaults to 6379	number	null	no
security_group_ids	Set of VPC Security Group ID-s to associate with this cluster	list(string)	null	no
snapshot_arns	List of ARN-s that uniquely identify RDB snapshot files stored in S3. The snapshot files will be used to populate the new cluster	list(string)	null	no
snapshot_name	The name of a snapshot from which to restore data into the new cluster	string	null	no
snapshot_retention_limit	The number of days for which MemoryDB retains automatic snapshots before deleting them. When set to 0, automatic backups are disabled. Defaults to 0	number	null	no
snapshot_window	The daily time range (in UTC) during which MemoryDB begins taking a daily snapshot of your shard. Example: 05:00-09:00	string	null	no
sns_topic_arn	ARN of the SNS topic to which cluster notifications are sent	string	null	no
subnet_group_description	Description for the subnet group. Defaults to Managed by Terraform	string	null	no
subnet_group_name	Name of subnet group to be created if create_subnet_group is true, otherwise its the name of an existing subnet group to use if create_subnet_group is false	string	null	no
subnet_group_tags	Additional tags for the subnet group created	map(string)	{}	no
subnet_group_use_name_prefix	Determines whether subnet_group_name is used as a prefix	bool	false	no
subnet_ids	Set of VPC Subnet ID-s for the subnet group. At least one subnet must be provided	list(string)	[]	no
tags	A map of tags to use on all resources	map(string)	{}	no
tls_enabled	A flag to enable in-transit encryption on the cluster. When set to false, the acl_name must be open-access. Defaults to true	bool	null	no
use_name_prefix	Determines whether name is used as a prefix for the cluster	bool	false	no
users	A map of user definitions (maps) to be created	any	{}	no

Outputs

Name	Description
acl_arn	The ARN of the ACL
acl_id	Name of the ACL
acl_minimum_engine_version	The minimum engine version supported by the ACL
cluster_arn	The ARN of the cluster
cluster_endpoint_address	DNS hostname of the cluster configuration endpoint
cluster_endpoint_port	Port number that the cluster configuration endpoint is listening on
cluster_engine_patch_version	Patch version number of the Redis engine used by the cluster
cluster_id	Cluster name
cluster_shards	Set of shards in this cluster
parameter_group_arn	The ARN of the parameter group
parameter_group_id	Name of the parameter group
subnet_group_arn	ARN of the subnet group
subnet_group_id	Name of the subnet group
subnet_group_vpc_id	The VPC in which the subnet group exists
users	Map of attributes for the users created

License

Apache-2.0 Licensed. See LICENSE.

terraform-aws-memory-db's Issues

vector search enabled MemoryDB cluster via terraform module

via aws-cli we can create the cluster with vector search enabeld by passing the parameter group default.memorydb-redis7.search.preview, as stated in:

To create a vector search enabled MemoryDB cluster, you can use the MemoryDB [create-cluster](https://docs.aws.amazon.com/cli/latest/reference/memorydb/create-cluster.html) command by passing an immutable parameter group default.memorydb-redis7.search.preview to enable the preview mode for vector search capabilities.

However, when I do that via terraform:

module "memory_db" {
  source = "terraform-aws-modules/memory-db/aws"


  engine_version            = "7.1"
  node_type                    = "db.r7g.2xlarge"
  num_shards                 = 1
  
  # Parameter group
  create_parameter_group = false
  parameter_group_family = "default.memorydb-redis7.search.preview"
 (...)
 (...)
}

it's not enabled.
I've confirmed it:

-ERR Command not enabled, instance needs to be configured for Public Preview for Vector Similarity Search

terraform-aws-memory-db: include lifecycle block to aws_memorydb_cluster to avoid possible downtimes

Is your request related to a new offering from AWS?

Is this functionality available in the AWS provider for Terraform? See CHANGELOG.md, too.

• No 🛑: please wait to file a request until the functionality is avaialble in the AWS provider
• Yes ✅: please list the AWS provider version which introduced this functionality

Is your request related to a problem? Please describe.

I am using the terraform-aws-modules/terraform-aws-memory-db module but I am seeing creating and destroying of the aws_memorydb_cluster, simultaneously. This might cause an abrupt breaking change for an application that relies on the MemoryDB cluster and could lead to app crashes, possibly longer downtimes.

Describe the solution you'd like.

It would be great if had a lifecycle block (as shown below) on the aws_memorydb_cluster resource as well so we can reduce the amount of downtime for the application. We would still need to pass the newer cluster_endpoint_address downstream to dependent compute resources, like Lambda, EC2 and so on.

lifecycle {
  create_before_destroy = true
}

The proposed change could reduce the amount of time for the application to come back online.

Describe alternatives you've considered.

I would love to throw a lifecycle block on the module reference code in Terraform but lifecycle is not supported on modules yet. Refer hashicorp/terraform#27360.

I am willing to fork the repository and make the changes and submit a PR, if the changes/feature request makes sense.

Thank you for your contributions to the Terraform community!

Additional context