cnp-module-redis

This repository contains the module that enables you to create a Redis PaaS instance.

Usage

Recommended example for cost optimisation

Premium redis PaaS instance are very expensive, care must be taken when using them and only used in required environments. This should only be production unless you really need it in a different environment.

variables.tf

variable "family" {
  default     = "C"
  description = "The SKU family/pricing group to use. Valid values are `C` (for Basic/Standard SKU family) and `P` (for Premium). Use P for higher availability, but beware it costs a lot more."
}

variable "sku_name" {
  default     = "Basic"
  description = "The SKU of Redis to use. Possible values are `Basic`, `Standard` and `Premium`."
}

variable "capacity" {
  default     = "1"
  description = "The size of the Redis cache to deploy. Valid values are 1, 2, 3, 4, 5"
}

The following values are recommended for use in the production environment:

prod.tfvars

sku_name = "Premium"
family   = "P"
capacity = "1"

redis.tf

module "redis" {
  source                   = "git@github.com:hmcts/cnp-module-redis?ref=master"
  product                  = var.product
  location                 = var.location
  env                      = var.env
  common_tags              = var.common_tags
  redis_version            = "6"
  business_area            = "cft" # cft or sds
  sku_name                 = var.sku_name
  family                   = var.family
  capacity                 = var.capacity

  private_endpoint_enabled      = true
  public_network_access_enabled = false
}

resource "azurerm_key_vault_secret" "redis_access_key" {
  name         = "redis-access-key"
  value        = module.redis-activity-service.access_key
  key_vault_id = data.azurerm_key_vault.vault.id
}

If you need to increase cache size take a look at the pricing page for available options and cost impact.

Configuration

Providers

Name	Version
azurerm	n/a

Resources

Name	Type
azurerm_private_endpoint.this	resource
azurerm_redis_cache.redis	resource
azurerm_resource_group.cache-resourcegroup	resource
azurerm_subnet.private_endpoint_subnet	data source

Inputs

Name	Description	Type	Default	Required
availability_zones	Specifies a list of Availability Zones in which this Redis Cache should be located. Changing this forces a new Redis Cache to be created.	list(any)	null	no
business_area	business_area name - sds or cft	string	"cft"	no
capacity	The size of the Redis cache to deploy. Valid values are 1, 2, 3, 4, 5	string	"1"	no
common_tags	Map of tags to tag all resources with	map(string)	n/a	yes
env	Environment to deploy to	string	n/a	yes
family	The SKU family/pricing group to use. Valid values are C (for Basic/Standard SKU family) and P (for Premium). Use P for higher availability, but beware it costs a lot more.	string	"P"	no
location	Azure datacenter location	string	n/a	yes
maxfragmentationmemory_reserved	Value in megabytes reserved to accommodate for memory fragmentation	string	"642"	no
maxmemory_delta	The max-memory delta for this Redis instance.	string	"642"	no
maxmemory_policy	How Redis will select what to remove when maxmemory is reached	string	"volatile-lru"	no
maxmemory_reserved	Value in megabytes reserved for non-cache usage e.g. failover	string	"642"	no
minimum_tls_version	The minimum TLS version	string	"1.2"	no
name	Override the default name of $product-$env, useful when upgrading versions	string	null	no
private_endpoint_enabled	Deploy using a private endpoint rather than vnet integration (recommended)	bool	false	no
private_endpoint_subnet	Specify your own subnet for private link integration, if you don't specify one then it will be calculated for you.	string	""	no
product	https://hmcts.github.io/glossary/#platform	string	n/a	yes
public_network_access_enabled	Whether or not public network access is allowed for this Redis Cache. true means this resource could be accessed by both public and private endpoint. false means only private endpoint access is allowed. Defaults to true.	bool	true	no
redis_version	Redis version to be deployed 4 or 6 (4 is deprecated)	string	"4"	no
resource_group_name	Name of existing resource group to deploy resources into	string	null	no
sku_name	The SKU of Redis to use. Possible values are Basic, Standard and Premium.	string	"Premium"	no
subnetid	Subnet to deploy the Redis instance to	string	""	no

Outputs

Name	Description
access_key	Primary access key to connect to redis with
host_name	Host name of the Redis cache
redis_port	SSL port to connect to redis with