Terraform module to provision an ElastiCache
Redis Cluster or Serverless instance.
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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 / Serverless Instance.
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 or examples/serverless.
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
}
Important
In Cloud Posse's examples, we avoid pinning modules to specific versions to prevent discrepancies between the documentation and the latest released versions. However, for your own projects, we strongly advise pinning each module to the exact version you're using. This practice ensures the stability of your infrastructure. Additionally, we recommend implementing a systematic approach for updating versions to avoid unexpected changes.
Review the complete example or serverless example to see how to use this module.
Available targets:
help Help screen
help/all Display help for all targets
help/short This help short screen
lint Lint terraform code
Name | Version |
---|---|
terraform | >= 1.3 |
aws | >= 5.47 |
Name | Version |
---|---|
aws | >= 5.47 |
Name | Source | Version |
---|---|---|
aws_security_group | cloudposse/security-group/aws | 2.2.0 |
dns | cloudposse/route53-cluster-hostname/aws | 0.13.0 |
this | cloudposse/label/null | 0.25.0 |
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_serverless_cache.default | resource |
aws_elasticache_subnet_group.default | resource |
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 falseand 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, exceptfor 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 |
auth_token_update_strategy | Strategy to use when updating the auth_token. Valid values are SET , ROTATE , and DELETE . Defaults to ROTATE . |
string |
"ROTATE" |
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 |
{ |
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 beidentical 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 |
inline_rules_enabled | NOT RECOMMENDED. Create rules "inline" instead of as separate aws_security_group_rule resources.See #20046 for one of several issues with inline rules. See this post for details on the difference between inline rules and rule resources. |
bool |
false |
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 bechanged in later chained modules. Attempts to change it will be silently ignored. |
set(string) |
[ |
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({ |
[] |
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 |
preserve_security_group_id | When false and create_before_destroy is true , changes to security group rulescause a new security group to be created with the new rules, and the existing security group is then replaced with the new one, eliminating any service interruption. When true or when changing the value (from false to true or from true to false ),existing security group rules will be deleted before new ones are created, resulting in a service interruption, but preserving the security group itself. NOTE: Setting this to true does not guarantee the security group will never be replaced,it only keeps changes to the security group rules from triggering a replacement. See the README for further discussion. |
bool |
false |
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 |
revoke_rules_on_delete | Instruct Terraform to revoke all of the Security Group's attached ingress and egress rules before deleting the security group itself. This is normally not needed. |
bool |
false |
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 keepthe 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 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 |
serverless_cache_usage_limits | The usage limits for the serverless cache | map(any) |
{} |
no |
serverless_enabled | Flag to enable/disable creation of a serverless redis cluster | bool |
false |
no |
serverless_major_engine_version | The major version of the engine to use for the serverless cluster | string |
"7" |
no |
serverless_snapshot_time | The daily time that snapshots will be created from the serverless cache. | string |
"06:00" |
no |
serverless_user_group_id | User Group ID to associate with the replication group | string |
null |
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 |
target_security_group_id | The ID of an existing Security Group to which Security Group rules will be assigned. The Security Group's name and description will not be changed. Not compatible with inline_rules_enabled or revoke_rules_on_delete .If not provided (the default), this module will create a security group. |
list(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 |
transit_encryption_mode | A setting that enables clients to migrate to in-transit encryption with no downtime. Valid values are preferred and required . When enabling encryption on an existing replication group, this must first be set to preferred before setting it to required in a subsequent apply. See the TransitEncryptionMode field in the CreateReplicationGroup API documentation for additional details." |
string |
null |
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 |
Name | Description |
---|---|
arn | Elasticache Replication Group ARN |
cluster_enabled | Indicates if cluster mode is enabled |
endpoint | Redis primary, configuration or serverless endpoint , whichever is appropriate for the given configuration |
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 or serverless is being used. |
security_group_id | The ID of the created security group |
security_group_name | The name of the created security group |
serverless_enabled | Indicates if serverless mode is enabled |
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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