Module: elasticache-memcached
Terraform module to provision an ElastiCache
Memcached Cluster
Usage
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 "memcached" {
source = "cloudposse/elasticache-memcached/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
allowed_security_groups = [module.vpc.vpc_default_security_group_id]
subnets = module.subnets.private_subnet_ids
cluster_size = var.cluster_size
instance_type = var.instance_type
engine_version = var.engine_version
apply_immediately = true
zone_id = var.zone_id
elasticache_parameter_group_family = var.elasticache_parameter_group_family
context = module.this.context
}
Examples
Review the complete example to see how to use this module.
Variables
Required Variables
Optional Variables
additional_security_group_rules
(list(any)
) optionalA 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, setcreate_security_group
to false
and supply your own security group viaassociated_security_group_ids
.)
The keys and values of the objects are fully compatible with theaws_security_group_rule
resource, except
forsecurity_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 .Default value:
[ ]
alarm_actions
(list(string)
) optionalAlarm actions
Default value:
[ ]
alarm_cpu_threshold_percent
(number
) optionalCPU threshold alarm level
Default value:
75
alarm_memory_threshold_bytes
(number
) optionalAlarm memory threshold bytes
Default value:
10000000
allow_all_egress
(bool
) optionalIf
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.Default value:
true
allowed_cidr_blocks
(list(string)
) optionalA list of IPv4 CIDRs to allow access to the security group created by this module.
The length of this list must be known at "plan" time.Default value:
[ ]
allowed_ipv6_cidr_blocks
(list(string)
) optionalA list of IPv6 CIDRs to allow access to the security group created by this module.
The length of this list must be known at "plan" time.Default value:
[ ]
allowed_ipv6_prefix_list_ids
(list(string)
) optionalA list of IPv6 Prefix Lists IDs to allow access to the security group created by this module.
The length of this list must be known at "plan" time.Default value:
[ ]
allowed_security_group_ids
(list(string)
) optionalA list of IDs of Security Groups to allow access to the security group created by this module.
The length of this list must be known at "plan" time.Default value:
[ ]
allowed_security_groups
(list(string)
) optionalDEPRECATED: Use
allowed_security_group_ids
instead.Default value:
[ ]
apply_immediately
(bool
) optionalSpecifies whether any database modifications are applied immediately, or during the next maintenance window
Default value:
true
associated_security_group_ids
(list(string)
) optionalA 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, ifcreate_security_group
isfalse
, must have rules providing the desired access.Default value:
[ ]
availability_zone
(string
) optionalThe Availability Zone of the cluster. az_mode must be set to single-az when used.
Default value:
""
availability_zones
(list(string)
) optionalList of Availability Zones for the cluster. az_mode must be set to cross-az when used.
Default value:
[ ]
az_mode
(string
) optionalEnable or disable multiple AZs, eg: single-az or cross-az
Default value:
"single-az"
cloudwatch_metric_alarms_enabled
(bool
) optionalBoolean flag to enable/disable CloudWatch metrics alarms
Default value:
false
cluster_size
(number
) optionalCluster size
Default value:
1
create_security_group
(bool
) optionalSet
true
to create and configure a new security group. If false,associated_security_group_ids
must be provided.Default value:
true
dns_subdomain
(string
) optionalThe subdomain to use for the CNAME record. If not provided then the CNAME record will use var.name.
Default value:
""
elasticache_parameter_group_family
(string
) optionalElastiCache parameter group family
Default value:
"memcached1.5"
elasticache_subnet_group_name
(string
) optionalSubnet group name for the ElastiCache instance
Default value:
""
engine_version
(string
) optionalMemcached engine version. For more info, see https://docs.aws.amazon.com/AmazonElastiCache/latest/mem-ug/supported-engine-versions.html
Default value:
"1.5.16"
existing_security_groups
(list(string)
) optionalDEPRECATED: Use
associated_security_group_ids
instead.
Historical description: List of existing Security Group IDs to place the cluster into.
Setuse_existing_security_groups
totrue
to enable usingexisting_security_groups
as Security Groups for the cluster.Default value:
[ ]
instance_type
(string
) optionalElastic cache instance type
Default value:
"cache.t2.micro"
maintenance_window
(string
) optionalMaintenance window
Default value:
"wed:03:00-wed:04:00"
max_item_size
(number
) optionalMax item size
Default value:
10485760
network_type
(string
) optionalThe network type of the cluster. Valid values: ipv4, ipv6, dual_stack.
Default value:
"ipv4"
notification_topic_arn
(string
) optionalNotification topic arn
Default value:
""
port
(number
) optionalMemcached port
Default value:
11211
security_group_create_before_destroy
(bool
) optionalSet
true
to enable Terraformcreate_before_destroy
behavior on the created security group.
We only recommend setting thisfalse
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.Default value:
true
security_group_create_timeout
(string
) optionalHow long to wait for the security group to be created.
Default value:
"10m"
security_group_delete_timeout
(string
) optionalHow long to retry on
DependencyViolation
errors during security group deletion.Default value:
"15m"
security_group_description
(string
) optionalThe description to assign to the created Security Group.
Warning: Changing the description causes the security group to be replaced.Default value:
"Security group for Elasticache Memcached"
security_group_name
(list(string)
) optionalThe name to assign to the created security group. Must be unique within the VPC.
If not provided, will be derived from thenull-label.context
passed in.
Ifcreate_before_destroy
is true, will be used as a name prefix.Default value:
[ ]
subnets
(list(string)
) optionalAWS subnet ids
Default value:
[ ]
transit_encryption_enabled
(bool
) optionalBoolean flag to enable transit encryption (requires Memcached version 1.6.12+)
Default value:
false
use_existing_security_groups
(bool
) optionalDEPRECATED: Use
create_security_group
instead.
Historical description: Flag to enable/disable creation of Security Group in the module.
Set totrue
to disable Security Group creation and provide a list of existing security Group IDs inexisting_security_groups
to place the cluster into.
Historical default:false
Default value:
null
vpc_id
(string
) optionalVPC ID
Default value:
""
zone_id
(string
) optionalRoute53 DNS Zone ID
Default value:
""
Context Variables
The following variables are defined in the context.tf
file of this module and part of the terraform-null-label pattern.
context.tf
file of this module and part of the terraform-null-label pattern.additional_tag_map
(map(string)
) optionalAdditional key-value pairs to add to each map in
tags_as_list_of_maps
. Not added totags
orid
.
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.Required: No
Default value:
{ }
attributes
(list(string)
) optionalID element. Additional attributes (e.g.
workers
orcluster
) to add toid
,
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 thedelimiter
and treated as a single ID element.Required: No
Default value:
[ ]
context
(any
) optionalSingle object for setting entire context at once.
See description of individual variables for details.
Leave string and numeric variables asnull
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.Required: No
Default value:
{
"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
}delimiter
(string
) optionalDelimiter to be used between ID elements.
Defaults to-
(hyphen). Set to""
to use no delimiter at all.Required: No
Default value:
null
descriptor_formats
(any
) optionalDescribe 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 isany
so the map values can later be enhanced to provide additional options.)
format
is a Terraform format string to be passed to theformat()
function.
labels
is a list of labels, in order, to pass toformat()
function.
Label values will be normalized before being passed toformat()
so they will be
identical to how they appear inid
.
Default is{}
(descriptors
output will be empty).Required: No
Default value:
{ }
enabled
(bool
) optionalSet to false to prevent the module from creating any resources
Required: NoDefault value:
null
environment
(string
) optionalID element. Usually used for region e.g. 'uw2', 'us-west-2', OR role 'prod', 'staging', 'dev', 'UAT'
Required: NoDefault value:
null
id_length_limit
(number
) optionalLimit
id
to this many characters (minimum 6).
Set to0
for unlimited length.
Set tonull
for keep the existing setting, which defaults to0
.
Does not affectid_full
.Required: No
Default value:
null
label_key_case
(string
) optionalControls the letter case of the
tags
keys (label names) for tags generated by this module.
Does not affect keys of tags passed in via thetags
input.
Possible values:lower
,title
,upper
.
Default value:title
.Required: No
Default value:
null
label_order
(list(string)
) optionalThe 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.Required: No
Default value:
null
label_value_case
(string
) optionalControls 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 thetags
input.
Possible values:lower
,title
,upper
andnone
(no transformation).
Set this totitle
and setdelimiter
to""
to yield Pascal Case IDs.
Default value:lower
.Required: No
Default value:
null
labels_as_tags
(set(string)
) optionalSet 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 thetags
output.
Set to[]
to suppress all generated tags.
Notes:
The value of thename
tag, if included, will be theid
, not thename
.
Unlike othernull-label
inputs, the initial setting oflabels_as_tags
cannot be
changed in later chained modules. Attempts to change it will be silently ignored.Required: No
Default value:
[
"default"
]name
(string
) optionalID element. Usually the component or solution name, e.g. 'app' or 'jenkins'.
This is the only ID element not also included as atag
.
The "name" tag is set to the fullid
string. There is no tag with the value of thename
input.Required: No
Default value:
null
namespace
(string
) optionalID element. Usually an abbreviation of your organization name, e.g. 'eg' or 'cp', to help ensure generated IDs are globally unique
Required: NoDefault value:
null
regex_replace_chars
(string
) optionalTerraform 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.Required: No
Default value:
null
stage
(string
) optionalID element. Usually used to indicate role, e.g. 'prod', 'staging', 'source', 'build', 'test', 'deploy', 'release'
Required: NoDefault value:
null
tags
(map(string)
) optionalAdditional tags (e.g.
{'BusinessUnit': 'XYZ'}
).
Neither the tag keys nor the tag values will be modified by this module.Required: No
Default value:
{ }
tenant
(string
) optionalID element (Rarely used, not included by default). A customer identifier, indicating who this instance of a resource is for
Required: NoDefault value:
null
Outputs
cluster_address
Cluster address
cluster_configuration_endpoint
Cluster configuration endpoint
cluster_id
Cluster ID
cluster_urls
Cluster URLs
hostname
Cluster hostname
security_group_arn
The ARN of the created security group
security_group_id
The ID of the created security group
security_group_name
The name of the created security group
Dependencies
Requirements
terraform
, version:>= 1.0.0
aws
, version:>= 5.16
null
, version:>= 3.0
Providers
aws
, version:>= 5.16
null
, version:>= 3.0
Modules
Name | Version | Source | Description |
---|---|---|---|
aws_security_group | 2.2.0 | cloudposse/security-group/aws | n/a |
dns | 0.13.0 | cloudposse/route53-cluster-hostname/aws | n/a |
this | 0.25.0 | cloudposse/label/null | n/a |
Resources
The following resources are used by this module:
aws_cloudwatch_metric_alarm.cache_cpu
(resource)aws_cloudwatch_metric_alarm.cache_memory
(resource)aws_elasticache_cluster.default
(resource)aws_elasticache_parameter_group.default
(resource)aws_elasticache_subnet_group.default
(resource)null_resource.cluster_urls
(resource)
Data Sources
The following data sources are used by this module: