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Module: sns-topic

Terraform module to provision SNS topic

Introduction​

This module provides:

  • SNS topic creation
  • SNS topic policy
  • SNS topic subscriptions

It's possible to subscribe SQS as Dead Letter Queue.

Usage​

Amazon Simple Notification Service (Amazon SNS) is a web service that coordinates and manages the delivery or sending of messages to subscribing endpoints or clients. SNS documentation

There are many ways SNS can be used. As an example we can imagine CloudWatch sending alerts to SNS, by using subscribers such notifications can be sent further to PagerDuty, OpsGenie or any other oncall management tool.

Examples​

module "sns" {
  source = "cloudposse/sns-topic/aws"
  # Cloud Posse recommends pinning every module to a specific version
  # version     = "x.x.x"

  attributes = var.attributes
  name       = var.name
  namespace  = var.namespace
  stage      = var.stage

  subscribers = {
    opsgenie = {
      protocol = "https"
      endpoint = "https://api.example.com/v1/"
      endpoint_auto_confirms = true
    }
  }

  sqs_dlq_enabled = false
}

Variables​

Required Variables​

Optional Variables​

allowed_aws_services_for_sns_published (list(string)) optional

AWS services that will have permission to publish to SNS topic. Used when no external JSON policy is used


Default value: [ ]

allowed_iam_arns_for_sns_publish (list(string)) optional

IAM role/user ARNs that will have permission to publish to SNS topic. Used when no external json policy is used.


Default value: [ ]

content_based_deduplication (bool) optional

Enable content-based deduplication for FIFO topics


Default value: false

delivery_policy (string) optional

The SNS delivery policy as JSON.


Default value: null

delivery_status optional

Enable Message delivery status for the various SNS subscription endpoints.
The success_role_arn and failure_role_arn arguments are used to give Amazon SNS write
access to use CloudWatch Logs on your behalf.
The success_sample_rate argument is for specifying the sample rate percentage (0-100) of
successfully delivered messages.



Type:

object({
application = optional(object({
  success_role_arn    = string
  failure_role_arn    = string
  success_sample_rate = number
}))
firehose = optional(object({
  success_role_arn    = string
  failure_role_arn    = string
  success_sample_rate = number
}))
http = optional(object({
  success_role_arn    = string
  failure_role_arn    = string
  success_sample_rate = number
}))
lambda = optional(object({
  success_role_arn    = string
  failure_role_arn    = string
  success_sample_rate = number
}))
sqs = optional(object({
  success_role_arn    = string
  failure_role_arn    = string
  success_sample_rate = number
}))
})

Default value: { }

encryption_enabled (bool) optional

Whether or not to use encryption for SNS Topic. If set to true and no custom value for KMS key (kms_master_key_id) is provided, it uses the default alias/aws/sns KMS key.


Default value: true

fifo_queue_enabled (bool) optional

Whether or not to create a FIFO (first-in-first-out) queue


Default value: false

fifo_topic (bool) optional

Whether or not to create a FIFO (first-in-first-out) topic


Default value: false

kms_master_key_id (string) optional

The ID of an AWS-managed customer master key (CMK) for Amazon SNS or a custom CMK.


Default value: "alias/aws/sns"

redrive_policy (string) optional

The SNS redrive policy as JSON. This overrides the deadLetterTargetArn (supplied by var.fifo_queue = true) passed in by the module.


Default value: null

sns_topic_policy_json (string) optional

The fully-formed AWS policy as JSON


Default value: ""

sqs_dlq_enabled (bool) optional

Enable delivery of failed notifications to SQS and monitor messages in queue.


Default value: false

sqs_dlq_max_message_size (number) optional

The limit of how many bytes a message can contain before Amazon SQS rejects it. An integer from 1024 bytes (1 KiB) up to 262144 bytes (256 KiB). The default for this attribute is 262144 (256 KiB).


Default value: 262144

sqs_dlq_message_retention_seconds (number) optional

The number of seconds Amazon SQS retains a message. Integer representing seconds, from 60 (1 minute) to 1209600 (14 days).


Default value: 1209600

sqs_queue_kms_data_key_reuse_period_seconds (number) optional

The length of time, in seconds, for which Amazon SQS can reuse a data key to encrypt or decrypt messages before calling AWS KMS again


Default value: 300

sqs_queue_kms_master_key_id (string) optional

The ID of an AWS-managed customer master key (CMK) for Amazon SQS Queue or a custom CMK


Default value: "alias/aws/sqs"

subscribers optional

Required configuration for subscibres to SNS topic.


Type:

map(object({
protocol = string
# The protocol to use. The possible values for this are: sqs, sms, lambda, application. (http or https are partially supported, see below) (email is an option but is unsupported, see below).
endpoint = string
# The endpoint to send data to, the contents will vary with the protocol. (see below for more information)
endpoint_auto_confirms = optional(bool, false)
# Boolean indicating whether the end point is capable of auto confirming subscription e.g., PagerDuty (default is false)
filter_policy = optional(string, null)
# The filter policy JSON that is assigned to the subscription. For more information, see Amazon SNS Filter Policies.
filter_policy_scope = optional(string, null)
# The filter policy scope that is assigned to the subscription. Whether the `filter_policy` applies to `MessageAttributes` or `MessageBody`. Default is null.
raw_message_delivery = optional(bool, false)
# Boolean indicating whether or not to enable raw message delivery (the original message is directly passed, not wrapped in JSON with the original message in the message property) (default is false)
}))

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.

additional_tag_map (map(string)) optional

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.


Required: No

Default value: { }

attributes (list(string)) optional

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.


Required: No

Default value: [ ]

context (any) optional

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.


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) optional

Delimiter 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) optional

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).


Required: No

Default value: { }

enabled (bool) optional

Set to false to prevent the module from creating any resources
Required: No

Default value: null

environment (string) optional

ID element. Usually used for region e.g. 'uw2', 'us-west-2', OR role 'prod', 'staging', 'dev', 'UAT'
Required: No

Default value: null

id_length_limit (number) optional

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.


Required: No

Default value: null

label_key_case (string) optional

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.


Required: No

Default value: null

label_order (list(string)) optional

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.


Required: No

Default value: null

label_value_case (string) optional

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.


Required: No

Default value: null

labels_as_tags (set(string)) optional

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.


Required: No

Default value:

[
  "default"
]
name (string) optional

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.


Required: No

Default value: null

namespace (string) optional

ID element. Usually an abbreviation of your organization name, e.g. 'eg' or 'cp', to help ensure generated IDs are globally unique
Required: No

Default value: null

regex_replace_chars (string) optional

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.


Required: No

Default value: null

stage (string) optional

ID element. Usually used to indicate role, e.g. 'prod', 'staging', 'source', 'build', 'test', 'deploy', 'release'
Required: No

Default value: null

tags (map(string)) optional

Additional 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) optional

ID element (Rarely used, not included by default). A customer identifier, indicating who this instance of a resource is for
Required: No

Default value: null

Outputs​

aws_sns_topic_subscriptions

SNS topic subscription.

dead_letter_queue_arn

The ARN of the dead letter queue.

dead_letter_queue_id

The ID for the created dead letter queue. Same as the URL.

dead_letter_queue_name

The name for the created dead letter queue.

dead_letter_queue_url

The URL for the created dead letter SQS queue.

sns_topic

SNS topic.

sns_topic_arn

SNS topic ARN.

sns_topic_id

SNS topic ID.

sns_topic_name

SNS topic name.

sns_topic_owner

SNS topic owner.

Dependencies​

Requirements​

  • terraform, version: >= 1.3.0
  • aws, version: >= 3.0

Providers​

  • aws, version: >= 3.0

Modules​

NameVersionSourceDescription
this0.25.0cloudposse/label/nulln/a

Resources​

The following resources are used by this module:

Data Sources​

The following data sources are used by this module: