Module: cloudwatch-events

This is terraform-aws-cloudwatch-events module that creates CloudWatch Events rules and according targets.

Amazon CloudWatch Events delivers a near real-time stream of system events that describe changes in Amazon Web Services (AWS) resources. Using simple rules that you can quickly set up, you can match events and route them to one or more target functions or streams. CloudWatch Events becomes aware of operational changes as they occur. CloudWatch Events responds to these operational changes and takes corrective action as necessary, by sending messages to respond to the environment, activating functions, making changes, and capturing state information.

Usage

Here's how to invoke this example module in your projects

module "cloudwatch_event" {
  source = "cloudposse/cloudwatch-events/aws"
  version = "0.7.0"

  name          = var.name
  namespace     = var.namespace
  tenant        = var.tenant
  environment   = var.environment
  stage         = var.stage

  cloudwatch_event_rule_description = var.cloudwatch_event_rule_description
  cloudwatch_event_rule_pattern = var.cloudwatch_event_rule_pattern_json
  cloudwatch_event_target_arn = module.sns.sns_topic.arn
}

Variables

Required Variables

cloudwatch_event_rule_pattern (any) required

Event pattern described a HCL map which will be encoded as JSON with jsonencode function. See full documentation of CloudWatch Events and Event Patterns for details. http://docs.aws.amazon.com/AmazonCloudWatch/latest/DeveloperGuide/CloudWatchEventsandEventPatterns.html

cloudwatch_event_target_arn (string) required

The Amazon Resource Name (ARN) associated of the target.

Optional Variables

cloudwatch_event_rule_description (string) optional

The description of the rule.

Default value: ""

cloudwatch_event_rule_is_enabled (bool) optional

DEPRECATED (use cloudwatch_event_rule_state instead): Whether the rule should be enabled. Conflicts with cloudwatch_event_rule_is_enabled

Default value: null

cloudwatch_event_rule_state (string) optional

State of the rule. Valid values are DISABLED, ENABLED, and ENABLED_WITH_ALL_CLOUDTRAIL_MANAGEMENT_EVENTS.
When state is ENABLED, the rule is enabled for all events except those delivered by CloudTrail.
To also enable the rule for events delivered by CloudTrail, set state to ENABLED_WITH_ALL_CLOUDTRAIL_MANAGEMENT_EVENTS.

Default value: "ENABLED"

cloudwatch_event_target_id (string) optional

The unique target assignment ID. If missing, will generate a random, unique id.

Default value: null

cloudwatch_event_target_role_arn (string) optional

IAM role to be used for this target when the rule is triggered.

Default value: null

dead_letter_queue_enabled (bool) optional

Enable a Dead Letter Queue (SQS) for failed event deliveries. Useful for troubleshooting delivery issues.

Default value: false

dead_letter_queue_message_retention_seconds (number) optional

Number of seconds to retain messages in the Dead Letter Queue.

Default value: 1209600

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_cloudwatch_event_rule_arn

The Amazon Resource Name (ARN) of the rule.

aws_cloudwatch_event_rule_id

The name of the rule

dead_letter_queue_arn

The ARN of the Dead Letter Queue.

dead_letter_queue_url

The URL of the Dead Letter Queue.

Dependencies

Requirements

• terraform, version: >= 0.13.0
• aws, version: >= 3.29

Providers

• aws, version: >= 3.29

Modules

Name	Version	Source	Description
dlq_label	0.25.0	cloudposse/label/null	Dead Letter Queue for failed event deliveries When EventBridge fails to deliver an event to a target, the event is normally dropped. Enabling a DLQ captures failed events for troubleshooting delivery issues (e.g., permission errors).
rule_label	0.25.0	cloudposse/label/null	n/a
this	0.25.0	cloudposse/label/null	n/a

Resources

The following resources are used by this module:

• aws_cloudwatch_event_rule.this (resource)
• aws_cloudwatch_event_target.this (resource)
• aws_sqs_queue.dlq (resource)
• aws_sqs_queue_policy.dlq (resource)

Data Sources

The following data sources are used by this module:

• aws_iam_policy_document.dlq_policy (data source)