README.md

terraform-aws-sns-to-cloudwatch-logs-lambda

terraform-aws-sns-to-cloudwatch-logs-lambda is a Terraform module to provision a Lambda Function which routes SNS messages to CloudWatch Logs

• Terraform versions >= 0.12, use module version >= "3.0.1" (See exception)
• Terraform versions <= 0.11, use module version = "1.0.1"

Exception: if using var.aws_region to specify deployment region, use version = "2.0.1", until you can switch to provider aliases and explicit provider passing.

Terraform Module Features

This Module allows simple and rapid deployment

• Creates Lambda function, Lambda Layer, IAM Policies, Triggers, and Subscriptions
• Creates (or use existing) SNS Topic, CloudWatch Log Group and Log Group Stream
• Options:
  • Create CloudWatch Event to prevent Function hibernation
  • Set Log Group retention period
• Python function editable in repository and in Lambda UI
  • Python dependencies packages in Lambda Layers zip
• Optionally create custom Lambda Layer zip using build-lambda-layer-python
  • Enables adding/changing dependencies
  • Enables compiling for different version of Python
• Breaking Changes in 3.0.0 - required to enable new Terraform 0.13 module arguments for_each, count, and depends_on
  • The module's internal AWS provider block has been removed
  • var.aws_region has been removed and can't be used to set a target region
  • By default, modules inherit the region of the calling module's Provider
  • To specify alternate regions, use provider aliases and expicit provider passing
  • Additional information on module considerations can be found in the docs for Provider Configuration in Modules with 0.13

SNS to CloudWatch Logs Features

This Lambda Function forwards subject & body of SNS messages to CloudWatch Log Group Stream

• Enhances the value of CloudWatch Logs by enabling easy entry creation from any service, function and script that can send SNS notifications
• Enables cloud-init, bootstraps and functions to easily write log entries to a centralized CloudWatch Log
• Simplifies troubleshooting of solutions with decentralized logic
  • scripts and functions spread across instances, Lambda and services
• Easily add instrumentation to scripts: aws sns publish --topic-arn $TOPIC_ARN --message $LOG_ENTRY
  • Use with IAM instance policy requires --region $AWS_REGION parameter

Usage

module "sns_logger" {
  source            = "robertpeteuil/sns-to-cloudwatch-logs-lambda/aws"
  version           = "3.0.1"     # Use with Terraform >= 0.12 (including 0.13)
  # version           = "1.0.1"   # Latest version for Terraform <= 0.11

  sns_topic_name    = "projectx-logging"
  log_group_name    = "projectx"
  log_stream_name   = "script-logs"
}

NOTE: Make sure you are using version pinning to avoid unexpected changes when the module is updated.

Required Inputs

Name	Description	Type	Default	Required
sns_topic_name	Name of SNS Topic to be logged by Gateway	string	-	yes
log_group_name	Name of CloudWatch Log Group	string	-	yes
log_stream_name	Name of CloudWatch Log Stream	string	-	yes

Optional Inputs

Name	Description	Type	Default	Required
create_sns_topic	Create new SNS topic	string	true	no
create_log_group	Create new log group	string	true	no
create_log_stream	Create new log stream	string	true	no
log_group_retention_days	Log Group retention (days)	string	0 (forever)	no
lambda_func_name	Name for Lambda Function	string	dynamically calculated	no
lambda_description	Lambda Function Description	string	Route SNS messages to CloudWatch Logs	no
lambda_tags	Mapping of Tags to assign to Lambda function	map	{}	no
lambda_publish_func	Publish Lambda Function	string	false	no
lambda_runtime	Lambda runtime for Function	string	python3.6	no
lambda_timeout	Function time-out (seconds)	string	3	no
lambda_mem_size	Function RAM assigned (MB)	string	128	no
create_warmer_event	Create CloudWatch trigger event to prevent hibernation	string	false	no