AWS Notify Slack Terraform module

This module creates an SNS topic (or uses an existing one) and an AWS Lambda function that sends notifications to Slack using the incoming webhooks API.

Start by setting up an incoming webhook integration in your Slack workspace.

Doing serverless with Terraform? Check out serverless.tf framework, which aims to simplify all operations when working with the serverless in Terraform.

Supported Features

• AWS Lambda runtime Python 3.8
• Create new SNS topic or use existing one
• Support plaintext and encrypted version of Slack webhook URL
• Most of Slack message options are customizable
• Support different types of SNS messages:
  • AWS CloudWatch Alarms
  • AWS CloudWatch LogMetrics Alarms
  • AWS GuardDuty Findings
• Local pytest driven testing of the lambda to a Slack sandbox channel

Feature Roadmap

• More SNS message types: Send pull-request to add support of other message types

Usage

module "notify_slack" {
  source  = "terraform-aws-modules/notify-slack/aws"
  version = "~> 4.0"

  sns_topic_name = "slack-topic"

  slack_webhook_url = "https://hooks.slack.com/services/AAA/BBB/CCC"
  slack_channel     = "aws-notification"
  slack_username    = "reporter"
}

Upgrade from 2.0 to 3.0

Version 3 uses Terraform AWS Lambda module to handle most of heavy-lifting related to Lambda packaging, roles, and permissions, while maintaining the same interface for the user of this module after many of resources will be recreated.

Using with Terraform Cloud Agents

Terraform Cloud Agents are a paid feature, available as part of the Terraform Cloud for Business upgrade package.

This module requires Python 3.8. You can customize tfc-agent to include Python using this sample Dockerfile:

FROM hashicorp/tfc-agent:latest
RUN apt-get -y update && apt-get -y install python3.8 python3-pip
ENTRYPOINT ["/bin/tfc-agent"]

Use existing SNS topic or create new

If you want to subscribe the AWS Lambda Function created by this module to an existing SNS topic you should specify create_sns_topic = false as an argument and specify the name of existing SNS topic name in sns_topic_name.

Examples

• notify-slack-simple - Creates SNS topic which sends messages to Slack channel.
• cloudwatch-alerts-to-slack - End to end example which shows how to send AWS Cloudwatch alerts to Slack channel and use KMS to encrypt webhook URL.

Testing with pytest

To run the tests:

1. Set up a dedicated slack channel as a test sandbox with it's own webhook. See Slack Incoming Webhooks docs for details.

2. Make a copy of the sample pytest configuration and edit as needed.

   cp functions/pytest.ini.sample functions/pytest.ini
   

3. Run the tests:

   pytest functions/notify_slack_test.py
   

Requirements

Name	Version
terraform	>= 0.13.0
aws	>= 2.35

Providers

Name	Version
aws	>= 2.35

Modules

Name	Source	Version
lambda	terraform-aws-modules/lambda/aws	1.47.0

Resources

Name	Type
aws_cloudwatch_log_group.lambda	resource
aws_sns_topic.this	resource
aws_sns_topic_subscription.sns_notify_slack	resource
aws_caller_identity.current	data source
aws_iam_policy_document.lambda	data source
aws_partition.current	data source
aws_region.current	data source

Inputs

Name	Description	Type	Default	Required
cloudwatch_log_group_kms_key_id	The ARN of the KMS Key to use when encrypting log data for Lambda	string	null	no
cloudwatch_log_group_retention_in_days	Specifies the number of days you want to retain log events in log group for Lambda.	number	0	no
cloudwatch_log_group_tags	Additional tags for the Cloudwatch log group	map(string)	{}	no
create	Whether to create all resources	bool	true	no
create_sns_topic	Whether to create new SNS topic	bool	true	no
iam_role_boundary_policy_arn	The ARN of the policy that is used to set the permissions boundary for the role	string	null	no
iam_role_name_prefix	A unique role name beginning with the specified prefix	string	"lambda"	no
iam_role_tags	Additional tags for the IAM role	map(string)	{}	no
kms_key_arn	ARN of the KMS key used for decrypting slack webhook url	string	""	no
lambda_description	The description of the Lambda function	string	null	no
lambda_function_name	The name of the Lambda function to create	string	"notify_slack"	no
lambda_function_s3_bucket	S3 bucket to store artifacts	string	null	no
lambda_function_store_on_s3	Whether to store produced artifacts on S3 or locally.	bool	false	no
lambda_function_tags	Additional tags for the Lambda function	map(string)	{}	no
lambda_function_vpc_security_group_ids	List of security group ids when Lambda Function should run in the VPC.	list(string)	null	no
lambda_function_vpc_subnet_ids	List of subnet ids when Lambda Function should run in the VPC. Usually private or intra subnets.	list(string)	null	no
lambda_role	IAM role attached to the Lambda Function. If this is set then a role will not be created for you.	string	""	no
log_events	Boolean flag to enabled/disable logging of incoming events	bool	false	no
reserved_concurrent_executions	The amount of reserved concurrent executions for this lambda function. A value of 0 disables lambda from being triggered and -1 removes any concurrency limitations	number	-1	no
slack_channel	The name of the channel in Slack for notifications	string	n/a	yes
slack_emoji	A custom emoji that will appear on Slack messages	string	":aws:"	no
slack_username	The username that will appear on Slack messages	string	n/a	yes
slack_webhook_url	The URL of Slack webhook	string	n/a	yes
sns_topic_kms_key_id	ARN of the KMS key used for enabling SSE on the topic	string	""	no
sns_topic_name	The name of the SNS topic to create	string	n/a	yes
sns_topic_tags	Additional tags for the SNS topic	map(string)	{}	no
subscription_filter_policy	(Optional) A valid filter policy that will be used in the subscription to filter messages seen by the target resource.	string	null	no
tags	A map of tags to add to all resources	map(string)	{}	no

Outputs

Name	Description
lambda_cloudwatch_log_group_arn	The Amazon Resource Name (ARN) specifying the log group
lambda_iam_role_arn	The ARN of the IAM role used by Lambda function
lambda_iam_role_name	The name of the IAM role used by Lambda function
notify_slack_lambda_function_arn	The ARN of the Lambda function
notify_slack_lambda_function_invoke_arn	The ARN to be used for invoking Lambda function from API Gateway
notify_slack_lambda_function_last_modified	The date Lambda function was last modified
notify_slack_lambda_function_name	The name of the Lambda function
notify_slack_lambda_function_version	Latest published version of your Lambda function
this_slack_topic_arn	The ARN of the SNS topic from which messages will be sent to Slack

Authors

Module is maintained by Anton Babenko with help from these awesome contributors.

License

Apache 2 Licensed. See LICENSE for full details.