Terraform module which creates AWS SNS endpoint to post to Slack

Input variables

Variable	Type	Default	Description
name	string		name of lambda and SNS topic (suffix will be added to waranty uniqness)
webhook_path	string		web_hook path where to post messages
account_number	string		account on which you run. Needed for policy creation
notify_channel	string		Slack channel in which all notifications will be posted
error_channel	string	""	Slack channel in which only error notifications will be posted
username	string	"AWS Bot"	user name under which messeges will be posted
icon_emoji	string	":aws:"	user icon from emoji list to show

Output variables

Outputs	Type	Description
sns_arn	string	ARN of SNS topic to post messages
lambda_arn	string	ARN of lambda that will implement Slack posts
lambda_version	string	Version of lambda. Just for help purposes
lambda_publich_status	string	Public status of lambda. Just for help purposes

Notification levels

Now 3 levels are supported: OK, WARN, ERROR. In OK - message is quoted with green line, in WARN - with orange, in ERROR - with red.

In ERROR state if error_channel is provided - message duplicates to it

Current logic is:

• by default message status is OK
• if subject or text contains WARN (case insensitive) text - status WARN
• if subject or text contains ERROR (case insensitive) text - status ERROR

Usage

Implement in your environment

• copy/paste this code into some.tf file and fill the x's with real numbers

module "someSlackNotify" {
  source = "./../SNStoSlack"
  name = "someSlackNotify"
  webhook_path = "/services/xxxxxx/xxxxxxxxx/xxxxxxxxxxxxxxxxxxxxxxxx"
  account_number = "XXXXXXXXXXXX"
  notify_channel = "#notify_channel"
  error_channel = "#error_channel"
}

• run terraform init
• run terraform apply
• remember, save or pass further via terraform_remote_state sns_arn output to post on it

Posting

Via preconfigured AWS services

There a lot of AWS services that need only arn of SNS topic for posting - find this field and pase sns_arn into it

Via Python SDK boto3 example

import boto3
import json

client = boto3.client('sns')
response = client.publish(
    TargetArn = os.environ['SNS_ARN'],
    Subject = "Message header",
    Message = json.dumps({'default': "message text"}),
    MessageStructure = 'json'