chore: adding slack notifications

environments/prod/main.tf

@@ -51,12 +51,14 @@ module "billing_report" {
   # too much work to enable SES on AWS just for this notification
   #ses_sender_email       = "[email protected]"
   #ses_domain             = "kiraum.it"
-  recipient_emails       = ["[email protected]"]
-  notification_service   = "SNS"
-  daily_cost_threshold   = "0.01"
-  weekly_cost_threshold  = "1.00"
-  monthly_cost_threshold = "5.00"
-  yearly_cost_threshold  = "60.00"
+  recipient_emails          = ["[email protected]"]
+  notification_service      = "SNS"
+  enable_slack_notification = true
+  slack_webhook_url         = var.slack_webhook_url
+  daily_cost_threshold      = "0.01"
+  weekly_cost_threshold     = "1.00"
+  monthly_cost_threshold    = "5.00"
+  yearly_cost_threshold     = "60.00"
 }
 
 # Route53 module for DNS management

environments/prod/variables.tf

@@ -21,3 +21,8 @@ variable "cost_center" {
 #  description = "Data classification for tagging"
 #  type        = string
 #}
+
+variable "slack_webhook_url" {
+  description = "Slack webhook URL for notifications"
+  type        = string
+}

modules/billing_report/lambda_function.py

@@ -3,6 +3,7 @@
 import datetime
 import json
 import os
+import urllib.request
 
 import boto3
 from botocore.exceptions import ClientError
@@ -16,6 +17,40 @@
 NOTIFICATION_SERVICE = os.environ.get("NOTIFICATION_SERVICE", "SNS").upper()
 
 
+def get_ssm_parameter(parameter_name):
+    """
+    Retrieve a parameter value from AWS Systems Manager Parameter Store.
+
+    Args:
+        parameter_name (str): The name of the parameter to retrieve.
+
+    Returns:
+        str: The decrypted value of the parameter.
+    """
+    ssm = boto3.client("ssm")
+    response = ssm.get_parameter(Name=parameter_name, WithDecryption=True)
+    return response["Parameter"]["Value"]
+
+
+def send_slack_notification(message):
+    """
+    Send a notification to a Slack channel using a webhook URL stored in SSM.
+
+    Args:
+        message (str): The message to send to the Slack channel.
+    """
+    webhook_url = get_ssm_parameter("/billing_report/slack_webhook_url")
+    payload = json.dumps({"text": message}).encode("utf-8")
+    req = urllib.request.Request(
+        webhook_url, data=payload, headers={"Content-Type": "application/json"}
+    )
+    with urllib.request.urlopen(req) as response:
+        if response.getcode() != 200:
+            print(
+                f"Failed to send Slack notification. Status code: {response.getcode()}"
+            )
+
+
 def calculate_time_periods(time_period, current_date):
     """
     Calculate start and end dates for the given time period.
@@ -426,6 +461,8 @@ def lambda_handler(event, context):
         if current_costs > cost_threshold:
             print("Cost threshold exceeded. Sending notification.")
             send_notification(report, f"AWS Cost Report - {time_period.capitalize()}")
+            if os.environ.get("ENABLE_SLACK") == "true":
+                send_slack_notification(report)
         else:
             print(
                 f"Total cost ({current_costs:.7f} {unit}) did not exceed the threshold ({cost_threshold:.7f} {unit}). No notification sent."

modules/billing_report/lambda_mock_test.py

@@ -6,7 +6,6 @@
 from unittest.mock import MagicMock
 
 import boto3
-
 from lambda_function import lambda_handler
 
 

modules/billing_report/main.tf

@@ -16,6 +16,9 @@ terraform {
 # Get current AWS account information
 data "aws_caller_identity" "current" {}
 
+# Retrieve information about the current AWS region
+data "aws_region" "current" {}
+
 # Define Lambda function for billing report
 resource "aws_lambda_function" "billing_report" {
   filename         = data.archive_file.lambda_zip.output_path
@@ -32,6 +35,7 @@ resource "aws_lambda_function" "billing_report" {
       RECIPIENT_EMAILS       = jsonencode(var.recipient_emails)
       SNS_TOPIC_ARN          = aws_sns_topic.billing_report.arn
       NOTIFICATION_SERVICE   = var.notification_service
+      ENABLE_SLACK           = var.enable_slack_notification
       DAILY_COST_THRESHOLD   = var.daily_cost_threshold
       WEEKLY_COST_THRESHOLD  = var.weekly_cost_threshold
       MONTHLY_COST_THRESHOLD = var.monthly_cost_threshold
@@ -107,6 +111,13 @@ resource "aws_iam_role_policy" "lambda_policy" {
           "sns:Publish"
         ]
         Resource = aws_sns_topic.billing_report.arn
+      },
+      {
+        Effect = "Allow"
+        Action = [
+          "ssm:GetParameter"
+        ]
+        Resource = "arn:aws:ssm:${data.aws_region.current.name}:${data.aws_caller_identity.current.account_id}:parameter/billing_report/slack_webhook_url"
       }
     ]
   })
@@ -279,3 +290,10 @@ resource "aws_sns_topic_subscription" "billing_report_email" {
   protocol  = "email"
   endpoint  = var.recipient_emails[count.index]
 }
+
+# Store Slack webhook URL securely in SSM Parameter Store
+resource "aws_ssm_parameter" "slack_webhook_url" {
+  name  = "/billing_report/slack_webhook_url"
+  type  = "SecureString"
+  value = var.slack_webhook_url
+}

modules/billing_report/requirements.txt

@@ -1,12 +1,12 @@
 # This file was autogenerated by uv via the following command:
 #    uv pip compile pyproject.toml
-astroid==3.3.4
+astroid==3.3.5
     # via pylint
 black==24.8.0
     # via aws-cost-explorer-lambda (pyproject.toml)
-boto3==1.35.32
+boto3==1.35.34
     # via aws-cost-explorer-lambda (pyproject.toml)
-botocore==1.35.32
+botocore==1.35.34
     # via
     #   boto3
     #   s3transfer
@@ -38,7 +38,7 @@ pylint==3.3.1
     # via aws-cost-explorer-lambda (pyproject.toml)
 python-dateutil==2.9.0.post0
     # via botocore
-ruff==0.6.8
+ruff==0.6.9
     # via aws-cost-explorer-lambda (pyproject.toml)
 s3transfer==0.10.2
     # via boto3

modules/billing_report/variables.tf

@@ -47,3 +47,14 @@ variable "yearly_cost_threshold" {
   type        = string
   default     = "0.01"
 }
+
+variable "enable_slack_notification" {
+  description = "Enable Slack webhook notification"
+  type        = bool
+  default     = false
+}
+
+variable "slack_webhook_url" {
+  description = "Slack webhook URL for notifications"
+  type        = string
+}

modules/static_website/content/.well-known/security.txt

@@ -1,4 +1,3 @@
 Contact: mailto:[email protected]
 Expires: 2027-12-31T23:59:59.000Z
 Preferred-Languages: en
-

modules/static_website/content/styles.css

@@ -86,4 +86,3 @@ a:hover {
     height: 35px;
     margin: 0 5px;
 }
-