feat(billing-report): adding support for SNS/SES

environments/prod/main.tf

@@ -42,13 +42,19 @@ provider "aws" {
 module "billing_report" {
   source = "../../modules/billing_report"
 
-  lambda_function_name = "billing-report-lambda"
-  ses_sender_email     = "[email protected]"
-  ses_recipient_email  = "[email protected]"
-  ses_domain           = "kiraum.it"
+  lambda_function_name   = "billing-report-lambda"
+  ses_sender_email       = "[email protected]"
+  ses_domain             = "kiraum.it"
+  recipient_email        = "[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"
 }
 
 
+
 module "route53" {
   source = "../../modules/route53"
 

modules/billing_report/lambda_function.py

@@ -12,6 +12,8 @@
 MONTHLY_COST_THRESHOLD = float(os.environ.get("MONTHLY_COST_THRESHOLD", "0.01"))
 YEARLY_COST_THRESHOLD = float(os.environ.get("YEARLY_COST_THRESHOLD", "0.01"))
 
+NOTIFICATION_SERVICE = os.environ.get("NOTIFICATION_SERVICE", "SNS").upper()
+
 
 def calculate_time_periods(time_period, current_date):
     """
@@ -85,6 +87,80 @@ def process_cost_data(response, compare_response):
     return current_costs, compare_costs, unit
 
 
+def generate_text_report(
+    time_period,
+    start,
+    end,
+    current_costs,
+    compare_costs,
+    unit,
+    response,
+    compare_response,
+    cost_threshold,
+):
+    """
+    Generate a detailed text cost report.
+    Args:
+        time_period (str): The time period of the report.
+        start (datetime.date): The start date of the report.
+        end (datetime.date): The end date of the report.
+        current_costs (float): The total costs for the current period.
+        compare_costs (float): The total costs for the comparison period.
+        unit (str): The currency unit.
+        response (dict): The response from AWS Cost Explorer for the current period.
+        compare_response (dict): The response from AWS Cost Explorer for the comparison period.
+        cost_threshold (float): The cost threshold for the time period.
+    Returns:
+        str: A formatted text cost report.
+    """
+    text_template = """
+AWS Cost Report for {time_period}
+
+Period: {start_date} to {end_date}
+
+Summary:
+Current {time_period} cost: {current_costs:.7f} {unit}
+Previous {time_period} cost: {compare_costs:.7f} {unit}
+Difference: {difference:.7f} {unit}
+Threshold: {threshold:.7f} {unit}
+
+Breakdown by Service:
+{service_breakdown}
+    """
+
+    current_services = {
+        group["Keys"][0]: float(group["Metrics"]["UnblendedCost"]["Amount"])
+        for result in response["ResultsByTime"]
+        for group in result.get("Groups", [])
+    }
+    previous_services = {
+        group["Keys"][0]: float(group["Metrics"]["UnblendedCost"]["Amount"])
+        for result in compare_response["ResultsByTime"]
+        for group in result.get("Groups", [])
+    }
+    service_breakdown = ""
+    for service, cost in current_services.items():
+        if cost > 0:
+            previous_cost = previous_services.get(service, 0)
+            difference = cost - previous_cost
+            service_breakdown += f"{service}:\n"
+            service_breakdown += f"  Current: {cost:.7f} {unit}\n"
+            service_breakdown += f"  Previous: {previous_cost:.7f} {unit}\n"
+            service_breakdown += f"  Difference: {difference:.7f} {unit}\n\n"
+
+    return text_template.format(
+        time_period=time_period,
+        start_date=start.isoformat(),
+        end_date=(end - datetime.timedelta(days=1)).isoformat(),
+        current_costs=current_costs,
+        compare_costs=compare_costs,
+        unit=unit,
+        difference=current_costs - compare_costs,
+        threshold=cost_threshold,
+        service_breakdown=service_breakdown,
+    )
+
+
 def generate_html_report(
     time_period,
     start,
@@ -160,6 +236,7 @@ def generate_html_report(
     </body>
     </html>
     """
+
     current_services = {
         group["Keys"][0]: float(group["Metrics"]["UnblendedCost"]["Amount"])
         for result in response["ResultsByTime"]
@@ -177,12 +254,13 @@ def generate_html_report(
             difference = cost - previous_cost
             service_rows += f"""
                 <tr>
-                    <td>{service}</td>
-                    <td>{cost:.7f} {unit}</td>
-                    <td>{previous_cost:.7f} {unit}</td>
-                    <td>{difference:.7f} {unit}</td>
+                    <td style="border: 1px solid #ddd; padding: 8px; text-align: left;">{service}</td>
+                    <td style="border: 1px solid #ddd; padding: 8px; text-align: left;">{cost:.7f} {unit}</td>
+                    <td style="border: 1px solid #ddd; padding: 8px; text-align: left;">{previous_cost:.7f} {unit}</td>
+                    <td style="border: 1px solid #ddd; padding: 8px; text-align: left;">{difference:.7f} {unit}</td>
                 </tr>
             """
+
     return html_template.format(
         time_period=time_period,
         start_date=start.isoformat(),
@@ -196,6 +274,26 @@ def generate_html_report(
     )
 
 
+def send_sns(message, subject):
+    """
+    Send a message using AWS SNS.
+    Args:
+        message (str): The message to be sent.
+        subject (str): The subject of the message.
+    """
+    sns = boto3.client("sns")
+    topic_arn = os.environ["SNS_TOPIC_ARN"]
+
+    if not topic_arn:
+        raise ValueError("SNS_TOPIC_ARN must be set in the environment variables")
+
+    try:
+        response = sns.publish(TopicArn=topic_arn, Message=message, Subject=subject)
+        print(f"Message sent to SNS! Message ID: {response['MessageId']}")
+    except ClientError as e:
+        print(f"An error occurred while sending message via SNS: {e}")
+
+
 def send_ses(message, subject):
     """
     Send an HTML message using AWS SES.
@@ -234,12 +332,25 @@ def send_ses(message, subject):
         print(f"An error occurred while sending email via SES: {e}")
 
 
+def send_notification(message, subject):
+    """
+    Send a notification using either SES or SNS.
+    Args:
+        message (str): The message to be sent.
+        subject (str): The subject of the message.
+    """
+    if NOTIFICATION_SERVICE == "SES":
+        send_ses(message, subject)
+    else:  # Default to SNS
+        send_sns(message, subject)
+
+
 def lambda_handler(event, context):
     """
     AWS Lambda function to report AWS costs for various time periods.
     This function retrieves cost data from AWS Cost Explorer for a specified time period,
-    compares it with the previous period, and generates an HTML cost report. If the cost exceeds
-    a predefined threshold, it sends a notification via SES.
+    compares it with the previous period, and generates a cost report. If the cost exceeds
+    a predefined threshold, it sends a notification via SNS or SES.
     Args:
         event (dict): The Lambda event object containing input parameters.
             - time_period (str, optional): The time period for the cost report.
@@ -287,20 +398,33 @@ def lambda_handler(event, context):
             "monthly": MONTHLY_COST_THRESHOLD,
             "yearly": YEARLY_COST_THRESHOLD,
         }.get(time_period, DAILY_COST_THRESHOLD)
-        html_report = generate_html_report(
-            time_period,
-            start,
-            end,
-            current_costs,
-            compare_costs,
-            unit,
-            response,
-            compare_response,
-            cost_threshold,
-        )
+        if NOTIFICATION_SERVICE == "SES":
+            report = generate_html_report(
+                time_period,
+                start,
+                end,
+                current_costs,
+                compare_costs,
+                unit,
+                response,
+                compare_response,
+                cost_threshold,
+            )
+        else:
+            report = generate_text_report(
+                time_period,
+                start,
+                end,
+                current_costs,
+                compare_costs,
+                unit,
+                response,
+                compare_response,
+                cost_threshold,
+            )
         if current_costs > cost_threshold:
             print("Cost threshold exceeded. Sending notification.")
-            send_ses(html_report, f"AWS Cost Report - {time_period.capitalize()}")
+            send_notification(report, f"AWS Cost Report - {time_period.capitalize()}")
         else:
             print(
                 f"Total cost ({current_costs:.7f} {unit}) did not exceed the threshold ({cost_threshold:.7f} {unit}). No notification sent."

modules/billing_report/main.tf

@@ -1,5 +1,6 @@
 terraform {
   required_version = ">= 1.0.0"
+
   required_providers {
     aws = {
       source  = "hashicorp/aws"
@@ -27,8 +28,14 @@ resource "aws_lambda_function" "billing_report" {
 
   environment {
     variables = {
-      SES_SENDER_EMAIL    = var.ses_sender_email
-      SES_RECIPIENT_EMAIL = var.ses_recipient_email
+      SES_SENDER_EMAIL       = var.ses_sender_email
+      recipient_email        = var.recipient_email
+      SNS_TOPIC_ARN          = aws_sns_topic.billing_report.arn
+      NOTIFICATION_SERVICE   = var.notification_service
+      DAILY_COST_THRESHOLD   = var.daily_cost_threshold
+      WEEKLY_COST_THRESHOLD  = var.weekly_cost_threshold
+      MONTHLY_COST_THRESHOLD = var.monthly_cost_threshold
+      YEARLY_COST_THRESHOLD  = var.yearly_cost_threshold
     }
   }
 
@@ -93,11 +100,23 @@ resource "aws_iam_role_policy" "lambda_policy" {
           "ses:SendRawEmail"
         ]
         Resource = "*"
+      },
+      {
+        Effect = "Allow"
+        Action = [
+          "sns:Publish"
+        ]
+        Resource = aws_sns_topic.billing_report.arn
       }
     ]
   })
 }
 
+# Create SNS topic for billing report
+resource "aws_sns_topic" "billing_report" {
+  name = "billing-report-topic"
+}
+
 # Create CloudWatch event rules
 resource "aws_cloudwatch_event_rule" "daily_trigger" {
   name                = "billing-report-daily-schedule"
@@ -243,3 +262,9 @@ resource "aws_ses_domain_mail_from" "ses_domain_mail_from" {
   domain           = aws_ses_domain_identity.ses_domain.domain
   mail_from_domain = "mail.${aws_ses_domain_identity.ses_domain.domain}"
 }
+
+resource "aws_sns_topic_subscription" "billing_report_email" {
+  topic_arn = aws_sns_topic.billing_report.arn
+  protocol  = "email"
+  endpoint  = var.recipient_email
+}

modules/billing_report/outputs.tf

@@ -33,7 +33,7 @@ output "ses_sender_email" {
   value       = var.ses_sender_email
 }
 
-output "ses_recipient_email" {
-  description = "The email address receiving SES emails"
-  value       = var.ses_recipient_email
+output "recipient_email" {
+  description = "The email address receiving emails"
+  value       = var.recipient_email
 }

modules/billing_report/variables.tf

@@ -8,12 +8,42 @@ variable "ses_sender_email" {
   type        = string
 }
 
-variable "ses_recipient_email" {
-  description = "Email address to receive SES emails"
+variable "recipient_email" {
+  description = "Email address to receive emails"
   type        = string
 }
 
 variable "ses_domain" {
   description = "Domain for SES"
   type        = string
-}
+}
+
+variable "notification_service" {
+  description = "The notification service to use (SNS or SES)"
+  type        = string
+  default     = "SNS"
+}
+
+variable "daily_cost_threshold" {
+  description = "The daily cost threshold for billing alerts"
+  type        = string
+  default     = "0.01"
+}
+
+variable "weekly_cost_threshold" {
+  description = "The weekly cost threshold for billing alerts"
+  type        = string
+  default     = "0.01"
+}
+
+variable "monthly_cost_threshold" {
+  description = "The monthly cost threshold for billing alerts"
+  type        = string
+  default     = "0.01"
+}
+
+variable "yearly_cost_threshold" {
+  description = "The yearly cost threshold for billing alerts"
+  type        = string
+  default     = "0.01"
+}