AWS Cost Savings with Cost Explorer API

Introduction

An essential component of any AWS-based system is cloud cost management. Cost Explorer, a robust tool from AWS, aids in the visualization, analysis, and optimization of cloud expenses. Although the AWS Cost Explorer console is helpful, automation and more in-depth research are made possible by the Cost Explorer API, which provides programmatic access to AWS cost and consumption statistics.

API Operations

The AWS Cost Explorer API provides several operations:

GetCostAndUsage: Retrieves cost and usage data.
GetCostForecast: Forecasts future costs.
GetReservationUtilization: Analyzes AWS Reserved Instances utilization.
GetRightsizingRecommendation: Suggests instance right-sizing recommendations.

API Request Structure

Each request requires the following:

Time period (start and end date in YYYY-MM-DD format)
Granularity (DAILY, MONTHLY, HOURLY for some services)
Metrics (BlendedCost, UnblendedCost, UsageQuantity)
GroupBy (Optional: Service, Linked Account, Region, etc.)

IAM Role Template

AWSTemplateFormatVersion: "2010-09-09"
Description: "Template To Create IAM Role For CostTracker Project"

Parameters:
  RoleName:
    Type: String
    Description: IAM Role Name
    Default: "CostExplorer-Lambda-Role"


Resources:
  LambdaRole:
    Type: AWS::IAM::Role
    Properties:
      RoleName: !Ref RoleName
      AssumeRolePolicyDocument:
        Version: '2012-10-17'
        Statement:
          - Effect: Allow
            Principal:
              Service: lambda.amazonaws.com
            Action: sts:AssumeRole
      Policies:
        - PolicyName: CostExplorerPolicy
          PolicyDocument:
            Version: '2012-10-17'
            Statement:
              - Effect: Allow
                Action:
                  - ce:GetCostAndUsage
                Resource: "*"
      ManagedPolicyArns:
        - "arn:aws:iam::aws:policy/service-role/AWSLambdaBasicExecutionRole"
        - "arn:aws:iam::aws:policy/service-role/AWSLambdaRole"
        - "arn:aws:iam::aws:policy/service-role/AWSLambdaENIManagementAccess"
        - "arn:aws:iam::aws:policy/AmazonSNSFullAccess"

      Tags:
        - Key: StackName
          Value : !Sub "${AWS::StackName}"
        - Key: Name
          Value: !Ref RoleName

Outputs:
  LambdaRoleArn:
    Description: "ARN of the IAM role for Lambda"
    Value: !GetAtt LambdaRole.Arn

Lambda Code Template

AWSTemplateFormatVersion: '2010-09-09'
Description: "Template To Create Lambda For CostTracker Project"


Parameters:
  LambdaExecutionRole:
    Type: String
    Description: IAM Role Name
    Default: "CostExplorer-Lambda-Role"
  FunctionName:
    Type: String
    Description: Lambda Function Name
    Default: "Cost-Monitoring-Lambda"

Resources:
  CostExplorerLambda:
    Type: AWS::Lambda::Function
    Properties:
      FunctionName: !Ref FunctionName
      Runtime: python3.9
      Handler: index.lambda_handler
      Role: !Sub "arn:aws:iam::${AWS::AccountId}:role/${LambdaExecutionRole}"
      Code:
        ZipFile: |
          import json
          import boto3
          from datetime import datetime, timedelta

          def lambda_handler(event, context):
              client = boto3.client('ce')
              sns_client = boto3.client('sns')
              SNS_TOPIC_ARN = "<SNS_TOPIC_ARN>"
              today = datetime.today()
              end_date = today.strftime('%Y-%m-%d')
              monthly_start_date = today.replace(day=1).strftime('%Y-%m-%d')
              monthly_response = client.get_cost_and_usage(
                  TimePeriod={
                      'Start': monthly_start_date,
                      'End': end_date
                  },
                  Granularity='MONTHLY',
                  Metrics=['BlendedCost'],
                  GroupBy=[{'Type': 'DIMENSION', 'Key': 'SERVICE'}]
              )

              service_costs = {}
              for result in monthly_response['ResultsByTime']:
                  for group in result['Groups']:
                      service_name = group['Keys'][0]
                      cost = float(group['Metrics']['BlendedCost']['Amount'])
                      if cost > 0: 
                          service_costs[service_name] = cost

              email_subject = "AWS Monthly Cost Breakdown"
              email_body = "AWS Service-wise Cost Breakdown for the Month:\n\n"

              total_cost = 0
              for service, cost in service_costs.items():
                  email_body += f"{service}: ${cost:.2f}\n"
                  total_cost += cost

              email_body += f"\nTotal AWS Cost: ${total_cost:.2f}"

              # Send Email via SNS
              sns_client.publish(
                  TopicArn=SNS_TOPIC_ARN,
                  Subject=email_subject,
                  Message=email_body
              )

              print("AWS Cost Breakdown email sent successfully!")

              return {
                  'statusCode': 200,
              }
      Timeout: 60
      Tags:
        - Key: Name
          Value: FunctionName
        - Key: StackName
          Value : !Sub "${AWS::StackName}"

  LambdaLogGroup:
    Type: AWS::Logs::LogGroup
    Properties:
      LogGroupName: !Sub "/aws/lambda/${FunctionName}"
      RetentionInDays: 5

  LambdaPermission:
    Type: AWS::Lambda::Permission
    Properties:
      Action: lambda:InvokeFunction
      FunctionName: !Ref FunctionName
      Principal: events.amazonaws.com

  CloudWatchEventRule:
    Type: AWS::Events::Rule
    Properties:
      ScheduleExpression: rate(1 day)
      Targets:
        - Arn: !GetAtt CostExplorerLambda.Arn
          Id: LambdaCostCheck

Outputs:
  CostExplorerLambdaArn:
    Description: ARN of the created Lambda function
    Value: !GetAtt CostExplorerLambda.Arn

Email Result

Cost Optimization Tips

Optimizing AWS costs is the ultimate goal, but using the Cost Explorer API is fantastic. The following are examples of best practices:

Find Idle Resources: Check for underutilized services using GetCostAndUsage.
Establish Budgets and Alerts: Set expenditure caps in AWS Budgets.
Use Saved Plans & Reserved Instances: To optimize savings, examine GetReservationUtilization.
Use GetRightsizingRecommendation to optimize EC2 instances by rightsizing them.
Automate cost reports by scheduling them using AWS Lambda + SNS.

Conclusion

AWS consumption and expenses can be better understood with the help of the AWS Cost Explorer API. AWS Lambda automation and Python scripts can be used to efficiently track and optimize cloud costs. To guarantee a cost-effective AWS environment, begin incorporating these cost control strategies right now!

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Automating AWS Cost Savings with Cost Explorer API

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