AWS Cost Explorer Report Generator

Python SAM Lambda module for generating an Excel cost report with graphs, including month on month cost changes. Uses the AWS Cost Explorer API for data.

License Summary

This sample code is made available under a modified MIT license. See the LICENSE file.

AWS Costs

• AWS Lambda Invocation
  • Usually Free
• Amazon SES
  • Usually Free
• Amazon S3
  • Minimal usage
• AWS Cost Explorer API calls
  • $0.01 per API call (about 24 calls per run)

Prerequisites

• awscli
• Configure AWS credentials for target account
  • run aws configure
• Verfied Amazon SES Sender email
• If you verify an email, you can send from/to that address.
• To send to other addresses, you need to move SES out of sandbox mode.

Docker (optional for building the lambda python package with updated https://pypi.python.org/ third-party libraries)

Building (Optional, or use the prebuilt zip in /bin)

Run build.sh to build a new lambda deployment package. This requires Docker, as it builds the package in an Amazon Linux container.

sh build.sh

Deploying (SAM Application Repository)

Coming soon...

Deploying (SAM / Script)

Update the values in deploy.sh for your AWS account details.

Variable	Description
S3_BUCKET	S3 Bucket to use
SES_SEND	Email list to send to (comma separated)
SES_FROM	SES Verified Sender Email
SES_REGION	SES Region
COST_TAGS	List Of Cost Tag Keys (comma separated)
CURRENT_MONTH	true / false for if report does current partial month

And then run sh deploy.sh

Deploy Manually (Lambda Console)

1. Create a lambda function (python 3.6 runtime)
2. Create a lambda IAM execution role with ce:, ses:, s3:, organizations:ListAccounts
3. Upload zip to console from https://s3.amazonaws.com/aws-cost-explorer-report-bin/lambda.zip
4. Update ENV Variables in Lambda console
   • Detials in table above.
5. Create a trigger (CloudWatch Event)

Manually Running / Testing

Once the Lambda is created, find it in the AWS Lambda console. You can create ANY test event (as the event content is ignored), and hit the test button for a manual run.

https://docs.aws.amazon.com/lambda/latest/dg/tutorial-scheduled-events-test-function.html

Customise the report

Edit the main_handler segment of src/lambda.py

def main_handler(event=None, context=None): 
  costexplorer = CostExplorer(CurrentMonth=False)
  #Default addReport has filter to remove Credits / Refunds / UpfrontRI
  costexplorer.addReport(Name="Total", GroupBy=[],Style='Total')
  costexplorer.addReport(Name="TotalChange", GroupBy=[],Style='Change')
  costexplorer.addReport(Name="TotalInclCredits", GroupBy=[],Style='Total',NoCredits=False)
  costexplorer.addReport(Name="TotalInclCreditsChange", GroupBy=[],Style='Change',NoCredits=False)
  costexplorer.addReport(Name="Credits", GroupBy=[],Style='Total',CreditsOnly=True)
  costexplorer.addReport(Name="RIUpfront", GroupBy=[],Style='Total',UpfrontOnly=True)

  costexplorer.addRiReport(Name="RICoverage")
  costexplorer.addReport(Name="Services", GroupBy=[{"Type": "DIMENSION","Key": "SERVICE"}],Style='Total')
  costexplorer.addReport(Name="ServicesChange", GroupBy=[{"Type": "DIMENSION","Key": "SERVICE"}],Style='Change')
  costexplorer.addReport(Name="Accounts", GroupBy=[{"Type": "DIMENSION","Key": "LINKED_ACCOUNT"}],Style='Total')
  costexplorer.addReport(Name="AccountsChange", GroupBy=[{"Type": "DIMENSION","Key": "LINKED_ACCOUNT"}],Style='Change')
  costexplorer.addReport(Name="Regions", GroupBy=[{"Type": "DIMENSION","Key": "REGION"}],Style='Total')
  costexplorer.addReport(Name="RegionsChange", GroupBy=[{"Type": "DIMENSION","Key": "REGION"}],Style='Change')
  if os.environ.get('COST_TAGS'): #Support for multiple/different Cost Allocation tags
      for tagkey in os.environ.get('COST_TAGS').split(','):
          tabname = tagkey.replace(":",".") #Remove special chars from Excel tabname
          costexplorer.addReport(Name="{}".format(tabname)[:31], GroupBy=[{"Type": "TAG","Key": tagkey}],Style='Total')
          costexplorer.addReport(Name="Change-{}".format(tabname)[:31], GroupBy=[{"Type": "TAG","Key": tagkey}],Style='Change')
  costexplorer.generateExcel()
  return "Report Generated"