Fix CRLY.01180: Set Concurrent Execution Limit for Lambda Functions

[curly-review]

Issue Details

ID: CRLY.01180
Severity: MEDIUM
File: sam/cfn/cfn-lambda-core-functions.yaml

---

Remediation Summary

Description

The security finding indicates that the AWS Lambda function talrReceptionistFunction does not have a function-level concurrent execution limit set. This can lead to potential resource exhaustion and increased costs if not managed properly.

Steps

1. Update the CloudFormation Template:
   Add the ReservedConcurrentExecutions property under the Properties section of the talrReceptionistFunction.

2. Set a Reasonable Limit:
   Choose a concurrent execution limit based on your application's needs. For example, if you want to limit the function to 100 concurrent executions, set ReservedConcurrentExecutions to 100.

Here is the updated YAML snippet:

    talrReceptionistFunction:
        Type: AWS::Serverless::Function
        Properties:
            FunctionName: talr-receptionist1
            Description: Validates account request and starts workflow
            Runtime: python2.7
            CodeUri: ../functions/talr-receptionist
            Handler: handler.handler
            MemorySize: 128
            Timeout: 30
            Role: !GetAtt iamCoreFunctionsRolesStack.Outputs.iamRoleArnLambdaTalrReceptionist
            ReservedConcurrentExecutions: 100  # Set your desired limit here
        Variables:
            TALR_TABLENAME_CBINFO: !GetAtt dynamodbTablesStack.Outputs.dynamodbTableNameTalrCbInfo
            TALR_TABLENAME_TASKSTATUS: !GetAtt dynamodbTablesStack.Outputs.dynamodbTableNameTalrTaskStatus
            TALR_TABLENAME_ACCOUNTINFO: !GetAtt dynamodbTablesStack.Outputs.dynamodbTableNameTalrAccountInfo
            STAGE: !Ref stage

3. Deploy the Updated Template:
   Use your preferred CI/CD pipeline or AWS CLI to deploy the updated CloudFormation template.

aws cloudformation deploy --template-file sam/cfn/cfn-lambda-core-functions.yaml --stack-name your-stack-name --capabilities CAPABILITY_IAM

By following these steps, you will ensure that the talrReceptionistFunction has a function-level concurrent execution limit, improving the security and cost management of your AWS Lambda function.