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

[curly-review]

Issue Details

ID: CRLY.01180
Severity: MEDIUM
File: tailor.yaml

---

Remediation Summary

Description

The security finding indicates that the AWS Lambda function talrClaFunction is missing a function-level concurrent execution limit. This limit is crucial for controlling the number of simultaneous executions of the Lambda function, which can help prevent resource exhaustion and ensure predictable performance.

Steps

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

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

Here is the updated YAML snippet:

talrClaFunction:
  Type: AWS::Serverless::Function
  Properties:
    FunctionName: !Join [ "-", [ "talr-cla", !Ref stage ] ]
    Description: Invokes CLA call to create account
    Runtime: python2.7
    CodeUri: ./sam/functions/talr-cla
    Handler: handler.handler
    MemorySize: 128
    Timeout: 60
    Role:
      Fn::GetAtt:
        - iamCoreFunctionsRolesStack
        - Outputs.iamRoleArnLambdaTalrCla
    Events:
      talrClaRequest:
        Type: SNS
        Properties:
          Topic:
            Fn::GetAtt:
              - snsTopicsStack
              - Outputs.snsArnTalrClaRequest
    Environment:
      Variables:
        TAILOR_TABLENAME_CBINFO:
          Fn::GetAtt:
            - dynamodbTablesStack
            - Outputs.dynamodbTableNameTalrCbInfo
        TAILOR_TABLENAME_TASKSTATUS:
          Fn::GetAtt:
            - dynamodbTablesStack
            - Outputs.dynamodbTableNameTalrTaskStatus
        TAILOR_TABLENAME_CLASTATUS:
          Fn::GetAtt:
            - dynamodbTablesStack
            - Outputs.dynamodbTableNameTalrClaStatus
    ReservedConcurrentExecutions: 100  # Add this line