interface OurCompanyILamdaProps {
    assetPath: string, // what are we deploying
    environment?: any,
    handler?: string,
    description?: string,
    timeout?: number
}

export class Lambda extends cdk.Construct {

    public readonly function: lambda.Function;

    constructor(scope: cdk.Construct, id: string, props: OurCompanyILamdaProps) {
        super(scope, id);

        let env: any = props.environment ? props.environment : {};

        // make sure we always have the ENV available to the lambda function.
        env.DEPLOY_ENV = process.env.DEPLOY_ENV; 

        // construct ID needs to be unique
        let constructId = id + env.DEPLOY_ENV;

        let lam = new lambda.Function(scope, constructId, {
            code: lambda.Code.asset(props.assetPath),
            handler: props.handler ? props.handler : "index.handler",
            runtime: lambda.Runtime.NODEJS_10_X,
            environment: props.environment,
            description: props.description,
            timeout: cdk.Duration.seconds(props.timeout ? props.timeout : 60)
        })
 
       // Do stuff.. 
       // if prop.allowAccessSecrets ... create role and assign to lambda
       // if prop.addMonitoring ...
       // if prop.someThingElse ...

        this.function = lam;
    }
}

        import * as OurCompany from '../constructs/';

        let lambFunction = new OurCompany.Lambda(this, 'aThing', {
            assetPath: __dirname + '/lambda/function_a/',
            environment: environment
        }).function; // note .function here to get the underlying construct if needed
        aDynamoDBTable.grantReadWriteData(lambFunction);