Share code between AWS lambda functions in node.js

Question

It seems it is not possible to pass around some code (containing data and functions) that is invoked as a AWS lambda function within another AWS lambda function.

For example, take this customConfigLambda:

var callbackPayload = {};

callbackPayload.fooData = 'fooFromData';
callbackPayload.fooFunction = function() {return 'fooFromFunction'; };

exports.handler = (event, context, callback) => {
    callback(null, callbackPayload);
};

When I call the previous AWS lambda function in another AWS lambda function like here:

var AWS = require('aws-sdk');
AWS.config.update({accessKey: '123', secretAccessKey: 'abc', region: 'us-east-1' });
var lambda = new AWS.Lambda({region: 'us-east-1'});

exports.handler = (event, context, callback) => {
    var params = {FunctionName: 'customConfigLambda'};
    lambda.invoke(params, function(err, callbackPayload) {
        if (err) {
            // do nothing
        }
        else {
            console.log('callbackPayload:', JSON.stringify(callbackPayload, null, 2));
        }
    });
};

Then I can see only callbackPayload.fooData but not callbackPayload.fooFunction.

How can I have some callbackPayload.fooFunction(s) shared between multiple other AWS lambda functions?

Answer 1

As of AWS Reinvent 2018, Amazon has introduced Lambda Layers.

Lambda Layers, a way to centrally manage code and data that is shared across multiple functions.

The idea is that now you can put common components in a ZIP file and upload it as a Lambda Layer. Your function code doesn’t need to be changed and can reference the libraries in the layer as it would normally do instead of packaging them separately.