Both AWS module and SSM/secrets layer added, but not found at run-time by lambda nodejs code? - aws-lambda

Question

This is the code:
/* global AWS */
AWS.config.update({region: 'us-east-1'});
const ssm = new AWS.SSM();
console.log('Loading function...');
exports.handler = async (event, context) => {
//console.log('Received event:', JSON.stringify(event, null, 2));
console.log('value1 =', event.key1);
console.log('value2 =', event.key2);
console.log('value3 =', event.key3);
ssm.getParameters({
Names: [`/my/dev/scrt`],
WithDecryption: false,
}).promise()
.then(data => data.Parameters.length ? data.Parameters[0].Value : Promise.reject(new Error(`SSM Parameter was not set.`)))
.then(plainsecret => {
console.log(`the secret is ${scrt}`);
return `${scrt} - ${event.key1}`; // Echo back the first key value
});
};
The error:
Response
{
"errorType": "ReferenceError",
"errorMessage": "AWS is not defined",
"trace": [
"ReferenceError: AWS is not defined",
" at Object.<anonymous> (/var/task/index.js:2:1)",
" at Module._compile (internal/modules/cjs/loader.js:1085:14)",
" at Object.Module._extensions..js (internal/modules/cjs/loader.js:1114:10)",
" at Module.load (internal/modules/cjs/loader.js:950:32)",
" at Function.Module._load (internal/modules/cjs/loader.js:790:12)",
" at Module.require (internal/modules/cjs/loader.js:974:19)",
" at require (internal/modules/cjs/helpers.js:101:18)",
" at _tryRequireFile (/var/runtime/UserFunction.js:72:32)",
" at _tryRequire (/var/runtime/UserFunction.js:160:20)",
" at _loadUserApp (/var/runtime/UserFunction.js:219:12)"
]
}
Function Logs
[AWS Parameters and Secrets Lambda Extension] 2023/02/14 17:45:26 PARAMETERS_SECRETS_EXTENSION_LOG_LEVEL is not present. Log level set to info.
I thought /* global AWS */ was how you made the aws module available to lambda. Seems it doesn't work? Also, I added the layer AWS-Parameters-and-Secrets-Lambda-Extension, version 4, merge order 1. So again not sure why it's complaining?

Answer 1

Adding a comment in your code of /* global AWS */ doesn't magically provide anything. However the AWS SDK for NodeJS is included in the NodeJS Lambda runtime. Also, you don't need the AWS-Parameters-and-Secrets-Lambda-Extension if you are just using the standard AWS SDK to pull a secret value, as you appear to be doing.
Assuming you are using NodeJS 16 or earlier, with the AWS SDK v2 (which is what your code looks like) then you simply need to add the following line to the top of your file:
var AWS = require("aws-sdk");
If you are using NodeJS 18, then it comes with the AWS SDK v3, and you need to follow this guide to using it.