AWS Lambda - CredentialsProviderError

Hi Ben, thank you for your prompt response.

As I mentioned earlier, the Lambda function is quite straightforward. It simply retrieves a JSON file from an S3 bucket and returns the corresponding JSON response.

import { fromNodeProviderChain } from "@aws-sdk/credential-providers";
import { S3Client, GetObjectCommand } from "@aws-sdk/client-s3";

const credentials = fromNodeProviderChain();
const s3 = new S3Client({ credentials });

const Bucket = "<bucket-name>"
const Key = "<file-name>"

export const handler = async function (event) {
  try {
    const command = new GetObjectCommand({ Bucket, Key });
    const response = await s3.send(command);
    const str = await response.Body.transformToString(); 
    const body = JSON.parse(str);
    return {
      statusCode: 200,
      body,
    }
  } catch (err) {
    console.error('Failed to get the file from S3', err);
    throw err;
  }
};

Thanks for sharing the code. Is there a particular reason why you need the credentials explicitly? You can just create the S3 Client without additional configuration. See https://docs.aws.amazon.com/sdk-for-javascript/v3/developer-guide/setting-credentials-node.html for

AWS SDK for JavaScript V3 provides a default credential provider chain in Node.js, so you are not required to supply a credential provider explicitly.

Please be also aware that as per documentation https://docs.aws.amazon.com/sdk-for-javascript/v3/developer-guide/setting-credentials-node.html, you normally don't need to use fromNodeProviderChain explicitly:

but with default role assumers so you don't need to import them from STS client and supply them manually. You normally don't need to use this explicitly in the client constructor.

Appreciate the detailed explanation! I initially faced issues with the default configuration of the S3 client, resulting in Could not load credentials from any providers error. To address this, I added fromNodeProviderChain as a precautionary measure. Interestingly, it didn't resolve the issue either.

import { S3Client, GetObjectCommand } from "@aws-sdk/client-s3";

const s3 = new S3Client({ region: 'eu-west-1' });

const Bucket = "<bucket-name>"
const Key = "<file-name>"

export const handler = async function (event) {
  try {
    const command = new GetObjectCommand({ Bucket, Key });
    const response = await s3.send(command);
    const str = await response.Body.transformToString(); 
    const body = JSON.parse(str);
    return {
      statusCode: 200,
      body,
    }
  } catch (err) {
    console.error('Failed to get the file from S3', err);
    throw err;
  }
};

Hi, thanks for the quick response. Have you tried using the @aws-sdk/credential-provider-node instead. See also the comment on this question: https://repost.aws/questions/QUXMX9z9zCSb21qsnedFZQpg/having-trouble-converting-aws-node-sdk-v2-lambda-to-v3

Tried using the @aws-sdk/credential-provider-node as well. Still getting the same error

import { defaultProvider } from '@aws-sdk/credential-provider-node';
import { S3Client, GetObjectCommand } from "@aws-sdk/client-s3";

const s3 = new S3Client({ region:'eu-west-1',  credentials: defaultProvider() });