从 lambda (Nodejs) 上传 multipart/form-data 到 S3

Question

I want to upload multipart/form-data file to S3 using Nodejs.

I have tried various approaches but none of them are working. I was able to write content to S3 from lambda but when the file is downloaded from S3, it was corrupted.

Can someone provide me a working example or steps that could help me?

Thanking you in anticipation.

Please suggest another alternative if you think so.

Following is my lambda code:

export const uploadFile = async event => {
  const parser = require("lambda-multipart-parser");
  const result = await parser.parse(event);
  const { content, filename, contentType } = result.files[0];
  const params = {
    Bucket: "name-of-the-bucket",
    Key: filename,
    Body: content,
    ContentDisposition: `attachment; filename="${filename}";`,
    ContentType: contentType,
    ACL: "public-read"
  };

  const res = await s3.upload(params).promise();
  return {
        statusCode: 200,
        body: JSON.stringify({
            docUrl: res.Location
        })
    };
}

Answer 1

If want to upload file through lambda, one way is to open your AWS API Gateway console.

Go to

"API" -> {YourAPI} -> "Settings"

There you will find "Binary Media Types" section.

Add following media type:

multipart/form-data

Save your changes.

Then Go to "Resources" -> "proxy method"(eg. "ANY") -> "Method Request" -> "HTTP Request Headers" and add following headers "Content-Type", "Accept".

Finally deploy your api.

For more info visit: https://docs.aws.amazon.com/apigateway/latest/developerguide/api-gateway-payload-encodings-configure-with-console.html

Answer 2

There are 2 possible points of failure - Lambda receives corrupted data or you corrupt data while sending it to S3.

Sending multipart/form-data content to Lambda is not straightforward. You can see how to do that here .
After you did this and you're sure your data is correct in Lambda, check if you send it to S3 correctly (see S3 docs and examples for that).