SahanAmarsha/lambda-image-resizer/index.js

index.js

const aws = require("aws-sdk");
const sharp = require("sharp");
const s3 = new aws.S3();

exports.handler = async function (event, context) {
  console.log("Received S3 event:", JSON.stringify(event, null, 2));
  if (event.Records[0].eventName === "ObjectRemoved:Delete") {
    return;
  }
  const bucket = event.Records[0].s3.bucket.name;
  const key = event.Records[0].s3.object.key;
  console.log(`Bucket: ${bucket}`, `Key: ${key}`);
  try {
    // get image from s3
    let image = await s3.getObject({ Bucket: bucket, Key: key }).promise();

    // resize image
    image = await sharp(image.Body);
    const metadata = await image.metadata();
    if (metadata.width > 900) {
      const resizedImage = await image
        .resize({ width: 900 })
        .withMetadata()
        .toBuffer();
      
      // store image
      console.log("RESIZED IMAGE");
      await s3
        .putObject({ Bucket: bucket, Key: key, Body: resizedImage })
        .promise();
      return "RESIZED IMAGE";
    } else {
      console.log("NOT RESIZED IMAGE");
      return "NOT RESIZED IMAGE";
    }
  } catch (err) {
    context.fail(`Error resizing image: ${err}`);
  }
};

If this was called by a trigger - wouldn't the put object call to the same bucket end up invoking the trigger again? Infinite loop?