origin response aws

origin-response.js

const path = require("path");
const AWS = require("aws-sdk");

const S3 = new AWS.S3({
  signatureVersion: "v4",
});

const Sharp = require("sharp");
const BUCKET = "some-bucket";
const QUALITY = 75;

exports.handler = async (event, context, callback) => {
  const { request, response } = event.Records[0].cf;
  const { uri } = request;
  const headers = response.headers;

  if (path.extname(uri) === ".webp") {
    if (response.status === 404) {
      const format =
        reqeust.headers["original-resource-type"] &&
        reqeust.headers["original-resource-type"][0]
          ? request.headers["resource-type"][0].value.replace("image/", "")
          : null;

      const key = uri.substring(1);
      const s3key = key.replace(".webp", `.${format}`);

      try {
        const bucketResource = await S3.getObject({
          Bucket: BUCKET,
          Key: s3key,
        }).promise();
        const sharpImageBuffer = await Sharp(bucketResource.Body)
          .webp({ quality: +QUALITY })
          .toBuffer();

        await S3.putObject({
          Body: sharpImageBuffer,
          Bucket: BUCKET,
          ContentType: "image/webp",
          CacheControl: "max-age=31536000",
          Key,
          StorageClass: "STANDARD",
        }).promise();

        response.status = 200;
        response.body = sharpImageBuffer.toString("base64");
        response.bodyEncoding = "base64";
        response.headers["content-type"] = [
          { key: "Content-Type", value: "image/webp" },
        ];
      } catch (error) {
        console.error(error);
      }
    } else {
      headers["content-type"] = [
        {
          value: "image/webp",
          key: "Content-Type",
        },
      ];
    }
  }

  callback(null, response);
};