Set CORS for Cloudflare R2

cors.js

  import aws from "aws-sdk";
  
  const s3 = new aws.S3({
    endpoint: `https://${process.env.CLOUDFLARE_ACCOUNT_ID}.r2.cloudflarestorage.com`,
    accessKeyId: process.env.CLOUDFLARE_ACCESS_KEY,
    secretAccessKey: process.env.CLOUDFLARE_SECRET_ACCESS_KEY,
    signatureVersion: "v4",
  });
  
  const config = {
    AllowedHeaders: ["content-type"], // This seems to be necessary! Not including it gives errors. Putting it as * still gives CORS errors
    AllowedMethods: ["PUT"],
    AllowedOrigins: ["*"],
  };

  const bucketParams = {
    Bucket: process.env.CLOUDFLARE_BUCKET_NAME,
    CORSConfiguration: { CORSRules: new Array(config) },
  };

  s3.putBucketCors(bucketParams, function (err, data) {
    if (err) {
      console.log("Error", err);
    } else if (data) {
      console.log("Success", JSON.stringify(data.CORSRules));
    }
  });