オリジンへのアクセスを制御する

export default {
	async fetch(request, env, ctx) {
		// Here you can compute arbitrary imageURL and
		// resizingOptions from any request data ...
		return fetch(imageURL, { cf: { image: resizingOptions } });
	},
};

export default {
	async fetch(request, env, ctx) {
		const resizingOptions = {
			/* resizing options will be demonstrated in the next example */
		};

		const hiddenImageOrigin = "https://secret.example.com/hidden-directory";
		const requestURL = new URL(request.url);
		// Append the request path such as "/assets/image1.jpg" to the hiddenImageOrigin.
		// You could also process the path to add or remove directories, modify filenames, etc.
		const imageURL = hiddenImageOrigin + requestURL.pathname;
		// This will fetch image from the given URL, but to the website's visitors this
		// will appear as a response to the original request. Visitor’s browser will
		// not see this URL.
		return fetch(imageURL, { cf: { image: resizingOptions } });
	},
};

export default {
  async fetch(request, env, ctx) {
  const imageURL = … // detail omitted in this example, see the previous example

  const requestURL = new URL(request.url)
  const width = parseInt(requestURL.searchParams.get("width"), 10);
  const resizingOptions = { width }
  // If someone tries to manipulate your image URLs to reveal higher-resolution images,
  // you can catch that and refuse to serve the request (or enforce a smaller size, etc.)
  if (resizingOptions.width > 1000) {
    return new Response("We don't allow viewing images larger than 1000 pixels wide", { status: 400 })
  }
  return fetch(imageURL, {cf:{image:resizingOptions}})
},};

export default {
	async fetch(request, env, ctx) {
		const requestURL = new URL(request.url);
		const resizingOptions = {};

		// The regex selects the first path component after the "images"
		// prefix, and the rest of the path (e.g. "/images/first/rest")
		const match = requestURL.pathname.match(/images\/([^/]+)\/(.+)/);

		// You can require the first path component to be one of the
		// predefined sizes only, and set actual dimensions accordingly.
		switch (match && match[1]) {
			case "small":
				resizingOptions.width = 300;
				break;
			case "medium":
				resizingOptions.width = 600;
				break;
			case "large":
				resizingOptions.width = 900;
				break;
			default:
				throw Error("invalid size");
		}

		// The remainder of the path may be used to locate the original
		// image, e.g. here "/images/small/image1.jpg" would map to
		// "https://storage.example.com/bucket/image1.jpg" resized to 300px.
		const imageURL = "https://storage.example.com/bucket/" + match[2];
		return fetch(imageURL, { cf: { image: resizingOptions } });
	},
};

// generate signed headers (application specific)
const signedHeaders = generatedSignedHeaders();

fetch(private_url, {
	headers: signedHeaders,
	cf: {
		image: {
			format: "auto",
			"origin-auth": "share-publicly",
		},
	},
});