0Pricing
Edge Computing with Cloudflare Workers & Deno · レッスン

Denoとエッジストレージの統合

データ管理のためにCloudflare KVやDurable Objectsと連携するDeno関数を開発します

「Denoとエッジストレージの統合」はCoddyKit上の無料Edge Computing with Cloudflare Workers & Denoレッスンです。 これはレッスン3/4です。 下記で完全なレッスンを無料で読むことができます。その後、ブラウザ内の組み込みコードエディタと24時間対応のAIチューターでハンズオン演習できます。 これはEdge Computing with Cloudflare Workers & Deno学習パスの一部であり、ウェブとCoddyKitアプリ全体で進捗が同期されます。 Edge Computing with Cloudflare Workers & Denoコースには全4レッスンが含まれています。

このレッスンの一部はまだ翻訳されておらず、英語で表示されています。

Deno & Edge Storage Integration

Welcome! In previous lessons, we learned about Cloudflare KV and Durable Objects for storing data at the edge. Now, let's explore how Deno applications can interact with these powerful edge storage solutions.

Since Deno typically runs outside the Cloudflare Workers environment, we'll focus on how Deno can act as a client, communicating with Cloudflare Workers that then manage interactions with KV and Durable Objects.

Deno's Role: The Proxy Pattern

Deno applications, whether running locally or deployed on platforms like Deno Deploy, don't directly access Cloudflare's KV or Durable Objects.

Instead, Deno acts as a client, making standard HTTP requests to a Cloudflare Worker. This Worker then serves as a proxy, handling the actual interactions with KV or Durable Objects on the Cloudflare edge network.

  • Deno App: Sends HTTP requests (e.g., GET, POST).
  • Cloudflare Worker: Receives requests, accesses KV/DO, and sends responses.

Cloudflare KV: Quick Review

Remember, Cloudflare KV is a global, low-latency key-value store perfect for caching, configuration, and user preferences.

Workers interact with KV using simple APIs like KV.put() to store data and KV.get() to retrieve it. Our Deno client will send requests to a Worker, which will then use these KV operations.

Storing Data from Deno to KV

To store data from your Deno application into a Cloudflare KV namespace, the process typically involves these steps:

  1. Your Deno app sends an HTTP POST request to a specific endpoint on your Cloudflare Worker.
  2. The Worker receives this request, extracts the key and value from the request body.
  3. The Worker uses its bound KV namespace (e.g., MY_KV.put(key, value)) to store the data.
  4. The Worker sends an HTTP response back to the Deno app, confirming the operation.

Worker Proxy for KV Write

Here's a simple Cloudflare Worker that accepts POST requests to store data in a KV namespace named MY_KV. Remember to bind MY_KV in your wrangler.toml.

Try running this example:

export default {
  async fetch(request, env) {
    const url = new URL(request.url);
    if (request.method === "POST" && url.pathname === "/put") {
      try {
        const { key, value } = await request.json();
        if (!key || !value) {
          return new Response("Missing key or value", { status: 400 });
        }
        await env.MY_KV.put(key, value);
        return new Response(`Stored key: ${key}`, { status: 200 });
      } catch (error) {
        return new Response(`Error: ${error.message}`, { status: 500 });
      }
    }
    return new Response("Not found", { status: 404 });
  },
};

Deno Client Writing to KV

Now, let's create a Deno script that acts as the client. It will send a JSON payload to our Cloudflare Worker proxy to store data in KV.

You'll need to replace YOUR_WORKER_URL with your deployed Worker's URL.

Try running this example:

// main.ts
const workerUrl = "YOUR_WORKER_URL"; // e.g., "https://your-worker.your-account.workers.dev"

async function putDataToKv(key: string, value: string) {
  try {
    const response = await fetch(`${workerUrl}/put`, {
      method: "POST",
      headers: {
        "Content-Type": "application/json",
      },
      body: JSON.stringify({ key, value }),
    });

    if (response.ok) {
      console.log(`Successfully stored: ${await response.text()}`);
    } else {
      console.error(`Failed to store: ${response.status} ${response.statusText}`);
      console.error(await response.text());
    }
  } catch (error) {
    console.error("Network error:", error.message);
  }
}

// Example usage:
if (import.meta.main) {
  await putDataToKv("myKey", "myValue from Deno!");
  await putDataToKv("anotherKey", "Hello Edge!");
}

Retrieving Data from KV to Deno

Reading data follows a similar proxy pattern:

  1. Your Deno app sends an HTTP GET request to your Cloudflare Worker, usually including the key in the URL path or query parameters.
  2. The Worker receives this request, extracts the key.
  3. The Worker uses env.MY_KV.get(key) to retrieve the data.
  4. The Worker sends the retrieved value (or an error) as an HTTP response back to the Deno app.

Worker Proxy for KV Read

Let's add a GET endpoint to our Worker to fetch data from KV. This could be integrated into the previous Worker example.

Try running this example:

export default {
  async fetch(request, env) {
    const url = new URL(request.url);
    // Handle POST for putting data
    if (request.method === "POST" && url.pathname === "/put") {
      try {
        const { key, value } = await request.json();
        if (!key || !value) {
          return new Response("Missing key or value", { status: 400 });
        }
        await env.MY_KV.put(key, value);
        return new Response(`Stored key: ${key}`, { status: 200 });
      } catch (error) {
        return new Response(`Error: ${error.message}`, { status: 500 });
      }
    }
    // Handle GET for getting data
    if (request.method === "GET" && url.pathname.startsWith("/get/")) {
      const key = url.pathname.substring(5); // "/get/myKey" -> "myKey"
      if (!key) {
        return new Response("Missing key", { status: 400 });
      }
      const value = await env.MY_KV.get(key);
      if (value === null) {
        return new Response("Key not found", { status: 404 });
      }
      return new Response(value, { status: 200 });
    }
    return new Response("Not found", { status: 404 });
  },
};

Deno Client Reading from KV

Here's a Deno script to fetch data from the Worker's GET endpoint. This assumes you've already stored "myKey" and "anotherKey" using the previous Deno script.

Try running this example:

// main.ts
const workerUrl = "YOUR_WORKER_URL"; // e.g., "https://your-worker.your-account.workers.dev"

async function getDataFromKv(key: string) {
  try {
    const response = await fetch(`${workerUrl}/get/${key}`);

    if (response.ok) {
      console.log(`Value for '${key}': ${await response.text()}`);
    } else {
      console.error(`Failed to get data: ${response.status} ${response.statusText}`);
      console.error(await response.text());
    }
  } catch (error) {
    console.error("Network error:", error.message);
  }
}

// Example usage:
if (import.meta.main) {
  await getDataFromKv("myKey");
  await getDataFromKv("anotherKey");
  await getDataFromKv("nonExistentKey"); // Will show "Key not found"
}

Deno & Durable Objects

Durable Objects provide consistent state for individual users or entities at the edge. Just like KV, Deno applications interact with Durable Objects indirectly through a Cloudflare Worker.

The Worker will instantiate or get a reference to a Durable Object, call its methods, and then return the result to the Deno client. This pattern allows your Deno app to leverage stateful edge logic.

  • Deno App: Sends requests to a Worker.
  • Cloudflare Worker: Routes to a specific Durable Object instance, invokes methods.
  • Durable Object: Manages its internal state and responds.

Edge Storage Integration Check

Considering how Deno applications integrate with Cloudflare's edge storage services (KV and Durable Objects), what is the primary mechanism for this interaction?

Integrating Deno & Edge Storage

Great job! In this lesson, you've learned how to integrate Deno applications with Cloudflare KV and Durable Objects.

  • Deno acts as a client, sending HTTP requests.
  • Cloudflare Workers function as proxies, handling the actual storage operations.
  • This pattern allows Deno apps to leverage the power of edge data persistence securely and efficiently.

This integration opens up possibilities for building powerful full-stack applications with Deno on the client/server and Workers managing edge data.

よくある質問

「Denoとエッジストレージの統合」レッスンは無料ですか？

はい。「Denoとエッジストレージの統合」の完全なテキストはこのウェブで無料で読めます。インタラクティブに演習し（組み込みコードエディタと24時間対応のAIチューター）、Edge Computing with Cloudflare Workers & Denoコースの残りをアンロックするには、CoddyKit PROにアップグレードしてください。 Edge Computing with Cloudflare Workers & Denoコースには全4レッスンが含まれています。

「Denoとエッジストレージの統合」で何を学びますか？

データ管理のためにCloudflare KVやDurable Objectsと連携するDeno関数を開発します ブラウザで直接実行するハンズオンコードでEdge Computing with Cloudflare Workers & Denoを演習し、24時間対応のAIチューターがレッスンを進める中での質問に答えます。

Edge Computing with Cloudflare Workers & Denoを始めるのに経験は必要ですか？

事前経験は必要ありません。CoddyKitのEdge Computing with Cloudflare Workers & Denoは初級者から上級者向けに構成されているため、ここから始めるか最初から始めて、自分のペースで進むことができます。 これはレッスン3/4です。

「Denoとエッジストレージの統合」レッスンにはどのくらい時間がかかりますか？

ほとんどのCoddyKitレッスンは約5～10分かかります。各レッスンはコンパクトでインタラクティブなので、着実に進歩し、ウェブとアプリ全体で正確に前回の場所から再開できます。

このEdge Computing with Cloudflare Workers & Denoレッスンでコードを書いて実行できますか？

はい。すべてのEdge Computing with Cloudflare Workers & Denoレッスンに組み込みコードエディタが含まれているため、ブラウザでリアルコードを書いて実行し、即座のAIフィードバックを取得できます。ローカル設定は不要です。

このコースのすべてのレッスン

  1. Cloudflare KVストア
  2. Durable Objectsの概要
  3. Denoとエッジストレージの統合
  4. エッジでD1 SQLを使ってクエリする
← Edge Computing with Cloudflare Workers & Denoに戻る