Edge Computing with Cloudflare Workers & Deno · レッスン

Service Bindingsと連携

Service Bindingsを使って、Workersを他のCloudflareサービスや外部APIに接続します

「Service Bindingsと連携」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。

Intro to Service Bindings

Welcome to Service Bindings! In this lesson, you'll learn how Cloudflare Workers can communicate with each other and other Cloudflare services directly.

Think of Service Bindings as secure, internal connections that unlock powerful modularity for your edge applications.

Why Use Service Bindings?

Service Bindings offer several key advantages:

Modularity: Break down complex Workers into smaller, reusable components.
Performance: Direct internal communication is faster than public HTTP requests.
Security: Keep internal API calls off the public internet.
Abstraction: Treat other Workers or services like local modules.

Worker-to-Worker Communication

One of the most common uses for Service Bindings is allowing one Worker to invoke another. This is perfect for creating microservices at the edge.

You can call a 'target' Worker from an 'invoking' Worker, passing requests and receiving responses as if they were part of the same application.

Code: The Target Worker

First, let's create a simple 'target' Worker. This Worker will respond with a specific message when called.

Save this as target-worker/src/index.js:

export default {
  async fetch(request, env, ctx) {
    return new Response("Hello from the Target Worker!", {
      status: 200,
      headers: { 'Content-Type': 'text/plain' }
    });
  },
};

Code: The Invoking Worker

Now, let's create an 'invoking' Worker that uses a binding to call our 'target' Worker. Notice how env.TARGET_WORKER.fetch(request) is used.

Save this as invoking-worker/src/index.js:

export default {
  async fetch(request, env, ctx) {
    // 'TARGET_WORKER' is the binding name defined in wrangler.toml
    const response = await env.TARGET_WORKER.fetch(request);
    const text = await response.text();
    return new Response(`Invoker received: ${text}`, {
      status: 200,
      headers: { 'Content-Type': 'text/plain' }
    });
  },
};

Configuring Worker Bindings

To connect the 'invoking' Worker to the 'target' Worker, you need to add a service_binding entry in the wrangler.toml file of your invoking Worker.

This tells Cloudflare which Worker project to connect to and what name (e.g., TARGET_WORKER) to use in your code.

# In the invoking-worker's wrangler.toml
name = "invoking-worker"
main = "src/index.js"
compatibility_date = "2023-12-01"

[[service_bindings]]
name = "TARGET_WORKER"
service = "target-worker" # Name of the target Worker project

Make sure both Workers are deployed to Cloudflare.

Bindings to Cloudflare Services

Service Bindings aren't limited to Workers! You can also bind your Worker directly to other Cloudflare services like KV Namespaces, R2 buckets, D1 databases, and Durable Objects.

This provides your Worker with direct, secure, and performant access to these resources via the env object.

Code: KV Namespace Binding

Here's how you'd configure a binding to a KV Namespace in your wrangler.toml:

# In your Worker's wrangler.toml
name = "my-worker"
main = "src/index.js"
compatibility_date = "2023-12-01"

[[kv_namespaces]]
binding = "MY_KV" # The variable name in your Worker
id = "YOUR_KV_NAMESPACE_ID" # Replace with your actual KV ID

Then, access it in your Worker's code:

export default {
  async fetch(request, env, ctx) {
    // 'MY_KV' is the binding name from wrangler.toml
    await env.MY_KV.put("greeting", "Hello from KV!");
    const message = await env.MY_KV.get("greeting");
    return new Response(`KV says: ${message}`, {
      status: 200,
      headers: { 'Content-Type': 'text/plain' }
    });
  },
};

Test Your Knowledge!

Choose the best answer.

Recap: Bindings & Integrations

You've learned about Cloudflare Worker Service Bindings!

They provide a powerful way for Workers to communicate with other Workers or Cloudflare services directly.
Benefits include modularity, performance, and security.
You configure bindings in your wrangler.toml file.
They enable complex architectures where Workers act as building blocks.

Keep exploring how these bindings can simplify your edge development!

よくある質問

「Service Bindingsと連携」レッスンは無料ですか？

はい。「Service Bindingsと連携」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。

「Service Bindingsと連携」で何を学びますか？

Service Bindingsを使って、Workersを他のCloudflareサービスや外部APIに接続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。

「Service Bindingsと連携」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。

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