OAuth2 & OpenID Connect Deep Dive · レッスン

マイクロサービスとAPI Gatewayのセキュリティ

OAuth2による認可とエッジでのトークン検証を利用して、マイクロサービスアーキテクチャとAPI Gatewayを保護します。

「マイクロサービスとAPI Gatewayのセキュリティ」はCoddyKit上の無料OAuth2 & OpenID Connect Deep Diveレッスンです。これはレッスン2/4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OAuth2 & OpenID Connect Deep Dive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。 OAuth2 & OpenID Connect Deep Dive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。

Microservices & Gateway Basics

Modern applications often use microservices: small, independent services communicating over a network. This approach offers flexibility and scalability.

An API Gateway acts as a single entry point for all client requests, routing them to the correct microservice. It's like a traffic cop for your APIs.

Centralizing Security at the Edge

In a microservices architecture, you might have dozens or hundreds of services. Securing each one individually can be complex and error-prone.

An API Gateway provides a perfect place to centralize common security concerns, such as authentication and initial authorization. This is often called "security at the edge."

OAuth2 for Distributed AuthZ

OAuth2 is ideal for microservices because it provides a standardized way to issue and validate access tokens. These tokens are credentials that represent a user's permission to access resources.

When a client requests a resource, it first obtains an access token from an Authorization Server. This token is then presented to the API Gateway.

Gateway as Enforcement Point

The API Gateway acts as a Policy Enforcement Point (PEP). It intercepts incoming requests and performs critical security checks before forwarding them to the backend microservices.

Its primary security role is to validate the incoming OAuth2 access token. If the token is invalid, expired, or missing, the gateway rejects the request.

Token Validation Steps

When a request hits the API Gateway with an access token, here's a typical validation sequence:

Check Token Presence: Is there an Authorization: Bearer header?
Validate Format: Is it a well-formed JWT?
Verify Signature: Is the token signed by the trusted Authorization Server?
Check Expiry: Is the token still active (not expired)?
Validate Issuer & Audience: Is it from the correct issuer and intended for this resource?
Scope Check: Does the token have the necessary permissions (scopes) for the requested operation?

Gateway Token Validation Logic

Here's a conceptual look at how an API Gateway might validate an incoming JWT access token. This logic runs before any request reaches your microservices.

/* Pseudo-code for API Gateway Token Validation */
function validateAccessToken(request) {
  const token = extractToken(request.headers);
  if (!token) {
    return deny("Missing token");
  }

  try {
    const decodedToken = decodeJwt(token); // Header.Payload.Signature
    const publicKey = getPublicKey(decodedToken.header.kid); // From JWKS endpoint

    if (!verifySignature(token, publicKey)) {
      return deny("Invalid signature");
    }
    if (decodedToken.payload.exp < currentTime()) {
      return deny("Token expired");
    }
    if (decodedToken.payload.iss !== "your-auth-server") {
      return deny("Untrusted issuer");
    }
    if (!checkScopes(decodedToken.payload.scope, request.path)) {
      return deny("Insufficient scopes");
    }

    // Token is valid, attach claims for downstream
    request.context.userClaims = decodedToken.payload;
    return allow();

  } catch (error) {
    return deny("Token processing error");
  }
}

Propagating User Identity

After the API Gateway validates an access token, it often needs to pass the user's identity and authorization context to the downstream microservices.

This is typically done by injecting relevant claims from the validated token (e.g., user ID, roles, specific permissions) into custom HTTP headers or a new internal token before forwarding the request.

Microservice-to-Microservice Auth

What about when microservices need to communicate with each other directly, without a user in the loop? This is known as service-to-service authorization.

Client Credentials Flow: Services can use their own client ID and client secret to obtain an access token from the Authorization Server.
mTLS (Mutual TLS): Another option is to use mutual Transport Layer Security, where both the client and server present certificates to authenticate each other.

Fine-Grained Authorization

While the API Gateway handles initial authorization, individual microservices might need to perform more granular checks based on the specific resource being accessed.

For example, a "user profile" service might check if the authenticated user is requesting their own profile or if they have an "admin" role to view any profile. This uses the claims propagated from the gateway.

Gateway Security Role

The API Gateway plays a crucial role in securing microservices.

Recap: Microservices Security

In this lesson, we explored how to secure microservices using OAuth2 and an API Gateway.

The API Gateway acts as a central Policy Enforcement Point for initial token validation.
It propagates validated identity claims to downstream services.
We also touched upon service-to-service authorization and fine-grained authorization within individual microservices.

よくある質問

「マイクロサービスとAPI Gatewayのセキュリティ」レッスンは無料ですか？

はい。「マイクロサービスとAPI Gatewayのセキュリティ」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）、OAuth2 & OpenID Connect Deep Dive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。 OAuth2 & OpenID Connect Deep Diveコースには全4レッスンが含まれています。

「マイクロサービスとAPI Gatewayのセキュリティ」で何を学びますか？

OAuth2による認可とエッジでのトークン検証を利用して、マイクロサービスアーキテクチャとAPI Gatewayを保護します。ブラウザで直接実行するハンズオンコードでOAuth2 & OpenID Connect Deep Dive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。

OAuth2 & OpenID Connect Deep Dive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OAuth2 & OpenID Connect Deep Dive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2/4です。

「マイクロサービスとAPI Gatewayのセキュリティ」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OAuth2 & OpenID Connect Deep Dive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OAuth2 & OpenID Connect Deep Dive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

← OAuth2 & OpenID Connect Deep Diveに戻る