為 GKE 啟用 IAP

本頁面說明如何使用 Identity-Aware Proxy (IAP) 保護 Google Kubernetes Engine (GKE) 執行個體。

總覽

IAP 是透過 GKE 的 Ingress 整合。這項整合功能可讓您控管員工的資源層級存取權，而不必使用 VPN。

在 GKE 叢集中，傳入流量是由 Cloud Load Balancing 的元件 HTTP(S) 負載平衡處理。HTTP(S) 負載平衡器通常由 Kubernetes Ingress 控制器設定。Ingress 控制器會從與一或多個 Service 物件相關聯的 Kubernetes Ingress 物件取得設定資訊。每個 Service 物件都含有轉送資訊，用於將傳入的要求導向特定 Pod 和通訊埠。

從 Kubernetes 1.10.5-gke.3 版開始，您可以將 Service 與 BackendConfig 物件建立關聯，藉此新增負載平衡器的設定。BackendConfig 是在 kubernetes/ingress-gce 存放區中定義的自訂資源定義。

Kubernetes Ingress 控制器會從 BackendConfig 讀取設定資訊，並據此設定負載平衡器。BackendConfig 包含 Cloud Load Balancing 專屬的設定資訊，可讓您為每個 HTTP(S) 負載平衡後端服務定義獨立設定。

事前準備

如要為 GKE 啟用 IAP，請先準備好下列項目：

  • 已啟用計費功能的 Google Cloud 控制台專案。
  • 一或多個 GKE 執行個體的群組，由 HTTPS 負載平衡器提供服務。當您在 GKE 叢集中建立 Ingress 物件時，系統應會自動建立負載平衡器。
  • 已註冊至您負載平衡器位址的網域名稱。
  • 確認所有要求都擁有身分識別資訊的應用程式程式碼。
IAP 會使用 Google 代管的 OAuth 用戶端驗證使用者。 只有組織內的使用者可以存取已啟用 IAP 的應用程式。如要允許組織外部的使用者存取，請參閱「為外部應用程式啟用 IAP」。

啟用 IAP

If you haven't configured your project's OAuth consent screen, you'll be prompted to do so. To configure your OAuth consent screen, see Setting up your OAuth consent screen.

If you are running GKE version 1.24 or later, you can configure IAP and GKE by using the Kubernetes Gateway API. To do so, complete the following steps and then follow the instructions in Configure IAP. Do not configure BackendConfig.

Setting up IAP access

  1. Go to the Identity-Aware Proxy page.
    Go to the Identity-Aware Proxy page
  2. Select the project you want to secure with IAP.

  3. Select the checkbox next to the resource you want to grant access to.

    If you don't see a resource, ensure that the resource is created and that the BackendConfig and Compute Engine ingress controller are synced.

    To verify that the backend service is available, run the following gcloud command:

    gcloud compute backend-services list
  4. On the right side panel, click Add principal.
  5. In the Add principals dialog that appears, enter the email addresses of groups or individuals who should have the IAP-secured Web App User role for the project.

    The following kinds of principals can have this role:

    • Google Account: user@gmail.com
    • Google Group: admins@googlegroups.com
    • Service account: server@example.gserviceaccount.com
    • Google Workspace domain: example.com

    Make sure to add a Google Account that you have access to.

  6. Select Cloud IAP > IAP-secured Web App User from the Roles drop-down list.
  7. Click Save.

Configuring BackendConfig

You can configure a BackendConfig for IAP by adding an iap block.

Adding an iap block to the BackendConfig

To configure the BackendConfig for IAP, you need to specify the enabled value. Ensure that you have the compute.backendServices.update permission and add the iap block to BackendConfig.

For GKE versions 1.16.8-gke.3 and higher, use the cloud.google.com/v1 API version. If you are using an earlier GKE version, use cloud.google.com/v1beta1. 

apiVersion: cloud.google.com/v1
kind: BackendConfig
metadata:
  name: CONFIG_DEFAULT
  namespace: my-namespace
spec:
  iap:
    enabled: true

Associate a service port with a BackendConfig

You also need to associate Service ports with your BackendConfig to trigger turning on IAP. One way to make this association is to make all ports for the service default to your BackendConfig, which you can do by adding the following annotation to your Service resource: 

metadata:
  annotations:
    cloud.google.com/backend-config: '{"default": "CONFIG_DEFAULT"}'

Verify the BackendConfig

To test the configuration, run kubectl get event. If you see the message "no BackendConfig for service port exists", then you successfully associated a service port with your BackendConfig, but the BackendConfig resource wasn't found. This error can occur if you haven't created the BackendConfig resource, created it in the wrong namespace, or misspelled the reference in the Service annotation.

Turning IAP off

To turn IAP off, you must set enabled to false in the BackendConfig. If you delete the IAP block from BackendConfig, the settings will persist. For example, if IAP is enabled and you delete the block, then IAP will still be turned on.

後續步驟