Authenticate users with Google Accounts

This quickstart shows you how to enable Identity-Aware Proxy (IAP) to secure an App Engine standard or flexible environment application and grant access to users with Google Accounts.

If you plan to serve resources from a content delivery network (CDN), see the caching best practices guide for important information.

When an App Engine application consists of multiple services, you can configure different IAP permissions across services, including making only some services publicly accessible while keeping others protected.

Before you begin

  1. In the Google Cloud console, on the project selector page, select or create a Google Cloud project.

    Roles required to select or create a project

    • Select a project: Selecting a project doesn't require a specific IAM role—you can select any project that you've been granted a role on.
    • Create a project: To create a project, you need the Project Creator role (roles/resourcemanager.projectCreator), which contains the resourcemanager.projects.create permission. Learn how to grant roles.

    Go to project selector

  2. If you're using an existing project for this guide, verify that you have the permissions required to complete this guide. If you created a new project, then you already have the required permissions.

  3. Verify that billing is enabled for your Google Cloud project.

  4. To enable IAP for App Engine, you need to set up the App Engine instance. If you don't have your App Engine instance set up already, see Deploying to App Engine for a complete walkthrough.

    By default, IAP uses a Google-managed OAuth client, which requires your project to belong to an organization and only allows access to internal users.

Required roles

To get the permissions that you need to authenticate users with Google Accounts, ask your administrator to grant you the IAP Policy Admin (roles/iap.policyAdmin) IAM role on your project. For more information about granting roles, see Manage access to projects, folders, and organizations.

You might also be able to get the required permissions through custom roles or other predefined roles.

Enable IAP

Console

If your project does not belong to an organization, you must use custom OAuth credentials.

Dynamic include file

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.

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.
  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.
    • 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.

Turning on IAP

  1. On the Identity-Aware Proxy page, under Applications, find the application you want to restrict access to. To turn on IAP for a resource,
  2. In the Turn on IAP window that appears, click Turn On to confirm that you want IAP to secure your resource. After you turn on IAP, it requires login credentials for all connections to your load balancer. Only principals with the IAP-Secured Web App User (roles/iap.httpsResourceAccessor) role on the project will be given access.

gcloud

在设置项目和 IAP 之前，您需要最新版本的 gcloud CLI。如需了解如何安装 gcloud CLI，请参阅安装 gcloud CLI。

  1. 如需进行身份验证，请使用 Google Cloud CLI 并运行以下命令。 
    gcloud auth login
  2. 点击显示的网址并登录。
  3. 登录后，复制显示的验证码并将其粘贴到命令行中。
  4. 运行以下命令，指定包含您要使用 IAP 保护的应用的项目。 
    gcloud config set project PROJECT_ID
  5. 如需启用 IAP，请运行以下命令。 
    gcloud iap web enable --resource-type=app-engine --versions=version
  6. 向项目添加应具有“IAP-secured Web 应用 User”角色的主体。
    gcloud projects add-iam-policy-binding PROJECT_ID \
       --member=PRINCIPAL_IDENTIFIER \
       --role=roles/iap.httpsResourceAccessor
    • 将 PROJECT_ID 替换为您的项目 ID。
    • 将 PRINCIPAL_IDENTIFIER 替换为必需的主账号。可以是网域、群组、服务账号或用户类型。例如， user:myemail@example.com。

启用 IAP 后，您可以使用 gcloud CLI 通过 IAM 角色 roles/iap.httpsResourceAccessor 修改 IAP 访问权限政策。详细了解如何管理角色和权限。

API

  1. 运行以下命令以准备 settings.json 文件。 

    cat << EOF > settings.json
{
"iap":
  {
    "enabled":true
  }
}
EOF

  2. 运行以下命令以启用 IAP。 

    curl -X PATCH \
-H "Authorization: Bearer $(gcloud auth print-access-token)" \
-H "Accept: application/json" \
-H "Content-Type: application/json" \
-d @settings.json \
"https://appengine.googleapis.com/v1/apps/PROJECT_ID?updateMask=iap"

启用 IAP 后，您可以使用 Google Cloud CLI 通过 IAM 角色 roles/iap.httpsResourceAccessor 修改 IAP 访问权限政策。详细了解如何管理角色和权限。

You can enable IAP on a App Engine service within your project. To make some services publicly accessible and require authentication for others, you can use different access levels across services. To learn more, see Manage access with IAP. To make services publicly accessible, grant the IAP-secured Web App User role to allAuthenticatedUsers.

Test user authentication

  1. After the role is granted, principals can access the app by authenticating with IAP. Access the app URL from a Google Account that was granted the IAP-secured Web App User (roles/iap.httpsResourceAccessor) role.

  2. To test access, open an Incognito window in Chrome, access the app URL, and sign in when prompted. Users who are granted the IAP-secured Web App User (roles/iap.httpsResourceAccessor) role and have successfully authenticated can access the app. Users who aren't granted the required role or fail to authenticate cannot access the app.

What's next