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使用 Pub/Sub 构建在防火墙后的 Google Chat 应用

本页介绍了如何使用 Pub/Sub 创建 Chat 应用。如果您的组织有防火墙，可能会阻止 Chat 向您的 Chat 应用发送消息，或者如果 Chat 应用使用 Google Workspace Events API，那么这种 Chat 应用架构会非常有用。不过，由于这些聊天应用只能发送和接收异步消息，因此这种架构存在以下限制：

无法在消息中使用对话框。请改用卡片消息。
无法使用同步响应更新各个卡片。请改为调用 patch 方法来更新整个消息。

下图展示了使用 Pub/Sub 构建的聊天应用的架构：

使用 Pub/Sub 实现的 Chat 应用的架构。

在上图中，与 Pub/Sub Chat 应用互动的用户的信息流如下：

用户在 Chat 中通过私信或聊天室向 Chat 应用发送消息，或者 Chat 聊天室中发生 Chat 应用已有效订阅的事件。
聊天功能将消息发送到 Pub/Sub 主题。
应用服务器（即包含 Chat 应用逻辑的云端或本地系统）订阅 Pub/Sub 主题，以便通过防火墙接收消息。
Chat 应用可以选择调用 Chat API 来异步发布消息或执行其他操作。

前提条件

构建 Chat 应用时，您必须在 Google Cloud 控制台的 Chat API 配置页面中取消选中将此 Chat 扩展应用作为 Google Workspace 插件构建。请参阅将应用发布到 Google Chat。

Node.js

拥有可访问 Google Chat 的 Google Workspace 商务版或企业版账号。
启用了结算功能的 Google Cloud 项目。如需检查现有项目是否已启用结算功能，请参阅验证项目的结算状态。如需创建项目并设置结算，请参阅创建 Google Cloud 项目。
Node.js 14 或更高版本
npm 软件包管理工具
已初始化的 Node.js 项目。如需初始化新项目，请创建并切换到新文件夹，然后在命令行界面中运行以下命令：
```
npm init
```

Python

拥有可访问 Google Chat 的 Google Workspace 商务版或企业版账号。
启用了结算功能的 Google Cloud 项目。如需检查现有项目是否已启用结算功能，请参阅验证项目的结算状态。如需创建项目并设置结算，请参阅创建 Google Cloud 项目。
Python 3.6 或更高版本
pip 软件包管理工具

Java

拥有可访问 Google Chat 的 Google Workspace 商务版或企业版账号。
启用了结算功能的 Google Cloud 项目。如需检查现有项目是否已启用结算功能，请参阅验证项目的结算状态。如需创建项目并设置结算，请参阅创建 Google Cloud 项目。
Java 11 或更高版本
Maven 软件包管理工具

设置环境

在使用 Google API 之前，您需要在 Google Cloud 项目中启用它们。您可以在单个 Google Cloud 项目中启用一个或多个 API。

在 Google Cloud 控制台中，启用 Google Chat API 和 Pub/Sub API。

启用 API

设置 Pub/Sub

创建一个 Pub/Sub 主题，供 Chat API 向其发送消息。建议您为每个 Chat 应用使用一个主题。
通过向以下服务账号分配 Pub/Sub 发布者角色，授予 Chat 发布权限：
```
chat-api-push@system.gserviceaccount.com
```
为 Chat 应用创建服务账号，以便使用 Pub/Sub 和 Chat 进行授权，并将私钥文件保存到您的工作目录。
创建对主题的拉取订阅。
为之前创建的服务账号分配订阅的 Pub/Sub 订阅者角色。

注意：如果您使用 VPC Service Controls，可能需要在服务边界中配置入站流量规则，以允许服务账号访问 Pub/Sub。如需了解详情，请参阅入站和出站规则。

编写脚本

Node.js

在 CLI 中，提供服务账号凭据：

export GOOGLE_APPLICATION_CREDENTIALS=SERVICE_ACCOUNT_FILE_PATH

在 CLI 中，提供 Google Cloud 项目 ID：
```
export PROJECT_ID=PROJECT_ID
```
在 CLI 中，提供您之前创建的 Pub/Sub 订阅的订阅 ID：
```
export SUBSCRIPTION_ID=SUBSCRIPTION_ID
```
在工作目录中，创建一个名为 package.json 的文件。
在 package.json 文件中，粘贴以下代码：

node/pub-sub-app/package.json

在 GitHub 上查看
```
{
  "name": "pub-sub-app",
  "version": "1.0.0",
  "description": "Google Chat App that listens for messages via Cloud Pub/Sub",
  "main": "index.js",
  "scripts": {
    "start": "node index.js",
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "dependencies": {
    "@google-apps/chat": "^0.4.0",
    "@google-cloud/pubsub": "^4.5.0"
  },
  "license": "Apache-2.0"
}
```
在工作目录中，创建一个名为 index.js 的文件。

在 index.js 中，粘贴以下代码：

node/pub-sub-app/index.js

在 GitHub 上查看

const {ChatServiceClient} = require('@google-apps/chat');
const {MessageReplyOption} = require('@google-apps/chat').protos.google.chat.v1.CreateMessageRequest;
const {PubSub} = require('@google-cloud/pubsub');
const {SubscriberClient} = require('@google-cloud/pubsub/build/src/v1');

// Receives messages from a pull subscription.
function receiveMessages() {
  const chat = new ChatServiceClient({
    keyFile: process.env.GOOGLE_APPLICATION_CREDENTIALS,
    scopes: ['https://www.googleapis.com/auth/chat.bot'],
  });

  const subscriptionPath = new SubscriberClient()
    .subscriptionPath(process.env.PROJECT_ID, process.env.SUBSCRIPTION_ID)
  const subscription = new PubSub()
    .subscription(subscriptionPath);

  // Handle incoming message, then ack/nack the received message
  const messageHandler = message => {
    console.log(`Id : ${message.id}`);
    const event = JSON.parse(message.data);
    console.log(`Data : ${JSON.stringify(event)}`);

    // Post the response to Google Chat.
    const request = formatRequest(event);
    if (request != null) {
      chat.createMessage(request);
    }

    // Ack the message.
    message.ack();
  }

  subscription.on('message', messageHandler);
  console.log(`Listening for messages on ${subscriptionPath}`);

  // Keep main thread from exiting while waiting for messages
  setTimeout(() => {
    subscription.removeListener('message', messageHandler);
    console.log(`Stopped listening for messages.`);
  }, 60 * 1000);
}

// Send message to Google Chat based on the type of event
function formatRequest(event) {
  const spaceName = event.space.name;
  const eventType = event.type;

  // If the app was removed, we don't respond.
  if (event.type == 'REMOVED_FROM_SPACE') {
    console.log(`App removed rom space ${spaceName}`);
    return null;
  } else if (eventType == 'ADDED_TO_SPACE' && !eventType.message) {
    // An app can also be added to a space by @mentioning it in a
    // message. In that case, we fall through to the message case
    // and let the app respond. If the app was added using the
    // invite flow, we just post a thank you message in the space.
    return {
      parent: spaceName,
      message: { text: 'Thank you for adding me!' }
    };
  } else if (eventType == 'ADDED_TO_SPACE' || eventType == 'MESSAGE') {
    // In case of message, post the response in the same thread.
    return {
      parent: spaceName,
      messageReplyOption: MessageReplyOption.REPLY_MESSAGE_FALLBACK_TO_NEW_THREAD,
      message: {
        text: 'You said: `' + event.message.text + '`',
        thread: { name: event.message.thread.name }
      }
    };
  }
}

if (!process.env.PROJECT_ID) {
  console.log('Missing PROJECT_ID env var.');
  process.exit(1);
}
if (!process.env.SUBSCRIPTION_ID) {
  console.log('Missing SUBSCRIPTION_ID env var.');
  process.exit(1);
}
if (!process.env.GOOGLE_APPLICATION_CREDENTIALS) {
  console.log('Missing GOOGLE_APPLICATION_CREDENTIALS env var.');
  process.exit(1);
}

receiveMessages();

Python

在 CLI 中，提供服务账号凭据：

export GOOGLE_APPLICATION_CREDENTIALS=SERVICE_ACCOUNT_FILE_PATH

在 CLI 中，提供 Google Cloud 项目 ID：
```
export PROJECT_ID=PROJECT_ID
```
在 CLI 中，提供您之前创建的 Pub/Sub 订阅的订阅 ID：
```
export SUBSCRIPTION_ID=SUBSCRIPTION_ID
```
在工作目录中，创建一个名为 requirements.txt 的文件。
在 requirements.txt 文件中，粘贴以下代码：

python/pub-sub-app/requirements.txt

在 GitHub 上查看
```
google-cloud-pubsub>=2.23.0
google-apps-chat==0.1.9
```
在工作目录中，创建一个名为 app.py 的文件。

在 app.py 中，粘贴以下代码：

python/pub-sub-app/app.py

在 GitHub 上查看

import json
import logging
import os
import sys
import time
from google.apps import chat_v1 as google_chat
from google.cloud import pubsub_v1
from google.oauth2.service_account import Credentials


def receive_messages():
  """Receives messages from a pull subscription."""

  scopes = ['https://www.googleapis.com/auth/chat.bot']
  service_account_key_path = os.environ.get(
    'GOOGLE_APPLICATION_CREDENTIALS')
  creds = Credentials.from_service_account_file(
    service_account_key_path)
  chat = google_chat.ChatServiceClient(
    credentials = creds,
    client_options = {
      "scopes": scopes
    })

  project_id = os.environ.get('PROJECT_ID')
  subscription_id = os.environ.get('SUBSCRIPTION_ID')
  subscriber = pubsub_v1.SubscriberClient()
  subscription_path = subscriber.subscription_path(
      project_id, subscription_id)

  # Handle incoming message, then ack/nack the received message
  def callback(message):
    event = json.loads(message.data)
    logging.info('Data : %s', event)
    space_name = event['space']['name']

    # Post the response to Google Chat.
    request = format_request(event)
    if request is not None:
      chat.create_message(request)

    # Ack the message.
    message.ack()

  subscriber.subscribe(subscription_path, callback = callback)
  logging.info('Listening for messages on %s', subscription_path)

  # Keep main thread from exiting while waiting for messages
  while True:
    time.sleep(60)


def format_request(event):
  """Send message to Google Chat based on the type of event.
  Args:
    event: A dictionary with the event data.
  """
  space_name = event['space']['name']
  event_type = event['type']

  # If the app was removed, we don't respond.
  if event['type'] == 'REMOVED_FROM_SPACE':
    logging.info('App removed rom space %s', space_name)
    return
  elif event_type == 'ADDED_TO_SPACE' and 'message' not in event:
    # An app can also be added to a space by @mentioning it in a
    # message. In that case, we fall through to the message case
    # and let the app respond. If the app was added using the
    # invite flow, we just post a thank you message in the space.
    return google_chat.CreateMessageRequest(
        parent = space_name,
        message = {
          'text': 'Thank you for adding me!'
        }
    )
  elif event_type in ['ADDED_TO_SPACE', 'MESSAGE']:
    # In case of message, post the response in the same thread.
    return google_chat.CreateMessageRequest(
        parent = space_name,
        message_reply_option = google_chat.CreateMessageRequest.MessageReplyOption.REPLY_MESSAGE_FALLBACK_TO_NEW_THREAD,
        message = {
          'text': 'You said: `' + event['message']['text'] + '`',
          'thread': {
            'name': event['message']['thread']['name']
          }
        }
    )


if __name__ == '__main__':
  if 'PROJECT_ID' not in os.environ:
    logging.error('Missing PROJECT_ID env var.')
    sys.exit(1)

  if 'SUBSCRIPTION_ID' not in os.environ:
    logging.error('Missing SUBSCRIPTION_ID env var.')
    sys.exit(1)

  if 'GOOGLE_APPLICATION_CREDENTIALS' not in os.environ:
    logging.error('Missing GOOGLE_APPLICATION_CREDENTIALS env var.')
    sys.exit(1)

  logging.basicConfig(
      level=logging.INFO,
      style='{',
      format='{levelname:.1}{asctime} {filename}:{lineno}] {message}')
  receive_messages()

Java

在 CLI 中，提供服务账号凭据：

export GOOGLE_APPLICATION_CREDENTIALS=SERVICE_ACCOUNT_FILE_PATH

在 CLI 中，提供 Google Cloud 项目 ID：
```
export PROJECT_ID=PROJECT_ID
```
在 CLI 中，提供您之前创建的 Pub/Sub 订阅的订阅 ID：
```
export SUBSCRIPTION_ID=SUBSCRIPTION_ID
```
在工作目录中，创建一个名为 pom.xml 的文件。

在 pom.xml 文件中，粘贴以下代码：

java/pub-sub-app/pom.xml

在 GitHub 上查看

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>

  <groupId>com.google.chat</groupId>
  <artifactId>pub-sub-app</artifactId>
  <version>0.1.0</version>

  <name>pub-sub-app-java</name>

  <properties>
    <maven.compiler.release>21</maven.compiler.release>
    <maven.compiler.source>1.8</maven.compiler.source>
    <maven.compiler.target>1.8</maven.compiler.target>
  </properties>

  <dependencies>
    <!-- Google Chat GAPIC library -->
    <dependency>
      <groupId>com.google.api.grpc</groupId>
      <artifactId>proto-google-cloud-chat-v1</artifactId>
      <version>0.8.0</version>
    </dependency>
    <dependency>
      <groupId>com.google.api</groupId>
      <artifactId>gax</artifactId>
      <version>2.48.1</version>
    </dependency>
    <dependency>
      <groupId>com.google.cloud</groupId>
      <artifactId>google-cloud-chat</artifactId>
      <version>0.1.0</version>
    </dependency>
    <!-- Google Cloud Pub/Sub library -->
    <dependency>
      <groupId>com.google.cloud</groupId>
      <artifactId>google-cloud-pubsub</artifactId>
    <version>1.125.8</version>
    </dependency>
    <!-- JSON utilities -->
    <dependency>
      <groupId>com.fasterxml.jackson.core</groupId>
      <artifactId>jackson-databind</artifactId>
      <version>2.14.2</version>
    </dependency>
  </dependencies>

</project>

在工作目录中，创建目录结构 src/main/java。
在 src/main/java 目录中，创建一个名为 Main.java 的文件。

在 Main.java 中，粘贴以下代码：

java/pub-sub-app/src/main/java/Main.java

在 GitHub 上查看

import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.google.api.gax.core.FixedCredentialsProvider;
import com.google.auth.oauth2.GoogleCredentials;
import com.google.chat.v1.ChatServiceClient;
import com.google.chat.v1.ChatServiceSettings;
import com.google.chat.v1.CreateMessageRequest;
import com.google.chat.v1.CreateMessageRequest.MessageReplyOption;
import com.google.chat.v1.Message;
import com.google.chat.v1.Thread;
import com.google.cloud.pubsub.v1.AckReplyConsumer;
import com.google.cloud.pubsub.v1.MessageReceiver;
import com.google.cloud.pubsub.v1.Subscriber;
import com.google.pubsub.v1.ProjectSubscriptionName;
import com.google.pubsub.v1.PubsubMessage;
import java.io.FileInputStream;
import java.util.Collections;

public class Main {

  public static final String PROJECT_ID_ENV_PROPERTY = "PROJECT_ID";
  public static final String SUBSCRIPTION_ID_ENV_PROPERTY = "SUBSCRIPTION_ID";
  public static final String CREDENTIALS_PATH_ENV_PROPERTY = "GOOGLE_APPLICATION_CREDENTIALS";

  public static void main(String[] args) throws Exception {
    ProjectSubscriptionName subscriptionName = ProjectSubscriptionName.of(
      System.getenv(Main.PROJECT_ID_ENV_PROPERTY),
      System.getenv(Main.SUBSCRIPTION_ID_ENV_PROPERTY));

    // Instantiate app, which implements an asynchronous message receiver.
    EchoApp echoApp = new EchoApp();

    // Create a subscriber for <var>SUBSCRIPTION_ID</var> bound to the message receiver
    final Subscriber subscriber = Subscriber.newBuilder(subscriptionName, echoApp).build();
    System.out.println("Subscriber is listening to events...");
    subscriber.startAsync();

    // Wait for termination
    subscriber.awaitTerminated();
  }
}

/**
 * A demo app which implements {@link MessageReceiver} to receive messages. It simply echoes the
 * incoming messages.
 */
class EchoApp implements MessageReceiver {

  // Path to the private key JSON file of the service account to be used for posting response
  // messages to Google Chat.
  // In this demo, we are using the same service account for authorizing with Cloud Pub/Sub to
  // receive messages and authorizing with Google Chat to post messages. If you are using
  // different service accounts, please set the path to the private key JSON file of the service
  // account used to post messages to Google Chat here.
  private static final String SERVICE_ACCOUNT_KEY_PATH =
    System.getenv(Main.CREDENTIALS_PATH_ENV_PROPERTY);

  // Developer code for Google Chat API scope.
  private static final String GOOGLE_CHAT_API_SCOPE = "https://www.googleapis.com/auth/chat.bot";

  private static final String ADDED_RESPONSE = "Thank you for adding me!";

  ChatServiceClient chatServiceClient;

  EchoApp() throws Exception {
    GoogleCredentials credential = GoogleCredentials
      .fromStream(new FileInputStream(SERVICE_ACCOUNT_KEY_PATH))
      .createScoped(Collections.singleton(GOOGLE_CHAT_API_SCOPE));

    // Create the ChatServiceSettings with the app credentials
    ChatServiceSettings chatServiceSettings = ChatServiceSettings.newBuilder()
      .setCredentialsProvider(FixedCredentialsProvider.create(credential)).build();

    // Set the Chat service client
    chatServiceClient = ChatServiceClient.create(chatServiceSettings);
  }

  // Called when a message is received by the subscriber.
  @Override
  public void receiveMessage(PubsubMessage pubsubMessage, AckReplyConsumer consumer) {
    System.out.println("Id : " + pubsubMessage.getMessageId());
    // Handle incoming message, then ack/nack the received message
    try {
      ObjectMapper mapper = new ObjectMapper();
      JsonNode dataJson = mapper.readTree(pubsubMessage.getData().toStringUtf8());
      System.out.println("Data : " + dataJson.toString());
      handle(dataJson);
      consumer.ack();
    } catch (Exception e) {
      System.out.println(e);
      consumer.nack();
    }
  }

  // Send message to Google Chat based on the type of event.
  public void handle(JsonNode eventJson) throws Exception {
    CreateMessageRequest createMessageRequest;
    switch (eventJson.get("type").asText()) {
      case "ADDED_TO_SPACE":
        // An app can also be added to a space by @mentioning it in a message. In that case, we fall
        // through to the MESSAGE case and let the app respond. If the app was added using the
        // invite flow, we just post a thank you message in the space.
        if (!eventJson.has("message")) {
          createMessageRequest = CreateMessageRequest.newBuilder()
            .setParent(eventJson.get("space").get("name").asText())
            .setMessage(Message.newBuilder().setText(ADDED_RESPONSE).build()).build();
          break;
        }
      case "MESSAGE":
        // In case of message, post the response in the same thread.
        createMessageRequest = CreateMessageRequest.newBuilder()
          .setParent(eventJson.get("space").get("name").asText())
          .setMessageReplyOption(MessageReplyOption.REPLY_MESSAGE_FALLBACK_TO_NEW_THREAD)
          .setMessage(Message.newBuilder()
            .setText("You said: `" + eventJson.get("message").get("text").asText() + "`")
            .setThread(Thread.newBuilder()
              .setName(eventJson.get("message").get("thread").get("name").asText())
              .build()).build()).build();
        break;
      case "REMOVED_FROM_SPACE":
      default:
        // Do nothing
        return;
    }

    // Post the response to Google Chat.
    chatServiceClient.createMessage(createMessageRequest);
  }
}

使用 Pub/Sub 构建在防火墙后的 Google Chat 应用 使用集合让一切井井有条 根据您的偏好保存内容并对其进行分类。

前提条件

Node.js

Python

Java

设置环境

设置 Pub/Sub

编写脚本

Node.js

Python

Java

将应用发布到 Chat

使用 Pub/Sub 构建在防火墙后的 Google Chat 应用