Google Cloud Pub/Sub: Node.js Client

GCP Pub/Sub GCP Pub/Sub, Node.js Comments

Google Cloud Pub/Sub: Node.js Client

1. 啟用 API 服務

API 服務

2. 建立服務帳戶金鑰

建立服務帳戶金鑰

建立服務帳戶金鑰

3. 啟用驗證

將下載的檔案放到專案中並指定路徑

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export GOOGLE_APPLICATION_CREDENTIALS="[PATH]"

4. install Package

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npm install @google-cloud/pubsub

5. Create Topic

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// Imports the Google Cloud client library
const { PubSub } = require('@google-cloud/pubsub');

async function quickstart(
  projectId = 'your-project-id', // Your Google Cloud Platform project ID
  topicName = 'my-topic' // Name for the new topic to create
) {
  // Instantiates a client
  const pubsub = new PubSub({ projectId });

  // Creates the new topic
  const [topic] = await pubsub.createTopic(topicName);
  console.log(`Topic ${topic.name} created.`);
}
quickstart();

6. Create Subscription

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async function createSubscription(topicName, subscriptionName) {
  // [START pubsub_create_pull_subscription]
  // Imports the Google Cloud client library
  const { PubSub } = require('@google-cloud/pubsub');

  // Creates a client
  const pubsub = new PubSub();

  /**
   * TODO(developer): Uncomment the following lines to run the sample.
   */
  // const topicName = 'my-topic';
  // const subscriptionName = 'my-sub';

  // Creates a new subscription
  await pubsub.topic(topicName).createSubscription(subscriptionName);
  console.log(`Subscription ${subscriptionName} created.`);

  // [END pubsub_create_pull_subscription]
}
createSubscription('my-topic', 'my-topic-Subscription');

7. Push Message

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async function publishMessage(topicName, data) {
  // [START pubsub_publish]
  // [START pubsub_quickstart_publisher]
  // Imports the Google Cloud client library
  const { PubSub } = require('@google-cloud/pubsub');

  // Creates a client
  const pubsub = new PubSub();

  /**
   * TODO(developer): Uncomment the following lines to run the sample.
   */
  // const topicName = 'my-topic';
  // const data = JSON.stringify({ foo: 'bar' });

  // Publishes the message as a string, e.g. "Hello, world!" or JSON.stringify(someObject)
  const dataBuffer = Buffer.from(data);

  const messageId = await pubsub.topic(topicName).publish(dataBuffer);
  console.log(`Message ${messageId} published.`);

  // [END pubsub_publish]
  // [END pubsub_quickstart_publisher]
}
publishMessage('my-topic', 'TestData');

8. Pull Message

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function listenForMessages(subscriptionName, timeout) {
  // [START pubsub_subscriber_async_pull]
  // [START pubsub_quickstart_subscriber]
  // Imports the Google Cloud client library
  const { PubSub } = require('@google-cloud/pubsub');

  // Creates a client
  const pubsub = new PubSub();

  /**
   * TODO(developer): Uncomment the following lines to run the sample.
   */
  // const subscriptionName = 'my-sub';
  // const timeout = 60;

  // References an existing subscription
  const subscription = pubsub.subscription(subscriptionName);

  // Create an event handler to handle messages
  let messageCount = 0;
  const messageHandler = message => {
    console.log(`Received message ${message.id}:`);
    console.log(`\tData: ${message.data}`);
    console.log(`\tAttributes: ${message.attributes}`);
    messageCount += 1;

    // "Ack" (acknowledge receipt of) the message
    message.ack();
  };

  // Listen for new messages until timeout is hit
  subscription.on(`message`, messageHandler);

  setTimeout(() => {
    subscription.removeListener('message', messageHandler);
    console.log(`${messageCount} message(s) received.`);
  }, timeout * 1000);
  // [END pubsub_subscriber_async_pull]
  // [END pubsub_quickstart_subscriber]
}
listenForMessages('my-topic-Subscription', 3);

範例

Reference