建立 App Engine 工作

本頁面說明如何透過程式建立工作並排入 Cloud Tasks 佇列。您可以明確指定由特定服務和處理常式來處理這項工作,並可選擇將工作專屬資料傳送到處理常式。

您可以將工作建立為 HTTP 要求的形式,並依照喜歡的方式來建構工作內容。不過就如同下列範例所示,使用 Google Cloud 用戶端程式庫有助您管理與伺服器之間的低階通訊詳細資料,其中也包括 Google 驗證。

C#

using Google.Cloud.Tasks.V2;
using Google.Protobuf;
using Google.Protobuf.WellKnownTypes;
using System;

class CreateAppEngineTask
{
    public string CreateTask(
        string projectId = "YOUR-PROJECT-ID",
        string location = "us-central1",
        string queue = "my-queue",
        string payload = "Hello World!",
        int inSeconds = 0)
    {
        CloudTasksClient client = CloudTasksClient.Create();
        QueueName parent = new QueueName(projectId, location, queue);

        var response = client.CreateTask(new CreateTaskRequest
        {
            Parent = parent.ToString(),
            Task = new Task
            {
                AppEngineHttpRequest = new AppEngineHttpRequest
                {
                    HttpMethod = HttpMethod.Post,
                    RelativeUri = "/log_payload",
                    Body = ByteString.CopyFromUtf8(payload)
                },
                ScheduleTime = Timestamp.FromDateTime(
                    DateTime.UtcNow.AddSeconds(inSeconds))
            }
        });

        Console.WriteLine($"Created Task {response.Name}");
        return response.Name;
    }
}

Python

"""Create a task for a given queue with an arbitrary payload."""

from google.cloud import tasks_v2
from google.protobuf import timestamp_pb2

# Create a client.
client = tasks_v2.CloudTasksClient()

# TODO(developer): Uncomment these lines and replace with your values.
# project = 'my-project-id'
# queue = 'my-appengine-queue'
# location = 'us-central1'
# payload = 'hello'

# Construct the fully qualified queue name.
parent = client.queue_path(project, location, queue)

# Construct the request body.
task = {
        'app_engine_http_request': {  # Specify the type of request.
            'http_method': 'POST',
            'relative_uri': '/example_task_handler'
        }
}
if payload is not None:
    # The API expects a payload of type bytes.
    converted_payload = payload.encode()

    # Add the payload to the request.
    task['app_engine_http_request']['body'] = converted_payload

if in_seconds is not None:
    # Convert "seconds from now" into an rfc3339 datetime string.
    d = datetime.datetime.utcnow() + datetime.timedelta(seconds=in_seconds)

    # Create Timestamp protobuf.
    timestamp = timestamp_pb2.Timestamp()
    timestamp.FromDatetime(d)

    # Add the timestamp to the tasks.
    task['schedule_time'] = timestamp

# Use the client to build and send the task.
response = client.create_task(parent, task)

print('Created task {}'.format(response.name))
return response

請注意 requirements.txt 檔案:

Flask==1.0.2
gunicorn==19.9.0
google-cloud-tasks==0.6.0

Java

// Instantiates a client.
try (CloudTasksClient client = CloudTasksClient.create()) {

  // Variables provided by the CLI.
  // projectId = "my-project-id";
  // queueName = "my-appengine-queue";
  // location = "us-central1";
  // payload = "hello";

  // Construct the fully qualified queue name.
  String queuePath = QueueName.of(projectId, location, queueName).toString();

  // Construct the task body.
  Task.Builder taskBuilder = Task
      .newBuilder()
      .setAppEngineHttpRequest(AppEngineHttpRequest.newBuilder()
          .setBody(ByteString.copyFrom(payload, Charset.defaultCharset()))
          .setRelativeUri("/tasks/create")
          .setHttpMethod(HttpMethod.POST)
          .build());

  if (params.hasOption(IN_SECONDS_OPTION.getOpt())) {
    // Add the scheduled time to the request.
    int seconds = Integer.parseInt(params.getOptionValue(IN_SECONDS_OPTION.getOpt()));
    taskBuilder.setScheduleTime(Timestamp
        .newBuilder()
        .setSeconds(Instant.now(Clock.systemUTC()).plusSeconds(seconds).getEpochSecond()));
  }

  // Send create task request.
  Task task = client.createTask(queuePath, taskBuilder.build());
  System.out.println("Task created: " + task.getName());
}

請注意 pom.xml 檔案:

<?xml version="1.0" encoding="UTF-8"?>
<!--
Copyright 2018 Google LLC

 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
 You may obtain a copy of the License at

       http://www.apache.org/licenses/LICENSE-2.0

 Unless required by applicable law or agreed to in writing, software
 distributed under the License is distributed on an "AS IS" BASIS,
 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 See the License for the specific language governing permissions and
 limitations under the License.
-->
<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>
  <packaging>war</packaging>
  <version>1.0-SNAPSHOT</version>
  <groupId>com.example.appengine</groupId>
  <artifactId>appengine-tasks-j8</artifactId>

  <!--
    The parent pom defines common style checks and testing strategies for our samples.
    Removing or replacing it should not affect the execution of the samples in anyway.
  -->
  <parent>
    <groupId>com.google.cloud.samples</groupId>
    <artifactId>shared-configuration</artifactId>
    <version>1.0.10</version>
    <relativePath></relativePath>
  </parent>

  <properties>
    <maven.compiler.target>1.8</maven.compiler.target>
    <maven.compiler.source>1.8</maven.compiler.source>
    <failOnMissingWebXml>false</failOnMissingWebXml>
  </properties>

  <dependencies>
    <!-- Compile/runtime dependencies -->
    <dependency>
      <groupId>javax.servlet</groupId>
      <artifactId>javax.servlet-api</artifactId>
      <version>3.1.0</version>
      <type>jar</type>
      <scope>provided</scope>
    </dependency>
    <dependency>
      <groupId>com.google.cloud</groupId>
      <artifactId>google-cloud-tasks</artifactId>
      <version>0.86.0-beta</version>
    </dependency>
    <dependency>
      <groupId>commons-cli</groupId>
      <artifactId>commons-cli</artifactId>
      <version>1.4</version>
      <scope>compile</scope>
    </dependency>
  </dependencies>

  <build>
    <!-- for hot reload of the web application-->
    <outputDirectory>${project.build.directory}/${project.build.finalName}/WEB-INF/classes
    </outputDirectory>
    <plugins>
      <plugin>
        <groupId>com.google.cloud.tools</groupId>
        <artifactId>appengine-maven-plugin</artifactId>
        <version>1.3.2</version>
        <configuration>
          <deploy.promote>true</deploy.promote>
          <deploy.stopPreviousVersion>true</deploy.stopPreviousVersion>
        </configuration>
      </plugin>

      <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-war-plugin</artifactId>
        <version>3.1.0</version>
      </plugin>

      <plugin>
        <groupId>org.codehaus.mojo</groupId>
        <artifactId>exec-maven-plugin</artifactId>
        <version>1.6.0</version>
        <configuration>
          <mainClass>com.example.task.CreateTask</mainClass>
          <cleanupDaemonThreads>false</cleanupDaemonThreads>
        </configuration>
      </plugin>
    </plugins>
  </build>
</project>

PHP

use Google\Cloud\Tasks\V2\AppEngineHttpRequest;
use Google\Cloud\Tasks\V2\CloudTasksClient;
use Google\Cloud\Tasks\V2\HttpMethod;
use Google\Cloud\Tasks\V2\Task;

/** Uncomment and populate these variables in your code */
// $projectId = 'The Google project ID';
// $locationId = 'The Location ID';
// $queueId = 'The Cloud Tasks App Engine Queue ID';
// $payload = 'The payload your task should carry to the task handler. Optional';

// Instantiate the client and queue name.
$client = new CloudTasksClient();
$queueName = $client->queueName($projectId, $locationId, $queueId);

// Create an App Engine Http Request Object.
$httpRequest = new AppEngineHttpRequest();
// The path of the HTTP request to the App Engine service.
$httpRequest->setRelativeUri('/task_handler');
// POST is the default HTTP method, but any HTTP method can be used.
$httpRequest->setHttpMethod(HttpMethod::POST);
// Setting a body value is only compatible with HTTP POST and PUT requests.
if (isset($payload)) {
    $httpRequest->setBody($payload);
}

// Create a Cloud Task object.
$task = new Task();
$task->setAppEngineHttpRequest($httpRequest);

// Send request and print the task name.
$response = $client->createTask($queueName, $task);
printf('Created task %s' . PHP_EOL, $response->getName());

請注意 composer.json 檔案:

{
    "require": {
        "google/cloud-tasks": "^0.8.0"
    },
    "require-dev": {
        "phpunit/phpunit": "^5",
        "google/cloud-tools": "^0.8.5"
    }
}

Go

// Command create_task constructs and adds a task to an App Engine Queue.
package main

import (
	"context"
	"fmt"

	cloudtasks "cloud.google.com/go/cloudtasks/apiv2"
	taskspb "google.golang.org/genproto/googleapis/cloud/tasks/v2"
)

// createTask creates a new task in your App Engine queue.
func createTask(projectID, locationID, queueID, message string) (*taskspb.Task, error) {
	// Create a new Cloud Tasks client instance.
	// See https://godoc.org/cloud.google.com/go/cloudtasks/apiv2
	ctx := context.Background()
	client, err := cloudtasks.NewClient(ctx)
	if err != nil {
		return nil, fmt.Errorf("NewClient: %v", err)
	}

	// Build the Task queue path.
	queuePath := fmt.Sprintf("projects/%s/locations/%s/queues/%s", projectID, locationID, queueID)

	// Build the Task payload.
	// https://godoc.org/google.golang.org/genproto/googleapis/cloud/tasks/v2#CreateTaskRequest
	req := &taskspb.CreateTaskRequest{
		Parent: queuePath,
		Task: &taskspb.Task{
			// https://godoc.org/google.golang.org/genproto/googleapis/cloud/tasks/v2#AppEngineHttpRequest
			MessageType: &taskspb.Task_AppEngineHttpRequest{
				AppEngineHttpRequest: &taskspb.AppEngineHttpRequest{
					HttpMethod:  taskspb.HttpMethod_POST,
					RelativeUri: "/task_handler",
				},
			},
		},
	}

	// Add a payload message if one is present.
	if message != "" {
		req.Task.GetAppEngineHttpRequest().Body = []byte(message)
	}

	createdTask, err := client.CreateTask(ctx, req)
	if err != nil {
		return nil, fmt.Errorf("cloudtasks.CreateTask: %v", err)
	}

	return createdTask, nil
}

Node.js

// Imports the Google Cloud Tasks library.
const {CloudTasksClient} = require('@google-cloud/tasks');

// Instantiates a client.
const client = new CloudTasksClient();

// TODO(developer): Uncomment these lines and replace with your values.
// const project = 'my-project-id';
// const queue = 'my-appengine-queue';
// const location = 'us-central1';
// const options = {payload: 'hello'};

// Construct the fully qualified queue name.
const parent = client.queuePath(project, location, queue);

const task = {
  appEngineHttpRequest: {
    httpMethod: 'POST',
    relativeUri: '/log_payload',
  },
};

if (payload) {
  task.appEngineHttpRequest.body = Buffer.from(payload).toString('base64');
}

if (inSeconds) {
  task.scheduleTime = {
    seconds: inSeconds + Date.now() / 1000,
  };
}

const request = {
  parent: parent,
  task: task,
};

console.log('Sending task:');
console.log(task);
// Send create task request.
const [response] = await client.createTask(request);
const name = response.name;
console.log(`Created task ${name}`);

請注意 package.json 檔案:

{
  "name": "appengine-cloudtasks",
  "description": "Google App Engine Cloud Tasks example.",
  "license": "Apache-2.0",
  "author": "Google Inc.",
  "private": true,
  "engines": {
    "node": ">=8"
  },
  "scripts": {
    "test": "mocha",
    "start": "node server.js"
  },
  "dependencies": {
    "@google-cloud/tasks": "^0.5.0",
    "body-parser": "^1.18.3",
    "express": "^4.16.3",
    "yargs": "^13.0.0"
  },
  "devDependencies": {
    "chai": "^4.2.0",
    "mocha": "^6.1.3",
    "uuid": "^3.3.2"
  }
}

Ruby

require "google/cloud/tasks"

# Create an App Engine Task
#
# @param [String] project_id Your Google Cloud Project ID.
# @param [String] location_id Your Google Cloud Project Location ID.
# @param [String] queue_id Your Google Cloud App Engine Queue ID.
# @param [String] payload The request body of your task.
# @param [Integer] seconds The delay, in seconds, to process your task.
def create_task project_id, location_id, queue_id, payload: nil, seconds: nil
  # Instantiates a client.
  cloud_tasks = Google::Cloud::Tasks.new

  # Construct the fully qualified queue name.
  parent = cloud_tasks.queue_path project_id, location_id, queue_id

  # Construct task.
  task = {
    app_engine_http_request: {
      http_method:  "POST",
      relative_uri: "/log_payload"
    }
  }

  # Add payload to task body.
  if payload
    task[:app_engine_http_request][:body] = payload
  end

  # Add scheduled time to task.
  if seconds
    timestamp = Google::Protobuf::Timestamp.new
    timestamp.seconds = Time.now.to_i + seconds.to_i
    task[:schedule_time] = timestamp
  end

  # Send create task request.
  puts "Sending task #{task}"
  response = cloud_tasks.create_task parent, task

  puts "Created task #{response.name}" if response.name
end

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