MQTT to Pub/Sub 範本

/*
 * Copyright (C) 2023 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.
 */
package com.google.cloud.teleport.v2.templates;

import com.google.cloud.teleport.metadata.Template;
import com.google.cloud.teleport.metadata.TemplateCategory;
import com.google.cloud.teleport.metadata.TemplateParameter;
import java.nio.charset.StandardCharsets;
import org.apache.beam.sdk.Pipeline;
import org.apache.beam.sdk.PipelineResult;
import org.apache.beam.sdk.io.gcp.pubsub.PubsubIO;
import org.apache.beam.sdk.io.mqtt.MqttIO;
import org.apache.beam.sdk.options.PipelineOptions;
import org.apache.beam.sdk.options.PipelineOptionsFactory;
import org.apache.beam.sdk.options.Validation;
import org.apache.beam.sdk.transforms.DoFn;
import org.apache.beam.sdk.transforms.ParDo;

/**
 * Dataflow template which reads data from Mqtt Topic and writes it to Cloud PubSub.
 *
 * <p>Check out <a
 * href="https://github.com/GoogleCloudPlatform/DataflowTemplates/blob/main/v2/mqtt-to-pubsub/README_Mqtt_to_PubSub.md">README</a>
 * for instructions on how to use or modify this template.
 */
@Template(
    name = "Mqtt_to_PubSub",
    category = TemplateCategory.STREAMING,
    displayName = "MQTT to Pubsub",
    description =
        "The MQTT to Pub/Sub template is a streaming pipeline that reads messages from an MQTT topic and writes them to Pub/Sub. "
            + "It includes the optional parameters <code>username</code> and <code>password</code> in case authentication is required by the MQTT server.",
    optionsClass = MqttToPubsub.MqttToPubsubOptions.class,
    flexContainerName = "mqtt-to-pubsub",
    contactInformation = "https://cloud.google.com/support",
    documentation =
        "https://cloud.google.com/dataflow/docs/guides/templates/provided/mqtt-to-pubsub",
    preview = true,
    requirements = {
      "The Pub/Sub output topic name must exist.",
      "The MQTT host IP must exist and have the proper network configuration for worker machines to reach the MQTT host.",
      "The MQTT topic that data is extracted from must have a name."
    },
    streaming = true,
    supportsAtLeastOnce = true)
public class MqttToPubsub {

  /**
   * Runs a pipeline which reads data from Mqtt topic and writes it to Cloud PubSub.
   *
   * @param args arguments to the pipeline
   */
  public static void main(String[] args) {
    MqttToPubsubOptions options =
        PipelineOptionsFactory.fromArgs(args).withValidation().as(MqttToPubsubOptions.class);
    run(options);
  }

  public static void validate(MqttToPubsubOptions options) {
    if (options != null) {
      if ((options.getUsername() != null && !options.getUsername().isEmpty())
          && (options.getPassword() == null || options.getPassword().isBlank())) {
        throw new IllegalArgumentException(
            "While username is provided, password is required for authentication");
      }
    }
  }

  public static PipelineResult run(MqttToPubsubOptions options) {
    validate(options);
    Pipeline pipeline = Pipeline.create(options);
    MqttIO.Read<byte[]> mqttIo;
    if (!options.getUsername().isEmpty() || !options.getPassword().isBlank()) {
      mqttIo =
          MqttIO.read()
              .withConnectionConfiguration(
                  MqttIO.ConnectionConfiguration.create(
                          options.getBrokerServer(), options.getInputTopic())
                      .withUsername(options.getUsername())
                      .withPassword(options.getPassword()));
    } else {
      mqttIo =
          MqttIO.read()
              .withConnectionConfiguration(
                  MqttIO.ConnectionConfiguration.create(
                      options.getBrokerServer(), options.getInputTopic()));
    }

    return pipeline
        .apply("ReadFromMqttTopic", mqttIo)
        .apply(ParDo.of(new ByteToStringTransform()))
        .apply("WriteToPubSubTopic", PubsubIO.writeStrings().to(options.getOutputTopic()))
        .getPipeline()
        .run();
  }

  static class ByteToStringTransform extends DoFn<byte[], String> {
    @ProcessElement
    public void processElement(@Element byte[] word, OutputReceiver<String> out) {
      out.output(new String(word, StandardCharsets.UTF_8));
    }
  }

  /**
   * The {@link MqttToPubsubOptions} interface provides the custom execution options passed by the
   * executor at the command-line.
   */
  public interface MqttToPubsubOptions extends PipelineOptions {
    @TemplateParameter.Text(
        order = 1,
        groupName = "Source",
        optional = true,
        regexes = {"[,\\/:a-zA-Z0-9._-]+"},
        description = "MQTT Broker IP",
        helpText = "The MQTT broker server IP or host.",
        example = "tcp://host:1883")
    @Validation.Required
    String getBrokerServer();

    void setBrokerServer(String brokerServer);

    @TemplateParameter.Text(
        order = 2,
        groupName = "Source",
        optional = false,
        regexes = {"[\\/a-zA-Z0-9._-]+"},
        description = "MQTT topic(s) to read the input from",
        helpText = "The name of the MQTT topic that data is read from.",
        example = "topic")
    @Validation.Required
    String getInputTopic();

    void setInputTopic(String inputTopics);

    @TemplateParameter.PubsubTopic(
        order = 3,
        groupName = "Target",
        description = "Output Pub/Sub topic",
        helpText = "The name of the output Pub/Sub topic that data is written to.",
        example = "projects/your-project-id/topics/your-topic-name")
    @Validation.Required
    String getOutputTopic();

    void setOutputTopic(String outputTopic);

    @TemplateParameter.Text(
        order = 4,
        description = "MQTT Username",
        helpText = "The username to use for authentication on the MQTT server.",
        example = "sampleusername")
    String getUsername();

    void setUsername(String username);

    @TemplateParameter.Password(
        order = 5,
        description = "MQTT Password",
        helpText = "The password associated with the provided username.",
        example = "samplepassword")
    String getPassword();

    void setPassword(String password);
  }
}