python - 提供 pubsub 主题作为参数的数据流错误

问题描述

我有一个问题，我正在使用 python 创建一个数据流模板，并且这个模板在启动一个新的数据流作业时需要接受 3 个用户定义的参数。

问题出现在 beam.io.gcp.pubsub.WriteToPubSub() 中，我尝试从 ValueProvider 提供主题名称，根据谷歌文档，创建模板时需要该名称：

https://cloud.google.com/dataflow/docs/guides/templates/creating-templates

源 beam.io.ReadFromPubSub() 与转换 beam.io.gcp.bigquery.WriteToBigQuery() 一样，成功接受订阅值的值提供程序。

显然分享我的代码会有所帮助:)

首先是通常的进口：

from __future__ import absolute_import

import argparse
import apache_beam as beam
from apache_beam.options.pipeline_options import PipelineOptions
from apache_beam.options.pipeline_options import SetupOptions
from apache_beam.options.pipeline_options import StandardOptions
from apache_beam.options.value_provider import StaticValueProvider
import json
import time
from datetime import datetime
import dateutil.parser
import sys

接下来是我为提供给模板的输入参数定义的类：

class userOptions(PipelineOptions):
    @classmethod
    def _add_argparse_args(cls, parser):
        parser.add_value_provider_argument(
            '--subscription',  
            default='projects/MYPROJECT/subscrpiptions/subscription', 
            help='PubSub subscription to listen on')
        parser.add_value_provider_argument(
            '--bqtable', 
            default='dataset.table', 
            help='Big Query Table Name in the format project:dataset.table') 
        parser.add_value_provider_argument(
            '--topic',  
            default='projects/MYPROJECT/subscrpiptions/subscription', 
            help='PubSub topic to write failed messages to')

管道本身定义为（注意我省略了地图功能）

def run():

    user_options = PipelineOptions().view_as(userOptions)

    pipeline_options = PipelineOptions()
    pipeline_options.view_as(SetupOptions).save_main_session = True
    pipeline_options.view_as(StandardOptions).streaming = True

    with beam.Pipeline(options=pipeline_options) as p:

        records = ( 
        p  | 'Read from PubSub' 
            >> beam.io.ReadFromPubSub(
                subscription=str(user_options.subscription),
                id_label='Message_ID',
                with_attributes=True)
        | 'Format Message' >> 
            beam.Map(format_message_element)
        | 'Transform null records to empty list' >>
            beam.Map(transform_null_records)
        | 'Transform Dates' >>
            beam.Map(format_dates)
        | 'Write to Big Query' >>
            beam.io.gcp.bigquery.WriteToBigQuery(
                table=user_options.bqtable,
                create_disposition='CREATE_IF_NEEDED',
                write_disposition='WRITE_APPEND',
                insert_retry_strategy='RETRY_NEVER'
            )
        | 'Write Failures to Pub Sub' >>
            beam.io.gcp.pubsub.WriteToPubSub(user_options.topic)
        )

现在，当我尝试使用 powershell 命令生成模板时：

python profiles-pipeline.py --project xxxx-xxxxxx-xxxx `
--subscription projects/xxxx-xxxxxx-xxxx/subscriptions/sub-xxxx-xxxxxx-xxxx-dataflow `
--bqtable xxxx-xxxxxx-xxxx:dataset.table `
--topic projects/xxxx-xxxxxx-xxxx/topics/top-xxxx-xxxxxx-xxxx-failures `
--runner DataflowRunner `
--temp_location gs://xxxx-xxxxxx-xxxx/temp/ `
--staging_location gs://xxxx-xxxxxx-xxxx/staging/ `
--template_location gs://xxxx-xxxxxx-xxxx/template

我收到此错误：

File "pipeline.py", line 193, in <module>
    run()
  File "pipeline.py", line 183, in run
    beam.io.gcp.pubsub.WriteToPubSub(user_options.topic)
  File "C:\github\pipeline-dataflow-jobs\dataflow\lib\site-packages\apache_beam\io\gcp\pubsub.py", line 292, in __init__
    topic, id_label, with_attributes, timestamp_attribute)
  File "C:\github\pipeline-dataflow-jobs\dataflow\lib\site-packages\apache_beam\io\gcp\pubsub.py", line 430, in __init__
    self.project, self.topic_name = parse_topic(topic)
  File "C:\github\pipeline-dataflow-jobs\dataflow\lib\site-packages\apache_beam\io\gcp\pubsub.py", line 325, in parse_topic
    match = re.match(TOPIC_REGEXP, full_topic)
  File "c:\program files\python37\lib\re.py", line 173, in match
    return _compile(pattern, flags).match(string)
TypeError: expected string or bytes-like object

我之前在尝试使用 beam.io.WriteToBigQuery() 时遇到过这个错误，但是一旦我更改为 beam.io.gcp.bigquery.WriteToBigQuery() 错误就得到了解决，因为它接受表名的 ValueProvider。但是对于 pubsub，我找不到有效的写入方法。

非常感激任何的帮助。

标签： pythonapache-beam

python - 提供 pubsub 主题作为参数的数据流错误

问题描述

解决方案

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