Luigi Pipeline從S3開始

Question

我的初始文件在AWS S3 。 有人能指出我需要在Luigi Task設置這個嗎？

我查看了文檔並找到了luigi.S3但我不清楚該怎么做，然后我在網上搜索，只獲得了從mortar-luigi和實施在luigi頂部的鏈接。

UPDATE

按照為@matagus提供的示例（我也按照建議創建了~/.boto文件）：

# coding: utf-8

import luigi

from luigi.s3 import S3Target, S3Client

class MyS3File(luigi.ExternalTask):
    def output(self):
        return S3Target('s3://my-bucket/19170205.txt')

class ProcessS3File(luigi.Task):

    def requieres(self):
        return MyS3File()

    def output(self):
        return luigi.LocalTarget('/tmp/resultado.txt')

    def run(self):
        result = None

        for input in self.input():
           print("Doing something ...")
           with input.open('r') as f:
               for line in f:
                   result = 'This is a line'

        if result:
            out_file = self.output().open('w')
            out_file.write(result)

當我執行它時沒有任何反應

DEBUG: Checking if ProcessS3File() is complete
INFO: Informed scheduler that task   ProcessS3File()   has status   PENDING
INFO: Done scheduling tasks
INFO: Running Worker with 1 processes
DEBUG: Asking scheduler for work...
DEBUG: Pending tasks: 1
INFO: [pid 21171] Worker Worker(salt=226574718, workers=1, host=heliodromus, username=nanounanue, pid=21171) running   ProcessS3File()
INFO: [pid 21171] Worker Worker(salt=226574718, workers=1, host=heliodromus, username=nanounanue, pid=21171) done      ProcessS3File()
DEBUG: 1 running tasks, waiting for next task to finish
INFO: Informed scheduler that task   ProcessS3File()   has status   DONE
DEBUG: Asking scheduler for work...
INFO: Done
INFO: There are no more tasks to run at this time
INFO: Worker Worker(salt=226574718, workers=1, host=heliodromus, username=nanounanue, pid=21171) was stopped. Shutting down Keep-Alive thread

如你所見，消息Doing something...從不打印。 怎么了？

Answer 1

這里的關鍵是定義一個沒有輸入的外部任務 ，哪個輸出是你在S3中生活的那些文件。 Luigi docs在要求另一項任務中提到這一點：

請注意，requires（）無法返回Target對象。 如果您有一個在外部創建的簡單Target對象，則可以將其包裝在Task類中

所以，基本上你最終得到這樣的東西：

import luigi

from luigi.s3 import S3Target

from somewhere import do_something_with


class MyS3File(luigi.ExternalTask):

    def output(self):
        return luigi.S3Target('s3://my-bucket/path/to/file')

class ProcessS3File(luigi.Task):

    def requires(self):
        return MyS3File()

    def output(self):
        return luigi.S3Target('s3://my-bucket/path/to/output-file')

    def run(self):
        result = None
        # this will return a file stream that reads the file from your aws s3 bucket
        with self.input().open('r') as f:
            result = do_something_with(f)

        # and the you 
        out_file = self.output().open('w')
        # it'd better to serialize this result before writing it to a file, but this is a pretty simple example
        out_file.write(result)

更新：

Luigi使用boto從AWS S3讀取文件和/或將它們寫入AWS S3，因此為了使此代碼正常工作，您需要在boto配置文件中提供您的憑據~/boto （ 在此處查找其他可能的配置文件位置） ）：

[Credentials]
aws_access_key_id = <your_access_key_here>
aws_secret_access_key = <your_secret_key_here>