OSError: Errno 30Read-only file system: 我正在尝试使用 Lambda 将一些文件从 FTP 传输到 S3。 该代码适用于笔记本电脑，文件在 S3 中可见

Question

I tried to use different libraries as s3fs and wrote a new code which also returned the same error. This code have been working on my laptop fine and I could see the files from FTP server in S3 bucket, but no luck on running on lambda. The handler name have been updated in lambda. It looks like something is wrong while trying to download the files itself. I am a newbie to coding, especially Python. Any help or Insights are welcomed. The error at lambda execution is: Downloading: on_dth2_tv_sources_v22_20210602.xml.gz [ERROR] OSError: [Errno 30] Read-only file system: 'on_dth2_tv_sources_v22_20210602.xml.gz' Traceback (most recent call last):

The code is:

import boto3 
import os
import ftplib
#FTP HOST AND CREDENTIALS
FTP_HOST = "*******"
FTP_USER = "*****"
FTP_PASS = "*****"

#AWS Bucket
s3 = boto3.resource('s3')
bucket = "*******"
def lambda_handler(event, context):
    Epg_Ftp = ftplib.FTP(FTP_HOST) #Connecting to FTP server
    Epg_Ftp.login(FTP_USER, FTP_PASS) #logging in to FTP
    print(Epg_Ftp.pwd())
    path = "*****" #epg directory
    Epg_Ftp.cwd(path)  #moving to epg directory
    print(Epg_Ftp.pwd())
    filenames = Epg_Ftp.nlst() # get filenames within the directory
    # print(filenames)   
    for file in filenames:
        print(f"\nDownloading : {file}")
        with open(file, "wb") as bfile:
            Epg_Ftp.retrbinary(f"RETR {file}", bfile.write)
            s3.meta.client.upload_file( + file, bucket, file) #uploading to S3
            print(f"File {file} uploaded to S3")
        Epg_Ftp.quit

Answer 1

The problem you're having is that you can't write to the directory that your lambda code is executing in when you do open(file, "wb") . Lambda does provide a 500MB temporary disk at /tmp . So if you change the path for file to be in /tmp it should work.

        with open('/tmp/' + file, "wb") as bfile:

You'll probably also want to delete the files in the loop as well so that you don't use up all the 500MB of disk space. If any single file is over 500MB, you won't be able to do it this way.