错误“只读文件系统"从 S3 下载文件时在 AWS Lambda 中 [英] Error "Read-only file system" in AWS Lambda when downloading a file from S3

问题描述

当我将 file.csv 放入 S3 存储桶时，我在 lambda 函数中看到以下错误.该文件并不大，我什至在打开文件进行读取之前添加了 60 秒的睡眠，但由于某种原因，该文件附加了额外的.6CEdFe7C".这是为什么?

I'm seeing the below error from my lambda function when I drop a file.csv into an S3 bucket. The file is not large and I even added a 60 second sleep prior to opening the file for reading, but for some reason the file has the extra ".6CEdFe7C" appended to it. Why is that?

[Errno 30] Read-only file system: u'/file.csv.6CEdFe7C': IOError
Traceback (most recent call last):
File "/var/task/lambda_function.py", line 75, in lambda_handler
s3.download_file(bucket, key, filepath)
File "/var/runtime/boto3/s3/inject.py", line 104, in download_file
extra_args=ExtraArgs, callback=Callback)
File "/var/runtime/boto3/s3/transfer.py", line 670, in download_file
extra_args, callback)
File "/var/runtime/boto3/s3/transfer.py", line 685, in _download_file
self._get_object(bucket, key, filename, extra_args, callback)
File "/var/runtime/boto3/s3/transfer.py", line 709, in _get_object
extra_args, callback)
File "/var/runtime/boto3/s3/transfer.py", line 723, in _do_get_object
with self._osutil.open(filename, 'wb') as f:
File "/var/runtime/boto3/s3/transfer.py", line 332, in open
return open(filename, mode)
IOError: [Errno 30] Read-only file system: u'/file.csv.6CEdFe7C'

代码:

def lambda_handler(event, context):

    s3_response = {}
    counter = 0
    event_records = event.get("Records", [])

    s3_items = []
    for event_record in event_records:
        if "s3" in event_record:
            bucket = event_record["s3"]["bucket"]["name"]
            key = event_record["s3"]["object"]["key"]
            filepath = '/' + key
            print(bucket)
            print(key)
            print(filepath)
            s3.download_file(bucket, key, filepath)

上面的结果是:

mytestbucket
file.csv
/file.csv
[Errno 30] Read-only file system: u'/file.csv.6CEdFe7C'

如果密钥/文件是file.csv"，那么为什么 s3.download_file 方法会尝试下载file.csv.6CEdFe7C"?我猜当函数被触发时，文件是 file.csv.xxxxx 但是当它到达第 75 行时，文件被重命名为 file.csv?

If the key/file is "file.csv", then why does the s3.download_file method try to download "file.csv.6CEdFe7C"? I'm guessing when the function is triggered, the file is file.csv.xxxxx but by the time it gets to line 75, the file is renamed to file.csv?

推荐答案

似乎只有 /tmp 在 AWS Lambda 中是可写的.

Only /tmp seems to be writable in AWS Lambda.

因此这会起作用:

filepath = '/tmp/' + key

参考文献:

• https://aws.amazon.com/blogs/compute/choosing-between-aws-lambda-data-storage-options-in-web-apps
• https://docs.aws.amazon.com/lambda/latest/dg/gettingstarted-limits.html

这篇关于错误“只读文件系统"从 S3 下载文件时在 AWS Lambda 中的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！