错误18:无效的跨设备链接

Question

我在amazon lambda上写了一个函数，并写了下面的脚本，但我得到了一个错误。只要将对象放入S3存储桶中，脚本就会运行。

s3 = boto3.client('s3')

def lambda_handler(event, context):
    path = '/tmp/videos'
    if not os.path.exists(path):
        os.makedirs(path)
    for record in event['Records']:
        bucket = record['s3']['bucket']['name']
        key = record['s3']['object']['key'] 
        try:
            response = s3.get_object(Bucket=bucket, Key=key)
            print("CONTENT TYPE: " + response['ContentType'])
            video_path = '/tmp/{}'.format(key)
            download_path = '/tmp/'
            print('video path: ' + video_path)
            print('download path: ' + download_path)
            print('key: ' + key)
            print('bucket: ' + bucket)
            s3.download_file(bucket, key, download_path)
        except Exception as e:
            print(e)
            print('Error getting object {} from bucket {}. Make sure they exist and your bucket is in the same region as this function.'.format(key, bucket))
            raise e

我测试了这个函数，得到了以下输出：

START RequestId: aa42300f-5f52-11e6-a14e-a3511b08d368 Version: $LATEST
CONTENT TYPE: video/mp4
video path: /tmp/videos/20160810-182413-jjrni-capturedvideo.mp4
download path: /tmp/
key: videos/20160810-182413-jjrni-capturedvideo.mp4
bucket: bucket
[Errno 18] Invalid cross-device link
Error getting object videos/20160810-182413-jjrni-capturedvideo.mp4 from bucket bucket. Make sure they exist and your bucket is in the same region as this function.
[Errno 18] Invalid cross-device link: OSError
Traceback (most recent call last):
  File "/var/task/CreateThumbnail.py", line 48, in lambda_handler
    raise e
OSError: [Errno 18] Invalid cross-device link
END RequestId: aa42300f-5f52-11e6-a14e-a3511b08d368

错误来自：

s3.download_file(bucket, key, download_path)

我不确定为什么当s3可以从以下位置检索密钥和存储桶时，下载文件时会出现错误：

response = s3.get_object(Bucket=bucket, Key=key)

如有任何帮助，我们不胜感激！( S3存储桶采用美国标准，我认为是US-East1，而Lambda函数采用US-N。弗吉尼亚州)

Answer 1

您的问题看起来类似于这个https://github.com/amorton/cassback/issues/2

从/tmp构建相对路径而不是文件怎么样？

还有，为什么你需要把文件放到服务器上？