Error uploading to google storage: wrong content-type

I am using boto3 to upload data to Google Storage. This works fine with Minio locally, however it fails with medium-sized files (seems to work with files under 10 MB, probably because it doesn’t multipart).

Is this a bug with Google? Is there a missing content-type in boto3 like the error suggests?

>>> import boto3
>>> from botocore.client import Config
>>> s3 = boto3.resource(
...     's3', endpoint_url='https://storage.googleapis.com',
...     aws_access_key_id='GOOGxxx',
...     aws_secret_access_key='xxx',
...     config=Config(signature_version='s3v4'),
... )
>>> s3.meta.client.upload_file('80-mb-file', 'rpz-staging-experiments', 'testup1508')
    ...
DEBUG:s3transfer.futures:Submitting task UploadPartTask(transfer_id=0, {'bucket': 'rpz-staging-experiments', 'key': 'testup1508', 'part_number': 10, 'extra_args': {}}) to executor <s3transfer.futures.BoundedExecutor object at 0x7f22e09224e0> for transfer request: 0.
DEBUG:s3transfer.tasks:UploadPartTask(transfer_id=0, {'bucket': 'rpz-staging-experiments', 'key': 'testup1508', 'part_number': 9, 'extra_args': {}}) about to wait for <s3transfer.futures.ExecutorFuture object at 0x7f22e08be0b8>
DEBUG:s3transfer.utils:Acquiring 0
DEBUG:s3transfer.futures:Submitting task CompleteMultipartUploadTask(transfer_id=0, {'bucket': 'rpz-staging-experiments', 'key': 'testup1508', 'extra_args': {}}) to executor <s3transfer.futures.BoundedExecutor object at 0x7f22e09224e0> for transfer request: 0.
DEBUG:s3transfer.utils:Acquiring 0
DEBUG:s3transfer.utils:Releasing acquire 0/None
DEBUG:urllib3.connectionpool:https://storage.googleapis.com:443 "POST /rpz-staging-experiments/testup1508?uploads HTTP/1.1" 400 188
DEBUG:botocore.parsers:Response headers: {'X-GUploader-UploadID': 'AEnB2UpbuUOI0xfCna_66UOniFYBFGM9jRmLg5bXqdWQcJGgNEl9FJvYjggDSfN11lxU2WTn8D53ygUrGF7hA-quabCwHg7EAg', 'Content-Type': 'application/xml; charset=UTF-8', 'Content-Length': '188', 'Vary': 'Origin', 'Date': 'Sat, 16 Nov 2019 20:10:59 GMT', 'Server': 'UploadServer', 'Alt-Svc': 'quic=":443"; ma=2592000; v="46,43",h3-Q050=":443"; ma=2592000,h3-Q049=":443"; ma=2592000,h3-Q048=":443"; ma=2592000,h3-Q046=":443"; ma=2592000,h3-Q043=":443"; ma=2592000'}
DEBUG:botocore.parsers:Response body:
b"<?xml version='1.0' encoding='UTF-8'?><Error><Code>InvalidArgument</Code><Message>Invalid argument.</Message><Details>POST object expects Content-Type multipart/form-data</Details></Error>"
    ...

[diehlaws]

Thanks for reaching out to us @remram44. It appears this behavior is due to a difference in implementation of object storage services between S3 and Google Storage. S3 does not require including a Content-Type header in UploadPart or CompleteMultipartUpload requests, as a result boto3 does not include this header for these requests. However, judging by the error you received it looks like Google Storage does require this header to have a value of multipart/form-data for one of these operations.

The fix you mentioned works because it is not performing a multi-part upload, as such I recommend checking the limits on single-PUT uploads for Google Storage (S3 supports up to 5GB files to be uploaded in a single PUT). Another approach is to adjust the multipart_threshold value in a TransferConfig object that gets passed into the upload_file() call as shown here.

[diehlaws]

No problem! Sorry to hear that modifying the request’s content-type doesn’t work as expected but I’m glad to hear you at least have a workaround to fit your use case. Please don’t hesitate to reach out again if you have additional questions for us.