Permission denied on Windows when template > TEMPLATE_BODY_SIZE_LIMIT

[alytle]

When a template file size is greater than TEMPLATE_BODY_SIZE_LIMIT on Windows, we see this error:

Successfully packaged artifacts and uploaded to s3://awscfncli-853215655166-us-east-1.
Template body is too large, uploading as artifact.
Template uploaded to s3://awscfncli-<account>-us-east-1/stack/<guid>.template.json
PermissionError: [Errno 13] Permission denied: 'C:\\Users\\USER~1\\AppData\\Local\\Temp\\1\\tmpldldvc8h'

The problem is here:

awscfncli/awscfncli2/runner/runbook/package.py

Lines 112 to 130 in 42297e6

	with tempfile.NamedTemporaryFile(mode='wb') as fp:
	# write template body to local temp file
	fp.write(template_data)
	fp.flush()
	# upload to s3
	template_location = s3_uploader.upload_with_dedup(
	fp.name,
	extension='template.json')
	ppt.secho('Template uploaded to %s' % template_location)
	# get s3 object key ...upload_with_dedup() returns s3://bucket/key
	template_key = template_location.replace('s3://%s/' % bucket_name, '')
	# generate a pre-signed url for CloudFormation as the object in S3
	# is private by default
	template_url = s3_client.generate_presigned_url(
	ClientMethod='get_object',
	Params={'Bucket': bucket_name, 'Key': template_key},
	ExpiresIn=3600
	)

Referring to a NamedTemporaryFile by name after instantiation is not cross platform, and fails on Windows. From http://docs.python.org/library/tempfile.html#tempfile.NamedTemporaryFile:

Whether the name can be used to open the file a second time, while
the named temporary file is still open, varies across platforms (it can
be so used on Unix; it cannot on Windows NT or later)

See bravoserver/bravo#111 for another example of this issue.

See also bravoserver/bravo#111 (comment) for a suggestion on a Windows alternative.

Another suggestion (from deepchem/deepchem#707 (comment)) is to stop using NamedTemporaryFile entirely:

Consider using os.path.join(tempfile.gettempdir(), os.urandom(24).hex()) instead. It's reliable, cross-platform, and the only caveat is that it doesn't work on FAT partitions.

[Kotaimen]

Hi @GlieseRay:

Do you still have that Surface laptop to reproduce this? It may be a bit late but considering adding a test? (and figure out how to run windows tests on CodeBuild)

Kotaimen

[GlieseRay]

@Kotaimen Sure, will take look

[GlieseRay]

Tested on local windows machine. Seems OK now. Close this ticket.