I'm trying to download an OpenStack image from glance using only the Openstack Python SDK, but I only get this error:
Traceback (most recent call last):
File "/home/openstack/discovery/discovery.py", line 222, in <module>
main(sys.argv[1:])
File "/home/openstack/discovery/discovery.py", line 117, in main
image_service.download_image(image)
File "/usr/local/lib/python2.7/dist-packages/openstack/image/v2/_proxy.py", line 72, in download_image
return image.download(self.session)
File "/usr/local/lib/python2.7/dist-packages/openstack/image/v2/image.py", line 166, in download
checksum = resp.headers["Content-MD5"]
File "/usr/local/lib/python2.7/dist-packages/requests/structures.py", line 54, in __getitem__
return self._store[key.lower()][1]
KeyError: 'content-md5'
The weird part is that if I run the code using an IDE (PyCharm with remote debug) or as a script (python script.py -i ...) I get the error, but if I run each line using a python interpreter (ipython/python) the error does not happen! Have no idea why.
Here is the code I'm using:
...
image_name = node.name + "_" + time.strftime("%Y-%m-%d_%H-%M-%S")
print "Getting data from", node.name
compute_service.create_server_image(node, image_name)
image = image_service.find_image(image_name)
image_service.wait_for_status(image, 'active')
fileName = "%s.img" % image.name
with open(str(fileName), 'w+') as imgFile:
imgFile.write(image.download(conn.image.session))
...
This code ends up calling the API in this file /usr/local/lib/python2.7/dist-packages/openstack/image/v2/image.py
, with this method:
def download(self, session):
"""Download the data contained in an image"""
# TODO(briancurtin): This method should probably offload the get
# operation into another thread or something of that nature.
url = utils.urljoin(self.base_path, self.id, 'file')
resp = session.get(url, endpoint_filter=self.service)
checksum = resp.headers["Content-MD5"]
digest = hashlib.md5(resp.content).hexdigest()
if digest != checksum:
raise exceptions.InvalidResponse("checksum mismatch")
return resp.content
The resp.headers variable has no key "Content-MD5". This is the value I found for it:
{'Date': 'Thu, 01 Sep 2016 20:17:01 GMT', 'Transfer-Encoding': 'chunked',
'Connection': 'keep-alive', 'Content-Type': 'application/octet-stream',
'X-Openstack-Request-Id': 'req-9eb16897-1398-4ab2-9cd4-45706e92819c'}
But according to the REST API documentationm the response should return with the key Content-MD5: http://developer.openstack.org/api-ref/image/v2/?expanded=download-binary-image-data-detail
If I just comment the MD5 check the download works fine, but this is inside the SDK so I can't/shouldn't change it. Anyone have any suggestion on how to achieve this using the OpenStack Python SDK? Is this an SDK bug?
Turns out this was indeed a bug SDK/Glance. More details about it can be found here: https://bugs.launchpad.net/python-openstacksdk/+bug/1619675
And the fix implemented can be seen here: https://github.com/openstack/python-openstacksdk/commit/759651f4a9eae2ba546f46613550a4cb10ddd964