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# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.
import hashlib
"""
Download an image with the Image service.
For a full guide see
https://docs.openstack.org/openstacksdk/latest/user/guides/image.html
"""
def download_image_stream(conn):
print("Download Image via streaming:")
# Find the image you would like to download.
image = conn.image.find_image("myimage")
# As the actual download now takes place outside of the library
# and in your own code, you are now responsible for checking
# the integrity of the data. Create an MD5 has to be computed
# after all of the data has been consumed.
md5 = hashlib.md5()
with open("myimage.qcow2", "wb") as local_image:
response = conn.image.download_image(image, stream=True)
# Read only 1 MiB of memory at a time until
# all of the image data has been consumed.
for chunk in response.iter_content(chunk_size=1024 * 1024):
# With each chunk, add it to the hash to be computed.
md5.update(chunk)
local_image.write(chunk)
# Now that you've consumed all of the data the response gave you,
# ensure that the checksums of what the server offered and
# what you downloaded are the same.
if response.headers["Content-MD5"] != md5.hexdigest():
raise Exception("Checksum mismatch in downloaded content")
def download_image(conn):
print("Download Image:")
# Find the image you would like to download.
image = conn.image.find_image("myimage")
with open("myimage.qcow2", "w") as local_image:
response = conn.image.download_image(image)
# Response will contain the entire contents of the Image.
local_image.write(response)
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