diff --git a/examples/image/download.py b/examples/image/download.py new file mode 100644 index 000000000..8b68dd6aa --- /dev/null +++ b/examples/image/download.py @@ -0,0 +1,64 @@ +# 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 +http://developer.openstack.org/sdks/python/openstacksdk/users/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 1024 bytes of memory at a time until + # all of the image data has been consumed. + for chunk in response.iter_content(chunk_size=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)