Before working with the Image service, you’ll need to create a connection
to your OpenStack cloud by following the Connect user guide. This will
provide you with the conn
variable used in the examples below.
The primary resource of the Image service is the image.
An image is a collection of files for a specific operating system that you use to create or rebuild a server. OpenStack provides pre-built images. You can also create custom images, or snapshots, from servers that you have launched. Images come in different formats and are sometimes called virtual machine images.
Full example: image resource list
Create an image by uploading its data and setting its attributes.
Full example: image resource create
Create an image then use interoperable image import process to download data from a web URL.
For more information about the image import process, please check interoperable image import
Full example: image resource import
As images are often very large pieces of data, storing their entire contents in the memory of your application can be less than desirable. A more efficient method may be to iterate over a stream of the response data.
By choosing to stream the response content, you determine the chunk_size
that is appropriate for your needs, meaning only that many bytes of data are
read for each iteration of the loop until all data has been consumed.
See requests.Response.iter_content()
for more information.
When you choose to stream an image download, openstacksdk is no longer able to compute the checksum of the response data for you. This example shows how you might do that yourself, in a very similar manner to how the library calculates checksums for non-streamed responses.
If you wish to download an image’s contents all at once and to memory,
simply set stream=False
, which is the default.
Full example: image resource download
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