xenapi: Use supported interfaces for image upload/download

Registered by Mate Lakat

Use supported interfaces for image upload / download to/from XenAPI compute nodes.
At the moment XenServer is using tarballs of vhd chains as images, and using a dom0 plugin to download/upload them.
This is a non-supported way, and using non-supported tools. This blueprint is about to come up with an image upload/download method through a supported interface.

Blueprint information

Russell Bryant
Mate Lakat
Mate Lakat
Series goal:
Accepted for havana
Milestone target:
milestone icon 2013.2
Started by
Russell Bryant
Completed by
Russell Bryant

Related branches



Can we be clear about the required steps to create an "supported" import mechanism? Glance is planning to do image conversion, so you could assume a raw image is available from glance, rather than doing the conversion on the DomU -- johngarbutt

The proposed solution is:

Glance images are raw disk image files inside a tar.gz. This is how we get sparse format, and "metadata" information. We are expecting only one raw disk image file per glance image.

Download - import an image to the hypervisor:
  - Look at the beginning of the image, and get hold of the size of the raw file
  - Create a VDI with a size retrieved in the previous step
  - Attach the VDI to domU, and unpack the raw disk image to the vdi
Upload - upload an image to glance:
  - Attach the VDI
  - On-line compress its contents and stream it to glance.

Gerrit topic: https://review.openstack.org/#q,topic:bp/xenapi-supported-image-import-export,n,z

Addressed by: https://review.openstack.org/40906
    xenapi: refactor - extract get_stream_funct_for

Addressed by: https://review.openstack.org/40907
    xenapi: refactor - extract get_virtual_size

Addressed by: https://review.openstack.org/40908
    xenapi: ovf - virtual size retrieved from stream

Addressed by: https://review.openstack.org/40909
    xenapi: ovf - decompress image stream

Addressed by: https://review.openstack.org/40708
    xenapi: test functions for _stream_disk

Image upload is implemented here:

All code submitted, waiting for review.

Addressed by: https://review.openstack.org/44034
    xenapi: refactor - extract image_utils


Work Items

Work items:
Implement image download: INPROGRESS
Implement image upload: INPROGRESS

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