def _cache_image(self, context, instance, image_meta):
"""Fetch the instance's image from Glance
This method pulls the relevant AMI and associated kernel and ramdisk,
and the deploy kernel and ramdisk from Glance, and writes them
to the appropriate places on local disk.
Both sets of kernel and ramdisk are needed for Tilera booting, so these
are stored under CONF.tftp_root.
At present, the AMI is cached and certain files are injected.
Debian/ubuntu-specific assumptions are made regarding the injected
files. In a future revision, this functionality will be replaced by a
more scalable and os-agnostic approach: the deployment ramdisk will
fetch from Glance directly, and write its own last-mile configuration.
"""
fileutils.ensure_tree(get_image_dir_path(instance))
image_path = get_image_file_path(instance)
LOG.debug(_("Fetching image %(ami)s for instance %(name)s") %
{'ami': image_meta['id'], 'name': instance['name']})
utils.cache_image(context=context,
target=image_path,
image_id=image_meta['id'],
user_id=instance['user_id'],
project_id=instance['project_id']
)
return [image_meta['id'], image_path]
def _cache_tftp_images(self, context, instance, image_info):
"""Fetch the necessary kernels and ramdisks for the instance."""
fileutils.ensure_tree(
os.path.join(CONF.tftp_root, instance['uuid']))
LOG.debug(_("Fetching kernel and ramdisk for instance %s") %
instance['name'])
for label in image_info.keys():
(uuid, path) = image_info[label]
utils.cache_image(
context=context,
target=path,
image_id=uuid,
user_id=instance['user_id'],
project_id=instance['project_id'],
)