2035bc1dab
Rather than providing two mutually exlusive image access methods (loop and qemu-nbd), try each in turn. This is to prepare for a follow up patch which will add libguestfs as a method to try. * nova/virt/mount.py: A new Mount class to abstract the devce allocation, partition mapping and file sys mounting, for each access type. * nova/virt/disk/loop.py: A specialization of the base Mount class to provide loop back mounting support. * nova/virt/disk/nbd.py: A specialization of the base Mount class to provide qemu-nbd mounting support. * nova/virt/disk/api.py: A new file containing the nova.virt.disk module interface. (img_handlers): A new list of access methods to try, with the order being honored. (_DiskImage): An internal helper class that uses the plugin classes above, to provide the operations available on a disk image file. When mounting, iterate over each access method until one succeeds. If a hint is provided about a CoW format image, the list of methods to try will be reduced accordingly. Note expected errors are no longer raised as exceptions during mounting. Instead, on failure to mount an image, errors are collated and raised. Interveining errors are logged in debug mode for successful mounts. * nova/virt/libvirt/connection.py: Adjust the function parameter names to be more general, rather than referencing specific implementations like 'nbd' and 'tune2fs'. Simplify the destroy_container() by storing and passing back a reference to the _DiskImage object, which has the necessary state to unmount. * nova/utils.py (trycmd): A helper function to both deal with, commands that issue ignorable warnings to stderr, and commands that EXIT_SUCCESS while issuing errors to stderr. nova/virt/xenapi/vm_utils.py: Adjust for the moved virt.disk package Change-Id: If3a4b1c8f4e2f2e7300a21071340dcc839cb36d7
The Choose Your Own Adventure README for Nova
You have come across a cloud computing fabric controller. It has identified itself as "Nova." It is apparent that it maintains compatibility with the popular Amazon EC2 and S3 APIs.
To monitor it from a distance: follow @openstack on twitter.
To tame it for use in your own cloud: read http://docs.openstack.org
To study its anatomy: read http://nova.openstack.org
To dissect it in detail: visit http://github.com/openstack/nova
To taunt it with its weaknesses: use http://bugs.launchpad.net/nova
To watch it: http://jenkins.openstack.org
To hack at it: read HACKING
To cry over its pylint problems: http://jenkins.openstack.org/job/nova-pylint/violations