virt: Fix host IP lookup assumption

Looking up an IP address for the host system should not depend
on guest networking configuration.  For example, if guest is
using nettype=user, then (technically) the netdst param contents
are not applicable and may not even be set!  However,
utils_net.get_host_ip_address() assumes netdst param will
always point at a host networking device.

Another problematic situation is when a guest is installed
with unattended_install using a network-based method,
however guest is initially configured WITHOUT any networking
device (possible with libvirt/virt-install).

A safer assumption, is that a default route is defined to
deliver packets via a valid local networking device.  With IPv4,
this networking device _must_ have an associated IP address
which is unlikely to be invalid or a black-hole.  Therefor,
this address is a much safer option than relying on guest
networking configuration.

Signed-off-by: Chris Evich <cevich@redhat.com>
virt: Reduce virtnet and rewrite unittests

Component classes of virtnet had their behavior bound together,
making them less flexible and more difficult to use.  An auxiliary
class was then used to support customization but it was not at the
right level in the stack, nor did it help untangle any bound
behavior.

This update takes the intention of the auxiliary class
(VMNetStyle) and folds it into the virtnet component classes
in a more heirarchical manner.  Additionally, VirtNet itself
has been split up into an ABC, and multiple subclasses which
operate on different data sources, but through a common interface.

This places the burden/responsibility for managing data and it's source
on the virtnet consumer.  It allows for greater flexibility and eases
maintenance since class responsibility and interfaces are more clearly
defined and don't come with any cross-dependencies.

Finally, since a prior update made PropCan instances fully pickleable,
there is no need to perform string conversion/parsing for storage.
Further, since a proper ABC model was implemented, storage can
be performed agnostic to inner container-class type.  These changes
permit rich comparison between the various VirtNet classes, including
the ability to select specific properties to NOT be compared, at
runtime.

The unittests were nearly completely re-written to cover the most
critical points in the new structure.  Test coverage is a little
less robust than previous, however it also runs roughly 10x faster.
The cartesian-based testing was updated to reflect recent changes
to the vm classes, and cut back on a lot of redundant tests.

Signed-off-by: Chris Evich <cevich@redhat.com>
virt: Share virtnet specialization and cleanup

Choosing which networking inner-storage class for virtnet
now happens at the VM level.  Also, the cache database
location can be made common, allowing for a shared
clean_tmp_files() implementation.

Signed-off-by: Chris Evich <cevich@redhat.com>
virt: Let VM subclasses decide init virtnet

Rather than one-size-fits all, provide a common set of
network initialization, caching, storage, and syncing
functions, and allow higher-levels to decide when/how to
setup networking.

Signed-off-by: Chris Evich <cevich@redhat.com>
virt: Mac/IP loop readability

Clean up some variable names and virtnet calls to make it more
obvious what is being returned and operated on.

Signed-off-by: Chris Evich <cevich@redhat.com>
virt: BaseVM VirtNet updates

Simplify base-class networking code related to dynamic
addition/removal of networking devices.  Even though
all device info is cached in database, only pull
mac addresses from it for new devices.  Otherwise
always trust current params are ultimate authority
for setup info.

Signed-off-by: Chris Evich <cevich@redhat.com>
virt-qemu: Remove deprecated script support

While still supported in qemu, virt-test has long since
dropped support for networking up/down scripts.  However,
some remnents remained inside vm.make_create_command().

Signed-off-by: Chris Evich <cevich@redhat.com>
virt: utils_net helpers

Move commonly used helper functions to methods on virtnet
classes.  This helps organize them closer to relevant data
and while keeping the global and local namespaces clean.
This also helps prevents the need for burried, private
functions, and organizes them in a common location where
they can be unittested.

Signed-off-by: Chris Evich <cevich@redhat.com>
virt: QemuIface auto-convert int() from str. params.

For parameters which expect integers, QemuIface will
attempt to parse them as integers, but provides for
disabling this conversion if necessary (i.e. unittesting).
Therefor, explicit calls to int on reference are no
longer necessary.

Signed-off-by: Chris Evich <cevich@redhat.com>
virt-qemu: Initialize/Persist virtnet when needed

Previously it was very un-clear where/how networking parameters were
referenced in terms of initializing or restoring virtnet during
a VM instance's life-cycle.  With the recent updates, it's now possible
to initialize and update close to where those stages are required
and do so in an unambiguous way.

Signed-off-by: Chris Evich <cevich@redhat.com>
virt-qemu: Don't be ambiguous about method params.

Previously, add/del nic and netdev methods accepted an arbitrary number
of keyword arguments that were never defined anywhere.  Replace this
with a single parameter defined as dict-like, and rely on duck-typing
to ensure it references expected values.

Signed-off-by: Chris Evich <cevich@redhat.com>
virt-qemu: Clarify variable name

'propertea' while "cute", doesn't convey the actual meaning and use of
this particular variable.  Rename it to 'prop' - short for 'property'
(which is a python keyword).

Signed-off-by: Chris Evich <cevich@redhat.com>
virt-qemu: Update add netdev/nic methods

Much of the id/fd creative-work has been reorganized
centrally into utils_net.QemuIface.  This commit reflects
that change.

Looking through the other add netdev/nic methods, I found using
the set_if_none() method has hidden-implication of property
existence.  Instead, it's clearer to just use a ``if nic.get() is None``
construct which is clear it also checks for existence

Signed-off-by: Chris Evich <cevich@redhat.com>
virt-qemu: Update _cleanup to use new VirtNet

Signed-off-by: Chris Evich <cevich@redhat.com>
virt-qemu: Make vm.make_create_command() VirtNet

Some networking parameters were being parsed outside of virtnet, leading
to ambiguity and possibly interoperability problems with libvirt's use
of virtnet.  These extra parameters have been included into the qemu-kvm
specific QemuIface VirtNet container class.  This ensures they're
defined and properly accounted for.  It also makes the code easier
to read/maintain since all networking information is coming from a
single source.

Signed-off-by: Chris Evich <cevich@redhat.com>
virt-qemu: Update vm.create() to use new VirtNet

Some networking parameters were being parsed outside of virtnet, leading
to ambiguity and possibly interoperability problems with libvirt's use
of virtnet.  These extra parameters have been included into the
qemu-kvm specific QemuIface VirtNet container class.  This ensures they're
defined and properly accounted for.  It also makes the code easier
to read/maintain since all networking information is coming from a
single source.

Signed-off-by: Chris Evich <cevich@redhat.com>
virt: Expand two acronyms in docstrings

Signed-off-by: Chris Evich <cevich@redhat.com>
virt: Standardize vm.clone() and md5sum checks

Reduce code duplication and ongoing maintenance since the majority
of this code can be shared between VM subclasses.  The
single exception can override only the necessary behavior.

Signed-off-by: Chris Evich <cevich@redhat.com>
virt-libvirt: libvirt_vm cobweb removal

*  Cleaned up a few docstrings / whitespace

*  vm.create() is so dissimilar from qemu-kvm it doesn't
   need to represent disused parameters or their docstrings.

*  Since create locking cleanup is mostly centralized now,
   it can referr to a common filename in base module.

*  Nic-hotplug is handled in test code, no need to provide
   generalized methods for it.

Signed-off-by: Chris Evich <cevich@redhat.com>
virt-libvirt: Update libvirt_vm virtnet usage

*  Virtnet now has xen-specific networking-info container class.
   This will allow for easier extension or special-handling
   as they related to xen specific networking.  No need to hold
   libvirt hostage to xen limitations or behavior.

*  The VM subclasses dictate their own use of networking info.
   cache.  For libvirt, virsh/virt commands are used to manupulate
   it, however for vm.clone() and mac-address allocation, specialized
   searching is required.

*  Made some mostly cosmetic updates to make_create_command()'s
   add_nic() nested-function.

*  The BaseVM.destroy() method specifies a 'free_mac_addresses'
   parameter that doesn't apply to libvirt_vm.  However, class
   shouldn't silently ignore the parameter in case it's ever
   helpful to debugging.

Signed-off-by: Chris Evich <cevich@redhat.com>