This acceptance test, validates that a full blown Linux guest can
successfully boot in QEMU.  In this specific case, the guest chosen is
Fedora version 31.

 * x86_64, pc-i440fx and pc-q35 machine types, with TCG and KVM as
   accelerators

 * aarch64 and virt machine type, with TCG and KVM as accelerators

 * ppc64 and pseries machine type with TCG as accelerator

 * s390x and s390-ccw-virtio machine type with TCG as accelerator

The Avocado vmimage utils library is used to download and cache the
Linux guest images, and from those images a snapshot image is created
and given to QEMU.  If a qemu-img binary is available in the build
directory, it's used to create the snapshot image, so that matching
qemu-system-* and qemu-img are used in the same test run.  If qemu-img
is not available in the build tree, one is attempted to be found
installed system-wide (in the $PATH).  If qemu-img is not found in the
build dir or in the $PATH, the test is canceled.

The method for checking the successful boot is based on "cloudinit"
and its "phone home" feature.  The guest is given an ISO image with
the location of the phone home server, and the information to post
(the instance ID).  Upon receiving the correct information, from the
guest, the test is considered to have PASSed.

This test is currently limited to user mode networking only, and
instructs the guest to connect to the "router" address that is hard
coded in QEMU.

To create the cloudinit ISO image that will be used to configure the
guest, the pycdlib library is also required and has been added as
requirement to the virtual environment created by "check-venv".

The console output is read by a separate thread, by means of the
Avocado datadrainer utility module.

Signed-off-by: Cleber Rosa <crosa@redhat.com>
Reviewed-by: Wainer dos Santos Moschetta <wainersm@redhat.com>
Reviewed-by: Willian Rampazzo <willianr@redhat.com>
Tested-by: Willian Rampazzo <willianr@redhat.com>
Message-Id: <20200317141654.29355-3-crosa@redhat.com>
Signed-off-by: Cleber Rosa <crosa@redhat.com>