Adds deployment via snapshot

New arguments are added to allow snapshot deployment:
--snapshot, --snap-cache

The previous tripleo-quickstart code has been removed/replaced
with the snapshot option.

Snapshot deployments are supported on CentOS and Fedora, and snapshot
artifacts use a similar caching system as the standard deployment.
Snapshots are produced daily by Apex, and include latest as well as n-1
OpenStack versions. The os-odl-nofeature scenario is used for the
snapshots. Additionally multiple topology verions of Snapshots are
available. The Snapshot pulled at deploy time depends on the
deploy-settings and number of virtual-computes used at deploy time.

Since there is only one network used with snapshot deployments (admin),
there is no reason to pass in network settings for snapshot deployments.
That argument is now optional. Previously we required even in Standard
virtual deployments that the network settings be provided. However that
is also unnecessary, as we can default to the virtual network settings.

Includes minor fix to the tox.ini to allow specifying test cases
to run (useful for developers writing tests). Default behavior of
tox is unchanged.

JIRA: APEX-548

Change-Id: I1e08c4e54eac5aae99921f61ab7f69693ed12b47
Signed-off-by: Tim Rozet <trozet@redhat.com>

1 files changed, 147 insertions, 0 deletions

diff --git a/apex/overcloud/node.py b/apex/overcloud/node.py
new file mode 100644
index 00000000..622d1fd1
--- /dev/null
+++ b/apex/overcloud/node.py
@@ -0,0 +1,147 @@
+##############################################################################
+# Copyright (c) 2018 Tim Rozet (trozet@redhat.com) and others.
+#
+# All rights reserved. This program and the accompanying materials
+# are made available under the terms of the Apache License, Version 2.0
+# which accompanies this distribution, and is available at
+# http://www.apache.org/licenses/LICENSE-2.0
+##############################################################################
+
+import logging
+import os
+import shutil
+import xml.etree.ElementTree as ET
+
+import distro
+import libvirt
+
+from apex.common.exceptions import OvercloudNodeException
+
+
+class OvercloudNode:
+    """
+    Overcloud server
+    """
+    def __init__(self, role, ip, ovs_ctrlrs, ovs_mgrs, name, node_xml,
+                 disk_img):
+        self.role = role
+        self.ip = ip
+        self.ovs_ctrlrs = ovs_ctrlrs
+        self.ovs_mgrs = ovs_mgrs
+        self.name = name
+        self.node_xml_file = node_xml
+        self.node_xml = None
+        self.vm = None
+        self.disk_img = None
+        if not os.path.isfile(self.node_xml_file):
+            raise OvercloudNodeException('XML definition file not found: '
+                                         '{}'.format(self.node_xml_file))
+        if not os.path.isfile(disk_img):
+            raise OvercloudNodeException('Disk image file not found: '
+                                         '{}'.format(disk_img))
+        self.conn = libvirt.open('qemu:///system')
+        if not self.conn:
+            raise OvercloudNodeException('Unable to open libvirt connection')
+
+        self.create(src_disk=disk_img)
+
+    def _configure_disk(self, disk):
+        # find default storage pool path
+        pool = self.conn.storagePoolLookupByName('default')
+        if pool is None:
+            raise OvercloudNodeException('Cannot find default storage pool')
+        pool_xml = pool.XMLDesc()
+        logging.debug('Default storage pool xml: {}'.format(pool_xml))
+        etree = ET.fromstring(pool_xml)
+        try:
+            path = etree.find('target').find('path').text
+            logging.info('System libvirt default pool path: {}'.format(path))
+        except AttributeError as e:
+            logging.error('Failure to find libvirt storage path: {}'.format(
+                e))
+            raise OvercloudNodeException('Cannot find default storage path')
+        # copy disk to system path
+        self.disk_img = os.path.join(path, os.path.basename(disk))
+        logging.info('Copying disk image to: {}. This may take some '
+                     'time...'.format(self.disk_img))
+        shutil.copyfile(disk, self.disk_img)
+
+    @staticmethod
+    def _update_xml(xml, disk_path=None):
+        """
+        Updates a libvirt XML file for the current architecture and OS of this
+        machine
+        :param xml: XML string of Libvirt domain definition
+        :param disk_path: Optional file path to update for the backing disk
+        image
+        :return: Updated XML
+        """
+        logging.debug('Parsing xml')
+        try:
+            etree = ET.fromstring(xml)
+        except ET.ParseError:
+            logging.error('Unable to parse node XML: {}'.format(xml))
+            raise OvercloudNodeException('Unable to parse node XML')
+
+        try:
+            type_element = etree.find('os').find('type')
+            if 'machine' in type_element.keys():
+                type_element.set('machine', 'pc')
+                logging.debug('XML updated with machine "pc"')
+        except AttributeError:
+            logging.warning('Failure to set XML machine type')
+
+        # qemu-kvm path may differ per system, need to detect it and update xml
+        linux_ver = distro.linux_distribution()[0]
+        if linux_ver == 'Fedora':
+            qemu_path = '/usr/bin/qemu-kvm'
+        else:
+            qemu_path = '/usr/libexec/qemu-kvm'
+
+        try:
+            etree.find('devices').find('emulator').text = qemu_path
+            logging.debug('XML updated with emulator location: '
+                          '{}'.format(qemu_path))
+            xml = ET.tostring(etree).decode('utf-8')
+        except AttributeError:
+            logging.warning('Failure to update XML qemu path')
+
+        if disk_path:
+            try:
+                disk_element = etree.find('devices').find('disk').find(
+                    'source')
+                disk_element.set('file', disk_path)
+                logging.debug('XML updated with file path: {}'.format(
+                    disk_path))
+            except AttributeError:
+                logging.error('Failure to parse XML and set disk type')
+                raise OvercloudNodeException(
+                    'Unable to set new disk path in xml {}'.format(xml))
+
+        return ET.tostring(etree).decode('utf-8')
+
+    def create(self, src_disk):
+        # copy disk to pool and get new disk location
+        logging.debug('Preparing disk image')
+        self._configure_disk(src_disk)
+        logging.debug('Parsing node XML from {}'.format(self.node_xml_file))
+        with open(self.node_xml_file, 'r') as fh:
+            self.node_xml = fh.read()
+        # if machine is not pc we need to set, also need to update qemu-kvm and
+        # storage location
+        self.node_xml = self._update_xml(self.node_xml, self.disk_img)
+        logging.info('Creating node {} in libvirt'.format(self.name))
+        self.vm = self.conn.defineXML(self.node_xml)
+
+    def start(self):
+        """
+        Boot node in libvirt
+        :return:
+        """
+        try:
+            self.vm.create()
+            logging.info('Node {} started'.format(self.name))
+        except libvirt.libvirtError as e:
+            logging.error('Failed to start domain: {}'.format(self.name))
+            raise OvercloudNodeException('Failed to start VM. Reason: '
+                                         '{}'.format(e))