1 files changed, 84 insertions, 0 deletions
diff --git a/morphlib/exts/kvm.check b/morphlib/exts/kvm.check
new file mode 100755
index 00000000..1bb4007a
--- /dev/null
+++ b/morphlib/exts/kvm.check
@@ -0,0 +1,84 @@
+#!/usr/bin/python
+# Copyright (C) 2014  Codethink Limited
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; version 2 of the License.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License along
+# with this program; if not, write to the Free Software Foundation, Inc.,
+# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+
+'''Preparatory checks for Morph 'kvm' write extension'''
+
+import cliapp
+import re
+import urlparse
+
+import morphlib.writeexts
+
+
+class KvmPlusSshCheckExtension(morphlib.writeexts.WriteExtension):
+
+    location_pattern = '^/(?P<guest>[^/]+)(?P<path>/.+)$'
+
+    def process_args(self, args):
+        if len(args) != 1:
+            raise cliapp.AppException('Wrong number of command line args')
+
+        self.require_btrfs_in_deployment_host_kernel()
+
+        upgrade = self.get_environment_boolean('UPGRADE')
+        if upgrade:
+            raise cliapp.AppException(
+                'Use the `ssh-rsync` write extension to deploy upgrades to an '
+                'existing remote system.')
+
+        location = args[0]
+        ssh_host, vm_name, vm_path = self.check_and_parse_location(location)
+
+        self.check_ssh_connectivity(ssh_host)
+        self.check_no_existing_libvirt_vm(ssh_host, vm_name)
+        self.check_extra_disks_exist(ssh_host, self.parse_attach_disks())
+
+    def check_and_parse_location(self, location):
+        '''Check and parse the location argument to get relevant data.'''
+
+        x = urlparse.urlparse(location)
+
+        if x.scheme != 'kvm+ssh':
+            raise cliapp.AppException(
+                'URL schema must be kvm+ssh in %s' % location)
+
+        m = re.match(self.location_pattern, x.path)
+        if not m:
+            raise cliapp.AppException('Cannot parse location %s' % location)
+
+        return x.netloc, m.group('guest'), m.group('path')
+
+    def check_no_existing_libvirt_vm(self, ssh_host, vm_name):
+        try:
+            cliapp.ssh_runcmd(ssh_host,
+                ['virsh', '--connect', 'qemu:///system', 'domstate', vm_name])
+        except cliapp.AppException as e:
+            pass
+        else:
+            raise cliapp.AppException(
+                'Host %s already has a VM named %s. You can use the ssh-rsync '
+                'write extension to deploy upgrades to existing machines.' %
+                (ssh_host, vm_name))
+
+    def check_extra_disks_exist(self, ssh_host, filename_list):
+        for filename in filename_list:
+            try:
+                cliapp.ssh_runcmd(ssh_host, ['ls', filename])
+            except cliapp.AppException as e:
+                raise cliapp.AppException('Did not find file %s on host %s' %
+                                          (filename, ssh_host))
+
+KvmPlusSshCheckExtension().run()