Management command for removing backend

snf-cyclades-app/synnefo/logic/management/commands/backend-remove.py

+# Copyright 2011-2012 GRNET S.A. All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions
+# are met:
+#
+#   1. Redistributions of source code must retain the above copyright
+#      notice, this list of conditions and the following disclaimer.
+#
+#  2. Redistributions in binary form must reproduce the above copyright
+#     notice, this list of conditions and the following disclaimer in the
+#     documentation and/or other materials provided with the distribution.
+#
+# THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+# ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+# SUCH DAMAGE.
+#
+# The views and conclusions contained in the software and documentation are
+# those of the authors and should not be interpreted as representing official
+# policies, either expressed or implied, of GRNET S.A.
+#
+
+from django.core.management.base import BaseCommand, CommandError
+from synnefo.db.models import Backend, VirtualMachine, BackendNetwork
+
+
+class Command(BaseCommand):
+    can_import_settings = True
+
+    help = "Remove a backend from the Database. Backend should be set\n" \
+           "to drained before trying to remove it, in order to avoid the\n" \
+           "allocation of a new instances in this Backend.\n\n" \
+           "Removal of a backend will fail if the backend hosts any\n" \
+           "non-deleted instances."
+
+    output_transaction = True  # The management command runs inside
+                               # an SQL transaction
+
+    def handle(self, *args, **options):
+        if len(args) < 1:
+            raise CommandError("Please provide a backend ID")
+
+        try:
+            backend_id = int(args[0])
+            backend = Backend.objects.get(id=backend_id)
+        except ValueError:
+            raise CommandError("Invalid backend ID")
+        except Backend.DoesNotExist:
+            raise CommandError("Backend not found in DB")
+
+        self.stdout.write('Trying to remove backend: %s\n' % backend.clustername)
+
+        vms_in_backend = VirtualMachine.objects.filter(backend=backend,
+                                                       deleted=False)
+
+        if vms_in_backend:
+            raise CommandError('Backend hosts non-deleted vms. Can not delete')
+
+        networks = BackendNetwork.objects.filter(backend=backend, deleted=False)
+        networks = [net.network.backend_id for net in networks]
+
+        backend.delete()
+
+        self.stdout.write('Successfully removed backend.\n')
+
+        if networks:
+            self.stdout.write('Left the following orphans networks in Ganeti:\n')
+            self.stdout.write('  ' + '\n  * '.join(networks) + '\n')
+            self.stdout.write('Manually remove them.\n')