fixes remove_instance error

* Initialize object attribute to None so a later if check that depends
on that attributes succeeds. The attribute is related to unifying the
command line args to the *_instance command set.
* Added regression test case

awx/main/management/commands/_base_instance.py

@@ -21,6 +21,7 @@ class BaseCommandInstance(BaseCommand):
 
     def __init__(self):
         super(BaseCommandInstance, self).__init__()
+        self.enforce_primary_role = False
         self.enforce_roles = False
         self.enforce_hostname_set = False
         self.enforce_unique_find = False

awx/main/tests/commands/__init__.py

@@ -7,3 +7,5 @@ from .run_fact_cache_receiver import * # noqa
 from .commands_monolithic import * # noqa
 from .cleanup_facts import * # noqa
 from .age_deleted import * # noqa
+from .remove_instance import * # noqa
+

awx/main/tests/commands/remove_instance.py

@@ -0,0 +1,39 @@
+# Copyright (c) 2015 Ansible, Inc.
+# All Rights Reserved
+
+# Python
+import uuid
+
+# AWX
+from awx.main.tests.base import BaseTest
+from awx.main.tests.commands.base import BaseCommandMixin
+from awx.main.models import * # noqa
+
+__all__ = ['RemoveInstanceCommandFunctionalTest']
+
+class RemoveInstanceCommandFunctionalTest(BaseCommandMixin, BaseTest):
+    uuids = []
+    instances = []
+
+    def setup_instances(self):
+        self.uuids = [uuid.uuid4().hex for x in range(0, 3)]
+        self.instances.append(Instance(uuid=settings.SYSTEM_UUID, primary=True, hostname='127.0.0.1'))
+        self.instances.append(Instance(uuid=self.uuids[0], primary=False, hostname='127.0.0.2'))
+        self.instances.append(Instance(uuid=self.uuids[1], primary=False, hostname='127.0.0.3'))
+        self.instances.append(Instance(uuid=self.uuids[2], primary=False, hostname='127.0.0.4'))
+        for x in self.instances:
+            x.save()
+
+    def setUp(self):
+        super(RemoveInstanceCommandFunctionalTest, self).setUp()
+        self.create_test_license_file()
+        self.setup_instances()
+        self.setup_users()
+
+    def test_default(self):
+        self.assertEqual(Instance.objects.filter(hostname="127.0.0.2").count(), 1)
+        result, stdout, stderr = self.run_command('remove_instance', hostname='127.0.0.2')
+        self.assertIsNone(result)
+        self.assertEqual(stdout, 'Successfully removed instance (uuid="%s",hostname="127.0.0.2",role="secondary").\n' % (self.uuids[0]))
+        self.assertEqual(Instance.objects.filter(hostname="127.0.0.2").count(), 0)
+