Make bmc caching configurable

In ci we want to enable caching of instance status to reduce load
on the host cloud, but for interactive developer setups it can be
confusing.  If a user shuts off a baremetal vm without using the
BMC then the BMC won't recognize that its state has changed.

This change makes caching configurable, and disabled by default.
In CI we can enable it explicitly and regular users won't get any
confusing behavior by default.

bin/install_openstackbmc.sh

@@ -57,6 +57,10 @@ export OS_PROJECT_DOMAIN_ID=$os__project_domain
 private_subnet=$(neutron net-show -f value -c subnets $private_net | sed "s/\[u'\(.*\)'\]/\1/")
 default_gw=$(neutron subnet-show $private_subnet -f value -c gateway_ip)
 prefix_len=$(neutron subnet-show -f value -c cidr $private_subnet | awk -F / '{print $2}')
+cache_status=
+if [ "$bmc_use_cache" != "False" ]; then
+    cache_status="--cache-status"
+fi
 
 mkdir /etc/os-net-config
 echo "network_config:" > /etc/os-net-config/config.yaml
@@ -108,7 +112,7 @@ Requires=config-bmc-ips.service
 After=config-bmc-ips.service
 
 [Service]
-ExecStart=/usr/local/bin/openstackbmc  --os-user $os_user --os-password $os_password --os-tenant "$os_tenant" --os-auth-url $os_auth_url --os-project "$os_project" --os-user-domain "$os_user_domain" --os-project-domain "$os_project_domain" --instance $bm_instance --address $bmc_ip
+ExecStart=/usr/local/bin/openstackbmc  --os-user $os_user --os-password $os_password --os-tenant "$os_tenant" --os-auth-url $os_auth_url --os-project "$os_project" --os-user-domain "$os_user_domain" --os-project-domain "$os_project_domain" --instance $bm_instance --address $bmc_ip $cache_status
 Restart=always
 
 User=root

openstack_virtual_baremetal/openstackbmc.py

@@ -35,7 +35,7 @@ import pyghmi.ipmi.bmc as bmc
 
 class OpenStackBmc(bmc.Bmc):
     def __init__(self, authdata, port, address, instance, user, password, tenant,
-                 auth_url, project, user_domain, project_domain):
+                 auth_url, project, user_domain, project_domain, cache_status):
         super(OpenStackBmc, self).__init__(authdata, port=port, address=address)
         if not '/v3' in auth_url:
             # novaclient 7+ is backwards-incompatible :-(
@@ -53,6 +53,7 @@ class OpenStackBmc(bmc.Bmc):
                                                 user_domain_name=user_domain,
                                                 project_domain_name=project_domain)
         self.instance = None
+        self.cache_status = cache_status
         self.cached_status = None
         self.target_status = None
         # At times the bmc service is started before important things like
@@ -113,7 +114,9 @@ class OpenStackBmc(bmc.Bmc):
         sys.exit(0)
 
     def _instance_active(self):
-        if self.cached_status is None or self.cached_status != self.target_status:
+        if (self.cached_status is None or
+                self.cached_status != self.target_status or
+                not self.cache_status):
             self.cached_status = self.novaclient.servers.get(self.instance).status
         return self.cached_status == 'ACTIVE'
 
@@ -220,6 +223,14 @@ def main():
                         required=False,
                         default='',
                         help='The project domain for connecting to OpenStack')
+    parser.add_argument('--cache-status',
+                        dest='cache_status',
+                        default=False,
+                        action='store_true',
+                        help='Cache the status of the managed instance.  This '
+                             'can reduce load on the host cloud, but if the '
+                             'instance status is changed outside the BMC then '
+                             'it may become out of sync.')
     args = parser.parse_args()
     # Default to ipv6 format, but if we get an ipv4 address passed in use the
     # appropriate format for pyghmi to listen on it.
@@ -235,7 +246,8 @@ def main():
                          auth_url=args.auth_url,
                          project=args.project,
                          user_domain=args.user_domain,
-                         project_domain=args.project_domain)
+                         project_domain=args.project_domain,
+                         cache_status=args.cache_status)
     mybmc.listen()
 
 

openstack_virtual_baremetal/tests/test_openstackbmc.py

@@ -45,7 +45,8 @@ class TestOpenStackBmcInit(unittest.TestCase):
                                         auth_url='http://keystone:5000',
                                         project='',
                                         user_domain='',
-                                        project_domain=''
+                                        project_domain='',
+                                        cache_status=False
                                         )
         if old_nova:
             mock_nova.assert_called_once_with(2, 'admin', 'password', 'admin',
@@ -91,7 +92,8 @@ class TestOpenStackBmcInit(unittest.TestCase):
                                         auth_url='http://keystone:5000/v3',
                                         project='admin',
                                         user_domain='default',
-                                        project_domain='default'
+                                        project_domain='default',
+                                        cache_status=False
                                         )
         mock_nova.assert_called_once_with(2, 'admin', 'password',
                                           auth_url='http://keystone:5000/v3',
@@ -125,7 +127,8 @@ class TestOpenStackBmcInit(unittest.TestCase):
                                         auth_url='http://keystone:5000',
                                         project='',
                                         user_domain='',
-                                        project_domain=''
+                                        project_domain='',
+                                        cache_status=False
                                         )
         mock_nova.assert_called_once_with(2, 'admin', 'password', 'admin',
                                           'http://keystone:5000')
@@ -159,12 +162,14 @@ class TestOpenStackBmc(unittest.TestCase):
                                              auth_url='http://keystone:5000',
                                              project='',
                                              user_domain='',
-                                             project_domain=''
+                                             project_domain='',
+                                             cache_status=False
                                              )
         self.bmc.novaclient = self.mock_client
         self.bmc.instance = 'abc-123'
         self.bmc.cached_status = None
         self.bmc.target_status = None
+        self.bmc.cache_status = False
 
     def test_find_instance(self, mock_nova, mock_log, mock_init):
         self._create_bmc(mock_nova)
@@ -263,15 +268,26 @@ class TestOpenStackBmc(unittest.TestCase):
         self.mock_client.servers.get.return_value = mock_server
         self.bmc.target_status = 'ACTIVE'
         self.bmc.cached_status = 'SHUTOFF'
+        self.bmc.cache_status = True
         self.assertTrue(self.bmc._instance_active())
 
     def test_instance_active_cached(self, mock_nova, mock_log, mock_init):
         self._create_bmc(mock_nova)
         self.bmc.target_status = 'ACTIVE'
         self.bmc.cached_status = 'ACTIVE'
+        self.bmc.cache_status = True
         self.assertTrue(self.bmc._instance_active())
         self.assertFalse(self.mock_client.servers.get.called)
 
+    def test_cache_disabled(self, mock_nova, mock_log, mock_init):
+        self._create_bmc(mock_nova)
+        self.bmc.target_status = 'ACTIVE'
+        self.bmc.cached_status = 'ACTIVE'
+        mock_server = mock.Mock()
+        mock_server.status = 'SHUTOFF'
+        self.mock_client.servers.get.return_value = mock_server
+        self.assertFalse(self.bmc._instance_active())
+
     @mock.patch('openstack_virtual_baremetal.openstackbmc.OpenStackBmc.'
                 '_instance_active')
     def test_get_power_state(self, mock_active, mock_nova, mock_log,
@@ -364,7 +380,8 @@ class TestMain(unittest.TestCase):
                                          auth_url='http://host:5000/v2.0',
                                          project='',
                                          user_domain='',
-                                         project_domain=''
+                                         project_domain='',
+                                         cache_status=False
                                          )
         mock_instance.listen.assert_called_once_with()
 
@@ -388,6 +405,7 @@ class TestMain(unittest.TestCase):
                                          auth_url='http://host:5000/v2.0',
                                          project='',
                                          user_domain='',
-                                         project_domain=''
+                                         project_domain='',
+                                         cache_status=False
                                          )
         mock_instance.listen.assert_called_once_with()

templates/virtual-baremetal.yaml

@@ -17,6 +17,14 @@ parameters:
       The base image for the bmc instance.  A CentOS 7 image is currently the
       only one supported.
 
+  bmc_use_cache:
+    type: boolean
+    default: false
+    description: |
+      Enable instance status caching on the BMC.  This can reduce load on the
+      host cloud, but if an instance's status is changed outside the BMC it may
+      become out of sync.
+
   baremetal_flavor:
     type: string
     default: baremetal
@@ -172,6 +180,7 @@ resources:
             $bm_node_count: {get_param: node_count}
             $bmc_prefix: {get_param: bmc_prefix}
             $bmc_utility: {get_attr: [bmc_port, ip_address]}
+            $bmc_use_cache: {get_param: bmc_use_cache}
             $bm_prefix: {get_param: baremetal_prefix}
             $private_net: {get_param: private_net}
             $openstackbmc_script: {get_file: ../bin/openstackbmc}