Updated scheduler and compute for multiple capabilities.

Part 1 of 6: blueprint general-bare-metal-provisioning-framework.

This patch includes updates on scheduler and compute codes for
multiple capabilities. This feature is needed in bare-metal
provisioning which is implemented in later patches --- a bare-metal
nova-compute manages multiple bare-metal nodes where instances are
provisioned. Nova DB's compute_nodes entry needs to be created for
each bare-metal node, and a scheduler can choose an appropriate
bare-metal node to provision an instance.

With this patch, one service entry with multiple compute_node entries
can be registered by nova-compute. Distinct 'node name' is given for
each node and is stored at compute_node['hypervisor_hostname'].
And we added a new column "node" to "instances" table in Nova DB to
associate instances with compute_node. FilterScheduler puts <nodename>
to the column when it provisions the instance. And nova-computes
respect <nodename> when run/stop instances and when calculate
resources.

Also, 'capability’ is extended from a dictionary to a list of
dictionaries to describe the multiple capabilities of the multiple
nodes.

Change-Id: I527febe4dbd887b2e6596ce7226c1ae3386e2ae6
Co-authored-by: Mikyung Kang <mkkang@isi.edu>
Co-authored-by: David Kang <dkang@isi.edu>
Co-authored-by: Ken Igarashi <igarashik@nttdocomo.co.jp>
Co-authored-by: Arata Notsu <notsu@virtualtech.jp>

8 files changed, 72 insertions, 11 deletions

diff --git a/nova/virt/baremetal/driver.py b/nova/virt/baremetal/driver.py
index b0576aa38..4e63d35ed 100644
--- a/nova/virt/baremetal/driver.py
+++ b/nova/virt/baremetal/driver.py
@@ -661,7 +661,7 @@ class BareMetalDriver(driver.ComputeDriver):
         # Bare metal doesn't currently support security groups
         pass
 
-    def get_available_resource(self):
+    def get_available_resource(self, nodename):
         """Updates compute manager resource info on ComputeNode table.
 
         This method is called when nova-coompute launches, and
diff --git a/nova/virt/driver.py b/nova/virt/driver.py
index cb960466f..d5edcffed 100644
--- a/nova/virt/driver.py
+++ b/nova/virt/driver.py
@@ -347,12 +347,15 @@ class ComputeDriver(object):
         """Restore the specified instance"""
         raise NotImplementedError()
 
-    def get_available_resource(self):
+    def get_available_resource(self, nodename):
         """Retrieve resource information.
 
         This method is called when nova-compute launches, and
         as part of a periodic task
 
+        :param nodename:
+            node which the caller want to get resources from
+            a driver that manages only one node can safely ignore this
         :returns: Dictionary describing resources
         """
         raise NotImplementedError()
@@ -735,3 +738,16 @@ class ComputeDriver(object):
             }
         """
         raise NotImplementedError()
+
+    def get_available_nodes(self):
+        """Returns nodenames of all nodes managed by the compute service.
+
+        This method is for multi compute-nodes support. If a driver supports
+        multi compute-nodes, this method returns a list of nodenames managed
+        by the service. Otherwise, this method should return
+        [hypervisor_hostname].
+        """
+        stats = self.get_host_stats(refresh=True)
+        if not isinstance(stats, list):
+            stats = [stats]
+        return [s['hypervisor_hostname'] for s in stats]
diff --git a/nova/virt/fake.py b/nova/virt/fake.py
index 79d98c5cf..f2415e131 100644
--- a/nova/virt/fake.py
+++ b/nova/virt/fake.py
@@ -36,6 +36,32 @@ from nova.virt import virtapi
 LOG = logging.getLogger(__name__)
 
 
+_FAKE_NODES = ['fake-mini']
+
+
+def set_nodes(nodes):
+    """Sets FakeDriver's node.list.
+
+    It has effect on the following methods:
+        get_available_nodes()
+        get_available_resource
+        get_host_stats()
+
+    To restore the change, call restore_nodes()
+    """
+    global _FAKE_NODES
+    _FAKE_NODES = nodes
+
+
+def restore_nodes():
+    """Resets FakeDriver's node list modified by set_nodes().
+
+    Usually called from tearDown().
+    """
+    global _FAKE_NODES
+    _FAKE_NODES = ['fake-mini']
+
+
 class FakeInstance(object):
 
     def __init__(self, name, state):
@@ -56,7 +82,7 @@ class FakeDriver(driver.ComputeDriver):
     def __init__(self, virtapi, read_only=False):
         super(FakeDriver, self).__init__(virtapi)
         self.instances = {}
-        self.host_status = {
+        self.host_status_base = {
           'host_name-description': 'Fake Host',
           'host_hostname': 'fake-mini',
           'host_memory_total': 8000000000,
@@ -252,12 +278,14 @@ class FakeDriver(driver.ComputeDriver):
     def refresh_provider_fw_rules(self):
         pass
 
-    def get_available_resource(self):
+    def get_available_resource(self, nodename):
         """Updates compute manager resource info on ComputeNode table.
 
            Since we don't have a real hypervisor, pretend we have lots of
            disk and ram.
         """
+        if nodename not in _FAKE_NODES:
+            raise exception.NovaException("node %s is not found" % nodename)
 
         dic = {'vcpus': 1,
                'memory_mb': 8192,
@@ -267,7 +295,7 @@ class FakeDriver(driver.ComputeDriver):
                'local_gb_used': 0,
                'hypervisor_type': 'fake',
                'hypervisor_version': '1.0',
-               'hypervisor_hostname': 'fake-mini',
+               'hypervisor_hostname': nodename,
                'cpu_info': '?'}
         return dic
 
@@ -319,7 +347,19 @@ class FakeDriver(driver.ComputeDriver):
 
     def get_host_stats(self, refresh=False):
         """Return fake Host Status of ram, disk, network."""
-        return self.host_status
+        stats = []
+        for nodename in _FAKE_NODES:
+            host_status = self.host_status_base.copy()
+            host_status['hypervisor_hostname'] = nodename
+            host_status['host_hostname'] = nodename
+            host_status['host_name_label'] = nodename
+            stats.append(host_status)
+        if len(stats) == 0:
+            raise exception.NovaException("FakeDriver has no node")
+        elif len(stats) == 1:
+            return stats[0]
+        else:
+            return stats
 
     def host_power_action(self, host, action):
         """Reboots, shuts down or powers up the host."""
@@ -341,6 +381,9 @@ class FakeDriver(driver.ComputeDriver):
     def get_volume_connector(self, instance):
         return {'ip': '127.0.0.1', 'initiator': 'fake', 'host': 'fakehost'}
 
+    def get_available_nodes(self):
+        return _FAKE_NODES
+
 
 class FakeVirtAPI(virtapi.VirtAPI):
     def instance_update(self, context, instance_uuid, updates):
diff --git a/nova/virt/hyperv/driver.py b/nova/virt/hyperv/driver.py
index 6d9f66ff8..c9a7ed855 100644
--- a/nova/virt/hyperv/driver.py
+++ b/nova/virt/hyperv/driver.py
@@ -122,7 +122,7 @@ class HyperVDriver(driver.ComputeDriver):
     def poll_rescued_instances(self, timeout):
         pass
 
-    def get_available_resource(self):
+    def get_available_resource(self, nodename):
         return self._hostops.get_available_resource()
 
     def get_host_stats(self, refresh=False):
diff --git a/nova/virt/libvirt/driver.py b/nova/virt/libvirt/driver.py
index 7f962b45d..b0806537b 100644
--- a/nova/virt/libvirt/driver.py
+++ b/nova/virt/libvirt/driver.py
@@ -2204,12 +2204,13 @@ class LibvirtDriver(driver.ComputeDriver):
     def refresh_provider_fw_rules(self):
         self.firewall_driver.refresh_provider_fw_rules()
 
-    def get_available_resource(self):
+    def get_available_resource(self, nodename):
         """Retrieve resource info.
 
         This method is called as a periodic task and is used only
         in live migration currently.
 
+        :param nodename: ignored in this driver
         :returns: dictionary containing resource info
         """
         dic = {'vcpus': self.get_vcpu_total(),
diff --git a/nova/virt/powervm/driver.py b/nova/virt/powervm/driver.py
index 7a0da0b88..eea6e482d 100644
--- a/nova/virt/powervm/driver.py
+++ b/nova/virt/powervm/driver.py
@@ -142,7 +142,7 @@ class PowerVMDriver(driver.ComputeDriver):
         """Power on the specified instance"""
         self._powervm.power_on(instance['name'])
 
-    def get_available_resource(self):
+    def get_available_resource(self, nodename):
         """Retrieve resource info."""
         return self._powervm.get_available_resource()
 
diff --git a/nova/virt/vmwareapi/driver.py b/nova/virt/vmwareapi/driver.py
index 25cd05778..9a8d350d9 100644
--- a/nova/virt/vmwareapi/driver.py
+++ b/nova/virt/vmwareapi/driver.py
@@ -197,7 +197,7 @@ class VMWareESXDriver(driver.ComputeDriver):
                 'username': CONF.vmwareapi_host_username,
                 'password': CONF.vmwareapi_host_password}
 
-    def get_available_resource(self):
+    def get_available_resource(self, nodename):
         """This method is supported only by libvirt."""
         return
 
diff --git a/nova/virt/xenapi/driver.py b/nova/virt/xenapi/driver.py
index 55b67a931..ce45ca9de 100644
--- a/nova/virt/xenapi/driver.py
+++ b/nova/virt/xenapi/driver.py
@@ -390,12 +390,13 @@ class XenAPIDriver(driver.ComputeDriver):
                 'username': CONF.xenapi_connection_username,
                 'password': CONF.xenapi_connection_password}
 
-    def get_available_resource(self):
+    def get_available_resource(self, nodename):
         """Retrieve resource info.
 
         This method is called when nova-compute launches, and
         as part of a periodic task.
 
+        :param nodename: ignored in this driver
         :returns: dictionary describing resources
 
         """