libvirt: define XML schema for recording nova instance metadata

Define an XML schema to be used in the libvirt guest config as
a metadata block to provide information about the instance
that is being run. When querying the libvirt guest XML this
is visible thus:

<domain type='kvm' id='6'>
  <name>instance-00000004</name>
  <uuid>a173eb64-f8e6-419b-a2b7-2d3283ecb26c</uuid>
  <metadata>
    <nova:instance xmlns:nova="http://openstack.org/xmlns/libvirt/nova/1.0">
      <nova:package version="2014.2"/>
      <nova:name>demo</nova:name>
      <nova:creationTime>2014-06-27 11:22:25+GMT</nova:creationTime>
      <nova:flavor name="m1.small">
        <nova:memory>2048</nova:memory>
        <nova:disk>20</nova:disk>
        <nova:swap>0</nova:swap>
        <nova:vcpus>1</nova:vcpus>
      </nova:flavor>
      <nova:owner>
        <nova:user uuid="18509018d00743c89518135e476003e0">admin</nova:user>
        <nova:project uuid="38bd8e984a3e435a87e950a441ee55aa">admin</nova:project>
      </nova:owner>
      <nova:root type="image" uuid="f0f0d38c-0a5f-4c54-83e5-d48006b888a7"/>
    </nova:instance>
  </metadata>
  ...snip...
</domain>

Blueprint: libvirt-driver-domain-metadata
Change-Id: I19432cb93bc1471118d9d323c712cdd9756a5926

Author: berrange

nova/tests/virt/libvirt/test_config.py

@@ -1735,3 +1735,55 @@ def test_config_cputune_timeslice(self):
             <quota>50000</quota>
             <period>25000</period>
           </cputune>""")
+
+
+class LibvirtConfigGuestMetadataNovaTest(LibvirtConfigBaseTest):
+
+    def test_config_metadata(self):
+        meta = config.LibvirtConfigGuestMetaNovaInstance()
+        meta.package = "2014.2.3"
+        meta.name = "moonbuggy"
+        meta.creationTime = 1234567890
+        meta.roottype = "image"
+        meta.rootid = "fe55c69a-8b2e-4bbc-811a-9ad2023a0426"
+
+        owner = config.LibvirtConfigGuestMetaNovaOwner()
+        owner.userid = "3472c2a6-de91-4fb5-b618-42bc781ef670"
+        owner.username = "buzz"
+        owner.projectid = "f241e906-010e-4917-ae81-53f4fb8aa021"
+        owner.projectname = "moonshot"
+
+        meta.owner = owner
+
+        flavor = config.LibvirtConfigGuestMetaNovaFlavor()
+        flavor.name = "m1.lowgravity"
+        flavor.vcpus = 8
+        flavor.memory = 2048
+        flavor.swap = 10
+        flavor.disk = 50
+        flavor.ephemeral = 10
+
+        meta.flavor = flavor
+
+        xml = meta.to_xml()
+        self.assertXmlEqual(xml, """
+    <nova:instance xmlns:nova='http://openstack.org/xmlns/libvirt/nova/1.0'>
+      <nova:package version="2014.2.3"/>
+      <nova:name>moonbuggy</nova:name>
+      <nova:creationTime>2009-02-13 23:31:30</nova:creationTime>
+      <nova:flavor name="m1.lowgravity">
+        <nova:memory>2048</nova:memory>
+        <nova:disk>50</nova:disk>
+        <nova:swap>10</nova:swap>
+        <nova:ephemeral>10</nova:ephemeral>
+        <nova:vcpus>8</nova:vcpus>
+      </nova:flavor>
+      <nova:owner>
+        <nova:user
+         uuid="3472c2a6-de91-4fb5-b618-42bc781ef670">buzz</nova:user>
+        <nova:project
+         uuid="f241e906-010e-4917-ae81-53f4fb8aa021">moonshot</nova:project>
+      </nova:owner>
+      <nova:root type="image" uuid="fe55c69a-8b2e-4bbc-811a-9ad2023a0426"/>
+    </nova:instance>
+        """)

nova/virt/libvirt/config.py

@@ -23,6 +23,8 @@
 helpers for populating up config object instances.
 """
 
+import time
+
 from nova import exception
 from nova.openstack.common import log as logging
 from nova.openstack.common import units
@@ -33,6 +35,9 @@
 
 LOG = logging.getLogger(__name__)
 
+# Namespace to use for Nova specific metadata items in XML
+NOVA_NS = "http://openstack.org/xmlns/libvirt/nova/1.0"
+
 
 class LibvirtConfigObject(object):
 
@@ -43,18 +48,20 @@ def __init__(self, **kwargs):
         self.ns_prefix = kwargs.get('ns_prefix')
         self.ns_uri = kwargs.get('ns_uri')
 
-    @staticmethod
-    def _text_node(name, value):
-        child = etree.Element(name)
+    def _new_node(self, name):
+        if self.ns_uri is None:
+            return etree.Element(name)
+        else:
+            return etree.Element("{" + self.ns_uri + "}" + name,
+                                 nsmap={self.ns_prefix: self.ns_uri})
+
+    def _text_node(self, name, value):
+        child = self._new_node(name)
         child.text = str(value)
         return child
 
     def format_dom(self):
-        if self.ns_uri is None:
-            return etree.Element(self.root_name)
-        else:
-            return etree.Element("{" + self.ns_uri + "}" + self.root_name,
-                                 nsmap={self.ns_prefix: self.ns_uri})
+        return self._new_node(self.root_name)
 
     def parse_str(self, xmlstr):
         self.parse_dom(etree.fromstring(xmlstr))
@@ -1186,6 +1193,7 @@ def __init__(self, **kwargs):
         self.os_smbios = None
         self.os_mach_type = None
         self.devices = []
+        self.metadata = []
 
     def _format_basic_props(self, root):
         root.append(self._text_node("uuid", self.uuid))
@@ -1198,6 +1206,12 @@ def _format_basic_props(self, root):
         else:
             root.append(self._text_node("vcpu", self.vcpus))
 
+        if len(self.metadata) > 0:
+            metadata = etree.Element("metadata")
+            for m in self.metadata:
+                metadata.append(m.format_dom())
+            root.append(metadata)
+
     def _format_os(self, root):
         os = etree.Element("os")
         type_node = self._text_node("type", self.os_type)
@@ -1435,3 +1449,102 @@ def format_dom(self):
         dev.append(backend)
 
         return dev
+
+
+class LibvirtConfigGuestMetaNovaInstance(LibvirtConfigObject):
+
+    def __init__(self):
+        super(LibvirtConfigGuestMetaNovaInstance,
+              self).__init__(root_name="instance",
+                             ns_prefix="nova",
+                             ns_uri=NOVA_NS)
+
+        self.package = None
+        self.flavor = None
+        self.name = None
+        self.creationTime = None
+        self.owner = None
+        self.roottype = None
+        self.rootid = None
+
+    def format_dom(self):
+        meta = super(LibvirtConfigGuestMetaNovaInstance, self).format_dom()
+
+        pkg = self._new_node("package")
+        pkg.set("version", self.package)
+        meta.append(pkg)
+        if self.name is not None:
+            meta.append(self._text_node("name", self.name))
+        if self.creationTime is not None:
+            timestr = time.strftime("%Y-%m-%d %H:%M:%S",
+                                    time.gmtime(self.creationTime))
+            meta.append(self._text_node("creationTime", timestr))
+        if self.flavor is not None:
+            meta.append(self.flavor.format_dom())
+        if self.owner is not None:
+            meta.append(self.owner.format_dom())
+
+        if self.roottype is not None and self.rootid is not None:
+            root = self._new_node("root")
+            root.set("type", self.roottype)
+            root.set("uuid", str(self.rootid))
+            meta.append(root)
+
+        return meta
+
+
+class LibvirtConfigGuestMetaNovaFlavor(LibvirtConfigObject):
+
+    def __init__(self):
+        super(LibvirtConfigGuestMetaNovaFlavor,
+              self).__init__(root_name="flavor",
+                             ns_prefix="nova",
+                             ns_uri=NOVA_NS)
+
+        self.name = None
+        self.memory = None
+        self.disk = None
+        self.swap = None
+        self.ephemeral = None
+        self.vcpus = None
+
+    def format_dom(self):
+        meta = super(LibvirtConfigGuestMetaNovaFlavor, self).format_dom()
+        meta.set("name", self.name)
+        if self.memory is not None:
+            meta.append(self._text_node("memory", str(self.memory)))
+        if self.disk is not None:
+            meta.append(self._text_node("disk", str(self.disk)))
+        if self.swap is not None:
+            meta.append(self._text_node("swap", str(self.swap)))
+        if self.ephemeral is not None:
+            meta.append(self._text_node("ephemeral", str(self.ephemeral)))
+        if self.vcpus is not None:
+            meta.append(self._text_node("vcpus", str(self.vcpus)))
+        return meta
+
+
+class LibvirtConfigGuestMetaNovaOwner(LibvirtConfigObject):
+
+    def __init__(self):
+        super(LibvirtConfigGuestMetaNovaOwner,
+              self).__init__(root_name="owner",
+                             ns_prefix="nova",
+                             ns_uri=NOVA_NS)
+
+        self.userid = None
+        self.username = None
+        self.projectid = None
+        self.projectname = None
+
+    def format_dom(self):
+        meta = super(LibvirtConfigGuestMetaNovaOwner, self).format_dom()
+        if self.userid is not None and self.username is not None:
+            user = self._text_node("user", self.username)
+            user.set("uuid", self.userid)
+            meta.append(user)
+        if self.projectid is not None and self.projectname is not None:
+            project = self._text_node("project", self.projectname)
+            project.set("uuid", self.projectid)
+            meta.append(project)
+        return meta