libvirt: improve the specification of network disks

Allow zero or more hosts, and make the name optional, since only a
host is needed to use nbd. This allows cinder to fully specify the
location of a sheepdog or rbd volume without depending on extra
configuration files, and lays the groundwork for supporting nbd.

Rename the internal attribute source_host to source_name to reflect
its usage in the libvirt xml, and add source_hosts and source_ports
attributes to store the new information.

Fixes: bug 1077817
blueprint better-libvirt-network-volume-support
Signed-off-by: Josh Durgin <josh.durgin@inktank.com>

Change-Id: I8ac431751692e52ba0786768cea996388962922d

2 files changed, 73 insertions, 2 deletions

diff --git a/nova/tests/virt/libvirt/test_libvirt_config.py b/nova/tests/virt/libvirt/test_libvirt_config.py
index 8eed7136e..2d9e52f3c 100644
--- a/nova/tests/virt/libvirt/test_libvirt_config.py
+++ b/nova/tests/virt/libvirt/test_libvirt_config.py
@@ -434,7 +434,7 @@ class LibvirtConfigGuestDiskTest(LibvirtConfigBaseTest):
         obj = config.LibvirtConfigGuestDisk()
         obj.source_type = "network"
         obj.source_protocol = "iscsi"
-        obj.source_host = "foo.bar.com"
+        obj.source_name = "foo.bar.com"
         obj.driver_name = "qemu"
         obj.driver_format = "qcow2"
         obj.target_dev = "/dev/hda"
@@ -448,11 +448,56 @@ class LibvirtConfigGuestDiskTest(LibvirtConfigBaseTest):
               <target bus="ide" dev="/dev/hda"/>
             </disk>""")
 
+    def test_config_network_no_name(self):
+        obj = config.LibvirtConfigGuestDisk()
+        obj.source_type = 'network'
+        obj.source_protocol = 'nbd'
+        obj.source_hosts = ['foo.bar.com']
+        obj.source_ports = [None]
+        obj.driver_name = 'qemu'
+        obj.driver_format = 'raw'
+        obj.target_dev = '/dev/vda'
+        obj.target_bus = 'virtio'
+
+        xml = obj.to_xml()
+        self.assertXmlEqual(xml, """
+            <disk type="network" device="disk">
+              <driver name="qemu" type="raw"/>
+              <source protocol="nbd">
+                <host name="foo.bar.com"/>
+              </source>
+              <target bus="virtio" dev="/dev/vda"/>
+            </disk>""")
+
+    def test_config_network_multihost(self):
+        obj = config.LibvirtConfigGuestDisk()
+        obj.source_type = 'network'
+        obj.source_protocol = 'rbd'
+        obj.source_name = 'pool/image'
+        obj.source_hosts = ['foo.bar.com', '::1', '1.2.3.4']
+        obj.source_ports = [None, '123', '456']
+        obj.driver_name = 'qemu'
+        obj.driver_format = 'raw'
+        obj.target_dev = '/dev/vda'
+        obj.target_bus = 'virtio'
+
+        xml = obj.to_xml()
+        self.assertXmlEqual(xml, """
+            <disk type="network" device="disk">
+              <driver name="qemu" type="raw"/>
+              <source name="pool/image" protocol="rbd">
+                <host name="foo.bar.com"/>
+                <host name="::1" port="123"/>
+                <host name="1.2.3.4" port="456"/>
+              </source>
+              <target bus="virtio" dev="/dev/vda"/>
+            </disk>""")
+
     def test_config_network_auth(self):
         obj = config.LibvirtConfigGuestDisk()
         obj.source_type = "network"
         obj.source_protocol = "rbd"
-        obj.source_host = "pool/image"
+        obj.source_name = "pool/image"
         obj.driver_name = "qemu"
         obj.driver_format = "raw"
         obj.target_dev = "/dev/vda"
diff --git a/nova/tests/virt/libvirt/test_libvirt_volume.py b/nova/tests/virt/libvirt/test_libvirt_volume.py
index 86773dd10..567749a98 100644
--- a/nova/tests/virt/libvirt/test_libvirt_volume.py
+++ b/nova/tests/virt/libvirt/test_libvirt_volume.py
@@ -218,6 +218,32 @@ class LibvirtVolumeTestCase(test.TestCase):
         self.assertEqual(tree.find('./source/auth'), None)
         libvirt_driver.disconnect_volume(connection_info, "vde")
 
+    def test_libvirt_rbd_driver_hosts(self):
+        libvirt_driver = volume.LibvirtNetVolumeDriver(self.fake_conn)
+        name = 'volume-00000001'
+        vol = {'id': 1, 'name': name}
+        connection_info = self.rbd_connection(vol)
+        disk_info = {
+            "bus": "virtio",
+            "dev": "vde",
+            "type": "disk",
+            }
+        hosts = ['example.com', '1.2.3.4', '::1']
+        ports = [None, '6790', '6791']
+        connection_info['data']['hosts'] = hosts
+        connection_info['data']['ports'] = ports
+        conf = libvirt_driver.connect_volume(connection_info, disk_info)
+        tree = conf.format_dom()
+        self.assertEqual(tree.get('type'), 'network')
+        self.assertEqual(tree.find('./source').get('protocol'), 'rbd')
+        rbd_name = '%s/%s' % ('rbd', name)
+        self.assertEqual(tree.find('./source').get('name'), rbd_name)
+        self.assertEqual(tree.find('./source/auth'), None)
+        found_hosts = tree.findall('./source/host')
+        self.assertEqual([host.get('name') for host in found_hosts], hosts)
+        self.assertEqual([host.get('port') for host in found_hosts], ports)
+        libvirt_driver.disconnect_volume(connection_info, "vde")
+
     def test_libvirt_rbd_driver_auth_enabled(self):
         libvirt_driver = volume.LibvirtNetVolumeDriver(self.fake_conn)
         name = 'volume-00000001'