Fix launching libvirt instances with swap

The code in

  commit 7be531fe9462f2b07d4a1abf6687f649d1dfbb89
  Author: Daniel P. Berrange <berrange@redhat.com>
  Date:   Tue Jan 15 20:43:48 2013 +0000

    Refactor code for setting up libvirt disk mappings

accidentally broken launching of instances where
the flavor had non-zero swap specified. This was
not caught due to complete lack of test coverage
for the '_create_image' method. This adds two
test cases for that method, exercising this bug.
It also fixes a bug in netutils which was not
handling a NULL network mapping, which is a valid
scenario for several callers.

Fixes bug #1131306
Change-Id: I214561ba3ec6440d11a5afb0665e6b6f990bd148
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>

3 files changed, 128 insertions, 1 deletions

diff --git a/nova/tests/test_libvirt.py b/nova/tests/test_libvirt.py
index 945d627f4..b1135902d 100644
--- a/nova/tests/test_libvirt.py
+++ b/nova/tests/test_libvirt.py
@@ -2569,6 +2569,129 @@ class LibvirtConnTestCase(test.TestCase):
                    None)
         self.assertTrue(self.create_image_called)
 
+    def test_create_image_plain(self):
+        gotFiles = []
+
+        def fake_image(self, instance, name, image_type=''):
+            class FakeImage(imagebackend.Image):
+                def __init__(self, instance, name):
+                    self.path = os.path.join(instance['name'], name)
+
+                def create_image(self, prepare_template, base,
+                                 size, *args, **kwargs):
+                    pass
+
+                def cache(self, fetch_func, filename, size=None,
+                          *args, **kwargs):
+                    gotFiles.append({'filename': filename,
+                                     'size': size})
+
+                def snapshot(self, name):
+                    pass
+
+            return FakeImage(instance, name)
+
+        def fake_none(*args, **kwargs):
+            return
+
+        def fake_get_info(instance):
+            return {'state': power_state.RUNNING}
+
+        # Stop 'libvirt_driver._create_image' touching filesystem
+        self.stubs.Set(nova.virt.libvirt.imagebackend.Backend, "image",
+                       fake_image)
+
+        instance_ref = self.test_instance
+        instance_ref['image_ref'] = 1
+        instance = db.instance_create(self.context, instance_ref)
+
+        conn = libvirt_driver.LibvirtDriver(fake.FakeVirtAPI(), False)
+        self.stubs.Set(conn, 'to_xml', fake_none)
+        self.stubs.Set(conn, '_create_domain_and_network', fake_none)
+        self.stubs.Set(conn, 'get_info', fake_get_info)
+
+        image_meta = {'id': instance['image_ref']}
+        disk_info = blockinfo.get_disk_info(CONF.libvirt_type,
+                                            instance,
+                                            None,
+                                            image_meta)
+        xml = conn.to_xml(instance, None,
+                          disk_info, image_meta)
+        conn._create_image(context, instance, xml,
+                           disk_info['mapping'])
+
+        wantFiles = [
+            {'filename': '356a192b7913b04c54574d18c28d46e6395428ab',
+             'size': 10 * 1024 * 1024 * 1024},
+            {'filename': 'ephemeral_20_default',
+             'size': 20 * 1024 * 1024 * 1024},
+            ]
+        self.assertEquals(gotFiles, wantFiles)
+
+    def test_create_image_with_swap(self):
+        gotFiles = []
+
+        def fake_image(self, instance, name, image_type=''):
+            class FakeImage(imagebackend.Image):
+                def __init__(self, instance, name):
+                    self.path = os.path.join(instance['name'], name)
+
+                def create_image(self, prepare_template, base,
+                                 size, *args, **kwargs):
+                    pass
+
+                def cache(self, fetch_func, filename, size=None,
+                          *args, **kwargs):
+                    gotFiles.append({'filename': filename,
+                                     'size': size})
+
+                def snapshot(self, name):
+                    pass
+
+            return FakeImage(instance, name)
+
+        def fake_none(*args, **kwargs):
+            return
+
+        def fake_get_info(instance):
+            return {'state': power_state.RUNNING}
+
+        # Stop 'libvirt_driver._create_image' touching filesystem
+        self.stubs.Set(nova.virt.libvirt.imagebackend.Backend, "image",
+                       fake_image)
+
+        instance_ref = self.test_instance
+        instance_ref['image_ref'] = 1
+        instance = db.instance_create(self.context, instance_ref)
+
+        # Turn on some swap to exercise that codepath in _create_image
+        instance['instance_type']['swap'] = 500
+
+        conn = libvirt_driver.LibvirtDriver(fake.FakeVirtAPI(), False)
+        self.stubs.Set(conn, 'to_xml', fake_none)
+        self.stubs.Set(conn, '_create_domain_and_network', fake_none)
+        self.stubs.Set(conn, 'get_info', fake_get_info)
+
+        image_meta = {'id': instance['image_ref']}
+        disk_info = blockinfo.get_disk_info(CONF.libvirt_type,
+                                            instance,
+                                            None,
+                                            image_meta)
+        xml = conn.to_xml(instance, None,
+                          disk_info, image_meta)
+        conn._create_image(context, instance, xml,
+                           disk_info['mapping'])
+
+        wantFiles = [
+            {'filename': '356a192b7913b04c54574d18c28d46e6395428ab',
+             'size': 10 * 1024 * 1024 * 1024},
+            {'filename': 'ephemeral_20_default',
+             'size': 20 * 1024 * 1024 * 1024},
+            {'filename': 'swap_500',
+             'size': 500 * 1024 * 1024},
+            ]
+        self.assertEquals(gotFiles, wantFiles)
+
     def test_get_console_output_file(self):
         fake_libvirt_utils.files['console.log'] = '01234567890'
 
diff --git a/nova/virt/libvirt/driver.py b/nova/virt/libvirt/driver.py
index bcbd1de87..dfae88c23 100755
--- a/nova/virt/libvirt/driver.py
+++ b/nova/virt/libvirt/driver.py
@@ -1780,6 +1780,7 @@ class LibvirtDriver(driver.ComputeDriver):
                 ephemeral_size=eph['size'])
 
         if 'disk.swap' in disk_mapping:
+            mapping = disk_mapping['disk.swap']
             swap_mb = 0
 
             swap = driver.block_device_info_get_swap(block_device_info)
@@ -1787,7 +1788,7 @@ class LibvirtDriver(driver.ComputeDriver):
                 swap_mb = swap['swap_size']
             elif (inst_type['swap'] > 0 and
                   not block_device.volume_in_mapping(
-                    swap['dev'], block_device_info)):
+                    mapping['dev'], block_device_info)):
                 swap_mb = inst_type['swap']
 
             if swap_mb > 0:
diff --git a/nova/virt/netutils.py b/nova/virt/netutils.py
index eec2d6467..1277251b5 100644
--- a/nova/virt/netutils.py
+++ b/nova/virt/netutils.py
@@ -67,6 +67,9 @@ def get_injected_network_template(network_info, use_ipv6=CONF.use_ipv6,
     convert the type itself if necessary.
     """
 
+    if network_info is None:
+        return None
+
     # the code below depends on the legacy 'network_info'
     if hasattr(network_info, 'legacy'):
         network_info = network_info.legacy()