Able to boot without kernel or ramdisk. libvirt.xml.template is now a Cheetah template

3 files changed, 39 insertions, 17 deletions

diff --git a/nova/compute/libvirt.xml.template b/nova/compute/libvirt.xml.template
index a763e8a4d..6fb63feae 100644
--- a/nova/compute/libvirt.xml.template
+++ b/nova/compute/libvirt.xml.template
@@ -1,31 +1,35 @@
 <domain type='kvm'>
-    <name>%(name)s</name>
+    <name>${name}</name>
     <os>
-    <type>hvm</type>
-        <kernel>%(basepath)s/kernel</kernel>
-        <initrd>%(basepath)s/ramdisk</initrd>
+        <type>hvm</type>
+#if $getVar('kernel', None)
+        <kernel>${kernel}</kernel>
+    #if $getVar('ramdisk', None)
+        <initrd>${ramdisk}</initrd>
+    #end if
         <cmdline>root=/dev/vda1 console=ttyS0</cmdline>
+#end if
     </os>
     <features>
         <acpi/>
     </features>
-    <memory>%(memory_kb)s</memory>
-    <vcpu>%(vcpus)s</vcpu>
+    <memory>${memory_kb}</memory>
+    <vcpu>${vcpus}</vcpu>
     <devices>
         <emulator>/usr/bin/kvm</emulator>
         <disk type='file'>
-            <source file='%(basepath)s/disk'/>
+            <source file='${disk}'/>
             <target dev='vda' bus='virtio'/>
         </disk>
         <interface type='bridge'>
-            <source bridge='%(bridge_name)s'/>
-            <mac address='%(mac_address)s'/>
+            <source bridge='${bridge_name}'/>
+            <mac address='${mac_address}'/>
             <!--   <model type='virtio'/>  CANT RUN virtio network right now -->
         </interface>
         <serial type="file">
-            <source path='%(basepath)s/console.log'/>
+            <source path='${basepath}/console.log'/>
             <target port='1'/>
         </serial>
     </devices>
-    <nova>%(nova)s</nova>
+    <nova>${nova}</nova>
 </domain>
diff --git a/nova/compute/node.py b/nova/compute/node.py
index 8f829995b..7c3b9a677 100644
--- a/nova/compute/node.py
+++ b/nova/compute/node.py
@@ -34,6 +34,7 @@ from twisted.internet import defer
 from twisted.internet import task
 from twisted.application import service
 
+from Cheetah.Template import Template
 
 try:
     import libvirt
@@ -312,13 +313,30 @@ class Instance(object):
     def toXml(self):
         # TODO(termie): cache?
         logging.debug("Starting the toXML method")
-        libvirt_xml = open(FLAGS.libvirt_xml_template).read()
+        template_contents = open(FLAGS.libvirt_xml_template).read()
         xml_info = self.datamodel.copy()
         # TODO(joshua): Make this xml express the attached disks as well
 
         # TODO(termie): lazy lazy hack because xml is annoying
         xml_info['nova'] = json.dumps(self.datamodel.copy())
-        libvirt_xml = libvirt_xml % xml_info
+
+        if xml_info['kernel_id']:
+            xml_info['kernel'] = xml_info['basepath'] + "/kernel"
+
+        if xml_info['ramdisk_id']:
+            xml_info['ramdisk'] = xml_info['basepath'] + "/ramdisk"
+
+        if xml_info['ramdisk_id'] or xml_info['kernel_id']:
+            xml_info['disk'] = xml_info['basepath'] + "/disk"
+        else:
+            xml_info['disk'] = xml_info['basepath'] + "/disk-raw"
+
+        try:
+            libvirt_xml = str(Template(template_contents, searchList=[ xml_info ] ))
+        except Exception as e:
+            logging.warning("Error running template: %s" % e)
+            raise
+
         logging.debug("Finished the toXML method")
 
         return libvirt_xml
@@ -487,9 +505,9 @@ class Instance(object):
 
         if not os.path.exists(basepath('disk')):
            yield _fetch_file(data['image_id'], basepath('disk-raw'))
-        if not os.path.exists(basepath('kernel')):
+        if data['kernel_id'] and not os.path.exists(basepath('kernel')):
            yield _fetch_file(data['kernel_id'], basepath('kernel'))
-        if not os.path.exists(basepath('ramdisk')):
+        if data['ramdisk_id'] and not os.path.exists(basepath('ramdisk')):
            yield _fetch_file(data['ramdisk_id'], basepath('ramdisk'))
 
         execute = lambda cmd, input=None: self._pool.simpleExecute(cmd=cmd,
diff --git a/nova/endpoint/cloud.py b/nova/endpoint/cloud.py
index 3b7b4804b..b7a4fe20e 100644
--- a/nova/endpoint/cloud.py
+++ b/nova/endpoint/cloud.py
@@ -544,8 +544,8 @@ class CloudController(object):
         for num in range(int(kwargs['max_count'])):
             inst = self.instdir.new()
             inst['image_id'] = image_id
-            inst['kernel_id'] = kernel_id
-            inst['ramdisk_id'] = ramdisk_id
+            inst['kernel_id'] = kernel_id or ''
+            inst['ramdisk_id'] = ramdisk_id or ''
             inst['user_data'] = kwargs.get('user_data', '')
             inst['instance_type'] = kwargs.get('instance_type', 'm1.small')
             inst['reservation_id'] = reservation_id