Move domain templates to Jinja2

For now only for simple replacements, so there is not a big difference from what we had before. Signed-off-by: Nadav Goldin <[email protected]>
lago-project · Jun 22, 2017 · d94158e · d94158e
1 parent 5a7b499
commit d94158e
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Showing 5 changed files with 58 additions and 25 deletions.
diff --git a/lago.spec.in b/lago.spec.in
@@ -129,6 +129,7 @@ Requires: sudo
 %{python2_sitelib}/%{name}/providers/*.py*
 %{python2_sitelib}/%{name}/providers/libvirt/*.py*
 %{python2_sitelib}/%{name}/providers/libvirt/templates/*.xml
+%{python2_sitelib}/%{name}/providers/libvirt/templates/*.j2
 
 %{python2_sitelib}/%{name}-%{version}-py*.egg-info
 %{_bindir}/lagocli

diff --git a/...viders/libvirt/templates/dom_template.xml → ...ibvirt/templates/dom_template-base.xml.j2 b/...viders/libvirt/templates/dom_template.xml → ...ibvirt/templates/dom_template-base.xml.j2
@@ -1,6 +1,6 @@
 <domain type='kvm'>
-    <name>@NAME@</name>
-    <memory unit='MiB'>@MEM_SIZE@</memory>
+    <name>{{ name }}</name>
+    <memory unit='MiB'>{{ mem_size }}</memory>
     <iothreads>1</iothreads>
     <os>
       <type arch='x86_64' machine='pc'>hvm</type>
@@ -13,7 +13,7 @@
       <vmport state='off'/>
     </features>
     <devices>
-      <emulator>@QEMU_KVM@</emulator>
+      <emulator>{{ qemu_kvm }}</emulator>
       <memballoon model='none'/>
       <controller type='usb' model='none'>
       </controller>

diff --git a/...rs/libvirt/templates/dom_template-el6.xml → ...libvirt/templates/dom_template-el6.xml.j2 b/...rs/libvirt/templates/dom_template-el6.xml → ...libvirt/templates/dom_template-el6.xml.j2
@@ -1,6 +1,6 @@
 <domain type='kvm'>
-    <name>@NAME@</name>
-    <memory unit='MiB'>@MEM_SIZE@</memory>
+    <name>{{ name }}</name>
+    <memory unit='MiB'>{{ mem_size }}</memory>
     <iothreads>1</iothreads>
     <os>
       <type arch='x86_64' machine='pc'>hvm</type>
@@ -13,7 +13,7 @@
       <vmport state='off'/>
     </features>
     <devices>
-      <emulator>@QEMU_KVM@</emulator>
+     <emulator>{{ qemu_kvm }}</emulator>
       <memballoon model='none'/>
       <controller type='usb' model='none'>
       </controller>

diff --git a/lago/providers/libvirt/utils.py b/lago/providers/libvirt/utils.py
@@ -21,11 +21,15 @@
 Utilities to help deal with the libvirt python bindings
 """
 import libvirt
-import pkg_resources
 import xmltodict
 import lxml.etree
+import logging
+import pkg_resources
+from jinja2 import Environment, PackageLoader, TemplateNotFound
 from lago.config import config
 
+LOGGER = logging.getLogger(__name__)
+
 #: Mapping of domain statuses values to human readable strings
 DOMAIN_STATES = {
     libvirt.VIR_DOMAIN_NOSTATE: 'no state',
@@ -100,6 +104,33 @@ def get_template(basename):
     )
 
 
+def get_domain_template(distro, libvirt_ver, **kwargs):
+    """
+    Get a rendered Jinja2 domain template
+
+    Args:
+        distro(str): domain distro
+        libvirt_ver(int): libvirt version
+        kwargs(dict): args for template render
+
+    Returns:
+        str: rendered template
+    """
+    env = Environment(
+        loader=PackageLoader('lago', 'providers/libvirt/templates'),
+        trim_blocks=True,
+        lstrip_blocks=True,
+    )
+
+    template_name = 'dom_template-{0}.xml.j2'.format(distro)
+    try:
+        template = env.get_template(template_name)
+    except TemplateNotFound:
+        LOGGER.debug('could not find template %s using default', template_name)
+        template = env.get_template('dom_template-base.xml.j2')
+    return template.render(libvirt_ver=libvirt_ver, **kwargs)
+
+
 def dict_to_xml(spec, full_document=False):
     """
     Convert dict to XML

diff --git a/lago/providers/libvirt/vm.py b/lago/providers/libvirt/vm.py
@@ -51,6 +51,7 @@ def __init__(self, vm):
             name=self.vm.virt_env.uuid + libvirt_url,
             libvirt_url=libvirt_url,
         )
+        self._libvirt_ver = self.libvirt_con.getVersion()
 
         caps_raw_xml = self.libvirt_con.getCapabilities()
         self._caps = ET.fromstring(caps_raw_xml)
@@ -367,19 +368,10 @@ def cpu_vendor(self):
         """
         return self._cpu.vendor
 
-    def _load_domain_xml(self):
-        if self.vm.distro() == 'el6':
-            dom_raw_xml = libvirt_utils.get_template('dom_template-el6.xml')
-        else:
-            dom_raw_xml = libvirt_utils.get_template('dom_template.xml')
-        return dom_raw_xml
-
     def _libvirt_name(self):
         return self.vm.virt_env.prefixed_name(self.vm.name())
 
-    def _libvirt_xml(self):
-        dom_raw_xml = self._load_domain_xml()
-
+    def _get_qemu_kvm_path(self):
         qemu_kvm_path = self._caps.findtext(
             "guest[os_type='hvm']/arch[@name='x86_64']/domain[@type='kvm']"
             "/emulator"
@@ -393,19 +385,28 @@ def _libvirt_xml(self):
             )
 
         if not qemu_kvm_path:
-            raise Exception('kvm executable not found')
+            raise utils.LagoException('kvm executable not found')
+
+        return qemu_kvm_path
 
-        replacements = {
-            '@NAME@': self._libvirt_name(),
-            '@MEM_SIZE@': self.vm._spec.get('memory', 16 * 1024),
-            '@QEMU_KVM@': qemu_kvm_path,
+    def _load_xml(self):
+
+        args = {
+            'distro': self.vm.distro(),
+            'libvirt_ver': self._libvirt_ver,
+            'name': self._libvirt_name(),
+            'mem_size': self.vm.spec.get('memory', 16 * 1024),
+            'qemu_kvm': self._get_qemu_kvm_path()
         }
 
-        for key, val in replacements.items():
-            dom_raw_xml = dom_raw_xml.replace(key, str(val), 1)
+        dom_raw_xml = libvirt_utils.get_domain_template(**args)
 
         parser = ET.XMLParser(remove_blank_text=True)
-        dom_xml = ET.fromstring(dom_raw_xml, parser)
+        return ET.fromstring(dom_raw_xml, parser)
+
+    def _libvirt_xml(self):
+
+        dom_xml = self._load_xml()
 
         for child in self._cpu:
             dom_xml.append(child)