[Kimchi-devel] [PATCH V10 4/7] manually manage the metadata element

[shaohef at linux.vnet.ibm.com]

From: ShaoHe Feng <shaohef at linux.vnet.ibm.com>

virDomain.metadata and virDomain.setMetadata does not work in all livirt
versions used in the supported distros.

So if libvirt do not support these two API.

let kimchi manually manage the metadata element

Signed-off-by: ShaoHe Feng <shaohef at linux.vnet.ibm.com>
Signed-off-by: Royce Lv <lvroyce at linux.vnet.ibm.com>
---
 src/kimchi/model/utils.py | 105 +++++++++++++++++++++++++++++++++++++---------
 1 file changed, 85 insertions(+), 20 deletions(-)

diff --git a/src/kimchi/model/utils.py b/src/kimchi/model/utils.py
index 3136402..2614008 100644
--- a/src/kimchi/model/utils.py
+++ b/src/kimchi/model/utils.py
@@ -18,9 +18,10 @@
 # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301 USA
 
 from kimchi.exception import OperationFailed
+from kimchi.model.config import CapabilitiesModel
 import libvirt
-from lxml import etree
-from lxml.builder import E
+from lxml import etree, objectify
+from lxml.builder import E, ElementMaker
 
 
 KIMCHI_META_URL = "https://github.com/kimchi-project/kimchi"
@@ -37,6 +38,15 @@ def get_vm_name(vm_name, t_name, name_list):
     raise OperationFailed("KCHUTILS0003E")
 
 
+def create_metadata_node(tag):
+    if CapabilitiesModel().metadata_support:
+        return E(tag)
+    else:
+        EM = ElementMaker(namespace=KIMCHI_META_URL,
+                          nsmap={KIMCHI_NAMESPACE: KIMCHI_META_URL})
+        return EM(tag)
+
+
 def get_vm_config_flag(dom, mode="persistent"):
     # libvirt.VIR_DOMAIN_AFFECT_CURRENT is 0
     # VIR_DOMAIN_AFFECT_LIVE is 1, VIR_DOMAIN_AFFECT_CONFIG is 2
@@ -50,6 +60,30 @@ def get_vm_config_flag(dom, mode="persistent"):
     return flag[mode]
 
 
+def _kimchi_set_metadata_node(dom, node_xml):
+    node = etree.fromstring(node_xml)
+    # some other tools will not let libvirt create a persistent
+    # configuration, raise exception.
+    if not dom.isPersistent():
+        msg = 'The VM has not a persistent configuration'
+        raise OperationFailed("KCHVM0030E",
+                              {'name': dom.name(), "err": msg})
+    xml = dom.XMLDesc(libvirt.VIR_DOMAIN_XML_INACTIVE)
+    root = etree.fromstring(xml)
+    metadata = root.find("metadata")
+    if metadata is None:
+        metadata = E.metadata()
+        root.append(metadata)
+    kimchi = root.find("metadata/{%s}kimchi" % KIMCHI_META_URL)
+    if kimchi is None:
+        kimchi = create_metadata_node("kimchi")
+        metadata.append(kimchi)
+    old_node = kimchi.find(node.tag)
+    (kimchi.replace(old_node, node) if old_node is not None
+     else kimchi.append(node))
+    dom.connect().defineXML(etree.tostring(root))
+
+
 def libvirt_get_kimchi_metadata_node(dom, mode="current"):
     try:
         xml = dom.metadata(libvirt.VIR_DOMAIN_METADATA_ELEMENT,
@@ -61,29 +95,60 @@ def libvirt_get_kimchi_metadata_node(dom, mode="current"):
 
 
 def set_metadata_node(dom, node_xml, mode="all"):
-    element = etree.fromstring(node_xml)
-    kimchi = libvirt_get_kimchi_metadata_node(dom, mode)
-    old_node = None
-    if kimchi is not None:
-        old_node = kimchi.find(element.tag)
-    else:
-        kimchi = E.kimchi()
-    (kimchi.replace(old_node, element) if old_node is not None
-     else kimchi.append(element))
+    if CapabilitiesModel().metadata_support:
+        element = etree.fromstring(node_xml)
+        kimchi = libvirt_get_kimchi_metadata_node(dom, mode)
+        old_node = None
+        if kimchi is not None:
+            old_node = kimchi.find(element.tag)
+        else:
+            kimchi = E.kimchi()
+        (kimchi.replace(old_node, element) if old_node is not None
+         else kimchi.append(element))
 
-    node_xml = etree.tostring(kimchi)
-    # From libvirt doc, Passing None for @metadata says to remove that
-    # element from the domain XML (passing the empty string leaves the
-    # element present).  Do not support remove the old metadata.
-    dom.setMetadata(libvirt.VIR_DOMAIN_METADATA_ELEMENT, node_xml,
-                    KIMCHI_NAMESPACE, KIMCHI_META_URL,
-                    flags=get_vm_config_flag(dom, mode))
+        node_xml = etree.tostring(kimchi)
+        # From libvirt doc, Passing None for @metadata says to remove that
+        # element from the domain XML (passing the empty string leaves the
+        # element present).  Do not support remove the old metadata.
+        dom.setMetadata(libvirt.VIR_DOMAIN_METADATA_ELEMENT, node_xml,
+                        KIMCHI_NAMESPACE, KIMCHI_META_URL,
+                        flags=get_vm_config_flag(dom, mode))
+    else:
+    # FIXME remove this code when all distro libvirt supports metadata element
+        _kimchi_set_metadata_node(dom, node_xml)
 
 
-def get_metadata_node(dom, tag, mode="current"):
-    kimchi = libvirt_get_kimchi_metadata_node(dom, mode)
+def _kimchi_get_metadata_node(dom, tag):
+    # some other tools will not let libvirt create a persistent
+    # configuration, just return empty
+    if not dom.isPersistent():
+        return ""
+    xml = dom.XMLDesc(libvirt.VIR_DOMAIN_XML_INACTIVE)
+    root = etree.fromstring(xml)
+    kimchi = root.find("metadata/{%s}kimchi" % KIMCHI_META_URL)
+    #remove the "kimchi" prifix of xml
     if kimchi is not None:
+        for child in kimchi.getiterator():
+            i = child.tag.find('}')
+            if i >= 0:
+                child.tag = child.tag[i+1:]
+        objectify.deannotate(kimchi, cleanup_namespaces=True)
+        kimchi_xml = etree.tostring(kimchi)
+        kimchi = etree.fromstring(kimchi_xml)
         node = kimchi.find(tag)
         if node is not None:
             return etree.tostring(node)
     return ""
+
+
+def get_metadata_node(dom, tag, mode="current"):
+    if CapabilitiesModel().metadata_support:
+        kimchi = libvirt_get_kimchi_metadata_node(dom, mode)
+        if kimchi is not None:
+            node = kimchi.find(tag)
+            if node is not None:
+                return etree.tostring(node)
+        return ""
+    else:
+    # FIXME remove this code when all distro libvirt supports metadata element
+        return _kimchi_get_metadata_node(dom, tag)
-- 
1.9.0