[Kimchi-devel] [PATCH V11 4/7] manually manage the metadata element
Aline Manera
alinefm at linux.vnet.ibm.com
Mon Apr 28 22:04:42 UTC 2014
On 04/28/2014 12:44 PM, shaohef at linux.vnet.ibm.com wrote:
> 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))
> +
> +
There is a some duplicated code here and in set_metadata_node()
We should have special function only for special matters.
See below
> 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"):
Why node_xml? Use node directly as we use ET to create the element in
model/vms.py
That way we avoid ET node -> string -> ET node
> - 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))
There is already an if/else statement above, use the same one to append
or replace the new node
if kimchi is None:
node = kimchi.find(element.tag)
kimchi.replace(node, element)
else:
kimchi = E.kimchi()
kimchi.append(element)
Joining common code in one place:
def set_metadata_node(dom, node, mode="all")
kimchi = get_kimchi_metadata_node(dom, mode)
if kimchi is None:
kimchi = create_metadata_node("kimchi")
else:
old_node = kimchi.find(node.tag)
kimchi.replace(old_node, node)
if CapabilitiesModel().metadata_support:
return dom.setMetadata(libvirt.VIR_DOMAIN_METADATA_ELEMENT,
node_xml,
KIMCHI_NAMESPACE, KIMCHI_META_URL,
flags=get_vm_config_flag(dom, mode))
# Without metadata support
# 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 metadtaa is None:
metadata = E.metadata()
root.append(metadata)
old_node = root.find("metadata/{%s}kimchi" % KIMCHI_META_URL)
metadata.replace(old_node, kimchi) if old_node else
metadata.append(kimchi)
dom.connect().defineXML(etree.tostring(root))
def get_kimchi_metadata_node(dom, mode):
if CapabilitiesModel().metadata_support:
xml = dom.metadata(libvirt.VIR_DOMAIN_METADATA_ELEMENT,
KIMCHI_META_URL,
flags=get_vm_config_flag(dom, mode))
return etree.fromstring(xml)
# Without metadata support
xml = dom.XMLDesc(libvirt.VIR_DOMAIN_XML_INACTIVE)
root = etree.fromstring(xml)
metadata = root.find("metadata")
return root.find("metadata/{%s}kimchi" % KIMCHI_META_URL)
>
> - 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 ""
What about?
if kimchi is None:
return ""
kimchi_xml = etree.tostring(kimchi)
Kimchi = kimchi_xml.replace("{%s}" % KIMCHI_META_URL, "")
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)
More information about the Kimchi-devel
mailing list