[Kimchi-devel] [PATCH 3/3] (WIP) CDROM Management: Devices management model implementation

Rodrigo Trujillo rodrigo.trujillo at linux.vnet.ibm.com
Mon Feb 10 12:52:43 UTC 2014


This patch adds the CREATE, LOOKUP, UPDATE and DELETE functionalities
to guest storage devices support.

Signed-off-by: Rodrigo Trujillo <rodrigo.trujillo at linux.vnet.ibm.com>
---
 src/kimchi/model/vms.py | 167 +++++++++++++++++++++++++++++++++++++++++++++++-
 src/kimchi/xmlutils.py  |   5 ++
 2 files changed, 171 insertions(+), 1 deletion(-)

diff --git a/src/kimchi/model/vms.py b/src/kimchi/model/vms.py
index 4623e28..069ab7c 100644
--- a/src/kimchi/model/vms.py
+++ b/src/kimchi/model/vms.py
@@ -20,8 +20,11 @@
 # License along with this library; if not, write to the Free Software
 # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301 USA
 
+import libvirt
 import os
+import socket
 import time
+import urlparse
 import uuid
 from xml.etree import ElementTree
 
@@ -36,7 +39,8 @@ from kimchi.model.config import CapabilitiesModel
 from kimchi.model.templates import TemplateModel
 from kimchi.model.utils import get_vm_name
 from kimchi.screenshot import VMScreenshot
-from kimchi.utils import run_setfacl_set_attr, template_name_from_uri
+from kimchi.utils import kimchi_log, run_setfacl_set_attr
+from kimchi.utils import template_name_from_uri
 
 
 DOM_STATE_MAP = {0: 'nostate',
@@ -47,6 +51,10 @@ DOM_STATE_MAP = {0: 'nostate',
                  5: 'shutoff',
                  6: 'crashed'}
 
+DEV_TYPE_SRC_ATTR_MAP = {'file': 'file',
+                         'block': 'dev',
+                         'dir': 'dir'}
+
 GUESTS_STATS_INTERVAL = 5
 VM_STATIC_UPDATE_PARAMS = {'name': './name'}
 VM_LIVE_UPDATE_PARAMS = {}
@@ -474,3 +482,160 @@ class LibvirtVMScreenshot(VMScreenshot):
             stream.finish()
         finally:
             os.close(fd)
+
+
+class StoragesModel(object):
+    def __init__(self, **kargs):
+        self.conn = kargs['conn']
+
+    def _get_storage_xml(self, params):
+        storage = """
+            <disk type='%(src_type)s' device='%(dev_type)s'>
+              <driver name='qemu' type='raw'/>%(source)s
+              <target dev='%(dev)s' bus='ide'/>
+            </disk>
+        """
+        info = {}
+        info['dev'] = params.get('dev')
+        info['dev_type'] = params.get('type')
+        info['src_type'] = params.get('src_type')
+
+        # Working with url paths
+        if info['src_type'] == 'network':
+            net = {}
+            output = urlparse.urlparse(params.get('path'))
+            net['protocol'] = output.scheme
+            net['port'] = output.port or socket.getservbyname(output.scheme)
+            net['hostname'] = output.hostname
+            net['url_path'] = output.path
+            info['source'] = """
+              <source protocol='%(protocol)s' name='%(url_path)s'>
+                <host name='%(hostname)s' port='%(port)s'/>
+              </source>""" % net
+        else:
+            # Fixing source attribute
+            info['source'] = """
+               <source %s='%s'/>""" % (DEV_TYPE_SRC_ATTR_MAP[info['src_type']],
+                                       params.get('path'))
+        return storage % info
+
+    def create(self, vm_name, params):
+        #TODO: Check if device name is already use
+        path = params.get('path')
+
+        # Checking if path exist, if not url
+        if path.startswith('/'):
+            if not os.path.exists(path):
+                msg = "Path specified for device is not valide"
+                raise InvalidParameter(msg)
+            elif path.endswith('.iso') or os.path.isfile(path):
+                params['src_type'] = 'file'
+            elif os.path.isdir(path):
+                params['src_type'] = 'dir'
+            else:
+                params['src_type'] = 'block'
+        else:
+            params['src_type'] = 'network'
+
+        # Add device to VM
+        dev_xml = self._get_storage_xml(params)
+        try:
+            conn = self.conn.get()
+            dom = conn.lookupByName(vm_name)
+            dom.attachDeviceFlags(dev_xml, libvirt.VIR_DOMAIN_AFFECT_CURRENT)
+        except Exception as e:
+            msg = 'Was not possible to attach storage device: %s' % e.message
+            kimchi_log.error(msg)
+            raise OperationFailed(e.message)
+        return params['dev']
+
+
+    def get_list(self, dev):
+        dom = VMModel.get_vm(dev, self.conn)
+        xml = dom.XMLDesc(0)
+        device_xml = xmlutils.xml_get_child(xml, './devices')
+        storages = self._parse_vm_disks(device_xml, ['disk', 'cdrom'])
+        return storages
+
+    def _parse_vm_disks(self, xml_str, filter_list):
+        # xml_str: xml_str of device with all devices
+        # filter_list: List of which device type to retrieve
+        root = ElementTree.fromstring(xml_str)
+        ret = []
+        for opt in filter_list:
+            xpath = ".disk/[@device='%s']" % opt
+            for disk in root.findall(xpath):
+                name = disk.find('./target').attrib['dev']
+                ret.append(name)
+        return ret
+
+
+class StorageModel(object):
+    def __init__(self, **kargs):
+        self.conn = kargs['conn']
+        self.kargs = kargs
+
+    def _get_device_xml(self, vm_name, dev_name):
+        # Get VM xml and then devices xml
+        dom = VMModel.get_vm(vm_name, self.conn)
+        device_xml = xmlutils.xml_get_child(dom.XMLDesc(0), './devices')
+        dev_root = ElementTree.fromstring(device_xml)
+        xpath = "./disk/target[@dev='%s']/.." % dev_name
+        return dev_root.find(xpath)
+
+    def lookup(self, vm_name, dev_name):
+        # Retrieve disk xml and format return dict
+        disk = self._get_device_xml(vm_name, dev_name)
+        if disk is not None:
+            source = disk.find('./source')
+            path = ""
+            if source is not None:
+                src_type = disk.attrib.get('type')
+                if src_type == 'network':
+                    host = source.find('./host')
+                    path = source.attrib.get('protocol') + '://' +\
+                           host.attrib.get('name') + ':' +\
+                           host.attrib.get('port') + source.attrib.get('name')
+                else:
+                    path = source.attrib.get(
+                       DEV_TYPE_SRC_ATTR_MAP[src_type])
+            dev_type = disk.attrib['device']
+            return { 'dev': dev_name,
+                     'type': dev_type,
+                     'path': path}
+        else:
+            msg = 'The storage device "%s" does not exist in the guest "%s"' % (
+                  dev_name,vm_name)
+            raise NotFoundError(msg)
+
+    def delete(self, vm_name, dev_name):
+        # Get storage device xml
+        disk = self._get_device_xml(vm_name, dev_name)
+        if disk is None:
+            msg = 'The storage device "%s" does not exist in the guest "%s"' % (
+                  dev_name,vm_name)
+            raise NotFoundError(msg)
+        try:
+            conn = self.conn.get()
+            dom = conn.lookupByName(vm_name)
+            dom.detachDeviceFlags(ElementTree.tostring(disk),
+                                  libvirt.VIR_DOMAIN_AFFECT_CURRENT)
+        except Exception as e:
+            msg = 'Was not possible to detach storage device: %s' % e.message
+            kimchi_log.error(msg)
+            raise OperationFailed(e.message)
+
+    def update(self, vm_name, dev_name, params):
+        try:
+            info = self.lookup(vm_name, dev_name)
+            self.delete(vm_name, dev_name)
+            info.update(params)
+            kargs = {'conn': self.conn}
+            stgModel = StoragesModel(**kargs)
+            dev_name = stgModel.create(vm_name, info)
+            return dev_name
+        except Exception as e:
+            raise
+            msg = 'Was not possible to update storage device: %s' % e.message
+            kimchi_log.error(msg)
+            raise OperationFailed(e.message)
diff --git a/src/kimchi/xmlutils.py b/src/kimchi/xmlutils.py
index 51ff0ec..176ceb1 100644
--- a/src/kimchi/xmlutils.py
+++ b/src/kimchi/xmlutils.py
@@ -40,3 +40,8 @@ def xml_item_update(xml, xpath, value):
     item = root.find(xpath)
     item.text = value
     return ElementTree.tostring(root, encoding="utf-8")
+
+def xml_get_child(xml, xpath):
+    root = ElementTree.fromstring(xml)
+    item = root.find(xpath)
+    return ElementTree.tostring(item, encoding="utf-8")
-- 
1.8.5.3




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