xenapi plugins must target only Python 2.4 features

Add a comment documenting the restriction that our xenapi plugins must
target Python 2.4 features because of restrictions with the XenServer
dom0 userspace.

Change-Id: Ide130923b16c0555c3190cbd63ce97e18d18aae0

plugins/xenserver/xenapi/etc/xapi.d/plugins/_bittorrent_seeder

@@ -14,6 +14,9 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+# NOTE: XenServer still only supports Python 2.4 in it's dom0 userspace
+# which means the Nova xenapi plugins must use only Python 2.4 features
+
 """Seed a bittorent image. This file should not be executed directly, rather it
 should be kicked off by the `bittorent` dom0 plugin."""
 

plugins/xenserver/xenapi/etc/xapi.d/plugins/agent

@@ -18,6 +18,9 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+# NOTE: XenServer still only supports Python 2.4 in it's dom0 userspace
+# which means the Nova xenapi plugins must use only Python 2.4 features
+
 #
 # XenAPI plugin for reading/writing information to xenstore
 #

plugins/xenserver/xenapi/etc/xapi.d/plugins/bandwidth

@@ -15,6 +15,9 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+# NOTE: XenServer still only supports Python 2.4 in it's dom0 userspace
+# which means the Nova xenapi plugins must use only Python 2.4 features
+
 """Fetch Bandwidth data from VIF network devices."""
 
 import utils

plugins/xenserver/xenapi/etc/xapi.d/plugins/bittorrent

@@ -14,6 +14,9 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+# NOTE: XenServer still only supports Python 2.4 in it's dom0 userspace
+# which means the Nova xenapi plugins must use only Python 2.4 features
+
 """Download images via BitTorrent."""
 
 import errno

plugins/xenserver/xenapi/etc/xapi.d/plugins/config_file

@@ -1,5 +1,8 @@
 #!/usr/bin/env python
 
+# NOTE: XenServer still only supports Python 2.4 in it's dom0 userspace
+# which means the Nova xenapi plugins must use only Python 2.4 features
+
 import XenAPIPlugin
 
 

plugins/xenserver/xenapi/etc/xapi.d/plugins/console

@@ -11,6 +11,9 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+# NOTE: XenServer still only supports Python 2.4 in it's dom0 userspace
+# which means the Nova xenapi plugins must use only Python 2.4 features
+
 """
 To configure this plugin, you must set the following xenstore key:
 /local/logconsole/@ = "/var/log/xen/guest/console.%d"

plugins/xenserver/xenapi/etc/xapi.d/plugins/glance

@@ -18,6 +18,9 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+# NOTE: XenServer still only supports Python 2.4 in it's dom0 userspace
+# which means the Nova xenapi plugins must use only Python 2.4 features
+
 """Handle the uploading and downloading of images via Glance."""
 
 import httplib

plugins/xenserver/xenapi/etc/xapi.d/plugins/ipxe

@@ -14,6 +14,9 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+# NOTE: XenServer still only supports Python 2.4 in it's dom0 userspace
+# which means the Nova xenapi plugins must use only Python 2.4 features
+
 """Inject network configuration into iPXE ISO for boot."""
 
 import os

plugins/xenserver/xenapi/etc/xapi.d/plugins/kernel

@@ -18,6 +18,9 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+# NOTE: XenServer still only supports Python 2.4 in it's dom0 userspace
+# which means the Nova xenapi plugins must use only Python 2.4 features
+
 """Handle the manipulation of kernel images."""
 
 import errno

plugins/xenserver/xenapi/etc/xapi.d/plugins/migration

@@ -15,6 +15,9 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+# NOTE: XenServer still only supports Python 2.4 in it's dom0 userspace
+# which means the Nova xenapi plugins must use only Python 2.4 features
+
 """
 XenAPI Plugin for transferring data between host nodes
 """

plugins/xenserver/xenapi/etc/xapi.d/plugins/nova_plugin_version

@@ -15,6 +15,9 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+# NOTE: XenServer still only supports Python 2.4 in it's dom0 userspace
+# which means the Nova xenapi plugins must use only Python 2.4 features
+
 """Returns the version of the nova plugins"""
 
 import utils

plugins/xenserver/xenapi/etc/xapi.d/plugins/pluginlib_nova.py

@@ -12,6 +12,9 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+# NOTE: XenServer still only supports Python 2.4 in it's dom0 userspace
+# which means the Nova xenapi plugins must use only Python 2.4 features
+
 #
 # Helper functions for the Nova xapi plugins.  In time, this will merge
 # with the pluginlib.py shipped with xapi, but for now, that file is not

plugins/xenserver/xenapi/etc/xapi.d/plugins/utils.py

@@ -12,6 +12,9 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+# NOTE: XenServer still only supports Python 2.4 in it's dom0 userspace
+# which means the Nova xenapi plugins must use only Python 2.4 features
+
 """Various utilities used by XenServer plugins."""
 
 import cPickle as pickle

plugins/xenserver/xenapi/etc/xapi.d/plugins/workarounds

@@ -15,6 +15,9 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+# NOTE: XenServer still only supports Python 2.4 in it's dom0 userspace
+# which means the Nova xenapi plugins must use only Python 2.4 features
+
 """Handle the uploading and downloading of images via Glance."""
 
 import os

plugins/xenserver/xenapi/etc/xapi.d/plugins/xenhost

@@ -17,6 +17,9 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+# NOTE: XenServer still only supports Python 2.4 in it's dom0 userspace
+# which means the Nova xenapi plugins must use only Python 2.4 features
+
 #
 # XenAPI plugin for host operations
 #

plugins/xenserver/xenapi/etc/xapi.d/plugins/xenstore.py

@@ -18,6 +18,9 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+# NOTE: XenServer still only supports Python 2.4 in it's dom0 userspace
+# which means the Nova xenapi plugins must use only Python 2.4 features
+
 #
 # XenAPI plugin for reading/writing information to xenstore
 #