Update TemplateVM with running AppVM: part 2

- support for template modify in qvm-core
- tool for commit changes to template

dom0/qvm-core/qubes.py

@@ -624,13 +624,14 @@ class QubesTemplateVm(QubesVm):
 
         dir_path = kwargs["dir_path"]
 
-        # TempleteVM doesn't use root-cow image
         if root_img is not None and os.path.isabs(root_img):
             self.root_img = root_img
         else:
             self.root_img = dir_path + "/" + (
                 root_img if root_img is not None else default_root_img)
 
+        self.rootcow_img = dir_path + "/" + default_rootcow_img
+
         if private_img is not None and os.path.isabs(private_img):
             self.private_img = private_img
         else:
@@ -711,6 +712,14 @@ class QubesTemplateVm(QubesVm):
                     format(src_template_vm.root_img, self.root_img)
         # We prefer to use Linux's cp, because it nicely handles sparse files
         retcode = subprocess.call (["cp", src_template_vm.root_img, self.root_img])
+        if retcode != 0:
+            raise IOError ("Error while copying {0} to {1}".\
+                           format(src_template_vm.root_img, self.root_img))
+        if verbose:
+            print "--> Copying the template's root COW image:\n{0} ==>\n{1}".\
+                    format(src_template_vm.rootcow_img, self.rootcow_img)
+        # We prefer to use Linux's cp, because it nicely handles sparse files
+        retcode = subprocess.call (["cp", src_template_vm.rootcow_img, self.rootcow_img])
         if retcode != 0:
             raise IOError ("Error while copying {0} to {1}".\
                            format(src_template_vm.root_img, self.root_img))
@@ -779,13 +788,29 @@ class QubesTemplateVm(QubesVm):
         if not self.is_updateable():
             raise QubesException ("Cannot start Template VM that is marked \"nonupdatable\"")
 
-        # First ensure that none of our appvms is running:
-        for appvm in self.appvms.values():
-            if appvm.is_running():
-                raise QubesException ("Cannot start TemplateVM when one of its AppVMs is running!")
+        # TODO?: check if none of running appvms are outdated
 
         return super(QubesTemplateVm, self).start(debug_console=debug_console, verbose=verbose)
 
+    def commit_changes (self):
+
+        assert not self.is_running(), "Attempt to commit changes on running Template VM!"
+
+        print "--> Commiting template updates... COW: {0}...".format (self.rootcow_img)
+
+        if dry_run:
+            return
+        if os.path.exists (self.rootcow_img):
+           os.remove (self.rootcow_img)
+
+
+        f_cow = open (self.rootcow_img, "w")
+        f_root = open (self.root_img, "r")
+        f_root.seek(0, os.SEEK_END)
+        f_cow.truncate (f_root.tell()) # make empty sparse file of the same size as root.img
+        f_cow.close ()
+        f_root.close()
+
     def create_xml_element(self):
         element = xml.etree.ElementTree.Element(
             "QubesTemplateVm",
@@ -795,6 +820,7 @@ class QubesTemplateVm(QubesVm):
             conf_file=self.conf_file,
             appvms_conf_file=self.appvms_conf_file,
             root_img=self.root_img,
+            rootcow_img=self.rootcow_img,
             private_img=self.private_img,
             uses_default_netvm=str(self.uses_default_netvm),
             netvm_qid=str(self.netvm_vm.qid) if self.netvm_vm is not None else "none",
@@ -1194,10 +1220,6 @@ class QubesAppVm(QubesVm):
         if self.is_running():
             raise QubesException("VM is already running!")
 
-        # First ensure that our template is *not* running:
-        if self.template_vm.is_running():
-            raise QubesException ("Cannot start AppVM when its template is running!")
-
         if not self.is_updateable():
             self.reset_cow_storage()
         self.reset_swap_cow_storage()
@@ -1728,3 +1750,4 @@ class QubesDaemonPidfile(object):
         self.remove_pidfile()
 
 
+# vim:sw=4:et:

dom0/qvm-tools/qvm-prefs

@@ -42,6 +42,8 @@ def do_list(vm):
     print fmt.format ("config", vm.conf_file)
     if not vm.is_appvm():
         print fmt.format ("root img", vm.root_img)
+    if vm.is_templete():
+        print fmt.format ("root COW img", vm.rootcow_img)
     if vm.is_appvm():
         print fmt.format ("root img", vm.template_vm.root_img)
         print fmt.format ("root COW img", vm.rootcow_img)

dom0/qvm-tools/qvm-template-commit

@@ -0,0 +1,67 @@
+#!/usr/bin/python2.6
+#
+# The Qubes OS Project, http://www.qubes-os.org
+#
+# Copyright (C) 2011  Marek Marczykowski <marmarek@mimuw.edu.pl>
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+#
+
+from qubes.qubes import QubesVmCollection
+from qubes.qubes import QubesException
+from optparse import OptionParser
+import subprocess
+
+qubes_guid_path = "/usr/bin/qubes_guid"
+
+def main():
+    usage = "usage: %prog [options] <vm-name>"
+    parser = OptionParser (usage)
+
+    (options, args) = parser.parse_args ()
+    if (len (args) != 1):
+        parser.error ("You must specify VM name!")
+    vmname = args[0]
+
+    qvm_collection = QubesVmCollection()
+    qvm_collection.lock_db_for_reading()
+    qvm_collection.load()
+    qvm_collection.unlock_db()
+
+    vm = qvm_collection.get_vm_by_name(vmname)
+    if vm is None:
+        print "A VM with the name '{0}' does not exist in the system.".format(vmname)
+        exit(1)
+
+    if not vm.is_templatevm():
+        print "A VM '{0}' is not template.".format(vmname)
+        exit(1)
+
+    if vm.is_running():
+        print "You must stop VM first."
+        exit(1)
+
+    try:
+        vm.verify_files()
+        vm.commit_changes()
+    except (IOError, OSError, QubesException) as err:
+        print "ERROR: {0}".format(err)
+        exit (1)
+
+	exit (0)
+
+
+main()