def test_set_parent(self):
child = Snapshot(SNAP_PREFIX + "2013-07-31_12:53:16-raring-to-go")
old_parent = child.parent
child.parent = None
parent_file = os.path.join(self.sandbox,
SNAP_PREFIX + "2013-07-31_12:53:16-raring-to-go", PARENT_LINK)
self.assertFalse(os.path.exists(parent_file))
new_parent = SNAP_PREFIX + "2013-07-26_14:50:53"
child.parent = new_parent
self.assertEqual(os.readlink(parent_file),
os.path.join(PARENT_DOTS, new_parent))
def set_default(self, snapshot, tag=""):
""" backup @ and replace @ with a copy of given snapshot """
if not tag:
tag = self._prompt_for_tag()
snapshot = Snapshot(snapshot)
new_root = os.path.join(self.mp, snapshot.name)
if (
os.path.isdir(new_root) and
snapshot.name.startswith(SNAP_PREFIX)):
default_root = os.path.join(self.mp, "@")
staging = os.path.join(self.mp, "@apt-btrfs-staging")
if os.path.lexists(staging):
raise Exception("Reserved directory @apt-btrfs-staging "
"exists\nPlease remove from btrfs volume root before "
"trying again")
# find and store dpkg changes
date, history = self._get_status()
Snapshot("@").changes = history
# snapshot the requested default so as not to remove it
res = self.commands.btrfs_subvolume_snapshot(new_root, staging)
if not res:
raise Exception("Could not create snapshot")
# make backup name
backup = os.path.join(self.mp,
SNAP_PREFIX + self._get_now_str()) + tag
# if backup name is already in use, wait a sec and try again
if os.path.exists(backup):
time.sleep(1)
backup = os.path.join(self.mp,
SNAP_PREFIX + self._get_now_str())
# move everything into place
os.rename(default_root, backup)
os.rename(staging, default_root)
# remove @/etc/apt-btrfs-changes & set root's new parent
new_default = Snapshot("@")
new_default.changes = None
new_default.parent = snapshot.name
print("Default changed to %s, please reboot for changes to take "
"effect." % snapshot.name)
else:
print("You have selected an invalid snapshot. Please make sure "
"that it exists, and that its name starts with "
"\"%s\"" % SNAP_PREFIX)
return True
