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-rw-r--r--contrail-agent/hooks/charmhelpers/core/fstab.py132
1 files changed, 132 insertions, 0 deletions
diff --git a/contrail-agent/hooks/charmhelpers/core/fstab.py b/contrail-agent/hooks/charmhelpers/core/fstab.py
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+++ b/contrail-agent/hooks/charmhelpers/core/fstab.py
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+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+
+# Copyright 2014-2015 Canonical Limited.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import io
+import os
+
+__author__ = 'Jorge Niedbalski R. <jorge.niedbalski@canonical.com>'
+
+
+class Fstab(io.FileIO):
+ """This class extends file in order to implement a file reader/writer
+ for file `/etc/fstab`
+ """
+
+ class Entry(object):
+ """Entry class represents a non-comment line on the `/etc/fstab` file
+ """
+ def __init__(self, device, mountpoint, filesystem,
+ options, d=0, p=0):
+ self.device = device
+ self.mountpoint = mountpoint
+ self.filesystem = filesystem
+
+ if not options:
+ options = "defaults"
+
+ self.options = options
+ self.d = int(d)
+ self.p = int(p)
+
+ def __eq__(self, o):
+ return str(self) == str(o)
+
+ def __str__(self):
+ return "{} {} {} {} {} {}".format(self.device,
+ self.mountpoint,
+ self.filesystem,
+ self.options,
+ self.d,
+ self.p)
+
+ DEFAULT_PATH = os.path.join(os.path.sep, 'etc', 'fstab')
+
+ def __init__(self, path=None):
+ if path:
+ self._path = path
+ else:
+ self._path = self.DEFAULT_PATH
+ super(Fstab, self).__init__(self._path, 'rb+')
+
+ def _hydrate_entry(self, line):
+ # NOTE: use split with no arguments to split on any
+ # whitespace including tabs
+ return Fstab.Entry(*filter(
+ lambda x: x not in ('', None),
+ line.strip("\n").split()))
+
+ @property
+ def entries(self):
+ self.seek(0)
+ for line in self.readlines():
+ line = line.decode('us-ascii')
+ try:
+ if line.strip() and not line.strip().startswith("#"):
+ yield self._hydrate_entry(line)
+ except ValueError:
+ pass
+
+ def get_entry_by_attr(self, attr, value):
+ for entry in self.entries:
+ e_attr = getattr(entry, attr)
+ if e_attr == value:
+ return entry
+ return None
+
+ def add_entry(self, entry):
+ if self.get_entry_by_attr('device', entry.device):
+ return False
+
+ self.write((str(entry) + '\n').encode('us-ascii'))
+ self.truncate()
+ return entry
+
+ def remove_entry(self, entry):
+ self.seek(0)
+
+ lines = [l.decode('us-ascii') for l in self.readlines()]
+
+ found = False
+ for index, line in enumerate(lines):
+ if line.strip() and not line.strip().startswith("#"):
+ if self._hydrate_entry(line) == entry:
+ found = True
+ break
+
+ if not found:
+ return False
+
+ lines.remove(line)
+
+ self.seek(0)
+ self.write(''.join(lines).encode('us-ascii'))
+ self.truncate()
+ return True
+
+ @classmethod
+ def remove_by_mountpoint(cls, mountpoint, path=None):
+ fstab = cls(path=path)
+ entry = fstab.get_entry_by_attr('mountpoint', mountpoint)
+ if entry:
+ return fstab.remove_entry(entry)
+ return False
+
+ @classmethod
+ def add(cls, device, mountpoint, filesystem, options=None, path=None):
+ return cls(path=path).add_entry(Fstab.Entry(device,
+ mountpoint, filesystem,
+ options=options))