summaryrefslogtreecommitdiffstats
path: root/ipapython/sysrestore.py
blob: 580df9a4fd6d0fae35602dad1f81d498fa8f0173 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
# Authors: Mark McLoughlin <markmc@redhat.com>
#
# Copyright (C) 2007  Red Hat
# see file 'COPYING' for use and warranty information
#
# 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 3 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, see <http://www.gnu.org/licenses/>.
#

#
# This module provides a very simple API which allows
# ipa-xxx-install --uninstall to restore certain
# parts of the system configuration to the way it was
# before ipa-server-install was first run

import os
import os.path
import shutil
from ipapython.ipa_log_manager import *
import ConfigParser
import random
import string

from ipapython import ipautil
from ipaplatform.tasks import tasks
from ipaplatform.paths import paths

SYSRESTORE_PATH = paths.TMP
SYSRESTORE_INDEXFILE = "sysrestore.index"
SYSRESTORE_STATEFILE = "sysrestore.state"

class FileStore:
    """Class for handling backup and restore of files"""

    def __init__(self, path = SYSRESTORE_PATH, index_file = SYSRESTORE_INDEXFILE):
        """Create a _StoreFiles object, that uses @path as the
        base directory.

        The file @path/sysrestore.index is used to store information
        about the original location of the saved files.
        """
        self._path = path
        self._index = os.path.join(self._path, index_file)

        self.random = random.Random()

        self.files = {}
        self._load()

    def _load(self):
        """Load the file list from the index file. @files will
        be an empty dictionary if the file doesn't exist.
        """

        root_logger.debug("Loading Index file from '%s'", self._index)

        self.files = {}

        p = ConfigParser.SafeConfigParser()
        p.read(self._index)

        for section in p.sections():
            if section == "files":
                for (key, value) in p.items(section):
                    self.files[key] = value


    def save(self):
        """Save the file list to @_index. If @files is an empty
        dict, then @_index should be removed.
        """
        root_logger.debug("Saving Index File to '%s'", self._index)

        if len(self.files) == 0:
            root_logger.debug("  -> no files, removing file")
            if os.path.exists(self._index):
                os.remove(self._index)
            return

        p = ConfigParser.SafeConfigParser()

        p.add_section('files')
        for (key, value) in self.files.items():
            p.set('files', key, str(value))

        f = file(self._index, "w")
        p.write(f)
        f.close()

    def backup_file(self, path):
        """Create a copy of the file at @path - so long as a copy
        does not already exist - which will be restored to its
        original location by restore_files().
        """
        root_logger.debug("Backing up system configuration file '%s'", path)

        if not os.path.isabs(path):
            raise ValueError("Absolute path required")

        if not os.path.isfile(path):
            root_logger.debug("  -> Not backing up - '%s' doesn't exist", path)
            return

        (reldir, backupfile) = os.path.split(path)

        filename = ""
        for i in range(8):
            h = "%02x" % self.random.randint(0,255)
            filename += h
        filename += "-"+backupfile

        backup_path = os.path.join(self._path, filename)
        if os.path.exists(backup_path):
            root_logger.debug("  -> Not backing up - already have a copy of '%s'", path)
            return

        shutil.copy2(path, backup_path)

        stat = os.stat(path)

        self.files[filename] = string.join([str(stat.st_mode),str(stat.st_uid),str(stat.st_gid),path], ',')
        self.save()

    def has_file(self, path):
        """Checks whether file at @path was added to the file store

        Returns #True if the file exists in the file store, #False otherwise
        """
        result = False
        for (key, value) in self.files.items():
            (mode,uid,gid,filepath) = string.split(value, ',', 3)
            if (filepath == path):
                result = True
                break
        return result

    def restore_file(self, path, new_path = None):
        """Restore the copy of a file at @path to its original
        location and delete the copy.

        Takes optional parameter @new_path which specifies the
        location where the file is to be restored.

        Returns #True if the file was restored, #False if there
        was no backup file to restore
        """

        if new_path is None:
            root_logger.debug("Restoring system configuration file '%s'", path)
        else:
            root_logger.debug("Restoring system configuration file '%s' to '%s'", path, new_path)

        if not os.path.isabs(path):
            raise ValueError("Absolute path required")
        if new_path is not None and not os.path.isabs(new_path):
            raise ValueError("Absolute new path required")

        mode = None
        uid = None
        gid = None
        filename = None

        for (key, value) in self.files.items():
            (mode,uid,gid,filepath) = string.split(value, ',', 3)
            if (filepath == path):
                filename = key
                break

        if not filename:
            raise ValueError("No such file name in the index")

        backup_path = os.path.join(self._path, filename)
        if not os.path.exists(backup_path):
            root_logger.debug("  -> Not restoring - '%s' doesn't exist", backup_path)
            return False

        if new_path is not None:
            path = new_path

        shutil.move(backup_path, path)
        os.chown(path, int(uid), int(gid))
        os.chmod(path, int(mode))

        tasks.restore_context(path)

        del self.files[filename]
        self.save()

        return True

    def restore_all_files(self):
        """Restore the files in the inbdex to their original
        location and delete the copy.

        Returns #True if the file was restored, #False if there
        was no backup file to restore
        """

        if len(self.files) == 0:
            return False

        for (filename, value) in self.files.items():

            (mode,uid,gid,path) = string.split(value, ',', 3)

            backup_path = os.path.join(self._path, filename)
            if not os.path.exists(backup_path):
                root_logger.debug("  -> Not restoring - '%s' doesn't exist", backup_path)
                continue

            shutil.move(backup_path, path)
            os.chown(path, int(uid), int(gid))
            os.chmod(path, int(mode))

            tasks.restore_context(path)

	#force file to be deleted
        self.files = {}
        self.save()

        return True

    def has_files(self):
        """Return True or False if there are any files in the index

        Can be used to determine if a program is configured.
        """

        return len(self.files) > 0

    def untrack_file(self, path):
        """Remove file at path @path from list of backed up files.

        Does not remove any files from the filesystem.

        Returns #True if the file was untracked, #False if there
        was no backup file to restore
        """

        root_logger.debug("Untracking system configuration file '%s'", path)

        if not os.path.isabs(path):
            raise ValueError("Absolute path required")

        mode = None
        uid = None
        gid = None
        filename = None

        for (key, value) in self.files.items():
            (mode,uid,gid,filepath) = string.split(value, ',', 3)
            if (filepath == path):
                filename = key
                break

        if not filename:
            raise ValueError("No such file name in the index")

        backup_path = os.path.join(self._path, filename)
        if not os.path.exists(backup_path):
            root_logger.debug("  -> Not restoring - '%s' doesn't exist", backup_path)
            return False

        try:
            os.unlink(backup_path)
        except Exception, e:
            root_logger.error('Error removing %s: %s' % (backup_path, str(e)))

        del self.files[filename]
        self.save()

        return True

class StateFile:
    """A metadata file for recording system state which can
    be backed up and later restored.
    StateFile gets reloaded every time to prevent loss of information
    recorded by child processes. But we do not solve concurrency
    because there is no need for it right now.
    The format is something like:

    [httpd]
    running=True
    enabled=False
    """

    def __init__(self, path = SYSRESTORE_PATH, state_file = SYSRESTORE_STATEFILE):
        """Create a StateFile object, loading from @path.

        The dictionary @modules, a member of the returned object,
        is where the state can be modified. @modules is indexed
        using a module name to return another dictionary containing
        key/value pairs with the saved state of that module.

        The keys in these latter dictionaries are arbitrary strings
        and the values may either be strings or booleans.
        """
        self._path = os.path.join(path, state_file)

        self.modules = {}

        self._load()

    def _load(self):
        """Load the modules from the file @_path. @modules will
        be an empty dictionary if the file doesn't exist.
        """
        root_logger.debug("Loading StateFile from '%s'", self._path)

        self.modules = {}

        p = ConfigParser.SafeConfigParser()
        p.read(self._path)

        for module in p.sections():
            self.modules[module] = {}
            for (key, value) in p.items(module):
                if value == str(True):
                    value = True
                elif value == str(False):
                    value = False
                self.modules[module][key] = value

    def save(self):
        """Save the modules to @_path. If @modules is an empty
        dict, then @_path should be removed.
        """
        root_logger.debug("Saving StateFile to '%s'", self._path)

        for module in self.modules.keys():
            if len(self.modules[module]) == 0:
                del self.modules[module]

        if len(self.modules) == 0:
            root_logger.debug("  -> no modules, removing file")
            if os.path.exists(self._path):
                os.remove(self._path)
            return

        p = ConfigParser.SafeConfigParser()

        for module in self.modules.keys():
            p.add_section(module)
            for (key, value) in self.modules[module].items():
                p.set(module, key, str(value))

        f = file(self._path, "w")
        p.write(f)
        f.close()

    def backup_state(self, module, key, value):
        """Backup an item of system state from @module, identified
        by the string @key and with the value @value. @value may be
        a string or boolean.
        """
        if not isinstance(value, (str, bool, unicode)):
            raise ValueError("Only strings, booleans or unicode strings are supported")

        self._load()

        if not self.modules.has_key(module):
            self.modules[module] = {}

        if not self.modules.has_key(key):
            self.modules[module][key] = value

        self.save()

    def get_state(self, module, key):
        """Return the value of an item of system state from @module,
        identified by the string @key.

        If the item doesn't exist, #None will be returned, otherwise
        the original string or boolean value is returned.
        """
        self._load()

        if not self.modules.has_key(module):
            return None

        return self.modules[module].get(key, None)

    def delete_state(self, module, key):
        """Delete system state from @module, identified by the string
        @key.

        If the item doesn't exist, no change is done.
        """
        self._load()

        try:
            del self.modules[module][key]
        except KeyError:
            pass
        else:
            self.save()

    def restore_state(self, module, key):
        """Return the value of an item of system state from @module,
        identified by the string @key, and remove it from the backed
        up system state.

        If the item doesn't exist, #None will be returned, otherwise
        the original string or boolean value is returned.
        """

        value = self.get_state(module, key)

        if value is not None:
            self.delete_state(module, key)

        return value

    def has_state(self, module):
        """Return True or False if there is any state stored for @module.

        Can be used to determine if a service is configured.
        """

        if self.modules.has_key(module):
            return True
        else:
            return False