Move sysrestore to ipa-python so it can be used by client scripts too.

Change backup format so files are all in a single directory (no dir
hierarchies) and use an index file so we can save also ownership and
permission info for the restore (and eventually other data later on).

1 files changed, 319 insertions, 0 deletions

diff --git a/ipa-python/sysrestore.py b/ipa-python/sysrestore.py
new file mode 100644
index 000000000..46233ef87
--- /dev/null
+++ b/ipa-python/sysrestore.py
@@ -0,0 +1,319 @@
+# 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; version 2 only
+#
+# 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+#
+
+#
+# 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 errno
+import shutil
+import logging
+import ConfigParser
+import random
+import string
+
+from ipa import ipautil
+
+SYSRESTORE_PATH = "/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):
+        """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+"/"+SYSRESTORE_INDEXFILE
+
+        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.
+        """
+
+        logging.debug("Loading Index file from '%s'", self._path)
+
+        self.files = {}
+
+        p = ConfigParser.SafeConfigParser()
+        p.read(self._path)
+
+        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 @_path. If @files is an empty
+        dict, then @_path should be removed.
+        """
+        logging.debug("Saving Index File to '%s'", self._path)
+
+        if len(self.files) == 0:
+            logging.debug("  -> no files, removing file")
+            if os.path.exists(self._path):
+                os.remove(self._path)
+            return
+
+        p = ConfigParser.SafeConfigParser()
+
+        p.add_section('files')
+        for (key, value) in self.files.items():
+            p.set('files', key, str(value))
+
+        f = file(self._path, "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().
+        """
+        logging.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):
+            logging.debug("  -> Not backing up - '%s' doesn't exist", path)
+            return
+
+        (reldir, file) = os.path.split(path)
+
+        filename = ""
+        for i in range(8):
+            h = "%02x" % self.random.randint(0,255)
+            filename += h
+        filename += "-"+file
+
+        backup_path = os.path.join(SYSRESTORE_PATH, filename)
+        if os.path.exists(backup_path):
+            logging.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 restore_file(self, path):
+        """Restore the copy of a file at @path to its original
+        location and delete the copy.
+
+        Returns #True if the file was restored, #False if there
+        was no backup file to restore
+        """
+
+        logging.debug("Restoring 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(SYSRESTORE_PATH, filename)
+        if not os.path.exists(backup_path):
+            logging.debug("  -> Not restoring - '%s' doesn't exist", backup_path)
+            return False
+
+        shutil.move(backup_path, path)
+        os.chown(path, int(uid), int(gid))
+        os.chmod(path, int(mode))
+
+        ipautil.run(["/sbin/restorecon", 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(SYSRESTORE_PATH, filename)
+            if not os.path.exists(backup_path):
+                logging.debug("  -> Not restoring - '%s' doesn't exist", backup_path)
+
+            shutil.move(backup_path, path)
+            os.chown(path, int(uid), int(gid))
+            os.chmod(path, int(mode))
+
+            ipautil.run(["/sbin/restorecon", path])
+
+	#force file to be deleted
+        self.files = {}
+        self.save()
+
+        return True
+
+class _StateFile:
+    """A metadata file for recording system state which can
+    be backed up and later restored. The format is something
+    like:
+
+    [httpd]
+    running=True
+    enabled=False
+    """
+
+    def __init__(self, path = SYSRESTORE_PATH):
+        """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 = path+"/"+SYSRESTORE_STATEFILE
+
+        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.
+        """
+        logging.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.
+        """
+        logging.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:
+            logging.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(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) or isinstance(value, bool)):
+        raise ValueError("Only strings or booleans supported")
+
+    state = _StateFile()
+
+    if not state.modules.has_key(module):
+        state.modules[module] = {}
+
+    if not state.modules.has_key(key):
+        state.modules[module][key] = value
+
+    state.save()
+
+def restore_state(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.
+    """
+    state = _StateFile()
+
+    if not state.modules.has_key(module):
+        return None
+
+    if not state.modules[module].has_key(key):
+        return None
+
+    value = state.modules[module][key]
+    del state.modules[module][key]
+
+    state.save()
+
+    return value