1 files changed, 239 insertions, 0 deletions
diff --git a/src/lib/Bcfg2/Server/Reports/Updater/__init__.py b/src/lib/Bcfg2/Server/Reports/Updater/__init__.py
new file mode 100644
index 000000000..3038e9691
--- /dev/null
+++ b/src/lib/Bcfg2/Server/Reports/Updater/__init__.py
@@ -0,0 +1,239 @@
+from django.db import connection, DatabaseError
+import django.core.management
+import logging
+import pkgutil
+import re
+import sys
+import traceback
+
+from Bcfg2.Server.Reports.reports.models import InternalDatabaseVersion
+from Bcfg2.Server.Reports.Updater.Routines import UpdaterRoutineException, \
+                UpdaterRoutine
+from Bcfg2.Server.Reports.Updater import Changes
+
+logger = logging.getLogger(__name__)
+
+class UpdaterError(Exception):
+    pass
+
+
+class SchemaTooOldError(UpdaterError):
+    pass
+
+
+def _walk_packages(path):
+    """Python 2.4 lacks this routine"""
+    import glob
+    submodules = []
+    for path in __path__:
+        for submodule in glob.glob("%s/*.py" % path):
+            mod = '.'.join(submodule.split("/")[-1].split('.')[:-1])
+            if mod != '__init__':
+                submodules.append((None, mod, False))
+    return submodules
+
+
+def _release_to_version(release):
+    """
+    Build a release base for a version
+
+    Expects a string of the form 00.00
+
+    returns an integer of the form MMmm00
+    """
+    regex = re.compile("^(\d+)\.(\d+)$")
+    m = regex.match(release)
+    if not m:
+        logger.error("Invalid release string: %s" % release)
+        raise TypeError
+    return int("%02d%02d00" % (int(m.group(1)), int(m.group(2))))
+
+
+class Updater(object):
+    """Database updater to standardize updates"""
+
+    def __init__(self, release):
+        self._cursor = None
+        self._release = release
+        try:
+            self._base_version = _release_to_version(release)
+        except:
+            raise UpdaterError
+
+        self._fixes = []
+        self._version = -1
+
+
+    def __cmp__(self, other):
+        return self._base_version - other._base_version
+
+    @property
+    def release(self):
+        return self._release
+
+    @property
+    def version(self):
+        if self._version < 0:
+            try:
+                iv = InternalDatabaseVersion.objects.latest()
+                self._version = iv.version
+            except InternalDatabaseVersion.DoesNotExist:
+                raise UpdaterError
+        return self._version
+
+    @property
+    def cursor(self):
+        if not self._cursor:
+            self._cursor = connection.cursor()
+        return self._cursor
+
+    @property
+    def target_version(self):
+        if(len(self._fixes) == 0):
+            return self._base_version
+        else:
+            return self._base_version + len(self._fixes) - 1
+
+
+    def add(self, update):
+        if type(update) == str or isinstance(update, UpdaterRoutine):
+            self._fixes.append(update)
+        else:
+            raise TypeError
+
+
+    def override_base_version(self, version):
+        """Override our starting point for old releases.  New code should
+           not use this method"""
+        self._base_version = int(version)
+
+
+    @staticmethod
+    def get_current_version():
+        """Queries the db for the latest version.  Returns 0 for a fresh install"""
+
+        if "call_command" in dir(django.core.management):
+            django.core.management.call_command("syncdb", interactive=False, verbosity=0)
+        else:
+            logger.warning("Unable to call syndb routine")
+            raise UpdaterError
+
+        try:
+            iv = InternalDatabaseVersion.objects.latest()
+            version = iv.version
+        except InternalDatabaseVersion.DoesNotExist:
+            version = 0
+
+        return version
+
+
+    def syncdb(self):
+        """Function to do the syncronisation for the models"""
+
+        self._version = Updater.get_current_version()
+        self._cursor = None
+
+
+    def increment(self):
+        """Increment schema version in the database"""
+        if self._version < self._base_version:
+            self._version = self._base_version
+        else:
+            self._version += 1
+        InternalDatabaseVersion.objects.create(version=self._version)
+
+    def apply(self):
+        """Apply pending schema changes"""
+
+        if self.version >= self.target_version:
+            logger.debug("No updates for release %s" % self._release)
+            return
+
+        logger.debug("Applying updates for release %s" % self._release)
+
+        if self.version < self._base_version:
+            start = 0
+        else:
+            start = self.version - self._base_version + 1
+
+        try:
+            for fix in self._fixes[start:]:
+                if type(fix) == str:
+                    self.cursor.execute(fix)
+                elif isinstance(fix, UpdaterRoutine):
+                    fix.run()
+                else:
+                    logger.error("Invalid schema change at %s" % \
+                        self._version + 1)
+                self.increment()
+                logger.debug("Applied schema change number %s: %s" % \
+                    (self.version, fix))
+            logger.info("Applied schema changes for release %s" % self._release)
+        except:
+            logger.error("Failed to perform db update %s (%s): %s" % \
+                (self._version + 1, fix, traceback.format_exc().splitlines()[-1]))
+            raise UpdaterError
+
+
+class UnsupportedUpdate(Updater):
+    """Handle an unsupported update"""
+
+    def __init__(self, release, version):
+        super(UnsupportedUpdate, self).__init__(release)
+        self._base_version = version
+
+    def apply(self):
+        """Raise an exception if we're too old"""
+
+        if self.version < self.target_version:
+            logger.error("Upgrade from release %s unsupported" % self._release)
+            raise SchemaTooOldError
+
+
+def update_database():
+    """method to search where we are in the revision
+    of the database models and update them"""
+    try:
+        logger.debug("Verifying database schema")
+
+        updaters = []
+        if hasattr(pkgutil, 'walk_packages'):
+            submodules = pkgutil.walk_packages(path=Changes.__path__)
+        else:
+            #python 2.4
+            submodules = _walk_packages(Changes.__path__)
+        for loader, submodule, ispkg in submodules:
+            if ispkg:
+                continue
+            try:
+                updates = getattr(
+                    __import__("%s.%s" % (Changes.__name__, submodule), 
+                        globals(), locals(), ['*']),
+                    "updates")
+                updaters.append(updates())
+            except ImportError:
+                logger.error("Failed to import %s" % submodule)
+            except AttributeError:
+                logger.warning("Module %s does not have an updates function" % submodule)
+            except:
+                logger.error("Failed to build updater for %s" % submodule, exc_info=1)
+                raise UpdaterError
+
+        current_version = Updater.get_current_version()
+        logger.debug("Database version at %s" % current_version)
+
+        if current_version > 0:
+            [u.apply() for u in sorted(updaters)]
+            logger.debug("Database version at %s" % Updater.get_current_version())
+        else:
+            target = updaters[-1].target_version
+            InternalDatabaseVersion.objects.create(version=target)
+            logger.info("A new database was created")
+
+    except UpdaterError:
+        raise
+    except:
+        logger.error("Error while updating the database")
+        for x in traceback.format_exc().splitlines():
+            logger.error(x)
+        raise UpdaterError