Add a tool to clean the legacy alarm tables

Since we have moved alarm out of ceilometer, when run ceilometer-dbsync,
the alarm tables will still be created and won't be removed. This change
added a tool that allow users to drop the legacy alarm and alarm_history
tables with SQL backends.

Change-Id: Ia831741319fd8e198f54a7d4a99b4d7833074e8e
Closes-Bug: #1578128
Signed-off-by: liusheng <liusheng@huawei.com>

ceilometer/cmd/storage.py

@@ -16,12 +16,13 @@
 
 from oslo_config import cfg
 from oslo_log import log
+import six.moves.urllib.parse as urlparse
+import sqlalchemy as sa
 
-from ceilometer.i18n import _LI
+from ceilometer.i18n import _LE, _LI
 from ceilometer import service
 from ceilometer import storage
 
-
 LOG = log.getLogger(__name__)
 
 
@@ -51,3 +52,72 @@ def expirer():
     else:
         LOG.info(_LI("Nothing to clean, database event time to live "
                      "is disabled"))
+
+
+def db_clean_legacy():
+    confirm = raw_input("Do you really want to drop the legacy alarm tables? "
+                        "This will destroy data definitely if it exist. "
+                        "Please type 'YES' to confirm: ")
+    if confirm != 'YES':
+        print("DB legacy cleanup aborted!")
+        return
+    service.prepare_service()
+    for purpose in ['metering', 'event']:
+        url = (getattr(cfg.CONF.database, '%s_connection' % purpose) or
+               cfg.CONF.database.connection)
+        parsed = urlparse.urlparse(url)
+
+        if parsed.password:
+            masked_netloc = '****'.join(parsed.netloc.rsplit(parsed.password))
+            masked_url = parsed._replace(netloc=masked_netloc)
+            masked_url = urlparse.urlunparse(masked_url)
+        else:
+            masked_url = url
+        LOG.info(_LI('Starting to drop alarm and alarm history tables in '
+                     '%(purpose)s backend: %(url)s'), {
+            'purpose': purpose, 'url': masked_url})
+
+        connection_scheme = parsed.scheme
+        conn = storage.get_connection_from_config(cfg.CONF, purpose)
+        if connection_scheme in ('mysql', 'mysql+pymysql', 'postgresql',
+                                 'sqlite'):
+            engine = conn._engine_facade.get_engine()
+            meta = sa.MetaData(bind=engine)
+            for table_name in ['alarm', 'alarm_history']:
+                if engine.has_table(table_name):
+                    alarm = sa.Table(table_name, meta, autoload=True)
+                    alarm.drop()
+                    LOG.info(_LI("Legacy %s table of SQL backend has been "
+                                 "dropped."), table_name)
+                else:
+                    LOG.info(_LI('%s table does not exist.'), table_name)
+
+        elif connection_scheme == 'hbase':
+            with conn.conn_pool.connection() as h_conn:
+                tables = h_conn.tables()
+                table_name_mapping = {'alarm': 'alarm',
+                                      'alarm_h': 'alarm history'}
+                for table_name in ['alarm', 'alarm_h']:
+                    try:
+                        if table_name in tables:
+                            h_conn.disable_table(table_name)
+                            h_conn.delete_table(table_name)
+                            LOG.info(_LI("Legacy %s table of Hbase backend "
+                                         "has been dropped."),
+                                     table_name_mapping[table_name])
+                        else:
+                            LOG.info(_LI('%s table does not exist.'),
+                                     table_name_mapping[table_name])
+                    except Exception as e:
+                        LOG.error(_LE('Error occurred while dropping alarm '
+                                      'tables of Hbase, %s'), e)
+
+        elif connection_scheme == 'mongodb':
+            for table_name in ['alarm', 'alarm_history']:
+                if table_name in conn.db.conn.collection_names():
+                    conn.db.conn.drop_collection(table_name)
+                    LOG.info(_LI("Legacy %s table of Mongodb backend has been "
+                                 "dropped."), table_name)
+                else:
+                    LOG.info(_LI('%s table does not exist.'), table_name)
+    LOG.info('Legacy alarm tables cleanup done.')

releasenotes/notes/add-db-legacy-clean-tool-7b3e3714f414c448.yaml

@@ -0,0 +1,6 @@
+---
+fixes:
+  - >
+    [`bug 1578128 <https://bugs.launchpad.net/ceilometer/+bug/1578128>`_]
+    Add a tool that allow users to drop the legacy alarm and alarm_history
+    tables.

setup.cfg

@@ -246,6 +246,7 @@ console_scripts =
     ceilometer-agent-notification = ceilometer.cmd.agent_notification:main
     ceilometer-send-sample = ceilometer.cmd.sample:send_sample
     ceilometer-dbsync = ceilometer.cmd.storage:dbsync
+    ceilometer-db-legacy-clean = ceilometer.cmd.storage:db_clean_legacy
     ceilometer-expirer = ceilometer.cmd.storage:expirer
     ceilometer-rootwrap = oslo_rootwrap.cmd:main
     ceilometer-collector = ceilometer.cmd.collector:main