ceph-volume: add type annotations to devices.lvm.prepare

This commit adds the Python type annotations to `devices.lvm.prepare`.

Signed-off-by: Guillaume Abrioux <[email protected]>

Author: guits

src/ceph-volume/ceph_volume/devices/lvm/prepare.py

@@ -1,9 +1,10 @@
 from __future__ import print_function
 import logging
+import argparse
 from textwrap import dedent
 from ceph_volume import objectstore
 from .common import prepare_parser
-
+from typing import List, Optional
 
 logger = logging.getLogger(__name__)
 
@@ -12,13 +13,13 @@ class Prepare(object):
 
     help = 'Format an LVM device and associate it with an OSD'
 
-    def __init__(self, argv, args=None):
-        self.objectstore = None
+    def __init__(self, argv: Optional[List[str]] = None, args: Optional[argparse.Namespace] = None) -> None:
+        self.objectstore: Optional[objectstore.baseobjectstore.BaseObjectStore] = None
         self.argv = argv
         self.args = args
         self.osd_id = None
 
-    def main(self):
+    def main(self) -> None:
         sub_command_help = dedent("""
         Prepare an OSD by assigning an ID and FSID, registering them with the
         cluster with an ID and FSID, formatting and mounting the volume, and
@@ -48,6 +49,8 @@ def main(self):
             prog='ceph-volume lvm prepare',
             description=sub_command_help,
         )
+        if self.argv is None:
+            self.argv = []
         if len(self.argv) == 0 and self.args is None:
             print(sub_command_help)
             return
@@ -56,4 +59,7 @@ def main(self):
         if self.args.bluestore:
             self.args.objectstore = 'bluestore'
         self.objectstore = objectstore.mapping['LVM'][self.args.objectstore](args=self.args)
-        self.objectstore.safe_prepare()
+        if self.objectstore is not None:
+            self.objectstore.safe_prepare()
+        else:
+            raise RuntimeError('Unexpected error while setting objectore backend.')