Prevent logging of restricted file contents

Prevent logging of sensitive data in restricted
files when privsep operations complete.

Dell PowerFlex: password appears in plain text when
- creating a volume from an image
- attaching a volume
- detatching a volume

Closes bug #2003179

Change-Id: Ic26a355e65b3392df9fb970170c9dbb60bbf4606

oslo_privsep/daemon.py

@@ -496,8 +496,8 @@ class Daemon(object):
             """
             try:
                 reply = result.result()
-                LOG.debug('privsep: reply[%(msgid)s]: %(reply)s',
-                          {'msgid': msgid, 'reply': reply})
+                LOG.debug('privsep: reply[%(msgid)s]: has_reply? %(reply)s',
+                          {'msgid': msgid, 'reply': reply is not None})
                 channel.send((msgid, reply))
             except IOError:
                 self.communication_error = sys.exc_info()

releasenotes/notes/bug-2003179-f88922a47abcf07a.yaml

@@ -0,0 +1,14 @@
+---
+fixes:
+  - |
+    `Bug #2003179  <https://bugs.launchpad.net/cinder/+bug/2003179>`_: Fixed
+    Prevent logging of restricted file contents
+
+    Prevent logging of sensitive data in restricted
+    files when privsep operations complete.
+
+    Dell PowerFlex: password appears in plain text when
+    - creating a volume from an image
+    - attaching a volume
+    - detatching a volume
+