Fix 'UnicodeEncodeError' for unicode values

Used '%' instead of format() because "%" formatting operation
returns a unicode string for both unicode and non-unicode
format strings.

Encoded the exception error message in novaclient.shell.main and
novaclient.utils.do_action_on_many method to avoid
"UnicodeEncodeError" and print valid message.

NOTE:
Not used u'{0}.format(<str>) because in python 3 everything
is unicode so no need to add explicit 'u' to format string.

Closes-Bug: #1403379
Change-Id: I13f1ef2e1b41299b417cad3759a5cda241890df7

novaclient/shell.py

@@ -982,9 +982,13 @@ def main():
         OpenStackComputeShell().main(argv)
     except Exception as exc:
         logger.debug(exc, exc_info=1)
-        print(_("ERROR (%(type)s): %(msg)s") % {
+        if six.PY2:
+            message = encodeutils.safe_encode(six.text_type(exc))
+        else:
+            message = encodeutils.exception_to_unicode(exc)
+        print("ERROR (%(type)s): %(msg)s" % {
               'type': exc.__class__.__name__,
-              'msg': encodeutils.exception_to_unicode(exc)},
+              'msg': message},
               file=sys.stderr)
         sys.exit(1)
     except KeyboardInterrupt:

novaclient/utils.py

@@ -407,7 +407,7 @@ def do_action_on_many(action, resources, success_msg, error_msg):
             print(success_msg % resource)
         except Exception as e:
             failure_flag = True
-            print(e)
+            print(encodeutils.safe_encode(six.text_type(e)))
 
     if failure_flag:
         raise exceptions.CommandError(error_msg)

novaclient/v2/hosts.py

@@ -76,7 +76,7 @@ class HostManager(base.ManagerWithFind):
         :param action: The action to perform
         returns: An instance of novaclient.base.TupleWithMeta
         """
-        url = '/os-hosts/{0}/{1}'.format(host, action)
+        url = '/os-hosts/%s/%s' % (host, action)
         resp, body = self.api.client.get(url)
         return base.TupleWithMeta((resp, body), resp)