Deprecate nova CLI

It is time to signal that we're fully committed to delivering a pure
OSC experience.

Based on the neutron change from 6 (!!) years ago [1]

[1] 3a64a7a166

Change-Id: Ib80548e104a751179f36f2a6ebff9916d38fdf1e
Signed-off-by: Stephen Finucane <stephenfin@redhat.com>

novaclient/shell.py

@@ -20,6 +20,7 @@ Command-line interface to the OpenStack Nova API.
 
 import argparse
 import logging
+import os
 import sys
 
 from keystoneauth1 import loading
@@ -816,9 +817,19 @@ class OpenStackHelpFormatter(argparse.HelpFormatter):
         super(OpenStackHelpFormatter, self).start_section(heading)
 
 
-def main():
+def main(argv=sys.argv[1:]):
     try:
-        argv = [encodeutils.safe_decode(a) for a in sys.argv[1:]]
+        # Special dansmith envvar to hide the warning. Don't rely on this
+        # because we will eventually remove all this stuff.
+        if os.environ.get("NOVACLIENT_ISHOULDNTBEDOINGTHIS") != "1":
+            print(
+                _(
+                    "nova CLI is deprecated and will be a removed in a future "
+                    "release"
+                ),
+                file=sys.stderr,
+            )
+        argv = [encodeutils.safe_decode(a) for a in argv]
         OpenStackComputeShell().main(argv)
     except Exception as exc:
         logger.debug(exc, exc_info=1)

novaclient/tests/unit/test_shell.py

@@ -624,26 +624,32 @@ class ShellTest(utils.TestCase):
                           self._test_service_type,
                           'unknown', 'compute', self.mock_client)
 
-    @mock.patch('sys.argv', ['nova'])
     @mock.patch('sys.stdout', io.StringIO())
     @mock.patch('sys.stderr', io.StringIO())
     def test_main_noargs(self):
         # Ensure that main works with no command-line arguments
         try:
-            novaclient.shell.main()
+            novaclient.shell.main([])
         except SystemExit:
             self.fail('Unexpected SystemExit')
 
         # We expect the normal usage as a result
-        self.assertIn('Command-line interface to the OpenStack Nova API',
+        self.assertIn(
-                      sys.stdout.getvalue())
+            'Command-line interface to the OpenStack Nova API',
+            sys.stdout.getvalue(),
+        )
+        # We also expect to see the deprecation warning
+        self.assertIn(
+            'nova CLI is deprecated and will be a removed in a future release',
+            sys.stderr.getvalue(),
+        )
 
     @mock.patch.object(novaclient.shell.OpenStackComputeShell, 'main')
     def test_main_keyboard_interrupt(self, mock_compute_shell):
         # Ensure that exit code is 130 for KeyboardInterrupt
         mock_compute_shell.side_effect = KeyboardInterrupt()
         try:
-            novaclient.shell.main()
+            novaclient.shell.main([])
         except SystemExit as ex:
             self.assertEqual(ex.code, 130)
 
@@ -766,9 +772,15 @@ class ShellTest(utils.TestCase):
             pass
         with mock.patch('sys.stderr', io.StringIO()):
             mock_compute_shell.side_effect = MyException('message')
-            self.assertRaises(SystemExit, novaclient.shell.main)
+            self.assertRaises(SystemExit, novaclient.shell.main, [])
             err = sys.stderr.getvalue()
-        self.assertEqual(err, 'ERROR (MyException): message\n')
+        # We expect to see the error propagated
+        self.assertIn('ERROR (MyException): message\n', err)
+        # We also expect to see the deprecation warning
+        self.assertIn(
+            'nova CLI is deprecated and will be a removed in a future release',
+            err,
+        )
 
 
 class TestLoadVersionedActions(utils.TestCase):

releasenotes/notes/deprecate-cli-75074850847a8452.yaml

@@ -0,0 +1,9 @@
+---
+deprecations:
+  - |
+    The ``nova`` CLI is now deprecated. This is the signal that it is
+    time to start using the openstack CLI. No new features will be
+    added to the ``nova`` CLI, though fixes to the CLI will be assessed
+    on a case by case basis. Fixes to the API bindings, development of
+    new API bindings, and changes to the compute commands in the openstack
+    CLI are exempt from this deprecation.