deprecate nova-all

This deprecates nova-all for the Newton release so we can remove it in
O.

Change-Id: Iae77e137cccbf3dbec7d19da60992368e9647b2a

nova/cmd/all.py

@@ -30,7 +30,7 @@ from oslo_log import log as logging
 
 import nova.conf
 from nova import config
-from nova.i18n import _LE
+from nova.i18n import _LE, _LW
 from nova import objects
 from nova import service
 from nova import utils
@@ -48,6 +48,9 @@ def main():
     objects.register_all()
     launcher = service.process_launcher()
 
+    # TODO(sdague): Remove in O
+    LOG.warning(_LW('The nova-all entrypoint is deprecated and will '
+                    'be removed in a future release'))
     # nova-api
     for api in CONF.enabled_apis:
         try:

releasenotes/notes/deprecate_nova_all-eee03c2b0e944699.yaml

@@ -0,0 +1,6 @@
+---
+deprecations:
+
+  - The ``nova-all`` binary is deprecated. This was an all in one
+    binary for nova services used for testing in the early days of
+    OpenStack, but was never intended for real use.