Enable python3 unit testing in zuul for nfv

This does not ensure nfv is python3 compatable, but
it does ensure that the current unit tests and code covered
by those tests work in python3.

The shell.py changes are due to a change in default values in argparse.

The instance director change is because python3 uses a reference
rather than a copy, for its dict keys.

Story: 2003427
Task: 28818
Change-Id: Iaccc0ab5fc4e30b41df108f817612abad8ec612c
Signed-off-by: Al Bailey <Al.Bailey@windriver.com>

.zuul.yaml

@@ -9,6 +9,7 @@
         - openstack-tox-linters
         - nfv-tox-pep8
         - nfv-tox-py27
+        - nfv-tox-py35
         - nfv-tox-pylint
         - nova-api-proxy-tox-pep8
         - nova-api-proxy-tox-pylint
@@ -21,6 +22,7 @@
         - openstack-tox-linters
         - nfv-tox-pep8
         - nfv-tox-py27
+        - nfv-tox-py35
         - nfv-tox-pylint
         - nova-api-proxy-tox-pep8
         - nova-api-proxy-tox-pylint
@@ -40,6 +42,16 @@
       tox_envlist: py27
       tox_extra_args: -c nfv/tox.ini
 
+- job:
+    name: nfv-tox-py35
+    parent: tox
+    description: Run py35 for nfv
+    required-projects:
+      - openstack/stx-fault
+    vars:
+      tox_envlist: py35
+      tox_extra_args: -c nfv/tox.ini
+
 - job:
     name: nfv-tox-pep8
     parent: tox

nfv/nfv-client/nfv_client/shell.py

@@ -28,6 +28,7 @@ def process_main(argv=sys.argv[1:]):  # pylint: disable=dangerous-default-value
         parser.add_argument('--os-interface', default=None)
 
         commands = parser.add_subparsers(title='Commands', metavar='')
+        commands.required = True
 
         # Software Patch Commands
         sw_patch_parser = commands.add_parser('patch-strategy',
@@ -36,6 +37,7 @@ def process_main(argv=sys.argv[1:]):  # pylint: disable=dangerous-default-value
 
         sw_patch_cmds = sw_patch_parser.add_subparsers(
             title='Software Patch Commands', metavar='')
+        sw_patch_cmds.required = True
 
         sw_patch_create_strategy_cmd \
             = sw_patch_cmds.add_parser('create', help='Create a strategy')
@@ -99,6 +101,7 @@ def process_main(argv=sys.argv[1:]):  # pylint: disable=dangerous-default-value
 
         sw_upgrade_cmds = sw_upgrade_parser.add_subparsers(
             title='Software Upgrade Commands', metavar='')
+        sw_upgrade_cmds.required = True
 
         sw_upgrade_create_strategy_cmd \
             = sw_upgrade_cmds.add_parser('create', help='Create a strategy')

nfv/nfv-vim/nfv_vim/directors/_instance_director.py

@@ -229,7 +229,9 @@ class InstanceDirector(object):
                         instances_failed.append(instance)
 
         # Remove reboot counts for instances that recovered
-        reboot_tracking_instance_uuids = self._reboot_count.keys()
+        # Make a copy of the keys for this to work in python3
+        # since _reboot_count is changing while iterating
+        reboot_tracking_instance_uuids = list(self._reboot_count.keys())
 
         for instance_uuid in reboot_tracking_instance_uuids:
             if instance_uuid not in instance_tracking_uuids: