Default --nic to 'auto' if creating a server with >= 2.37

Compute API version >= 2.37 requires a 'networks' value in
the server create request. The novaclient CLI defaults this
to 'auto' if not specified, but the novaclient ServerManager.create
python API binding code does not, as it wants clients to be explicit.

For the purposes of the OSC CLI, we should follow suit and if the
user is requesting OS_COMPUTE_API_VERSION>=2.37 without specific
nics, we should just default to 'auto'.

Change-Id: Ib760c55e31209223338a4086ff1f4fee88dc6959
Closes-Bug: #1750395
(cherry picked from commit 1008544882fbdae16b045abca05cf3e2e8a14787)

1 files changed, 8 insertions, 3 deletions

diff --git a/openstackclient/compute/v2/server.py b/openstackclient/compute/v2/server.py
index a6a59084..a1647421 100644
--- a/openstackclient/compute/v2/server.py
+++ b/openstackclient/compute/v2/server.py
@@ -809,9 +809,14 @@ class CreateServer(command.ShowOne):
                     raise exceptions.CommandError(msg)
                 nics = nics[0]
         else:
-            # Default to empty list if nothing was specified, let nova side to
-            # decide the default behavior.
-            nics = []
+            # Compute API version >= 2.37 requires a value, so default to
+            # 'auto' to maintain legacy behavior if a nic wasn't specified.
+            if compute_client.api_version >= api_versions.APIVersion('2.37'):
+                nics = 'auto'
+            else:
+                # Default to empty list if nothing was specified, let nova
+                # side to decide the default behavior.
+                nics = []
 
         # Check security group exist and convert ID to name
         security_group_names = []