compute: Migrate 'server create' to SDK

The final step. Future changes will clean up the remnants of the
novaclient usage. This is a rather large patch, owing to the number of
things that novaclient was handling for us which SDK does not, but the
combination of unit and functional tests mean we should be handling
all of these differences.

Change-Id: I623e8c772235438a3d1590e1bbd832748d6e62ea
Signed-off-by: Stephen Finucane <stephenfin@redhat.com>

Author: stephenfin

openstackclient/api/compute_v2.py

@@ -621,3 +621,40 @@ def find_security_group(compute_client, name_or_id):
         raise exceptions.NotFound(f'{name_or_id} not found')
 
     return found
+
+
+def find_network(compute_client, name_or_id):
+    """Find the ID for a given network name or ID
+
+    https://docs.openstack.org/api-ref/compute/#show-network-details
+
+    :param compute_client: A compute client
+    :param name_or_id: The name or ID of the network to look up
+    :returns: A network object
+    :raises exception.NotFound: If a matching network could not be found or
+        more than one match was found
+    """
+    response = compute_client.get(
+        f'/os-networks/{name_or_id}', microversion='2.1'
+    )
+    if response.status_code != http.HTTPStatus.NOT_FOUND:
+        # there might be other, non-404 errors
+        sdk_exceptions.raise_from_response(response)
+        return response.json()['network']
+
+    response = compute_client.get('/os-networks', microversion='2.1')
+    sdk_exceptions.raise_from_response(response)
+    found = None
+    networks = response.json()['networks']
+    for network in networks:
+        if network['label'] == name_or_id:
+            if found:
+                raise exceptions.NotFound(
+                    f'multiple matches found for {name_or_id}'
+                )
+            found = network
+
+    if not found:
+        raise exceptions.NotFound(f'{name_or_id} not found')
+
+    return found