DAOS-16484 test: Support mixed speeds when selecting a default interf…

…ace (#15050) (#15080)

Allow selecting a default interface that is running at a different speed
on different hosts.  Primarily this is to support selecting the ib0
interface by default when the launch node has a slower ib0 interface
than the cluster hosts.

Signed-off-by: Phil Henderson <phillip.henderson@intel.com>

src/tests/ftest/util/environment_utils.py

@@ -9,6 +9,7 @@
 
 from ClusterShell.NodeSet import NodeSet
 # pylint: disable=import-error,no-name-in-module
+from util.host_utils import get_local_host
 from util.network_utils import (PROVIDER_ALIAS, SUPPORTED_PROVIDERS, NetworkException,
  get_common_provider, get_fastest_interface)
 from util.run_utils import run_remote
@@ -326,7 +327,7 @@ def _default_interface(self, logger, hosts):
  # Find all the /sys/class/net interfaces on the launch node (excluding lo)
  logger.debug("Detecting network devices - D_INTERFACE not set")
  try:
- interface = get_fastest_interface(logger, hosts)
+ interface = get_fastest_interface(logger, hosts | get_local_host())
  except NetworkException as error:
  raise TestEnvironmentException("Error obtaining a default interface!") from error
  return interface

src/tests/ftest/util/network_utils.py

@@ -405,11 +405,12 @@ def get_fastest_interface(logger, hosts, verbose=True):
  for interface in common_interfaces:
  detected_speeds = get_interface_speeds(logger, hosts, interface, verbose)
  speed_list = []
+ speed_hosts = NodeSet()
  for speed, node_set in detected_speeds.items():
- if node_set == hosts:
-  # Only include detected homogeneous interface speeds
-  speed_list.append(speed)
- if speed_list:
+ speed_list.append(speed)
+ speed_hosts.add(node_set)
+ if speed_list and speed_hosts == hosts:
+  # Only include interface speeds if a speed is detected on all the hosts
  interface_speeds[interface] = min(speed_list)
 
  logger.info("Active network interface speeds on %s:", hosts)