Some CI tasks/commands like Iperf(), Ping() get multiple nodes (via XML
parameter "nodes") to potentially run UEs on different nodes (hosts) at
the same time. However, I argue that this is not good:
- we don't actually use this -- where we specify multiple UEs, it's
always "localhost localhost..."
- it is inconsistent, as we typically have a single "node", not nodes,
and there is a possibility to harmonize (see also next commit)
- if we needed it, there would be better ways to achieve the same.
First, for hardware-based UEs, the ci_infra.yaml can specify different
UEs. For simulated UEs, it would be feasible to have multiple XML
steps run in parallel, e.g., in the XML <parallel> tag, which would
clarify that multiple UEs on different hosts run in parallel
- it reduces code.
Hence, make a single <node> for these XML steps.
By configuring the Jenkins pythonExecutor to match the test machine, we can use
localhost as the node for running individual test cases. This change makes it
easy to move tests across machines, as the only adjustment needed is updating
the pythonExecutor in Jenkins.