Environment variables not configured in Linux namespaces

[liambrady]

Any environment variables configured through env in the munet schema do not seem to be actually configured within a Linux namespace node.

For example, configuring munet.yaml as follows:

topology:
  nodes:
    - name: temp
      cmd: echo $foo
      env:
        - name: foo
          value: bar

and entering the node temp through the command term temp, it can be observed that "bar" is missing from cmd.log. Similarly, echo $foo does not print "bar"

[choppsv1]

Indeed, and I'm having trouble finding in git history where this might have worked for anything but container nodes.

[choppsv1]

Add to this that CONFIGDIR and RUNDIR are also not being set in def run_dir() for linux namespaces. This was noted by @rwestphal