#!/bin/bash

# Attach to a Mininet host and run a command

if [ -z $1 ]; then
  echo "usage: $0 host cmd [args...]"
  exit 1
else
  host=$1
fi

pid=`ps ax | grep "mininet:$host$" | grep bash | awk '{print $1};'`

if echo $pid | grep -q ' '; then
  echo "Error: found multiple mininet:$host processes"
  exit 2
fi

if [ "$pid" == "" ]; then
  echo "Could not find Mininet host $host"
  exit 3
fi

if [ -z $2 ]; then
  cmd='bash'
else
  shift
  cmd=$*
fi

cgroup=/sys/fs/cgroup/cpu/$host
if [ -d "$cgroup" ]; then
  cg="-g $host"
fi

exec sudo mnexec -a $pid $cg $cmd