#!/bin/sh
#
# cluster-run.sh, Copyright © 2013 Matteo Cypriani <mcy@lm7.fr>
#
# This program is free software. It comes without any warranty, to
# the extent permitted by applicable law. You can redistribute it
# and/or modify it under the terms of the Do What The Fuck You Want
# To Public License, Version 2, as published by Sam Hocevar. See
# http://sam.zoy.org/wtfpl/COPYING for more details.
#
# Run a command on a list of remote hosts using Parallel SSH.

#set -x

print_usage()
{
  echo "Usage: $0 [-l login] <hosts_list> <command>"
}

# Parse the optional arguments with getopt
export POSIXLY_CORRECT=yes
export GETOPT_COMPATIBLE=yes
OPTSTRING="l:"
ARGS=$(getopt $OPTSTRING $*)
if [ $? -ne 0 ] ; then
  print_usage
  exit 1
fi
set -- $ARGS
while [ $# -ne 0 ] ; do
  case "$1" in
    -l)
      LOGIN="$2"
      shift
      shift
      ;;
    --)
      shift
      break
      ;;
    *)
      echo "Unknown argument:" $1
      exit 2
  esac
done

# Do we have at least a host list and a command?
if [ $# -lt 2 ] ; then
  print_usage
  exit 3
fi

# Check dependencies
PSSH=$(command -v parallel-ssh || command -v pssh)
if [ "$PSSH" = "" ] ; then
  echo "Parallel SSH (pssh) is required for this script to work."
  exit 4
fi

# Hosts' list file
HOSTS="$HOME/.config/cluster/$1.lst"
shift
echo "Using file '$HOSTS' as hosts' list."

# Login
if [ "$LOGIN" != "" ] ; then
  echo "Login: $LOGIN"
  LOGIN="-l $LOGIN"
fi

echo "Command:" "$@"

exec $PSSH --print $LOGIN -h "$HOSTS" -- "$@"