Run a script on remote hosts in batches

multisshrun

#!/bin/bash

# Name:    multisshrun
# Purpose: Runs a script on remote hosts over ssh, in defined batch sizes

help() {
cat <<EOF
$(basename ${0}) accepts a host list via stdin and expects a script name as an argument
It runs the script on all host in batches, controlled by -j or --jobs (default=4)

Example: 
$ cat /tmp/hostlist.txt | parallelize -j 5 script.sh

EOF
exit 1
}

until [ -z "$1" ]; do
  case $1 in
     -j|--jobs)   shift; JOBS=$1; shift;;
     *)           SCRIPT=$1; shift;;
  esac
done

JOBS=${JOBS:-4}
JOBDIR=$(mktemp -d)
mkdir -p "${JOBDIR}/results"

[[ ! -f "${SCRIPT}" ]] && help


RUNSLOT() {
  local lock=${JOBDIR}/$1
  local scriptname=$2
  local targethost=$3

  if [ $# -ne 3 ]; then
    echo RUNSLOT expects 3 args, got $#
    return 2
  fi

  if [ -f $lock ]; then
    return 1
  fi

  touch $lock
  (
    scp -o StrictHostKeyChecking=no 2>/dev/null $scriptname $targethost:/tmp </dev/null >/dev/null
    if [ $? -eq 0 ]; then
      ssh 2>/dev/null -o StrictHostKeyChecking=no -t -t $targethost "sudo chmod +x /tmp/$(basename $scriptname); bash -c /tmp/$(basename $scriptname)" </dev/null >> ${JOBDIR}/results/${targethost}
    else
      echo -n ' [FAILED]'
    fi
    rm -f $lock
  ) & return 0
}

# MAIN LOOP
while read HOST; do
  unset RESULT
  until [ "${RESULT}" == "0" ]; do
    for SLOT in $(seq 1 1 ${JOBS}); do
      RUNSLOT $SLOT $SCRIPT $HOST
      RESULT=$?
      if [ ${RESULT} -eq 0 ]; then
       echo " $HOST [slot:${SLOT}]"
       break
      fi
    done
  done
done

echo Results in ${JOBDIR}/results/