nit-parallel

gistfile1.txt

#!/bin/bash

# Usage:
#
#    nit-parallel [cosmos-running-instances args ...] -- [parallel args ...]
#
#  e.g.
#
#    ### No piped input: run command on all hosts
#    nit-parallel -e test pm-nitro-test-1 -- hostname
#
#    ### Piped input, use {} for each input
#    nit-parallel -e test pm-nitro-test-1 -- echo {} < list-of-pids
#
#    ### remember, after "--" is just passed to parallel, e.g. to ensure in same order:
#    seq 5 | ./nit-parallel -e test pm-nitro-test-1 -- -k echo {}

CRI_ARGS=""

for i in "$@"
do
  case $i in
    --) shift; break;;
    *) shift; CRI_ARGS="$CRI_ARGS $i";;
  esac
done

# Hardcoded for now, as Centos/AWS doesn't seem to provide number of cores
# (e.g. a hack)
function prepend_cores { xargs -L1 echo 4/ ;}

HOSTS=$(mktemp /tmp/hosts.XXX)

cosmos-running-instances -c $CRI_ARGS | prepend_cores > $HOSTS

P_ARGS="--sshloginfile $HOSTS"
if [[ -t 0 ]]
then # if we don't have STDIN connected, then just run command on all hosts
  P_ARGS="$P_ARGS --nonall"
fi

parallel $P_ARGS "$@" 2>/dev/null

rm $HOSTS