Run commands on multiple servers in parallel

README.md

Usage

For example create a file with multiple servers:

echo 192.168.1.1 >> production_servers

Use the file with run_on to execute a command on all servers in parallel:

./run_on.sh production_servers 'tail -f /etc/nginx/nginx_access.log'

parallel.sh

#!/bin/bash
set -o errexit

for command in "$@"
do
  $command &
done

function kill_jobs()
{
  job_pids=($(jobs -p))
  [ "${#job_pids[@]}" -eq 0 ] || kill "${job_pids[@]}"
}

trap 'kill_jobs' EXIT

wait

run_on.sh

#!/bin/bash

commands=()
servers=($(cat "$1"))
shift

commands=()
for cmd in "$@"
do
  for server in "${servers[@]}"
  do
    commands+=("ssh $server server=$server; ($cmd) 2>&1 | while read line; do echo \"\$server: \$line\"; done")
  done
done

./parallel.sh "${commands[@]}"