mux - takes a session name (optional) and list of hosts - then creates a new tmux session and opens SSH connections to the hosts in split panes

mux

#!/bin/bash

ssh="ssh -o StrictHostKeyChecking=no"

function split_tmux() {
  session=$1
  shift
  count=$(echo $@ | tr ' ' '\n' | wc -l)
  echo "Starting session to $count hosts in $session: [$@]"
  session="$session ($count)"
  length=$(echo $session | wc -m)
  tmux new-session -s "$session" -d "$ssh $1"
  tmux set-option -t "$session" status-left-length $((length+2))
  shift
  while [[ ! -z $1 ]]; do
    tmux split-window -t "$session" "$ssh $1"
    shift
  done
  tmux set -t "$session" sync on
  arrangement=even-vertical
  if [[ $count -gt 3 ]]; then
    arrangment=tiled
  fi
  tmux select-layout -t "$session" $arrangement
  tmux -2 attach-session -t "$session"
}

if [[ -x /usr/bin/keychain ]]; then
  eval $(keychain --eval -Q --quiet)
  keychain --agents ssh -Q --quiet ~/.ssh/id_rsa
fi

case $# in
  0)
    echo "Specify a name and host" >&2
    exit 1
    ;;
  1)
    session_name=$1
    hosts=$1
    ;;
  *)
    session_name=$1
    shift
    hosts=$*
    ;;
esac

session_name=$(echo $session_name | sed 's/\./_/g')

split_tmux $session_name $hosts