Scripted tmux to open syncronized and separate windows for a cluster of servers

tmux_cluster.sh

#!/bin/sh
# A rather simple example of tmux scripting
# Sets a new session for a cluster of listed servers
# Session has a single window with every server in a cluster as separate pane with synchronized input,
# and an additional window for every machine in a cluster

export DISABLE_AUTO_TITLE=true # needed to fix names of windows

SERVER_LIST="server-1 server-2 server-3"
CLUSTER_NAME="some-cluster" # will be a name of the tmux session
CONNECT_STRING='ssh  -i ~/.ssh/id_dsa_cluster $SERVER' # password-less login is recommended

window=1 # assuming base-index is set to 1
pane=1 # assuming pane-base-index is set to 1
number_of_servers=`echo $SERVER_LIST | wc -w`

tmux has-session -t $CLUSTER_NAME

if [ $? != 0 ]
then

	tmux new-session -s $CLUSTER_NAME -n cluster -d

	for fn in $SERVER_LIST; do
		SERVER=$fn
		eval `eval "echo tmux send-keys -t $CLUSTER_NAME:$window.$pane \'$CONNECT_STRING\' C-m"`
		if [ $number_of_servers -gt $pane ]; # little trick to not split for last server
		then
			let pane++
			tmux split-window -h -t $CLUSTER_NAME
		fi
	done
	
	tmux select-layout -t $CLUSTER_NAME:$window even-horizontal # you might prefer 'tiled' for large cluster

	tmux set-window-option -t $CLUSTER_NAME:$window synchronize-panes on

	for fn in $SERVER_LIST; do
		let window++
		tmux new-window -n $fn -t $CLUSTER_NAME
		SERVER=$fn
		eval `eval "echo tmux send-keys -t $CLUSTER_NAME:$window.1 \'$CONNECT_STRING\' C-m"`
	done
fi

tmux attach -t $CLUSTER_NAME