Dynamic shell script to use cssh to connect to multiple EC2 boxes by tag-name, via AWS CLI

cssh-ec2-connector.sh

#!/bin/bash

# Requirements:
# * AWS CLI installed and activated
# * cssh installed
#
# Usage:
# * Run "cssh-ec2-connector.sh some-tag-name" to have system open windows to all instances
# * Edit the ec2Tags array to have a list of frequently used instances for repeat use

# This is your SSH key for your AWS boxes
AWS_SSH_KEY="./ssh/aws-key.pem"

declare -A ec2Tags
# The key will be how you refer to the instance, the value will be the literal tag known to EC2
# Remember, this is bash, so no spaces around the equal sign
ec2Tags["Tag Set A"]="set-a"
ec2Tags["Another Tag Set"]="beta-group"


## DO NOT MODIFY BENEATH THIS POINT
## DO NOT MODIFY BENEATH THIS POINT
## DO NOT MODIFY BENEATH THIS POINT
## DO NOT MODIFY BENEATH THIS POINT
## DO NOT MODIFY BENEATH THIS POINT

cssh_ec2_connect(){
  ips=`aws ec2 describe-instances --filters Name=tag-value,Values=$1 | grep '"PrivateIpAddress"' |grep -Eo '([0-9]{1,3}\.){3}[0-9]{1,3}'|uniq`
  cssh -l ec2-user $ips -o "-i $AWS_SSH_KEY"
  return
}

if [ "$1" ]
then
  cssh_ec2_connect $1
  exit 0
fi

PS3='Please enter your choice: '

options=()
for i in "${!ec2Tags[@]}"
do
  options+=("$i")
done
options+=("Quit")
select opt in "${options[@]}"
do
  if [ "$opt" ]
  then
    if [ ${ec2Tags[$opt]} ]
    then
      cssh_ec2_connect ${ec2Tags[$opt]}
      break
    else
      break
    fi
  else
    echo invalid option
  fi
done