Script to find private IP addresses of all EC2 instances participating in the CloudFormation stack

cf-stack-find-ips.sh

#!/bin/bash

command -v aws >/dev/null 2>&1 || { echo >&2 "I require awscli but it's not installed.  Aborting."; exit 1; }
command -v curl >/dev/null 2>&1 || { echo >&2 "I require curl but it's not installed.  Aborting."; exit 1; }

# Find local instance_id
INSTANCE_ID=$(curl -s http://169.254.169.254/latest/meta-data/instance-id)

# Find cloudformation stack-id
STACK_ID=$(aws ec2 describe-instances --output text --instance-ids $INSTANCE_ID | grep -e 'TAGS\saws:cloudformation:stack-id' | awk '{print $3}')

aws ec2 describe-instances --output text --filters "Name=tag:aws:cloudformation:stack-id,Values=${STACK_ID}" | grep PRIVATEIPADDRESSES | awk '{print $4}'

Run this script from one of the EC2 instances participating in the stack to discover other stack members.