run-cloudformationupdate.sh

#!/bin/bash
echo "Using Account:$ACCID  Region:$AWS_DEFAULT_REGION"
ACCID=$(aws sts get-caller-identity --query 'Account' | tr -d '"')
ESTR=$((aws cloudformation update-stack --stack-name SC-IAC-automated-portfolio --parameters "[{\"ParameterKey\":\"LinkedRole2\",\"UsePreviousValue\":true},{\"ParameterKey\":\"LinkedRole1\",\"UsePreviousValue\":true},{\"ParameterKey\":\"LaunchRoleName\",\"UsePreviousValue\":true},{\"ParameterKey\":\"RepoRootURL\",\"ParameterValue\":\"https://$DEPLOY_BUCKET.s3.amazonaws.com/\"}]" --template-url "https://$DEPLOY_BUCKET.s3.amazonaws.com/ec2/sc-portfolio-ec2demo.json") 2>&1)
ECODE=$?
if [[ "$ECODE" -eq "255" && "$ESTR" =~ .(No updates are to be performed\.)$ ]]
then 
  echo "No updates, continue."
  exit 0
else
  echo "$ECODE $ESTR"
  exit $ECODE
fi