create-or-update-stack.sh

#!/usr/bin/env bash

usage="Usage: $(basename "$0") region stack-name [aws-cli-opts]

where:
  region       - the AWS region
  stack-name   - the stack name
  aws-cli-opts - extra options passed directly to create-stack/update-stack
"

if [ "$1" == "-h" ] || [ "$1" == "--help" ] || [ "$1" == "help" ] || [ "$1" == "usage" ] ; then
  echo "$usage"
  exit -1
fi

if [ -z "$1" ] || [ -z "$2" ] || [ -z "$3" ] ; then
  echo "$usage"
  exit -1
fi

shopt -s failglob
set -eu -o pipefail

echo "Checking if stack exists ..."

if ! aws cloudformation describe-stacks --region $1 --stack-name $2 ; then

  echo -e "\nStack does not exist, creating ..."
  aws cloudformation create-stack \
    --region $1 \
    --stack-name $2 \
    ${@:3}

  echo "Waiting for stack to be created ..."
  aws cloudformation wait stack-create-complete \
    --region $1 \
    --stack-name $2 \

else

  echo -e "\nStack exists, attempting update ..."

  set +e
  update_output=$( aws cloudformation update-stack \
    --region $1 \
    --stack-name $2 \
    ${@:3}  2>&1)
  status=$?
  set -e

  echo "$update_output"

  if [ $status -ne 0 ] ; then

    # Don't fail for no-op update
    if [[ $update_output == *"ValidationError"* && $update_output == *"No updates"* ]] ; then
      echo -e "\nFinished create/update - no updates to be performed"
      exit 0
    else
      exit $status
    fi

  fi

  echo "Waiting for stack update to complete ..."
  aws cloudformation wait stack-update-complete \
    --region $1 \
    --stack-name $2 \

fi

echo "Finished create/update successfully!"

Thank you @abdennour! You just saved me a lot of work. :)

#!/bin/bash
#set -x

api_stack_name="awsprojectspringboot"
#$API_STACK_NAME
api_region="us-east-1"
#$API_REGION

type_formation=""

if ! aws cloudformation describe-stacks --region $api_region --stack-name $api_stack_name ; then
    echo "1"
    type_formation='create-stack'
else
    type_formation='update-stack'
fi

declare -A parameters

#Se asigna key=value
parameters["EnvironmentName"]="dev"
#$ENVIRONMENT_NAME
parameters["AppName"]="awsprojectspringboot"
#$APP_NAME
parameters["AppImage"]="aws-project-springboot"
#$APP_IMAGE
parameters["AppImageTag"]="latest"
#$APP_IMAGE_TAG
parameters["AppDesiredCount"]=1
#$APP_DESIRED_COUNT
#parameters["SpringCloudConfigServerGitUsername"]=$SPRING_CLOUD_CONFIG_SERVER_GIT_USERNAME
#parameters["SpringCloudConfigServerGitPassword"]=$SPRING_CLOUD_CONFIG_SERVER_GIT_PASSWORD
#parameters["SpringCloudConfigServerGitUri"]=$SPRING_CLOUD_CONFIG_SERVER_GIT_URI
parameters["ApiVpcId"]="vpc-2ec5f255"
#$API_VPC_ID
parameters["VpcSubnets"]='"subnet-e2ef15cc\,subnet-c1be469d"'
#$VPC_SUBNETS
parameters["EcsAmiId"]="ami-04351e12"
#"ami-5253c32d"
parameters["EcsInstanceType"]="t2.small"
#$ECS_AMI_ID
#parameters["AlbAcmCertificate"]=$ALB_ACM_CERTIFICATE

file='api_ecs_cloud_formation.template.cf.yaml'

sed -i -- 's/ApiStackName-/'$api_stack_name'/g' $file

#se hace concatenacion de los parametros
s_parameters=''
for i in "${!parameters[@]}" ; do
    s_parameters=$s_parameters' '$(printf "ParameterKey=%s,ParameterValue=%s" $i ${parameters[${i}]})
done

echo "======================================== CREACION / ACTUALIZACION DEL STACK "
eval "aws --region $api_region cloudformation $type_formation --stack-name $api_stack_name --template-body 'file://$file' --parameters $s_parameters"
echo "======================================== VERIFICACION DEL STACK "
exec aws --region $api_region cloudformation describe-stacks --stack-name $api_stack_name

Thank you!

you would choose aws cloudformation deploy vs this method IF you are not planning on having your cloudformation parameters in a separate file. create-stack and update-stack have the --parameters variable that can be set to a file whilst aws cloudformation deploy does not.

also deploy does not support rollback configuration

Also useful as a workaround to serverless/serverless#2233 and serverless/serverless#2831.

The logic between lines 53 and 63 can be removed by simply adding --no-fail-on-empty-changeset to the aws cloudformation update-stack ... command.

Changed my mind - you actually do need separate logic for handling the case of "deploy to an existing stack, but there are no updates to apply". Consider a stack in CREATE_COMPLETE status, and we go to perform another deploy as an update. If we have no changes to apply, the stack will remain in CREATE_COMPLETE status, and we must not attempt to use aws cloudformation wait stack-update-complete because this command would hang forever. So I think the existing snippet is correct, and you should not use --no-fail-on-empty-changeset

Am getting the below error while trying to update the existing stack. What do I need to change in the script?
An error occurred (AlreadyExistsException) when calling the CreateStack operation: Stack [Test-stack] already exists

@viveksamaga I've not tested this since 2016 sorry, it's possible the AWS CLI has introduced some breaking changes