Painlessly create or update a CloudFormation stack in an idempotent way

When integrating CloudFormation into your CI/CD pipeline you are faced with the challenge of creating a CloudFormation stack on the first run of the pipeline, while you need to update the stack for all following pipeline runs. If you use the AWS CLI this is painful.

Pain

You may also have your code and template in the same repository. Therefore code changes without the template. But the AWS CLI threats an update without changes to a stack as an error which is not the behavior that you need in your pipeline.

cfn-create-or-update can create or update a CloudFormation stack. If no updates are to be performed, no error is thrown. cfn-create-or-update behaves exactly as the AWS CLI regarding input values, output will be different.

Installation

To install the CLI tool cfn-create-or-update, run:

npm install -g cfn-create-or-update

To create or update a stack, run:

cfn-create-or-update --stack-name test --template-body file://template.yml

The first time you run this command, a stack will be created. The second time an update will be performed but only if the template has changes.

CLI parameters

cfn-create-or-update behaves exactly as the AWS CLI regarding input values. Supported parameters (as documented in the AWS CLI create-stack or update-stack):

cfn-create-or-update
--stack-name
--template-body
--template-url
--parameters
--capabilities
--resource-types
--role-arn
--stack-policy-body
--stack-policy-url
--notification-arns
--tags

Global parameters (as documented in the AWS CLI

--profile
--region

Only used during create, otherwise ignored (as documented in the AWS CLI create-stack):

--disable-rollback | --no-disable-rollback
--timeout-in-minutes
--on-failure

Only used during update, otherwise ignored (as documented in the AWS CLI update-stack):

--use-previous-template | --no-use-previous-template]
--stack-policy-during-update-body
--stack-policy-during-update-url

Additional parameter, to wait for create complete / update complete.

---wait

cfn-create-or-update is available on GitHub for free (MIT license).

Other solutions to this problem:

Published on


Subscribe to free monthly updates.

One subscriber wins our book AWS in Action every month.

Michael Wittig

Michael Wittig

I’m the author of Amazon Web Services in Action. I work as a software engineer, and independent consultant focused on AWS and DevOps.

Is anything missing in my article? I'm looking forward to your feedback! @hellomichibye or michael@widdix.de.

marbot

Are you part of a highly motivated DevOps team? Use marbot, a friendly chatbot, to forward all kind of alerts from your AWS infrastructure to Slack. Alerts are escalated across your team automatically allowing you to focus on your daily work.

Amazon Web Services in Action

Amazon Web Services in Action introduces you to computing, storing, and networking in the AWS cloud.

Customer Reviews:

Subscribe to free monthly updates.

One subscriber wins our book AWS in Action every month.


Subscribe for free