I can't seem to find any documentation about what happens when you manually mess with Cloudformation's objects.
I see it tags its objects, but does it recover if, say, someone deletes a routing rule?

EDIT: Just got two contradicting answers. I'd like to request some documentation / evidence, since I have to decide what directions I'm giving my colleagues about modifying these resources.

3 Answers 3


CloudFormation only creates or modifies AWS resources during deployment, update, or deletion of a stack. It does not continually 'check and enforce' individual stack resources' configuration states - drift can definitely occur.

As an example, if I deploy a CF Stack and then later manually modify an Inbound Rule on one of its Security Groups, this modification will persist until I run an explicit CF Update or redeploy the stack.

Here are some helpful snippets / links:

Q: Can I manage individual AWS resources that are part of an AWS CloudFormation stack?

Yes. AWS CloudFormation does not get in the way; you retain full control of all elements of your infrastructure. You can continue using all your existing AWS and third-party tools to manage your AWS resources.

AWS CloudFormation Stacks Updates: http://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks.html

Prevent Updates to Stack Resources: http://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/protect-stack-resources.html

Please note the last link is only referring to protecting resources during a CloudFormation Update action, not ad-hoc changes made via the Management Console or API to individual resources.

  • 1
    Do you have actual experience with doing so, or is this just speculation? The documentation quote doesn't say anything about Cloudformation modifying/avoiding modifying your customizations.
    – Nitz
    Jun 18, 2015 at 7:36
  • 5
    Yes, I have deployed many CF stacks and have never witnessed CF enforcing configuration. I have shot myself in the foot before by accidentally modifying several SGs that were a part of a CF stack and had to redeploy it. You were right about lacking documentation - this is the best I could find in 10 minutes.
    – Adam
    Jun 18, 2015 at 15:33
  • 2
    Do you by 'redeploy' mean delete & deploy again, or is there another way? Jun 22, 2015 at 14:47
  • @DusanBajic one way to trick CF to "redeploy" some stack is to update the stack with a minor, innocuous change -- maybe adding an Output element?
    – solr
    Jul 29, 2021 at 22:14

If you mess with resources that Cloudformation deploys, the resources wont be recovered/restored/put into compliance, if you really need to enforce integrity you will need to redeploy the stack.


As far as I'm aware, CloudFormation will essentially enforce a "state of the world" and will correct misconfigured resources.

In your example, a deleted routing rule will be recreated. If someone has modified an ELB healthcheck, it will be reset back to the configuration declared in the template.

  • 5
    I disagree. It may be the case for some resource but not others. For example, someone deleted a couple of CloudFromation created Auto Scaling Groups on the console, and now the stack fails to update because it can't find them. Aug 6, 2015 at 15:21
  • 1
    @JeffStrunk that would be because CloudFormation will not recreate a resource if there were no changes to the properties of that resource. It does a diff of the template, not the actual resources to determine if it should trigger for those resources. So if you delete a resource and then change a property of that resource in your CloudFormation template, that resource will likely be recreated when the update action fails to find it. Aug 29, 2019 at 15:51

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct.

Not the answer you're looking for? Browse other questions tagged or ask your own question.