Updating and deleting stacks in AWS - Step-by-Step Execution

Process Flow - Updating and deleting stacks

Create or have existing stack

↓

Decide to update stack?

No→Exit

Yes↓

Prepare updated template or parameters

↓

Submit update request

↓

CloudFormation processes update

↓

Update success?

No→Rollback changes

Yes↓

Stack updated

↓

Decide to delete stack?

No→Exit

Yes↓

Submit delete request

↓

CloudFormation deletes resources

↓

Stack deleted

↓

End

This flow shows how you update an existing stack by submitting changes, then optionally delete the stack to remove all resources.

Execution Sample

AWS

aws cloudformation update-stack --stack-name MyStack --template-body file://update.yaml
aws cloudformation delete-stack --stack-name MyStack

Update a stack named MyStack with a new template, then delete the stack.

Process Table

Step	Action	Input	CloudFormation Behavior	Result
1	Check if stack exists	Stack: MyStack	Stack found	Ready for update
2	Submit update request	Template: update.yaml	Validates template, compares changes	Update in progress
3	Process update	Changes detected	Updates resources as needed	Resources updated
4	Update success?	Update status	Yes	Stack updated successfully
5	Decide to delete stack	User input: Yes	Accept delete request	Delete in progress
6	Process delete	Delete stack MyStack	Deletes all stack resources	Stack deleted
7	Check stack existence	Stack: MyStack	Stack not found	End - stack removed

💡 Stack is deleted, no longer exists in CloudFormation

Status Tracker

Variable	Start	After Step 2	After Step 4	After Step 6	Final
Stack Status	CREATE_COMPLETE	UPDATE_IN_PROGRESS	UPDATE_COMPLETE	DELETE_COMPLETE	DELETE_COMPLETE (stack removed)

Key Moments - 3 Insights

Why does the stack status change to UPDATE_IN_PROGRESS after submitting an update?

Because CloudFormation starts applying the changes, as shown in execution_table step 2 and 3, the status reflects the ongoing update process.

What happens if the update fails during processing?

CloudFormation rolls back to the previous stable state, preventing partial updates. This is implied in the flow after step 3 if update success is No.

Does deleting a stack remove all its resources automatically?

Yes, as shown in execution_table step 6, deleting the stack triggers deletion of all resources created by that stack.

Visual Quiz - 3 Questions

Look at the execution table, what is the stack status after step 4?

A CREATE_COMPLETE

B DELETE_IN_PROGRESS

C UPDATE_COMPLETE

D UPDATE_IN_PROGRESS

💡 Hint

Check the 'Stack Status' variable in variable_tracker after step 4

At which step does CloudFormation start deleting the stack resources?

A Step 4

B Step 6

C Step 5

D Step 7

💡 Hint

Refer to execution_table row where 'Process delete' action happens

If the update fails during processing, what would happen in the execution flow?

A CloudFormation rolls back to previous stack state

B Stack is deleted immediately

C Stack status changes to DELETE_IN_PROGRESS

D Update completes successfully

💡 Hint

See key_moments explanation about update failure and rollback

Concept Snapshot

Updating and deleting stacks in AWS CloudFormation:
- Update stack by submitting new template or parameters
- CloudFormation validates and applies changes
- If update fails, rollback restores previous state
- Delete stack to remove all resources
- Stack status shows progress (UPDATE_IN_PROGRESS, DELETE_IN_PROGRESS, etc.)

Full Transcript

This visual execution shows how AWS CloudFormation updates and deletes stacks. First, you check if the stack exists. Then you submit an update with a new template. CloudFormation validates and applies the update, changing the stack status to UPDATE_IN_PROGRESS and then UPDATE_COMPLETE if successful. If the update fails, it rolls back to the previous state. After updating, you can delete the stack, which triggers deletion of all resources and removes the stack from CloudFormation. The stack status changes accordingly during these steps, helping track progress.