ChangeSets
- When you update a stack, you need to know what changes before it happens for greater condidence
- ChangeSets won't say if the update will be successful
Nested Stacks
- Nested stacks are stacks as part of other stacks
- They allow you to isolate repeated patterns / common components in separate stacks and call them from other stacks
- Example:
- Load Balancer configuration that is re-used
- Security Group that is re-used
- Nested stacks are considered best practice
- To update a nested stack, always update the parent (root stack)
Cross vs Nested Stacks
- Cross Stacks
- Helpful when stacks have different lifecycles
- Use Outputs Export and Fn::ImportValue
- When you need to pass export values to many stacks (VPC Id, etc)
- Nested Stacks
- Helpful when components must be re-used
- Ex: re-use how to properly configure an Application Load Balancer
- The nested stack only is important to the higher level stack (it's not shared)
StackSets
- Create, update or delete stacks across multiple accounts and regions with a single operation
- Administrator account to create StackSets
- Trusted accounts to create, update, delete stack instances from StackSets
- When you update a stack set, all associated stack instances are updated throughout all accounts and regions.
