6: Nested Stacks / Cross-stack refs

Why nested stacks?

• Modularity
• Reusability
• Reuse smaller chunks of template in (perhaps hundreds of) parent templates
• More OOP-style

Why cross-stack refs?

• Get diff teams working on different template files
• Export values from one stack to another related one
• More API-style

How?

Nesting:

• Use AWS::CloudFormation::Stack resource

Cross-stack:

• Use cross-stack refs;
  • Use “output” section of templates
  • Use Fn::ImportValue to import outputs