🔧 Link Stack Dependencies

Follow this guide when one stack needs outputs produced by another stack.

1. Declare the dependency

Add the upstream stack to depends_on:

  payment-app-service:
    template: app.yaml
    depends_on:
      - payment-app-network
    parameters:
      DesiredCapacity: "2"
      VpcId:
        type: stack-output
        stack: payment-app-network
        output: VpcId

• Declaring the dependency is optional, but strongly recommended whenever you reference another stack’s outputs.
• Stackaroo uses it to deploy stacks in the correct order and wait for completion before resolving parameters.

2. Reference the output explicitly

Use type: stack-output for each value you need:

parameters:
  VpcId:
    type: stack-output
    stack: payment-app-network
    output: VpcId
  PublicSubnetIds:
    - type: stack-output
      stack: payment-app-network
      output: PublicSubnetA
    - type: stack-output
      stack: payment-app-network
      output: PublicSubnetB

Tips:

• stack must match the CloudFormation stack name. For stacks defined in stackaroo.yaml, use the stack key (the name used in the stacks map); you can also point at external stacks by specifying their deployed CloudFormation name.
• Treat list parameters as arrays—you can mix literals and output references inside the same list.
• Keep output keys consistent with the source template to avoid runtime errors.

3. Validate the wiring

After adding dependencies, run:

stackaroo diff development payment-app-service

If Stackaroo cannot resolve an output, the diff fails with the AWS error so you can correct the stack name or output key before deploying.