Amazon RDS Modify a DB Instance Class

arazzo: 1.0.1
info:
  title: Amazon RDS Modify a DB Instance Class
  summary: Resize a DB instance class immediately and poll until it stabilizes.
  description: >-
    Scales a DB instance up or down by changing its instance class with the
    modification applied immediately, then waits for the instance to finish
    applying the change. The workflow confirms the instance is available,
    submits the modify request with ApplyImmediately set, and polls
    DescribeDBInstances until the status settles back to available, looping
    while the instance is still modifying. Every step spells out its request
    inline so the flow can be read and executed without opening the underlying
    OpenAPI description.
  version: 1.0.0
sourceDescriptions:
- name: amazonRdsApi
  url: ../openapi/amazon-rds-openapi.yml
  type: openapi
workflows:
- workflowId: modify-instance-class
  summary: Change a DB instance class immediately and wait for it to stabilize.
  description: >-
    Confirms the instance is available, modifies the instance class with
    ApplyImmediately, then polls DescribeDBInstances until status is available.
  inputs:
    type: object
    required:
    - dbInstanceIdentifier
    - dbInstanceClass
    properties:
      dbInstanceIdentifier:
        type: string
        description: The identifier of the DB instance to resize.
      dbInstanceClass:
        type: string
        description: The new compute and memory capacity class (e.g. db.r5.large).
  steps:
  - stepId: confirmInstance
    description: >-
      Describe the DB instance to confirm it is available before applying a
      modification.
    operationId: describeDBInstances
    parameters:
    - name: DBInstanceIdentifier
      in: query
      value: $inputs.dbInstanceIdentifier
    successCriteria:
    - condition: $statusCode == 200
    - context: $response.body
      condition: $.dBInstances[0].dBInstanceStatus == 'available'
      type: jsonpath
    outputs:
      currentClass: $response.body#/dBInstances/0/dBInstanceClass
  - stepId: modifyInstance
    description: >-
      Submit the modify request changing the instance class with the change
      applied immediately rather than during the next maintenance window.
    operationId: modifyDBInstance
    parameters:
    - name: DBInstanceIdentifier
      in: query
      value: $inputs.dbInstanceIdentifier
    - name: DBInstanceClass
      in: query
      value: $inputs.dbInstanceClass
    - name: ApplyImmediately
      in: query
      value: true
    successCriteria:
    - condition: $statusCode == 200
    outputs:
      pendingStatus: $response.body#/dBInstance/dBInstanceStatus
  - stepId: pollInstance
    description: >-
      Describe the DB instance and inspect its status. While the instance is
      still modifying the workflow loops back to poll again; once it is
      available the flow ends.
    operationId: describeDBInstances
    parameters:
    - name: DBInstanceIdentifier
      in: query
      value: $inputs.dbInstanceIdentifier
    successCriteria:
    - condition: $statusCode == 200
    outputs:
      status: $response.body#/dBInstances/0/dBInstanceStatus
      appliedClass: $response.body#/dBInstances/0/dBInstanceClass
    onSuccess:
    - name: stillModifying
      type: goto
      stepId: pollInstance
      criteria:
      - context: $response.body
        condition: $.dBInstances[0].dBInstanceStatus != 'available'
        type: jsonpath
    - name: available
      type: end
      criteria:
      - context: $response.body
        condition: $.dBInstances[0].dBInstanceStatus == 'available'
        type: jsonpath
  outputs:
    status: $steps.pollInstance.outputs.status
    appliedClass: $steps.pollInstance.outputs.appliedClass