Amazon RDS Upgrade DB Engine Version

arazzo: 1.0.1
info:
  title: Amazon RDS Upgrade DB Engine Version
  summary: Resolve a target engine version, upgrade the instance, and poll until stable.
  description: >-
    Performs a database engine version upgrade by first discovering valid target
    versions for the engine, then applying the upgrade and waiting for the
    instance to finish. The workflow looks up available engine versions,
    confirms the instance is available, submits a modify request that sets the
    new EngineVersion with ApplyImmediately, and polls DescribeDBInstances until
    the status settles back to available. 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: upgrade-engine-version
  summary: Upgrade a DB instance engine version and wait for it to stabilize.
  description: >-
    Resolves available engine versions, confirms the instance is available,
    modifies the engine version with ApplyImmediately, and polls until
    DescribeDBInstances reports the instance available again.
  inputs:
    type: object
    required:
    - dbInstanceIdentifier
    - engine
    - engineVersion
    properties:
      dbInstanceIdentifier:
        type: string
        description: The identifier of the DB instance to upgrade.
      engine:
        type: string
        description: The database engine of the instance (e.g. postgres).
      engineVersion:
        type: string
        description: The target engine version to upgrade to.
  steps:
  - stepId: lookupVersions
    description: >-
      Describe the available engine versions for the supplied engine so the
      requested target version can be validated before upgrading.
    operationId: describeDBEngineVersions
    parameters:
    - name: Engine
      in: query
      value: $inputs.engine
    - name: EngineVersion
      in: query
      value: $inputs.engineVersion
    successCriteria:
    - condition: $statusCode == 200
  - stepId: confirmInstance
    description: >-
      Describe the DB instance to confirm it is available before applying the
      engine upgrade.
    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:
      currentVersion: $response.body#/dBInstances/0/engineVersion
  - stepId: upgradeInstance
    description: >-
      Submit the modify request setting the new engine version with the upgrade
      applied immediately.
    operationId: modifyDBInstance
    parameters:
    - name: DBInstanceIdentifier
      in: query
      value: $inputs.dbInstanceIdentifier
    - name: EngineVersion
      in: query
      value: $inputs.engineVersion
    - 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 upgrading 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
      appliedVersion: $response.body#/dBInstances/0/engineVersion
    onSuccess:
    - name: stillUpgrading
      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
    appliedVersion: $steps.pollInstance.outputs.appliedVersion