Amazon EC2 Place an Instance in an Availability Zone

arazzo: 1.0.1
info:
  title: Amazon EC2 Place an Instance in an Availability Zone
  summary: Describe regions and availability zones, then launch an instance in a chosen zone.
  description: >-
    Picks a placement target and launches into it. The workflow lists the
    enabled regions, lists the availability zones available in the current
    region, and then launches an instance using the supplied AMI and instance
    type. Every step spells out its request inline using the Amazon EC2 query
    protocol (Action and Version parameters) so the flow can be read and
    executed without opening the underlying OpenAPI description.
  version: 1.0.0
sourceDescriptions:
- name: amazonEc2Api
  url: ../openapi/amazon-ec2-openapi.yml
  type: openapi
workflows:
- workflowId: place-instance-in-zone
  summary: Survey regions and zones, then launch an instance.
  description: >-
    Chains DescribeRegions, DescribeAvailabilityZones, and RunInstances so a
    placement decision is informed by live region and zone data before launch.
  inputs:
    type: object
    required:
    - imageId
    - instanceType
    properties:
      imageId:
        type: string
        description: The AMI ID to launch the instance from.
      instanceType:
        type: string
        description: The EC2 instance type to launch.
      subnetId:
        type: string
        description: Optional subnet ID identifying the target zone placement.
  steps:
  - stepId: listRegions
    description: List the regions enabled for the account.
    operationId: describeRegions
    parameters:
    - name: Action
      in: query
      value: DescribeRegions
    - name: Version
      in: query
      value: '2016-11-15'
    successCriteria:
    - condition: $statusCode == 200
    outputs:
      regionsStatus: $statusCode
  - stepId: listZones
    description: List the availability zones in the current region.
    operationId: describeAvailabilityZones
    parameters:
    - name: Action
      in: query
      value: DescribeAvailabilityZones
    - name: Version
      in: query
      value: '2016-11-15'
    successCriteria:
    - condition: $statusCode == 200
    outputs:
      zonesStatus: $statusCode
  - stepId: launchInZone
    description: Launch an instance into the selected placement.
    operationId: runInstances
    parameters:
    - name: Action
      in: query
      value: RunInstances
    - name: Version
      in: query
      value: '2016-11-15'
    - name: ImageId
      in: query
      value: $inputs.imageId
    - name: InstanceType
      in: query
      value: $inputs.instanceType
    - name: MinCount
      in: query
      value: 1
    - name: MaxCount
      in: query
      value: 1
    - name: SubnetId
      in: query
      value: $inputs.subnetId
    successCriteria:
    - condition: $statusCode == 200
    outputs:
      instanceId: $response.body#/instances/0/instanceId
  outputs:
    instanceId: $steps.launchInZone.outputs.instanceId