Working with Cloud Assembly inputs

blueprint.yaml

formatVersion: 1
inputs:
  image:
    type: string
    title: Operating System
    enum:
      - ubuntu 16.04
      - ubuntu 18.04
    default: ubuntu 16.04
  count:
    type: integer
    title: Machine Count
    minimum: 2
    maximum: 5
    default: 2
  size:
    type: string
    title: Machine size
    description: Resource requirements for your workload.
    enum:
      - small
      - medium
    default: small
  tags:
    type: array
    title: Tags
    description: Freeform tags that you would like attached to the provisioned resources.
    items:
      type: object
      properties:
        key:
          type: string
          title: Key
        value:
          type: string
          title: Value
  platform:
    type: string
    title: Deploy to
    oneOf:
      - title: AWS
        const: 'platform:aws'
      - title: Azure
        const: 'platform:azure'
      - title: vSphere
        const: 'platform:vsphere'
  username:
    title: User Account
    type: string
    description: Name of the user account to be created. Can only contain letters and numbers.
    pattern: '^[a-zA-Z0-9]+$'
  shell:
    title: Default Shell
    type: string
    enum:
      - /bin/bash
      - /bin/sh
    default: /bin/bash
  ssh_public_key:
    type: string
    title: SSH public key
    encrypted: true
  password:
    type: string
    title: Password
    description: The initial password that will be required to logon to the machine. Will be set to reset on first login.
    writeOnly: true
  public_ip:
    type: boolean
    title: Assign public IP address
    description: Choose whether your machine should be internet facing.
    default: false
resources:
  Machine_1:
    type: Cloud.Machine
    properties:
      count: '${input.count}'
      image: '${input.image}'
      flavor: '${input.size}'
      tags: '${input.tags}'
      constraints:
        - tag: '${input.platform}'
      cloudConfig: |
        #cloud-config
        users: 
          - name: ${input.username}
            shell: ${input.shell}
            groups: sudo
            sudo: ['ALL=(ALL) NOPASSWD:ALL']
            ssh-authorized_keys:
              - ${input.ssh_public_key}
            passwd: ${input.password}
            chpasswd: {expire: True}
      networks:
        - name: '${resource.Network_1.name}'
          assignPublicIpAddress: '${input.public_ip}'
  Network_1:
    type: Cloud.Network
    properties:
      name: net1
      networkType: existing