Customize Blueprint to add a network with a ternary condition

Hello,

I want my blueprint to add a second network only if the value is "linux".

Here is an example :

  resources:

  Cloud_vSphere_Machine_1:

    type: Cloud.vSphere.Machine

    properties:

      image: '${input.image}'

      networks:

        - network: '${resource.Cloud_vSphere_Network_1.id}'

        - network: '${resource.Cloud_vSphere_Network_2.id}'

  Cloud_vSphere_Network_1:

    type: Cloud.vSphere.Network

    properties:

      networkType: existing

  Cloud_vSphere_Network_2:

    type: Cloud.vSphere.Network

    properties:

      networkType: existing

      count: '${input.image == "linux" ? 1 : 0 }

vRA8 indicates an error on the second network line saying that it can't create a network on the existing condition. Is there a way to do that ?