Machine and disk clusters in Cloud Assembly

Cloud Assembly template designs can deploy a cluster of machines and attach a cluster of disks.

To deploy clusters of machines and disks, take advantage of the allocatePerInstance resource flag, and count.index and map_to_object expression syntax in your cloud templates.

The following cloud template code examples can serve as guidelines for designs that deploy clusters.

Two machines that share a disk cluster

resources:
  app0:
    type: Cloud.Machine
    allocatePerInstance: true
    properties:
      image: ubuntu
      flavor: small
      attachedDisks: '${map_to_object(slice(resource.disk[*].id, 0,2), "source")}'
  app1:
    type: Cloud.Machine
    allocatePerInstance: true
    properties:
      image: ubuntu
      flavor: small
      attachedDisks: '${map_to_object(slice(resource.disk[*].id, 2,4), "source")}'
  disk:
    type: Cloud.Volume
    allocatePerInstance: true
    properties:
      count: 4
      capacityGb: 5

Variable number of machines with one disk each

inputs:
  count:
    type: integer
    default: 2
resources:
  Cloud_Machine_1:
    type: Cloud.Machine
    allocatePerInstance: true
    properties:
      image: ubuntu
      flavor: small
      count: '${input.count}'
      attachedDisks: '${map_to_object(slice(resource.disk[*].id, count.index, count.index + 1), "source")}'
  disk:
    type: Cloud.Volume
    allocatePerInstance: true
    properties:
      count: '${input.count}'
      capacityGb: 5

Variable number of machines with two disks each

inputs:
  count:
    type: integer
    default: 2
resources:
  Cloud_Machine_1:
    type: Cloud.Machine
    allocatePerInstance: true
    properties:
      image: ubuntu
      flavor: small
      count: ${input.count}
      attachedDisks: '${map_to_object(slice(resource.disk[*].id, 2*count.index, 2*(count.index + 1)), "source")}'
  disk:
    type: Cloud.Volume
    allocatePerInstance: true
    properties:
      count: ${2*input.count}
      capacityGb: 5

Set disk sizes at request time

inputs:
  disksize:
    type: array
    minItems: 2
    maxItems: 2
    items:
      type: object
      properties:
        size:
          type: integer
resources:
  app:
    type: Cloud.Machine
    allocatePerInstance: true
    properties:
      flavor: small
      image: ubuntu
      attachedDisks: ${map_to_object(slice(resource.disk[*].id, 0, 2), 'source')}
  disk:
    type: Cloud.Volume
    allocatePerInstance: true
    properties:
      count: 2
      capacityGb: ${input.disksize[count.index].size}