{
  "Name": "build-image",
  "Vars": {
    "source_image": {"Required": true, "Description": "URL of the source image to preload."},
    "output_image_name": {"Required": true, "Description": "Name of output image."},
    "output_image_family": {"Value": "", "Description": "Family of output image."},
    "output_image_project": {"Required": true, "Description": "Project of output image."},
    "cidata_img": {"Required": true, "Description": "Path to CIDATA vfat image containing cloud-init user-data and the provisioner program. Must be in .tar.gz format."},
    "scratch_img": {"Required": true, "Description": "Path to SCRATCH ext4 image. Must be in .tar.gz format."},
    "disk_type": {"Value": "pd-standard", "Description": "The disk type to use for preloading."},
    "disk_size_gb": {"Value": "10", "Description": "The disk size to use for preloading."},
    "host_maintenance": {"Value": "MIGRATE", "Description": "VM behavior when there is maintenance."},
    "machine_type": {"Required": true, "Description": "Machine type of the preload VM."},
    "network": {"Value": "", "Description": "Network to use for preload VM."},
    "subnet": {"Value": "", "Description":  "Subnetwork used for the preload VM."}
  },
  "Sources": {
    "cloud-config": "/data/startup.yaml",
    "scratch.tar.gz_": "${scratch_img}",
    "cidata.tar.gz_": "${cidata_img}"
  },
  "Steps": {
    "copy-gcs": {
      "CopyGCSObjects": [
        {
          "Source": "${SOURCESPATH}/cidata.tar.gz_",
          "Destination": "${SOURCESPATH}/cidata.tar.gz"
        },
        {
          "Source": "${SOURCESPATH}/scratch.tar.gz_",
          "Destination": "${SOURCESPATH}/scratch.tar.gz"
        }
      ]
    },
    "create-images": {
      "CreateImages": [
        {
          "Name": "cidata",
          "RawDisk": {
            "Source": "${SOURCESPATH}/cidata.tar.gz"
          }
        },
        {
          "Name": "scratch",
          "RawDisk": {
            "Source": "${SOURCESPATH}/scratch.tar.gz"
          }
        }
      ]
    },
    "setup": {
      "CreateDisks": [
	{{.ScratchDisks}}
        {
          "Name": "boot-disk",
          "SourceImage": "${source_image}",
          "Type": "${disk_type}",
          "SizeGb": "${disk_size_gb}"
        },
        {
          "Name": "cidata-disk",
          "SourceImage": "cidata",
          "Type": "${disk_type}"
        }
      ]
    },
    "run": {
      "CreateInstances": [
        {
          "Name": "preload-vm",
          "Disks": [{"Source": "boot-disk"}, {{.ScratchDiskSource}} {"Source": "cidata-disk"}],
          "Labels": {"cos-customizer-cleanup":""},
          "MachineType": "${machine_type}",
          "guestAccelerators": {{.Accelerators}},
          "scheduling": {
            "onHostMaintenance": "${host_maintenance}"
          },
          "networkInterfaces": [
            {
              "network": "${network}",
              "subnetwork": "${subnet}"
            }
          ],
          "Metadata": {
            "user-data": "${SOURCE:cloud-config}",
            "block-project-ssh-keys": "TRUE",
            "cos-update-strategy": "update_disabled"
          },
          "Scopes": [
            "https://www.googleapis.com/auth/devstorage.read_write",
            "https://www.googleapis.com/auth/cloud-platform"
          ]
        }
      ]
    },
    "wait-preload-finished": {
      "WaitForInstancesSignal": [
        {
          "Name": "preload-vm",
          "Interval": "30s",
          "SerialOutput": {
            "Port": 3,
            "FailureMatch": "BuildFailed:",
            "SuccessMatch": "BuildSucceeded:",
            "StatusMatch": "BuildStatus:"
          }
        }
      ]
    },
    "send-logging-end-msg": {
      "UpdateInstancesMetadata": [
        {
          "Instance": "preload-vm",
          "Metadata": {
            "DaisyEnd": "ack"
          }
        }
      ]
    },
    "wait-vm-shutdown": {
      "WaitForInstancesSignal": [
        {
          "Name": "preload-vm",
          "Interval": "2s",
          "Stopped": true
        }
      ]
    },
    "wait-for-resize": {
      {{.WaitResize}}
    },
    "resize-disk": {
      {{.ResizeDisks}}
    },
    "image": {
      "CreateImages": [
        {
          "RealName": "${output_image_name}",
          "Project": "${output_image_project}",
          "NoCleanup": true,
          "SourceDisk": "boot-disk",
          "labels": {{.Labels}},
          "description": "Derivative of ${source_image}.",
          "family": "${output_image_family}",
          "licenses": {{.Licenses}}
        }
      ]
    }
  },
  "Dependencies": {
    "create-images" : ["copy-gcs"],
    "setup": ["create-images"],
    "run": ["setup"],
    "wait-preload-finished": ["run"],
    "wait-for-resize": ["run"],
    "resize-disk": ["wait-for-resize"],
    "send-logging-end-msg": ["wait-preload-finished", "resize-disk"],
    "wait-vm-shutdown": ["send-logging-end-msg"],
    "image": ["wait-vm-shutdown"]
  }
}