packer.json

        {
            "type": "azure-arm",
            "client_id": "{{user `azure_client_id`}}",
            "client_secret": "{{user `azure_client_secret`}}",
            "subscription_id": "{{user `azure_subscription_id`}}",
            "tenant_id": "{{user `azure_tenant_id`}}",
            "resource_group_name": "{{user `azure_resource_group_name`}}",
            "build_resource_group_name": "{{user `azure_resource_group_name`}}",
            "storage_account": "{{user `azure_storage_account`}}",
            "capture_container_name": "{{user `azure_storage_account_container`}}",
            "capture_name_prefix": "Filecoin-{{user `latest_tag` | clean_resource_name}}",
            "disk_additional_size": ["{{user `volume_size`}}"],
            "os_type": "Linux",
            "image_publisher": "Canonical",
            "image_offer": "UbuntuServer",
            "image_sku": "18.04-LTS",
            "azure_tags": {
              "application": "Filecoin",
              "build": "{{user `latest_tag`}}"
            },
            "vm_size": "Standard_F4s_v2",
            "ssh_username": "ubuntu"
        }