State machine

First we’ll copy ManageIQ/Service/Provisioning/StateMachines/ServiceProvision_Template/default into our own domain and rename it EmptyService. We’ll add a pre5 relationship to a new instance that we’ll create, called /Service/Provisioning/StateMachines/Methods/RenameService (see Figure 37-6).

Figure 37-6. Schema of the EmptyService state machine

Method

The pre5 stage of this state machine is a relationship to a RenameService instance. This instance calls a rename_service method containing the following code:

begin
  service_template_provision_task = $evm.root['service_template_provision_task']
  service = service_template_provision_task.destination
  dialog_options = service_template_provision_task.dialog_options
  if dialog_options.has_key? 'dialog_service_name'
    service.name = "#{dialog_options['dialog_service_name']}"
  end
  if dialog_options.has_key? 'dialog_service_description'
    service.description = "#{dialog_options['dialog_service_description']}"
  end

  $evm.root['ae_result'] = 'ok'
  exit MIQ_OK
rescue => err
  $evm.log(:error, "[#{err}]
#{err.backtrace.join("
")}")
  $evm.root['ae_result'] = 'error'
  $evm.root['ae_reason'] = "Error: #{err.message}"
  exit MIQ_ERROR
end

Service dialog

We create a simple service dialog called New Service with element names service_name and service_description (see Figure 37-7).

Figure 37-7. Service dialog

Putting it all together

Finally, we assemble all of these parts by creating a new service catalog called General Services and a new catalog item of type Generic called Empty Service (see Figure 37-8).

Figure 37-8. The completed Empty Service service catalog item

We can order from this service catalog item to create our new empty services.

Button dialog

We create a simple button dialog with a dynamic drop-down element named service (see Figure 37-10).

Figure 37-10. Button dialog

Dialog element method

The dynamic drop-down element in the service dialog calls a method called list_services. We only wish to display a service in the drop-down list if the user has permissions to see it via their role-based access control (RBAC) filter. We define two methods: get_current_group_rbac_array to retrieve a user’s RBAC filter array, and service_visible? to check that a service has a tag that matches the filter:

def get_current_group_rbac_array(user, rbac_array=[])
  unless user.current_group.filters.blank?
    user.current_group.filters['managed'].flatten.each do |filter|
      next unless /(?<category>w*)/(?<tag>w*)$/i =~ filter
      rbac_array << {category=>tag}
    end
  end
  rbac_array
end

def service_visible?(rbac_array, service)
    $evm.log(:info, "Evaluating Service #{service.name}")
    if rbac_array.length.zero?
      $evm.log(:info, "No Filter, service: #{service.name} is visible to this user")
      return true
    else
      rbac_array.each do |rbac_hash|
        rbac_hash.each do |category, tag|
          if service.tagged_with?(category, tag)
            $evm.log(:info, "Service: #{service.name} is visible to this user")
            return true
          end
        end
      end
      false
    end
  end

When we enumerate the services, we check on visibility to the user before adding to the drop-down list:

$evm.vmdb(:service).find(:all).each do |service|
  if service['display']
    $evm.log(:info, "Found service: #{service.name}")
    if service_visible?(rbac_array, service)
      visible_services << service
    end
  end
end
if visible_services.length > 0
  if visible_services.length > 1
    values_hash['!'] = '-- select from list --'
  end
  visible_services.each do |service|
    values_hash[service.id] = service.name
  end
else
  values_hash['!'] = 'No services are available'
end

Here we use a simple technique of keeping the string '-- select from list --' at the top of the list, by using a key string of '!', which is the first ASCII printable nonwhitespace character.

Button method

The main instance and method called from the button are called AddToService and add_to_service, respectively. This method adds the current virtual machine or service into the service selected from the drop-down list. As we wish to be able to call this from a button on either a Service object type or a “VM and Instance” object type, we identify our context using $evm.root['vmdb_object_type'].

If we are adding a virtual machine to an existing service, we should allow for the fact that the virtual machine might itself have been provisioned from a service. We detect any existing service membership, and if the old service is empty after we move the virtual machine, we delete the service from the VMDB:

begin
  parent_service_id = $evm.root['dialog_service']
  parent_service = $evm.vmdb('service').find_by_id(parent_service_id)
  if parent_service.nil?
    $evm.log(:error, "Can't find service with ID: #{parent_service_id}")
    exit MIQ_ERROR
  else
    case $evm.root['vmdb_object_type']
    when 'service'
      $evm.log(:info, "Adding Service #{$evm.root['service'].name} to 
                                                 #{parent_service.name}")
      $evm.root['service'].parent_service = parent_service
    when 'vm'
      vm = $evm.root['vm']
      #
      # See if the VM is already part of a service
      #
      unless vm.service.nil?
        old_service = vm.service
        vm.remove_from_service
        if old_service.v_total_vms.zero?
          old_service.remove_from_vmdb
        end
      end
      $evm.log(:info, "Adding VM #{vm.name} to #{parent_service.name}")
      vm.add_to_service(parent_service)
    end
  end
  exit MIQ_OK
rescue => err
  $evm.log(:error, "[#{err}]
#{err.backtrace.join("
")}")
  exit MIQ_ERROR
end

The scripts in this chapter are available on GitHub.

Putting it all together

Finally, we create two Add to Service buttons: one on a Service object type, and one on a “VM and Instance” object type. We can go ahead and organize our service hierarchies.