Finding the Correct Element Names

We saw from Chapter 31 that CatalogItemInitialization recognizes and special-cases some element names, including vm_name and service_name, so we can create two of our elements with these names. If this is all we wish to prompt for, then we can move straight on to creating the service dialog.

For our use case, however, we are also prompting for number of CPUs and memory size. Any service dialog fields that we create with the intention of altering the final VM configuration (such as the number of CPUs or memory size) must also be named in a particular way. The element name must match the key in the provisioning task’s options hash that we wish to overwrite.

We can find this key name in either of two ways: by examining the YAML code that makes up the provisioning dialog, or by performing an interactive provision of a virtual machine and examining the provisioning task’s options hash during the provisioning process.

grep -i "memory|cpu|core|socket" miq_provision_redhat_dialogs_template.yaml
      :number_of_sockets:
        :description: Number of Sockets
      :cores_per_socket:
        :description: Cores per Socket
      :vm_memory:
        :description: Memory (MB)

Examining the options hash during provisioning

As an alternative (or confirmation) to finding the key names from the provisioning dialog, we can use one of the techniques that we learned in Chapter 10 to dump the contents of the provisioning task’s options hash during a normal interactive provision. Here is an example of calling object_walker after the Placement stage in the VMProvision_VM/template state machine (see Figure 33-1).

Figure 33-1. State added to the VM provisioning state machine to run ObjectWalker

Using the object_walker_reader after we’ve provisioned a virtual machine, we see that the same values are in the miq_provision task’s options hash:

object_walker_reader.rb | grep 'miq_provision' | grep "memory|cpu|core|socket"
     |    $evm.root['miq_provision'].options[:cores_per_socket] = [1, "1"]
     |    $evm.root['miq_provision'].options[:memory_reserve] = nil
     |    $evm.root['miq_provision'].options[:number_of_sockets] = [1, "1"]
     |    $evm.root['miq_provision'].options[:vm_memory] = ["1024", "1024"]

...
<% root_password = evm[:root_password] %>
chpasswd:
    list: |
        root:<%=root_password%>
    expire: False
...

Creating the Service Dialog

We know from the preceding investigation that we must name our service dialog elements vm_name, service_name, option_0_cores_per_socket, and option_0_vm_memory.

We’ll create a new service dialog called RHEL7 VM. Our new service dialog will be similar to the example that we created in Chapter 5, but this time we’ll create two boxes—Service and VM Names, and VM Characteristics—each containing two elements (see Figure 33-2).

Figure 33-2. Service dialog with two boxes and four elements

The Service Name and VM Name elements in the first box are both of type Text Box and have the names service_name and vm_name, respectively.

The Number of CPUs element in the second box is of type Drop Down List (see Figure 33-3).

Figure 33-3. Number of CPUs element

We’ll populate the list with options to provision one, two, or four CPUs (see Figure 33-4).

Figure 33-4. Defining the selection of available CPUs

The VM Memory element in the second box is of type Drop Down List (see Figure 33-5).

Figure 33-5. VM Memory element

We’ll populate the list with options to provision 1, 2, 4, or 8 GB of memory (see Figure 33-6).

Figure 33-6. Defining the selection of available memory

Create a Catalog

The first thing we should do is create a service catalog to store the service item. We can have many catalogs; they are used to organize or categorize our service items and bundles.

Navigate to the Catalogs section in the accordion, and select Configuration → Add a New Catalog (see Figure 33-7).

Figure 33-7. Adding a new catalog

Give the catalog a name (for this example we’ll use Generic Servers), leave everything else as the default, and click Add.

Creating the Catalog Item

Navigate to the Catalog Items section in the accordion, highlight the newly created Generic Servers catalog, and then select Configuration → Add a New Catalog Item (see Figure 33-8).

Figure 33-8. Adding a new catalog item

Select RHEV from the Catalog Item Type drop-down list (see Figure 33-9).

Figure 33-9. Selecting the catalog item type

Enter a name and description for the catalog item, and select the Display in Catalog checkbox to expose the remaining fields to be filled in. Select our newly created Generic Servers catalog and RHEL7 VM dialog in the appropriate drop-downs. For the Provisioning Entry Point field, navigate to ManageIQ/Service/Provisioning/StateMachines/ServiceProvision_Template/CatalogItemInitialization (see Figure 33-10).

Figure 33-10. Completing the basic info tab

Click on the Details tab, and enter some HTML-formatted text to describe the catalog item to anyone viewing in the catalog:

<h1>Generic RHEL 7 Server</h1>
<hr>
<p>This catalog item will deploy a <strong>Red Hat Enterprise Linux 7</strong>
server, built from the @Base package set, and patched to 01-March-2016.

A selection of CPU count and memory size can be made when ordering</p>

Click on the Request Info tab and fill in the details. Select an appropriate template and Environment, Hardware, and Network tab settings that are known to work when a VM is provisioned interactively (see Chapter 39). The VM name will be overwritten during the provisioning process, so here we just set it as changeme (see Figure 33-11).

Figure 33-11. Completing the Request Info tab

Finally, click the Add button.

Select a suitably sized icon for a custom image, and save.

Further Reading

Provisioning Virtual Machines and Hosts—Chapter 5, Catalogs and Services