Chapter 16. Provisioning a Virtual Machine
One of the most common things that we do as cloud or virtualization administrators is to create new virtual machines or instances. We get used to the procedure: picking a template; selecting a target cluster, datastore, and network; and choosing a suitable name. These are generally manual steps, but CloudForms has an out-of-the-box virtual machine provisioning workflow that automates the process.
There are many steps involved in automatically provisioning a virtual machine. The CloudForms provisioning workflow has been designed to be extremely flexible, and it allows a great deal of customization based on tagging, the requesting user’s group membership, and the destination provider type (e.g., RHEV, VMware, OpenStack, etc.).
The Provisioning Process
The virtual machine provisioning process starts with a user (the requester) selecting either Provision VMs from under the Infrastructure → Virtual Machines → Lifecycle button group, or Provision Instances from under the Cloud → Instances → Lifecycle button group (see Figure 16-1).
Figure 16-1. Initiating a provisioning operation
This takes us into a selection dialog where we pick an image or template to provision from and click the Continue button (see Figure 16-2).
Figure 16-2. Selecting the provisioning source template
Once we click Continue, we enter into the virtual machine provisioning workflow, starting with information retrieved from the profile and moving into the state machine.
Group-Specific Considerations, and Common Processing
Provisioning a virtual machine or instance involves many separate decisions, and steps that come together to form the VM provisioning workflow.
Some of these steps need to be performed or evaluated within the context of the requesting user’s access-control group membership, such as the choice of provisioning dialog to present to the user in the WebUI. We may, for example, wish to customize the WebUI dialog to present a restricted set of options to certain groups of users (see also Chapter 25). We can decide to apply quotas to access-control groups, or create specific customizations such as group-specific virtual machine naming schemes. Group-specific processing is typically performed in the request context, before the tasks are created (see Chapter 12 for a description of requests and tasks).
Other steps in the virtual machine provisioning workflow are common to all virtual machine or instance provisioning operations. These typically include the allocation of an IP address, registration with a CMDB, or emailing the requester that the provision has completed, for example.
The group-specific provisioning profile contains the per-group attributes, instance names, and state machine names that are used in processing the provisioning request and in preparing the provisioning task(s).
The more generic sequence of common steps involved in provisioning a virtual machine or instance comes from the VM provisioning state machine. This is processed in the context of the provisioning task.
Summary
This short chapter has introduced the group-specific provisioning profile and the more generic VM provisioning state machine that combine to form the virtual machine provisioning workflow.
In the following chapters, we will examine these in more detail, starting with the provisioning profile.