Chapter 15. Event Processing

One of the most powerful features of CloudForms Automate is its capability to process events. CloudForms can monitor and respond to external (provider) events, such as a virtual machine starting or stopping, or a hypervisor going into maintenance. These events can then be used as triggers for Automate operations. We might wish to initiate a SmartState Analysis scan on a new VMware virtual machine when a VmCreatedEvent event is detected, for example. Perhaps we’d like to intercept and cancel a USER_INITIATED_SHUTDOWN_VM event being detected on a critical Red Hat Enterprise Virtualization (RHEV) virtual machine that we’ve tagged as do_not_shutdown.

CloudForms Automate also raises its own events internally, which can then be used as workflow triggers. We see an example of this when we provision a new virtual machine (we cover VM provisioning in Part II of the book). The workflow for provisioning a virtual machine includes an approval stage—we can optionally allow administrators to approve large VM requests—followed by a quota-checking stage to ensure that users are not exceeding their quota. The successful approval of the VM provisioning request results in Automate raising a request_approved internal event. This request_approved event is then used as the trigger to automatically start the quota-checking workflow (see Chapter 19 for more details on this workflow).

In this chapter we’ll examine in detail how events are processed by the Automation Engine. ...

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