Trusted Flavors

As of Mitaka, Nova is capable of verifying digital signatures for Glance images. Currently, this feature can only be enabled by setting the verify_glance_signatures configuration option in Nova. If this flag is enabled, Nova can only boot signed images. This inconveniences end users or deployers who are comfortable with using unverified images in most cases, but would still like the option of using signature verification. This change allows the admin to create “trusted” flavors, or flavors of VM for which security features like image signature verification are enabled. Then the end user could enable these features on a per instance basis by creating instances using these “trusted” flavors.