The nova.scheduler.filters.trusted_filter Module

Filter to add support for Trusted Computing Pools.

Filter that only schedules tasks on a host if the integrity (trust) of that host matches the trust requested in the extra_specs for the flavor. The extra_specs will contain a key/value pair where the key is trust. The value of this pair (trusted/untrusted) must match the integrity of that host (obtained from the Attestation service) before the task can be scheduled on that host.

Note that the parameters to control access to the Attestation Service are in the nova.conf file in a separate trust section. For example, the config file will look something like:

[DEFAULT] verbose=True ... [trust] server=attester.mynetwork.com

Details on the specific parameters can be found in the file trust_attest.py.

Details on setting up and using an Attestation Service can be found at the Open Attestation project at:

https://github.com/OpenAttestation/OpenAttestation

class AttestationService

Bases: object

do_attestation(hosts)

Attests compute nodes through OAT service.

Parameters:hosts – hosts list to be attested Returns:dictionary for trust level and validate time

class ComputeAttestation

Bases: object

is_trusted(host, trust)

class ComputeAttestationCache

Bases: object

Cache for compute node attestation

Cache compute node’s trust level for sometime, if the cache is out of date, poll OAT service to flush the cache.

OAT service may have cache also. OAT service’s cache valid time should be set shorter than trusted filter’s cache valid time.

get_host_attestation(host)

Check host’s trust level.

class TrustedFilter

Bases: nova.scheduler.filters.BaseHostFilter

Trusted filter to support Trusted Compute Pools.

host_passes(host_state, filter_properties)

run_filter_once_per_request = True