ddef9dcfc0
Because we need to allow for a smooth upgrade from Ocata to Pike, we need Pike compute hosts to be tolerant of the bad accounting assumptions that Ocata compute hosts were making. If a user migrates an instance from an Ocata compute host to a Pike compute host, the Ocata compute host will continue essentially re-setting the instance allocation to be an allocation against only the source Ocata host (during the migration operation). We need to have the Pike destination compute host recognize when its in a mixed Ocata/Pike environment and tolerate this incorrect "healing" that the Ocata source host will do. To tolerate this, the Pike destination compute host must continue to behave like an Ocata compute host until all compute hosts are upgraded to Pike or beyond. Note that this adds service version caching for the compute service. We were already doing the lookup for the RPC pin and caching that, so this is not much of a change. Also note that we weren't clearing this caching in tests, so any test that ran code that cached the service version would affect later ones. This clears it as part of the base test setup too. Co-Authored-By: Jay Pipes <jaypipes@gmail.com> Change-Id: Ia93168b1560267178059284186fb2b7096c7e81f
OpenStack Nova Testing Infrastructure
This README file attempts to provide current and prospective contributors with everything they need to know in order to start creating unit tests for nova.
Note: the content for the rest of this file will be added as the work items in the following blueprint are completed: https://blueprints.launchpad.net/nova/+spec/consolidate-testing-infrastructure
Test Types: Unit vs. Functional vs. Integration
TBD
Writing Unit Tests
TBD
Using Fakes
TBD
test.TestCase
The TestCase class from nova.test (generally imported as test) will automatically manage self.stubs using the stubout module and self.mox using the mox module during the setUp step. They will automatically verify and clean up during the tearDown step.
If using test.TestCase, calling the super class setUp is required and calling the super class tearDown is required to be last if tearDown is overridden.
Writing Functional Tests
TBD
Writing Integration Tests
TBD
Tests and Exceptions
A properly written test asserts that particular behavior occurs. This can be a success condition or a failure condition, including an exception. When asserting that a particular exception is raised, the most specific exception possible should be used.
In particular, testing for Exception being raised is almost always a mistake since it will match (almost) every exception, even those unrelated to the exception intended to be tested.
This applies to catching exceptions manually with a try/except block, or using assertRaises().
Example:
self.assertRaises(exception.InstanceNotFound, db.instance_get_by_uuid,
elevated, instance_uuid)If a stubbed function/method needs a generic exception for testing purposes, test.TestingException is available.
Example:
def stubbed_method(self):
raise test.TestingException()
self.stubs.Set(cls, 'inner_method', stubbed_method)
obj = cls()
self.assertRaises(test.TestingException, obj.outer_method)Stubbing and Mocking
Whenever possible, tests SHOULD NOT stub and mock out the same function.
If it's unavoidable, tests SHOULD define stubs before mocks since the TestCase cleanup routine will un-mock before un-stubbing. Doing otherwise results in a test that leaks stubbed functions, causing hard-to-debug interference between tests1.
If a mock must take place before a stub, any stubs after the mock call MUST be manually unset using self.cleanUp calls within the test.