caca71376f
At present the Libvirt driver can preallocate file based disks using the fallocate command and importantly the `-n` option. This option allocates blocks on the filesystem past the initial EOF of a given file: ``` $ touch test.img ; fallocate -n -l $(( 1024 * 1024 )) test.img $ ll -lah test.img -rw-rw-r--. 1 stack stack 0 Apr 16 13:28 test.img $ du -h test.img 1.0M test.img ``` This results in a miscalculation of the total disk overcommit for file based (excluding ploop) disks as os.path.getsize is currently used to determine the allocated size of these disks: ``` >>> import os >>> os.path.getsize('test.img') 0 ``` Using the above example the disk overcommit would be reported as 1.0M as the disk appears empty yet will report a potential (virtual) size of 1.0M. However as the required blocks have already been allocated on the filesystem the host will report disk_available_least as missing an additional 1.0M, essentially doubling the allocation for each disk. To correct this the allocated size of file based (excluding ploop) disks is reported using `disk_size` from the `qemu-img info` command. This should ensure blocks allocated past the EOF of the file are taken into account and correctly reported as allocated. A future change should ultimately remove the use of the `-n` option with fallocate, however as this would not help disks that have already been allocated this has not been included in this change to simplify backports. Conflicts: nova/tests/unit/virt/libvirt/test_driver.py NOTE(lyarwood): I11e329ac5f5fe4b9819fefbcc32ff1ee504fc58b made get_domain private in Queens. Change-Id: If642e51a4e186833349a8e30b04224a3687f5594 Closes-bug: #1764489 (cherry picked from commit |
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.. | ||
api | ||
api_samples_test_base | ||
cells | ||
cert | ||
cmd | ||
compute | ||
conductor | ||
console | ||
consoleauth | ||
db | ||
fake_loadables | ||
image | ||
keymgr | ||
monkey_patch_example | ||
network | ||
notifications | ||
objects | ||
pci | ||
scheduler | ||
servicegroup | ||
ssl_cert | ||
virt | ||
volume | ||
README.rst | ||
__init__.py | ||
cast_as_call.py | ||
conf_fixture.py | ||
fake_block_device.py | ||
fake_build_request.py | ||
fake_console_auth_token.py | ||
fake_crypto.py | ||
fake_flavor.py | ||
fake_hosts.py | ||
fake_instance.py | ||
fake_ldap.py | ||
fake_network.py | ||
fake_network_cache_model.py | ||
fake_notifier.py | ||
fake_pci_device_pools.py | ||
fake_policy.py | ||
fake_processutils.py | ||
fake_request_spec.py | ||
fake_server_actions.py | ||
fake_volume.py | ||
fake_xvp_console_proxy.py | ||
image_fixtures.py | ||
matchers.py | ||
policy_fixture.py | ||
test_api_validation.py | ||
test_availability_zones.py | ||
test_baserpc.py | ||
test_block_device.py | ||
test_cache.py | ||
test_cinder.py | ||
test_conf.py | ||
test_configdrive2.py | ||
test_context.py | ||
test_crypto.py | ||
test_exception.py | ||
test_fixtures.py | ||
test_flavors.py | ||
test_hacking.py | ||
test_hash_ring.py | ||
test_hooks.py | ||
test_instance_types_extra_specs.py | ||
test_iptables_network.py | ||
test_ipv6.py | ||
test_loadables.py | ||
test_matchers.py | ||
test_metadata.py | ||
test_notifications.py | ||
test_notifier.py | ||
test_nova_manage.py | ||
test_pipelib.py | ||
test_policy.py | ||
test_profiler.py | ||
test_quota.py | ||
test_rpc.py | ||
test_safeutils.py | ||
test_service.py | ||
test_service_auth.py | ||
test_signature_utils.py | ||
test_test.py | ||
test_test_utils.py | ||
test_utils.py | ||
test_uuid_sentinels.py | ||
test_versions.py | ||
test_weights.py | ||
test_wsgi.py | ||
utils.py |
README.rst
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.