dfb304355b
Tempest provides a LockFixture to avoid two potentially interfering tests to run in parallel. However, this solution does not scale when we want to separate a set of tests from many other test cases. For example, host aggregate and availability zone testing needs compute hosts without any nova servers to be able to test moving computes between aggregates but a lot of other tests are creating nova servers. To fully separate these aggregate tests from the rest of the tempest test cases, this patch proposes a @serial class decorator to mark a test class to be run totally independently of any other test classes. Under the hood, the @serial decorator is implemented with a tempest-wide interprocess read-write lock. The serial test classes always take the write lock, while the non-serial classes take the read lock. The lock allows in many readers OR a single writer. So the serial tests are run independently from the rest. To minimize the time a serial test blocks other tempest tests run in parallel, this patch also introduced a serial_tests test directory to store the serial tests. The current test ordering in a fresh env uses alphabetical order so the serial tests will run at the end of the execution not randomly in the middle. The gate uses fresh VMs for every run so we can rely on this optimization there. In local envs where tests are re-run, the subsequent runs will be ordered at runtime by stestr. Therfore, a longer runtime might be observed due to locking, but the correctness of the test execution is still kept. Related-Bug: #821732 Change-Id: I0181517edab75f586464a38c4811417f888783b1 |
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| api | ||
| cmd | ||
| common | ||
| hacking | ||
| lib | ||
| scenario | ||
| serial_tests | ||
| test_discover | ||
| tests | ||
| README.rst | ||
| __init__.py | ||
| clients.py | ||
| config.py | ||
| exceptions.py | ||
| test.py | ||
| version.py | ||
README.rst
Tempest Field Guide Overview
Tempest is designed to be useful for a large number of different environments. This includes being useful for gating commits to OpenStack core projects, being used to validate OpenStack cloud implementations for both correctness, as well as a burn in tool for OpenStack clouds.
As such Tempest tests come in many flavors, each with their own rules and guidelines. Below is the overview of the Tempest repository structure to make this clear.
tempest/
api/ - API tests
scenario/ - complex scenario tests
tests/ - unit tests for Tempest internalsEach of these directories contains different types of tests. What belongs in each directory, the rules and examples for good tests, are documented in a README.rst file in the directory.
api_field_guide
API tests are validation tests for the OpenStack API. They should not use the existing Python clients for OpenStack, but should instead use the Tempest implementations of clients. Having raw clients let us pass invalid JSON to the APIs and see the results, something we could not get with the native clients.
When it makes sense, API testing should be moved closer to the projects themselves, possibly as functional tests in their unit test frameworks.
scenario_field_guide
Scenario tests are complex "through path" tests for OpenStack functionality. They are typically a series of steps where complicated state requiring multiple services is set up exercised, and torn down.
Scenario tests should not use the existing Python clients for OpenStack, but should instead use the Tempest implementations of clients.
unit_tests_field_guide
Unit tests are the self checks for Tempest. They provide functional verification and regression checking for the internal components of Tempest. They should be used to just verify that the individual pieces of Tempest are working as expected.