This is a set of integration tests to be run against a live OpenStack cluster. Tempest has batteries of tests for OpenStack API validation, Scenarios, and other specific tests useful in validating an OpenStack deployment.
Tempest Design Principles that we strive to live by.
To run Tempest, you first need to create a configuration file that will tell Tempest where to find the various OpenStack services and other testing behavior switches.
The easiest way to create a configuration file is to copy the sample one in the etc/ directory
$> cd $TEMPEST_ROOT_DIR $> cp etc/tempest.conf.sample etc/tempest.conf
After that, open up the etc/tempest.conf file and edit the configuration variables to match valid data in your environment. This includes your Keystone endpoint, a valid user and credentials, and reference data to be used in testing.
If you have a running devstack environment, tempest will be automatically configured and placed in /opt/stack/tempest. It will have a configuration file already set up to work with your devstack installation.
Tempest is not tied to any single test runner, but testr is the most commonly used tool. After setting up your configuration file, you can execute the set of Tempest tests by using testr
$> testr run --parallel
To run one single test
$> testr run --parallel tempest.api.compute.servers.test_servers_negative.ServersNegativeTestJSON.test_reboot_non_existent_server
Alternatively, you can use the run_tempest.sh script which will create a venv and run the tests or use tox to do the same.
Detailed configuration of tempest is beyond the scope of this document. The etc/tempest.conf.sample attempts to be a self documenting version of the configuration.
To generate the sample tempest.conf file, run the following command from the top level of the tempest directory:
The most important pieces that are needed are the user ids, openstack endpoints, and basic flavors and images needed to run tests.
Tempest was originally designed to primarily run against a full OpenStack deployment. Due to that focus, some issues may occur when running Tempest against devstack.
Running Tempest, especially in parallel, against a devstack instance may cause requests to be rate limited, which will cause unexpected failures. Given the number of requests Tempest can make against a cluster, rate limiting should be disabled for all test accounts.
Additionally, devstack only provides a single image which Nova can use. For the moment, the best solution is to provide the same image uuid for both image_ref and image_ref_alt. Tempest will skip tests as needed if it detects that both images are the same.
Tempest also has a set of unit tests which test the tempest code itself. These tests can be run by specifing the test discovery path:
$> OS_TEST_PATH=./tempest/tests testr run --parallel
By setting OS_TEST_PATH to ./tempest/tests it specifies that test discover should only be run on the unit test directory. The default value of OS_TEST_PATH is OS_TEST_PATH=./tempest/test_discover which will only run test discover on the tempest suite.
Alternatively, you can use the run_tests.sh script which will create a venv and run the unit tests. There are also the py26, py27, or py33 tox jobs which will run the unit tests with the corresponding version of python.
Starting in the kilo release the OpenStack services dropped all support for python 2.6. This change has been mirrored in tempest, starting after the tempest-2 tag. This means that proposed changes to tempest which only fix python 2.6 compatibility will be rejected, and moving forward more features not present in python 2.6 will be used. If you’re running you’re OpenStack services on an earlier release with python 2.6 you can easily run tempest against it from a remote system running python 2.7. (or deploy a cloud guest in your cloud that has python 2.7)
Starting with the OpenStack Icehouse release Tempest no longer has any stable branches. This is to better ensure API consistency between releases because the API behavior should not change between releases. This means that the stable branches are also gated by the Tempest master branch, which also means that proposed commits to Tempest must work against both the master and all the currently supported stable branches of the projects. As such there are a few special considerations that have to be accounted for when pushing new changes to tempest.
When adding tests for new features that were not in previous releases of the projects the new test has to be properly skipped with a feature flag. Whether this is just as simple as using the @test.requires_ext() decorator to check if the required extension (or discoverable optional API) is enabled or adding a new config option to the appropriate section. If there isn’t a method of selecting the new feature from the config file then there won’t be a mechanism to disable the test with older stable releases and the new test won’t be able to merge.
When trying to land a bug fix which changes a tested API you’ll have to use the following procedure:
- Propose change to the project, get a +2 on the change even with failing - Propose skip on Tempest which will only be approved after the corresponding change in the project has a +2 on change - Land project change in master and all open stable branches (if required) - Land changed test in Tempest
Otherwise the bug fix won’t be able to land in the project.
If a test is being added for a feature that exists in all the current releases of the projects then the only concern is that the API behavior is the same across all the versions of the project being tested. If the behavior is not consistent the test will not be able to merge.
For new tests being added to Tempest the assumption is that the API being tested is considered stable and adheres to the OpenStack API stability guidelines. If an API is still considered experimental or in development then it should not be tested by Tempest until it is considered stable.