Tempest - The OpenStack Integration Test Suite

The documentation for Tempest is officially hosted at: https://docs.openstack.org/tempest/latest/

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.

Team and repository tags

Design Principles

Tempest Design Principles that we strive to live by.

• Tempest should be able to run against any OpenStack cloud, be it a one node DevStack install, a 20 node LXC cloud, or a 1000 node KVM cloud.

• Tempest should be explicit in testing features. It is easy to auto discover features of a cloud incorrectly, and give people an incorrect assessment of their cloud. Explicit is always better.

• Tempest uses OpenStack public interfaces. Tests in Tempest should only touch public OpenStack APIs.

• Tempest should not touch private or implementation specific interfaces. This means not directly going to the database, not directly hitting the hypervisors, not testing extensions not included in the OpenStack base. If there are some features of OpenStack that are not verifiable through standard interfaces, this should be considered a possible enhancement.

• Tempest strives for complete coverage of the OpenStack API and common scenarios that demonstrate a working cloud.

• Tempest drives load in an OpenStack cloud. By including a broad array of API and scenario tests Tempest can be reused in whole or in parts as load generation for an OpenStack cloud.

• Tempest should attempt to clean up after itself, whenever possible we should tear down resources when done.

• Tempest should be self-testing.

Quickstart

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. Where the configuration file lives and how you interact with it depends on how you’ll be running Tempest. There are 2 methods of using Tempest. The first, which is a newer and recommended workflow treats Tempest as a system installed program. The second older method is to run Tempest assuming your working dir is the actually Tempest source repo, and there are a number of assumptions related to that. For this section we’ll only cover the newer method as it is simpler, and quicker to work with.

1. You first need to install Tempest. This is done with pip after you check out the Tempest repo:

   $ git clone https://opendev.org/openstack/tempest
   $ pip install tempest/
   

   This can be done within a venv, but the assumption for this guide is that the Tempest CLI entry point will be in your shell’s PATH.

2. Installing Tempest may create a /etc/tempest dir, however if one isn’t created you can create one or use ~/.tempest/etc or ~/.config/tempest in place of /etc/tempest. If none of these dirs are created Tempest will create ~/.tempest/etc when it’s needed. The contents of this dir will always automatically be copied to all etc/ dirs in local workspaces as an initial setup step. So if there is any common configuration you’d like to be shared between local Tempest workspaces it’s recommended that you pre-populate it before running tempest init.

3. Setup a local Tempest workspace. This is done by using the tempest init command:

   $ tempest init cloud-01
   

   which also works the same as:

   $ mkdir cloud-01 && cd cloud-01 && tempest init
   

   This will create a new directory for running a single Tempest configuration. If you’d like to run Tempest against multiple OpenStack deployments the idea is that you’ll create a new working directory for each to maintain separate configuration files and local artifact storage for each.

4. Then cd into the newly created working dir and also modify the local config files located in the etc/ subdir created by the tempest init command. Tempest is expecting a tempest.conf file in etc/ so if only a sample exists you must rename or copy it to tempest.conf before making any changes to it otherwise Tempest will not know how to load it. For details on configuring Tempest refer to the Tempest Configuration

5. Once the configuration is done you’re now ready to run Tempest. This can be done using the Tempest Run command. This can be done by either running:

   $ tempest run
   

   from the Tempest workspace directory. Or you can use the --workspace argument to run in the workspace you created regardless of your current working directory. For example:

   $ tempest run --workspace cloud-01
   

   There is also the option to use stestr directly. For example, from the workspace dir run:

   $ stestr run --exclude-regex '\[.*\bslow\b.*\]' '^tempest\.(api|scenario)'
   

   will run the same set of tests as the default gate jobs. Or you can use unittest compatible test runners such as stestr, pytest etc.

   Tox also contains several existing job configurations. For example:

   $ tox -e full
   

   which will run the same set of tests as the OpenStack gate. (it’s exactly how the gate invokes Tempest) Or:

   $ tox -e smoke
   

   to run the tests tagged as smoke.

Library

Tempest exposes a library interface. This interface is a stable interface and should be backwards compatible (including backwards compatibility with the old tempest-lib package, with the exception of the import). If you plan to directly consume Tempest in your project you should only import code from the Tempest library interface, other pieces of Tempest do not have the same stable interface and there are no guarantees on the Python API unless otherwise stated.

For more details refer to the library documentation

Release Versioning

Tempest Release Notes shows what changes have been released on each version.

Tempest’s released versions are broken into 2 sets of information. Depending on how you intend to consume Tempest you might need

The version is a set of 3 numbers:

X.Y.Z

While this is almost semver like, the way versioning is handled is slightly different:

X is used to represent the supported OpenStack releases for Tempest tests in-tree, and to signify major feature changes to Tempest. It’s a monotonically increasing integer where each version either indicates a new supported OpenStack release, the drop of support for an OpenStack release (which will coincide with the upstream stable branch going EOL), or a major feature lands (or is removed) from Tempest.

Y.Z is used to represent library interface changes. This is treated the same way as minor and patch versions from semver but only for the library interface. When Y is incremented we’ve added functionality to the library interface and when Z is incremented it’s a bug fix release for the library. Also note that both Y and Z are reset to 0 at each increment of X.

Configuration

Detailed configuration of Tempest is beyond the scope of this document, see Tempest Configuration Documentation for more details on configuring Tempest. The etc/tempest.conf.sample attempts to be a self-documenting version of the configuration.

You can generate a new sample tempest.conf file, run the following command from the top level of the Tempest directory:

$ tox -e genconfig

The most important pieces that are needed are the user ids, OpenStack endpoints, and basic flavors and images needed to run tests.

Unit Tests

Tempest also has a set of unit tests which test the Tempest code itself. These tests can be run by specifying the test discovery path:

$ stestr --test-path ./tempest/tests run

By setting --test-path option to ./tempest/tests it specifies that test discover should only be run on the unit test directory. The default value of test_path is test_path=./tempest/test_discover which will only run test discover on the Tempest suite.

Alternatively, there is the py39 tox job which will run the unit tests with the corresponding version of python.

One common activity is to just run a single test, you can do this with tox simply by specifying to just run py39 tests against a single test:

$ tox -e py39 -- -n tempest.tests.test_microversions.TestMicroversionsTestsClass.test_config_version_none_23

Or all tests in the test_microversions.py file:

$ tox -e py39 -- -n tempest.tests.test_microversions

You may also use regular expressions to run any matching tests:

$ tox -e py39 -- test_microversions

Additionally, when running a single test, or test-file, the -n/--no-discover argument is no longer required, however it may perform faster if included.

For more information on these options and details about stestr, please see the stestr documentation.

Python 3.x

Starting during the Pike cycle Tempest has a gating CI job that runs Tempest with Python 3. Any Tempest release after 15.0.0 should fully support running under Python 3 as well as Python 2.7.

Legacy run method

The legacy method of running Tempest is to just treat the Tempest source code as a python unittest repository and run directly from the source repo. When running in this way you still start with a Tempest config file and the steps are basically the same except that it expects you know where the Tempest code lives on your system and requires a bit more manual interaction to get Tempest running. For example, when running Tempest this way things like a lock file directory do not get generated automatically and the burden is on the user to create and configure that.

To start you need to create a configuration file. The easiest way to create a configuration file is to generate a sample in the etc/ directory

$ cd $TEMPEST_ROOT_DIR
$ oslo-config-generator --config-file \
    tempest/cmd/config-generator.tempest.conf \
    --output-file 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.

Note

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 stestr is the most commonly used tool. Also, the nosetests test runner is not recommended to run Tempest.

After setting up your configuration file, you can execute the set of Tempest tests by using stestr. By default, stestr runs tests in parallel

$ stestr run

To run one single test serially

$ stestr run --serial tempest.api.compute.servers.test_servers_negative.ServersNegativeTestJSON.test_reboot_non_existent_server