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diff --git a/docs/testing/user/ovpaddendum/exemption-strict-API-validation.rst b/docs/testing/user/ovpaddendum/exemption-strict-API-validation.rst new file mode 100644 index 00000000..3acc6ee8 --- /dev/null +++ b/docs/testing/user/ovpaddendum/exemption-strict-API-validation.rst @@ -0,0 +1,183 @@ +.. This work is licensed under a Creative Commons Attribution 4.0 International +.. License. +.. http://creativecommons.org/licenses/by/4.0 +.. (c) Ericsson and others + +============================================================== +Exemption Process - Disabling Strict API Validation in Tempest +============================================================== + +.. toctree:: + :maxdepth: 2 + + +Introduction +============ + +In 2015, the OpenStack QA team introduced a validation mechanism for Nova API +responses in Tempest [1]_ with the goal of enforcing Nova API micro-versions. +The API validation mechanism verifies that API responses only contain data +elements (properties) as explicitly defined in API response schemas [2]_. In +case additional data elements are found in Nova API responses, the +corresponding tests fail immediately without asserting whether or not the +particular API operation actually succeeded or not. + +Independently, cloud vendors have extended their commercial OpenStack cloud +implementations with additional functionality which requires API extensions. +Consequently, such cloud implementations do not pass Tempest tests which +validate API responses despite actually implementing and providing the tested +functionality. + +This document describes an exemption process for use within the OPNFV Verified +Program which + +i) allows vendors to pass Tempest tests if the tested functionality is + fully supported despite the presence of additional data elements in API + responses, and + +ii) makes the application of the exemption process transparently visible in + test results. + + +Background and benefits for OVP +=============================== + +Vendors of commercial NFV products have extended OpenStack to provide +additional (NFV) functionality to their customers and to fill functional gaps +in OpenStack. These add-ons potentially extend the OpenStack API in two ways: + +i) new API endpoints and + +ii) additional attributes returned by existing API endpoints. + +New API endpoints typically go unnoticed by OpenStack Tempest tests and hence +do not interfere with existing tests. In contrast, (Nova) Tempest tests +actively validate the responses returned by existing API endpoints against +pre-defined schemas. An API response is considered invalid if additional +attributes are present (see example below). Hence, this particular type of +functional extension of OpenStack causes existing Tempest tests to fail, +irrespective of whether or not the functionality which is supposed to be tested +is actually available. As a result, a Tempest test failing due to extended API +responses does not provide information about whether the tested functionality +is available or not. + +The OPNFV Verified Program has inherited the policy to strictly validate API +responses from OpenStack by including a selection of Tempest tests in its +compliance test suite. However, it was never discussed if OVP should adopt this +policy as well. It turns out that this policy causes challenges for vendors of +commercial NFV offerings to pass the OVP test suite. The exemption process +outlined in this document aims at allowing to selectively disable strict API +response validation in order to enable vendors to adopt OVP **if** the tested +functionality is supported. + +It must be clearly understood that this exemption targets **only** the scenario +in which additional attributes are included in API responses. It does not +provide a loophole for passing OVP tests if the OpenStack APIs have been +altered significantly as this is in conflict with the objective of OVP to +create industry alignment. + +In conclusion, the exemption process described here is deemed beneficial for +both the broader industry as well as for OVP: Enabling adoption of OVP by +vendors which extended OpenStack API responses facilitates adoption of OVP in +the industry. The limited validity period of an exemption incentivizes eventual +alignment within the industry around a clearly specified set of APIs. + + +Example: additional attributes per VM for HA policy +--------------------------------------------------- + +This fictional example showcases the presence of an additional attribute in an +API response. The example shows that the 'server details', i.e. the VM +metadata, includes an additional attribute 'ha-policy' which is used to +associate high-availability policies with a VM instance. This attribute is +utilized by a proprietary add-on component to manage VM migration and recovery +in case of compute host failures:: + + { + "server": { + "accessIPv4": "1.2.3.4", + "config_drive": "", + "flavor": {...}, + "image": {...}, + "ha_policy": "migrate" <-- additional attribute + "name": "new-server-test", + "status": "ACTIVE" + } + } + + + +Precedent in OpenStack +====================== + +In the OpenStack community, the OpenStack Interoperability Working Group +(Interop WG) [4]_ is maintaining multiple API interoperability compliance +programs [5]_. These programs utilize Tempest-based tests to determine if a +given commercial cloud is compliant to a selected set of OpenStack APIs. After +introduction of the strict API response validation, various cloud products +which previously passed the compliance program failed validation because of the +reasons outlined above. + +In order to mitigate this situation, the Interop WG consulted with the broader +OpenStack community [6]_ and eventually introduced an "additional properties +waiver" for its API compliance programs in July 2016. The waiver was +created with a clearly defined validity period, covering roughly one year - +equivalent to three iterations of interoperability guidelines (2015.07, +2016.01, and 2016.08). The limited lifetime of the waiver was intended to give +cloud product vendors a transition period for adapting their products to +achieve full API compliance by the end of the exemption period. All details of +the waiver are listed in [7]_. Finally, the waiver was officially canceled in +October 2017 [8]_ after about 15 months. + + +Exemption process for additional properties in API responses in the OVP +======================================================================= + +The details of the exemption process for disabling strict validation of API +responses is as follows: + +#. The Dovetail tool provides a new command line option "--non-strict-api" for + disabling strict API validation. This option needs to be explicitly given on + the command line to disable strict API validation. If this command line + option is omitted, the default behavior (i.e., strict API validation) is + applied. + +#. The test results created by the Dovetail tool includes an explicit print-out + stating if strict API validation was disabled during the test run or not. + +#. The OVP portal reads the uploaded result files and indicates for all + uploaded test results if strict API validation was disabled or not. + +#. Together with the application for certification, a company can request an + exemption from the requirement for strict API response checking. A rationale + for requesting the exemption has to be provided. The request is either + granted or rejected by the C&C committee. The rationale provided must + establish that the need for exemption is not in violation of the OVP's + objectives. + +#. Compliance badges obtained under exemption are valid for one year. + +#. OPNFV expects OVP participants to aim for full compliance without requiring + exemptions as soon as possible. Hence, an exemption can only be requested + twice for the same product (addressing new versions of OVP or new versions + of the product). + +#. The same logo will be used regardless of being obtained under exemption or + not. + +#. The exemption will be made available to participants of OVP as part of a + service release of OVP 2018.01. + +#. The C&C committee will monitor the situation around exemptions and may + decide changes to the above process at any time, including the possibility + to stop issuing exemptions. + + +.. [1] https://review.openstack.org/#/c/156130/ +.. [2] https://github.com/openstack/tempest/tree/master/tempest/lib/api_schema/response/compute +.. [3] https://developer.openstack.org/api-ref/compute/#show-server-details +.. [4] https://wiki.openstack.org/wiki/Governance/InteropWG +.. [5] https://refstack.openstack.org/ +.. [6] http://lists.openstack.org/pipermail/openstack-dev/2016-June/097349.html +.. [7] https://review.openstack.org/#/c/333067/ +.. [8] https://review.openstack.org/#/c/512447/ |