PADV-412: Add LTI 1.3 re-usable configuration ADR

docs/decisions/0008-lti-1p3-puggable-lti-configuration.rst

@@ -0,0 +1,95 @@
+PADV-412: LTI 1.3 Pluggable and re-usable LTI configuration
+===========================================================
+
+Status
+======
+
+Proposal
+
+Context
+=======
+
+In this discovery, we will describe a possible approach to add LTI 1.3 support
+for pluggable and re-usable LTI configurations on the lti_store plugin and
+xblock-lti-consumer XBlock.
+
+The #239 issue on xblock-lti-consumer [4]_ added support for LTI 1.1
+pluggability, on the Open edX roadmap ticket #143 [1]_, related to the feature
+of external pluggable LTI configuration, there was planned implementation for
+LTI 1.3 support, according to comments on #210 [3]_, progress on this effort
+has been stopped, currently, the remaining efforts to reach LTI 1.3 support are:
+
+- Expand the plugin support to allow storing and retrieval of LTI 1.3
+  configuration
+- Update the LTI Consumer to use the configuration from the filter pipeline to
+  load an external LTI tool using LTI 1.3 spec
+- Remove XBlock dependencies from LTI 1.3 launches (features related to LTI 1.3
+  authentication, for example, the keyset URL and the token URL).
+
+Why do we need this?
+====================
+
+This feature is important because it will allow us to eliminate the need to
+configure multiple LTI tools for each LTI 1.3 consumer XBlock (course authors
+may not have access to deploy LTI 1.3 tools) and allow LTI 1.3 consumer XBlock
+to share a common configuration, this will also allow for multi-tenancy model
+compatibility on the platform and ease the maintenance of courses that heavily
+depend on many LTI 1.3 XBlocks. We will also be able to use CCX XBlocks that
+use LTI 1.3 since the CCX XBlocks would not have a separate configuration from
+its master course counterpart.
+
+General Approach
+===============
+
+We will need to modify the lti_store plugin and xblock-lti-consumer to include
+these changes:
+
+Changes on xblock-lti-consumer
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+- Modify xblock-lti-consumer to allow setting the
+  "LTI Reusable Configuration ID" field and add the "Reusable Configuration"
+  option to the "Configuration Type" field on XBlocs using LTI 1.3 version.
+- Modify the _get_lti_1p3_consumer method on the LTI configuration model to use
+  the values from the external configuration when enabled.
+- Modify the get_lti_1p3_launch_info function to show the values from the
+  external configuration on the author view.
+
+Note: We aren't completely clear on what might need to change appart from
+_get_lti_1p3_consumer and get_lti_1p3_launch_info in xblock-lti-consumer
+to allow the use of LTI 1.3 external configurations.
+
+We also need to modify the LtiConfiguration model to sync the changes on
+the config store field and external ID field on all CCX XBlocks related to
+the master courser XBlock beign modified, this could be achieved by two method,
+first by copying the config store and external ID values when a CCX XBlock
+LtiConfiguration is beign created and by also sync changes from the master
+LtiConfiguration with a post save signal, in that signal we can iterate over
+any CCX LtiConfiguration related and sync the config ID and external ID values.
+
+Changes on lti_store
+~~~~~~~~~~~~~~~~~~~~
+
+- Add LTI 1.3 fields to lti_store ExternalLtiConfiguration model for the
+  client ID, private key, private key ID, public key or keyset URL, and
+  deployment id.
+- Add LTI 1.3 has a version choice on ExternalLtiConfiguration model.
+- Add a clean method to ExternalLtiConfiguration model to avoid mixing LTI 1.1
+  and LTI 1.3 fields.
+- Add an access token view to lti_store for LTI 1.3 external configurations.
+- Add a keyset view to lti_store for LTI 1.3 external configurations.
+
+Note: The private key ID on the LTI 1.3 external configuration model can be an
+auto-generated uuid4, just as how it's already being done on the
+_generate_lti_1p3_keys_if_missing method on the LtiConfiguration model in
+xblock-lti-consumer.
+
+References
+==========
+
+.. [1] #143 Open edX Roadmap - Central Management of LTI Configuration: https://github.com/openedx/platform-roadmap/issues/143
+.. [2] Pluggable and re-usable LTI configuration ADR: https://github.com/openedx/xblock-lti-consumer/blob/469d47dd2b3f1f742da429a64108b5a4ff03165d/docs/decisions/0006-pluggable-lti-configuration.rst
+.. [3] #210 Pluggable/reusable LTI configuration: https://github.com/openedx/xblock-lti-consumer/pull/210
+.. [4] #239 Support for external LTI configurations using openedx-filters: https://github.com/openedx/xblock-lti-consumer/pull/239
+.. [5] Openedx LTI Store: https://github.com/open-craft/openedx-ltistore
+.. [6] #273 Remove XBlock location dependencies from LTI 1.3 launches: https://github.com/openedx/xblock-lti-consumer/issues/273