fixup!: ADR

docs/decisions/0013-new-event-bus-producer-config.rst

@@ -0,0 +1,65 @@
+11. Enable producing to event bus via settings
+##############################################
+
+Status
+******
+
+**Accepted**
+
+Context
+*******
+
+In a previous ADR, we set the structure for the event bus publishing configuration to a dictionary like the following:
+
+.. code-block:: python
+
+    { 'org.openedx.content_authoring.xblock.published.v1': [
+           {'topic': 'content-authoring-xblock-lifecycle', 'event_key_field': 'xblock_info.usage_key', 'enabled': True},
+           {'topic': 'content-authoring-xblock-published', 'event_key_field': 'xblock_info.usage_key', 'enabled': False},
+       ],
+       'org.openedx.content_authoring.xblock.deleted.v1': [
+           {'topic': 'content-authoring-xblock-lifecycle', 'event_key_field': 'xblock_info.usage_key', 'enabled': True},
+       ],
+   }
+
+While attempting to implement this for edx-platform, we came across some problems with using this structure. In particular, it results in ambiguity
+because maintainers can accidentally add something like
+``{'topic': 'content-authoring-xblock-lifecycle', 'event_key_field': 'xblock_info.usage_key', 'enabled': True}`` and
+``{'topic': 'content-authoring-xblock-lifecycle', 'event_key_field': 'xblock_info.usage_key', 'enabled': False}`` to the same event_type.
+Also, as written, this configuration requires maintainers to copy over the entire configuration to override it, which is non-obvious
+to people who may only be trying to enable/disable a single event while keeping everything else the same.
+
+This ADR aims to propose a new structure that will provide greater flexibility in using this configuration.
+
+
+Decision
+********
+
+The new EVENT_BUS_PRODUCER_CONFIG will be added to KEYS_WITH_MERGED_VALUES in ``edx-platform`` with the following configuration format:
+
+.. code-block:: python
+
+   # .. setting_name: EVENT_BUS_PRODUCER_CONFIG
+   # .. setting_default: {}
+   # .. setting_description: Dictionary of event_types to dictionaries for topic related configuration.
+   #    Each topic configuration dictionary uses the topic as a key and contains a flag called `enabled`
+   #    denoting whether the event will be and `event_key_field` which is a period-delimited string path
+   #    to event data field to use as event key.
+   #    Note: The topic names should not include environment prefix as it will be dynamically added based on
+   #    EVENT_BUS_TOPIC_PREFIX setting.
+   EVENT_BUS_PRODUCER_CONFIG = {
+       'org.openedx.content_authoring.xblock.published.v1': {
+           'content-authoring-xblock-lifecycle': {'event_key_field': 'xblock_info.usage_key', 'enabled': False}
+           'content-authoring-xblock-published': {'event_key_field': 'xblock_info.usage_key', 'enabled': True}
+       },
+       'org.openedx.content_authoring.xblock.deleted.v1': {
+           'content-authoring-xblock-lifecycle': {'event_key_field': 'xblock_info.usage_key', 'enabled': True},
+       },
+   }
+
+
+Consequences
+************
+
+* Maintainers can add existing topics to new event_types without having to recreate the whole dictionary
+* There is no ambiguity about whether an events is enabled or disabled