feat: add docs for Typesense search backend

Document how to get started with the new Typesense search backend,
and some tips about clustered Typesense and using a web dashboard.

Private-ref: https://tasks.opencraft.com/browse/BB-10458

Author: samuelallan72

source/site_ops/how-tos/use_typesense_search_backend.rst

@@ -0,0 +1,175 @@
+.. _Use Typesense search backend:
+
+Use Typesense search backend
+############################
+
+.. tags:: site operator, how-to
+
+.. note::
+
+    Typesense search support has not been included in a release yet. Stay tuned!
+
+`Typesense <https://typesense.org/>`_ is supported for the following search areas:
+
+* Course info (course search on the Discover New page)
+* Courseware (course content search)
+* Forum (threads and comments)
+
+Typesense is supported as both a single node and as a cluster for high availability (HA).
+This is not the default though; Meilisearch is the default search backend.
+
+Getting started
+***************
+
+See below for how to start using Typesense with your Open edX instance, depending on whether you use Tutor or not:
+
+Tutor
+=====
+
+If you use Tutor, you can install the `tutor-contrib-typesense`_
+plugin, which will automatically deploy a single node Typesense instance
+and configure the platform to use it.
+
+.. note::
+
+   This plugin does not support deploying Typesense as a HA cluster. If you require a cluster, please follow the manual configuration section below.
+
+#. Install the plugin:
+
+   .. code-block:: shell
+
+      pip install -e https://github.com/open-craft/tutor-contrib-typesense
+      tutor plugins enable typesense
+
+#. Configure if required. For most cases, the defaults will be fine. Available configuration is documented on `the plugin's readme <https://github.com/open-craft/tutor-contrib-typesense?tab=readme-ov-file#configuration>`_.
+
+   If you require custom configuration, set them using Tutor, for example:
+
+   .. code-block:: shell
+
+      tutor config save --set TYPESENSE_COLLECTION_PREFIX=my_instance_
+
+#. Initialise the plugin - some examples:
+
+   .. code-block:: shell
+
+      # if an existing k8s deployment
+      tutor k8s do init --limit=typesense
+
+      # if launching a devstack
+      tutor dev launch
+
+#. Reindex content - if this is an existing deployment with content already, you will need to manually run a reindex (the Typesense indexes are created automatically):
+
+   .. code-block:: shell
+
+      # reindex courseware content and course info
+      tutor dev exec cms -- python manage.py cms reindex_course --active
+
+      # reindex forum threads and comments
+      tutor dev exec lms -- python manage.py lms rebuild_forum_indices
+
+#. Finally, to enable course content search on the frontend, create and enable a waffle flag named ``courseware.mfe_courseware_search``. You can do this from the LMS Django admin page, waffle flags section.
+
+Manual configuration
+====================
+
+If you aren't using Tutor, here are instructions for getting started manually.
+
+#. Deploy an instance of Typesense. See the `Typesense installation guide <https://typesense.org/docs/guide/install-typesense.html>`_ for more information.
+
+#. Create an API key. See the Typesense `API Keys doc <https://typesense.org/docs/latest/api/api-keys.html>`_ for more information.
+   Optionally, for extra security, you can scope the API key permissions to a custom collection prefix. This prefix can be configured for the Open edX platform in the following step (the ``TYPESENSE_COLLECTION_PREFIX`` setting).
+   For example:
+
+   .. code-block:: shell
+
+      curl -X POST 'http://localhost:8108/keys' \
+        -H 'Content-Type: application/json' -H 'X-TYPESENSE-API-KEY: mysecretadminkey' \
+        --data-binary '{
+            "value": "mysecretapikeyvalue",
+            "description": "API key for my Open edX instance",
+            "actions": ["*"],
+            "collections": ["^openedx_.*"]
+        }'
+
+
+#. Set the following Django settings for LMS and CMS:
+
+   .. code-block:: python
+
+      # Enable the Typesense backend.
+      TYPESENSE_ENABLED = True
+
+      # Set the API key for authenticating to Typesense.
+      TYPESENSE_API_KEY = "your-secret-api-key-for-typesense"
+
+      # Set the internal urls where the LMS/CMS can reach the Typesense API.
+      # If Typesense is deployed as a cluster, provide the urls to all nodes here.
+      TYPESENSE_URLS = ["https://typesense-1.example.com:8108", "https://typesense-2.example.com:8108"]
+
+      # The prefix that the backend should use for all collections (you can scope the API key permissions to this prefix for security).
+      # This is useful if the Typesense instance is shared with other software.
+      TYPESENSE_COLLECTION_PREFIX = "openedx_"
+
+      # Optional: if you need to override the forum search backend module for testing
+      #FORUM_SEARCH_BACKEND = "forum.search.typesense.TypesenseBackend"
+
+      # Optional: if you need to override the course search backend module for testing
+      #SEARCH_ENGINE = "search.typesense.TypesenseEngine"
+
+
+#. Reindex content - if this is an existing deployment with content already, you will need to manually run a reindex (the Typesense indexes are created automatically):
+
+   .. code-block:: shell
+
+      # In the CMS environment: reindex courseware content and course info
+      python manage.py cms reindex_course --active
+
+      # In the LMS environment: reindex forum threads and comments
+      python manage.py lms rebuild_forum_indices
+
+#. Finally, to enable course content search on the frontend, create and enable a waffle flag named ``courseware.mfe_courseware_search``. You can do this from the LMS Django admin page, waffle flags section.
+
+
+Clustered Typesense
+*******************
+
+Some notes regarding running Typesense in a cluster, for a HA setup.
+
+* For clustered Typesense, it's best to provide urls to all the nodes to ``TYPESENSE_URLS``, rather than putting it behind a load balancer.
+  This allows the Typesense client to manage load balancing and fallbacks itself.
+* Be careful when running a Typesense cluster on Kubernetes, as there can be issues related to how consensus is implemented and that Kubernetes pods don't necessarily have static IP addresses. See `typesense/typesense#465 <https://github.com/typesense/typesense/issues/465>`_ and `typesense/typesense#2049 <https://github.com/typesense/typesense/issues/2049>`_ for more information.
+
+
+Typesense web dashboard
+***********************
+
+Typesense doesn't come with an official web dashboard,
+but there is a community dashboard developed at https://github.com/bfritscher/typesense-dashboard.
+You can visit it directly on the web without installing at https://bfritscher.github.io/typesense-dashboard/.
+
+For example, to connect to a Typesense server from a local Tutor devstack using the Typesense plugin,
+visit the web dashboard url, and enter the following details at the login screen:
+
+* Api Key: (use the output from running ``tutor config printvalue TYPESENSE_API_KEY``)
+* protocol: ``http``
+* host: ``localhost``
+* port: ``8108``
+* path: (leave blank)
+
+
+.. seealso::
+
+    :ref:`Enable edX Search`
+
+
+**Maintenance chart**
+
++--------------+-------------------------------+----------------+--------------------------------+
+| Review Date  | Working Group Reviewer        |   Release      |Test situation                  |
++--------------+-------------------------------+----------------+--------------------------------+
+|              |                               |                |                                |
++--------------+-------------------------------+----------------+--------------------------------+
+
+.. _tutor-contrib-typesense: https://github.com/open-craft/tutor-contrib-typesense/