Add event caching, add event docs

docs/README.md

@@ -4,6 +4,7 @@
 - [Dependency Management](./dependencies.md)
 - [Development Setup Notes](./development_setup_notes.md)
 - [Environment Variables](./env_vars.md)
+- [Events Calendar](./calendar.md)
 - [Example Files](./examples/README.md) - Contains samples of `libraries.json`. `.gitmodules`, and other files that Boost data depends on
 - [Hosting](./hosting/README.md)
 - [Mailman](./mailman/README.md)

docs/calendar.md

@@ -0,0 +1,9 @@
+# Events Calendar
+
+The "Schedule of Events" section on the homepage dynamically display upcoming events from the Boost Google Calendar. See the settings in [Environment Variables](./env_vars.md).
+
+- See the settings in [Environment Variables](./env_vars.md).
+- Main code for event retrieval is in `core/calendar.py`
+- Raw data is extracted from the Google Calendar API
+- The raw data is processed to extract the event data that we want to display, and sorted into the order we want
+- The home page caches the result, and attempts to retrieve the events from the cache before hitting the Google Calendar API

docs/env_vars.md

@@ -36,8 +36,19 @@ This project uses environment variables to configure certain aspects of the appl
 - For **local development**, obtain valid value from the Boost team.
 - In **deployed environments**, the valid value is set in `kube/boost/values.yaml` (or the environment-specific yaml file).
 
-## `CALENDAR_API_KEY`
+## Boost Google Calendar settings
+
+### `BOOST_CALENDAR`
+
+- Address for the Boost Google Calendar
+- Hard-coded in `settings.py` in all environments
+### `CALENDAR_API_KEY`
 
 - API key for the Boost Google calendar
 - For **local development**, obtain valid value from the Boost team.
 - In **deployed environments**, the valid value is set in `kube/boost/values.yaml` (or the environment-specific yaml file).
+
+### `EVENTS_CACHE_KEY` and `EVENTS_CACHE_TIMEOUT`
+
+- The cache key and timeout length for the Google Calendar events
+- Hard-coded in `settings.py` in all environments