feat(StateMediator): add stop events children to S3 mediator

README.md

@@ -16,6 +16,16 @@ To start your Phoenix app:
 
 Now you can visit [`localhost:4000`](http://localhost:4000) from your browser.
 
+> [!WARNING]
+> Your app will fail when calling `mix phx.server` if `STOP_EVENTS_ENALBED` or `CR_CROWDING_ENABLED` are `true` unless:
+>
+> 1. `ExAws` can find AWS credentials (such as `AWS_ACCESS_KEY_ID` and `AWS_SECRET_ACCESS_KEY`)
+> 2. S3 bucket and object environment variables retrieved by `config/config.exs` are available
+> 3. Your credentials have permissions on those objects
+>
+> To circumvent these issues, set `STOP_EVENTS_ENALBED` and `CR_CROWDING_ENABLED` to `false`.
+
+
 ## Tests
 
 To run the tests, first install and setup Colima, Docker, and docker-compose:

apps/state/lib/state/stop_event.ex

@@ -4,6 +4,7 @@ defmodule State.StopEvent do
   """
   use State.Server,
     indices: [:id, :trip_id, :stop_id, :route_id, :vehicle_id],
+    parser: Parse.StopEvents,
     recordable: Model.StopEvent
 
   alias Model.Route

apps/state_mediator/config/config.exs

@@ -15,6 +15,11 @@ config :state_mediator, :commuter_rail_crowding,
   s3_object: {:system, "CR_CROWDING_S3_OBJECT"},
   source: {:system, "CR_CROWING_SOURCE", "s3"}
 
+config :state_mediator, :stop_events,
+  enabled: {:system, "STOP_EVENTS_ENABLED", "false"},
+  s3_bucket: {:system, "STOP_EVENTS_S3_BUCKET"},
+  s3_object: {:system, "STOP_EVENTS_S3_OBJECT"}
+
 config :state_mediator, Realtime,
   gtfs_url: {:system, "MBTA_GTFS_URL", "https://cdn.mbta.com/MBTA_GTFS.zip"},
   alert_url: {:system, "ALERT_URL", "https://cdn.mbta.com/realtime/Alerts_enhanced.json"}

apps/state_mediator/lib/state_mediator.ex

@@ -14,7 +14,8 @@ defmodule StateMediator do
         crowding_children(
           app_value(:commuter_rail_crowding, :enabled) == "true",
           crowding_source
-        )
+        ) ++
+        stop_event_children(app_value(:stop_events, :enabled) == "true")
 
     # See http://elixir-lang.org/docs/stable/elixir/Supervisor.html
     # for other strategies and supported options
@@ -155,6 +156,32 @@ defmodule StateMediator do
     []
   end
 
+  @spec stop_event_children(boolean()) :: [
+          :supervisor.child_spec() | {module(), term()} | module()
+        ]
+  defp stop_event_children(true) do
+    Logger.info("#{__MODULE__} STOP_EVENTS_ENABLED=true")
+
+    [
+      {
+        StateMediator.S3Mediator,
+        [
+          spec_id: :stop_event_mediator,
+          bucket_arn: app_value(:stop_events, :s3_bucket),
+          object: app_value(:stop_events, :s3_object),
+          interval: 3 * 1_000,
+          sync_timeout: 30_000,
+          state: State.StopEvent
+        ]
+      }
+    ]
+  end
+
+  defp stop_event_children(false) do
+    Logger.info("#{__MODULE__} STOP_EVENTS_ENABLED=false")
+    []
+  end
+
   @doc false
   def source_url(mod) do
     case Application.get_env(:state_mediator, mod)[:source] do

apps/state_mediator/lib/state_mediator/s3_mediator.ex

@@ -96,7 +96,7 @@ defmodule StateMediator.S3Mediator do
          state
        ) do
     Logger.warning(
-      "Received unknown response when getting commuter rail occupancies from S3: #{inspect(response)}"
+      "Received unknown response when fetching data via S3Mediator: #{inspect(response)}"
     )
 
     schedule_update(state)