From d0601a376c355d6859d345073177bcf53fe3481f Mon Sep 17 00:00:00 2001
From: roekatz <roe@roekatz.com>
Date: Wed, 13 Nov 2024 16:33:15 +0200
Subject: [PATCH] Health Check: Report healthy if Offline Mode is active.

The health check would instead return a boolean `online` in its response json, to reflect whether data is up to date with server (or loaded from backup)
---
 packages/opal-client/opal_client/client.py     | 18 ++++++++++++++----
 .../policy_store/base_policy_store_client.py   |  3 +++
 2 files changed, 17 insertions(+), 4 deletions(-)

diff --git a/packages/opal-client/opal_client/client.py b/packages/opal-client/opal_client/client.py
index 6a9958b98..b56006e55 100644
--- a/packages/opal-client/opal_client/client.py
+++ b/packages/opal-client/opal_client/client.py
@@ -257,6 +257,10 @@ def _init_fast_api_app(self):
         self._configure_lifecycle_callbacks(app)
         return app
 
+    async def _is_ready(self):
+        # Data loaded from file or from server
+        return self._backup_loaded or await self.policy_store.is_ready()
+
     def _configure_api_routes(self, app: FastAPI):
         """mounts the api routes on the app object."""
 
@@ -285,7 +289,15 @@ async def healthy():
 
             if healthy:
                 return JSONResponse(
-                    status_code=status.HTTP_200_OK, content={"status": "ok"}
+                    status_code=status.HTTP_200_OK,
+                    content={"status": "ok", "online": True},
+                )
+            elif self.offline_mode_enabled and await self._is_ready():
+                # When offline mode is enabled, OPAL should be considered healthy when no server updates are available
+                # TODO: Maybe if server updates were available but storing them to OPA wasn't successful, we should return 503 even with offline mode enabled
+                return JSONResponse(
+                    status_code=status.HTTP_200_OK,
+                    content={"status": "ok", "online": False},
                 )
             else:
                 return JSONResponse(
@@ -296,9 +308,7 @@ async def healthy():
         @app.get("/ready", include_in_schema=False)
         async def ready():
             """returns 200 if the policy store is ready to serve requests."""
-            ready = self._backup_loaded or await self.policy_store.is_ready()
-
-            if ready:
+            if await self._is_ready():
                 return JSONResponse(
                     status_code=status.HTTP_200_OK, content={"status": "ok"}
                 )
diff --git a/packages/opal-client/opal_client/policy_store/base_policy_store_client.py b/packages/opal-client/opal_client/policy_store/base_policy_store_client.py
index 94eac87d5..abab6f1fe 100644
--- a/packages/opal-client/opal_client/policy_store/base_policy_store_client.py
+++ b/packages/opal-client/opal_client/policy_store/base_policy_store_client.py
@@ -67,6 +67,9 @@ async def log_transaction(self, transaction: StoreTransaction):
     async def is_healthy(self) -> bool:
         raise NotImplementedError()
 
+    async def is_ready(self) -> bool:
+        raise NotImplementedError()
+
     async def full_export(self, writer: AsyncTextIOWrapper) -> None:
         raise NotImplementedError()