Fix the /health endpoint (#1847)

* Fix the /health endpoint

 #1846

Keep both the old and new locations until the deployments are upgraded.

server/app/app.py

@@ -99,6 +99,10 @@ def dataset_index(url_dataroot=None, dataset=None):
         )
 
 
+# TODO:  This route will be deprecated, but needs to be left for a short time until all the
+# deployments are upgraded to the new location for the health check (or else the upgrade will
+# fail).  Once the upgrade is complete, the deployments can move to the new health check URL
+# and this route will be removed.
 @webbp.route("/health", methods=["GET"])
 @cache_control_always(no_store=True)
 def health():
@@ -224,6 +228,13 @@ def dataroot_index():
         return redirect(config.server_config.multi_dataset__index)
 
 
+class HealthAPI(Resource):
+    @cache_control(no_store=True)
+    def get(self):
+        config = current_app.app_config
+        return health_check(config)
+
+
 class DatasetResource(Resource):
     """Base class for all Resources that act on datasets."""
 
@@ -312,8 +323,18 @@ class LayoutObsAPI(DatasetResource):
         return common_rest.layout_obs_put(request, data_adaptor)
 
 
-def get_api_resources(bp_api, url_dataroot=None):
-    api = Api(bp_api)
+def get_api_base_resources(bp_base):
+    """Add resources that are accessed from the api_base_url"""
+    api = Api(bp_base)
+
+    # Diagnostics routes
+    api.add_resource(HealthAPI, "/health")
+    return api
+
+
+def get_api_dataroot_resources(bp_dataroot, url_dataroot=None):
+    """Add resources that refer to a dataset"""
+    api = Api(bp_dataroot)
 
     def add_resource(resource, url):
         """convenience function to make the outer function less verbose"""
@@ -385,18 +406,23 @@ class Server:
             parse = urlparse(api_base_url)
             api_path = parse.path
 
+        bp_base = Blueprint("bp_base", __name__, url_prefix=api_path)
+        base_resources = get_api_base_resources(bp_base)
+        self.app.register_blueprint(base_resources.blueprint)
+
         if app_config.is_multi_dataset():
             # NOTE:  These routes only allow the dataset to be in the directory
             # of the dataroot, and not a subdirectory.  We may want to change
             # the route format at some point
             for dataroot_dict in server_config.multi_dataset__dataroot.values():
                 url_dataroot = dataroot_dict["base_url"]
-                bp_api = Blueprint(
+                bp_dataroot = Blueprint(
                     f"api_dataset_{url_dataroot}", __name__,
                     url_prefix=f"{api_path}/{url_dataroot}/<dataset>" + api_version
                 )
-                resources = get_api_resources(bp_api, url_dataroot)
-                self.app.register_blueprint(resources.blueprint)
+                dataroot_resources = get_api_dataroot_resources(bp_dataroot, url_dataroot)
+                self.app.register_blueprint(dataroot_resources.blueprint)
+
                 self.app.add_url_rule(
                     f"/{url_dataroot}/<dataset>/",
                     f"dataset_index_{url_dataroot}",
@@ -412,7 +438,7 @@ class Server:
 
         else:
             bp_api = Blueprint("api", __name__, url_prefix=f"{api_path}{api_version}")
-            resources = get_api_resources(bp_api)
+            resources = get_api_dataroot_resources(bp_api)
             self.app.register_blueprint(resources.blueprint)
             self.app.add_url_rule(
                 "/static/<path:filename>",

server/test/unit/common/test_app_config.py

@@ -142,7 +142,7 @@ class AppConfigTest(unittest.TestCase):
         config = AppConfig()
         backend_port = find_available_port("localhost", 10000)
         config.update_server_config(
-            app__api_base_url=f"http://localhost:{backend_port}/additional/path/before/dataroot",
+            app__api_base_url=f"http://localhost:{backend_port}/additional/path",
             multi_dataset__dataroot=f"{PROJECT_ROOT}/example-dataset"
         )
 
@@ -151,11 +151,21 @@ class AppConfigTest(unittest.TestCase):
         with test_server(["-p", str(backend_port)], app_config=config) as server:
             session = requests.Session()
             self.assertEqual(server, f"http://localhost:{backend_port}")
-            response = session.get(f"{server}/additional/path/before/dataroot/d/pbmc3k.h5ad/api/v0.2/config")
+            response = session.get(f"{server}/additional/path/d/pbmc3k.h5ad/api/v0.2/config")
             self.assertEqual(response.status_code, 200)
             data_config = response.json()
             self.assertEqual(data_config["config"]["displayNames"]["dataset"], "pbmc3k")
 
+            # test the health check at the correct url
+            response = session.get(f"{server}/additional/path/health")
+            assert response.json()["status"] == "pass"
+
+            # also check that the old URL still works.
+            # NOTE:  this old URL location will soon be deprecated, and when that happens
+            # this check can be removed.
+            response = session.get(f"{server}/health")
+            assert response.json()["status"] == "pass"
+
     def test_configfile_with_specialization(self):
         # test that per_dataset_config config load the default config, then the specialized config