Enable HC on driver

dcc/driver/apps.py

@@ -1,6 +1,11 @@
 from django.apps import AppConfig
+from health_check.plugins import plugin_dir
 
 
 class DriverConfig(AppConfig):
     default_auto_field = 'django.db.models.BigAutoField'
     name = 'driver'
+
+    def ready(self):
+        from driver.health import DriverHealthCheck
+        plugin_dir.register(DriverHealthCheck)

dcc/driver/health.py

@@ -0,0 +1,20 @@
+from health_check.backends import BaseHealthCheckBackend
+from health_check.exceptions import (ServiceUnavailable,
+                                     ServiceReturnedUnexpectedResult)
+
+from driver.connector import Connector
+
+
+class DriverHealthCheck(BaseHealthCheckBackend):
+    critical_service = False
+
+    def check_status(self):
+        try:
+            Connector().passthrough(b'<s>')
+        except ConnectionRefusedError as e:
+            self.add_error(ServiceUnavailable("IOError"), e)
+        except Exception as e:
+            self.add_error(ServiceReturnedUnexpectedResult("IOError"), e)
+
+    def identifier(self):
+        return "DriverDaemon"