260 support disabled timescaledb (#315)

* gracefully raise when a connection can't be established

* Adjust exception message

* fix import

shared/django_apps/db_settings.py

@@ -3,6 +3,7 @@
 import django_prometheus
 
 from shared.config import get_config
+from shared.timeseries.helpers import is_timeseries_enabled
 
 db_url = get_config("services", "database_url")
 if db_url:
@@ -48,7 +49,7 @@
     )
     DATABASE_READ_PORT = get_config("services", "database_read", "port", default=5432)
 
-TIMESERIES_ENABLED = get_config("setup", "timeseries", "enabled", default=False)
+TIMESERIES_ENABLED = is_timeseries_enabled()
 TIMESERIES_REAL_TIME_AGGREGATES = get_config(
     "setup", "timeseries", "real_time_aggregates", default=False
 )

shared/django_apps/legacy_migrations/management/commands/migrate.py

@@ -8,6 +8,7 @@
 
 from shared.django_apps.utils.config import RUN_ENV
 from shared.helpers.redis import get_redis_connection
+from shared.timeseries.helpers import is_timeseries_enabled
 
 log = logging.getLogger(__name__)
 
@@ -115,7 +116,13 @@ def _obtain_lock(self):
     def handle(self, *args, **options):
         log.info("Codecov is starting migrations...")
         database = options["database"]
-        db_connection = connections[database]
+        try:
+            db_connection = connections[database]
+        except Exception:
+            log.info(
+                f"Failed to establish connection with {database}. Cannot do migrations"
+            )
+            return None
         options["run_syncdb"] = False
 
         lock = self._obtain_lock()
@@ -129,7 +136,7 @@ def handle(self, *args, **options):
             with db_connection.cursor() as cursor:
                 self._fake_initial_migrations(cursor, args, options)
 
-                if database == "timeseries":
+                if database == "timeseries" and is_timeseries_enabled():
                     self._fake_initial_timeseries_migrations(cursor, args, options)
 
             super().handle(*args, **options)

shared/timeseries/helpers.py

@@ -0,0 +1,5 @@
+from shared.config import get_config
+
+
+def is_timeseries_enabled() -> bool:
+    return get_config("setup", "timeseries", "enabled", default=False)