Add workaround for aiopg "File not found" error

aio-libs/aiopg#837

app/postgis.py

@@ -1,8 +1,12 @@
 #!/usr/bin/env python3
+
+# aiopg bug workaround from https://github.com/aio-libs/aiopg/issues/837#issuecomment-864899918
+import selectors
+selectors._PollLikeSelector.modify = selectors._BaseSelectorImpl.modify
+
 import json
 
 import aiopg
-import psycopg2
 from psycopg2.extras import NamedTupleCursor
 import sentry_sdk
 
@@ -19,26 +23,25 @@ class PostgisClient:
     The server is assumed to already be populated, including having the
     soundscape_tile function installed.
     """
-    def __init__(self, server, user_agent, cache_dir, cache_days, cache_size):
-        # all the other args are only used by the OverpassClient
+    def __init__(self, server):
         self.server = server
 
     @sentry_sdk.trace
     async def query(self, x, y):
-        async with aiopg.connect(self.server) as conn:
-            async with conn.cursor(cursor_factory=NamedTupleCursor) as cursor:
-                response = await self._gentile_async(cursor, x, y)
-                return response
-
-    # based on https://github.com/microsoft/soundscape/blob/main/svcs/data/gentiles.py
-    async def _gentile_async(self, cursor, x, y, zoom=ZOOM_DEFAULT):
         try:
-            await cursor.execute(tile_query, {'zoom': int(zoom), 'tile_x': x, 'tile_y': y})
-            value = await cursor.fetchall()
-            return {
-                'type': 'FeatureCollection',
-                'features': list(map(lambda x: x._asdict(), value))
-            }
-        except psycopg2.Error as e:
+            async with aiopg.connect(self.server) as conn:
+                async with conn.cursor(cursor_factory=NamedTupleCursor) as cursor:
+                    response = await self._gentile_async(cursor, x, y)
+                    return response
+        except Exception as e:
             print(e)
             raise
+
+    # based on https://github.com/microsoft/soundscape/blob/main/svcs/data/gentiles.py
+    async def _gentile_async(self, cursor, x, y, zoom=ZOOM_DEFAULT):
+        await cursor.execute(tile_query, {'zoom': int(zoom), 'tile_x': x, 'tile_y': y})
+        value = await cursor.fetchall()
+        return {
+            'type': 'FeatureCollection',
+            'features': list(map(lambda x: x._asdict(), value))
+        }

app/server.py

@@ -53,9 +53,7 @@ def backend_client(backend_url, user_agent, cache_dir, cache_days, cache_size):
             backend_url, user_agent, cache_dir, cache_days, cache_size
         )
     elif url_parts.scheme in ('postgis', 'postgres'):
-        return PostgisClient(
-            backend_url, user_agent, cache_dir, cache_days, cache_size
-        )
+        return PostgisClient(backend_url)
     else:
         raise ValueError("Unrecognized protocol %r" % url_parts.scheme)