Fix CI for synapse_port_db (#6276)

* Don't use a virtualenv

* Generate the server's signing key to allow it to start

* Add signing key paths to CI configuration files

* Use a Python script to create the postgresql database

* Improve logging

.buildkite/scripts/create_postgres_db.py

@@ -0,0 +1,36 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+# Copyright 2019 The Matrix.org Foundation C.I.C.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import logging
+from synapse.storage.engines import create_engine
+
+logger = logging.getLogger("create_postgres_db")
+
+if __name__ == "__main__":
+    # Create a PostgresEngine.
+    db_engine = create_engine({"name": "psycopg2", "args": {}})
+
+    # Connect to postgres to create the base database.
+    # We use "postgres" as a database because it's bound to exist and the "synapse" one
+    # doesn't exist yet.
+    db_conn = db_engine.module.connect(
+        user="postgres", host="postgres", password="postgres", dbname="postgres"
+    )
+    db_conn.autocommit = True
+    cur = db_conn.cursor()
+    cur.execute("CREATE DATABASE synapse;")
+    cur.close()
+    db_conn.close()