Adding cache schema version

8Knot/cache_manager/alembic.ini

@@ -0,0 +1,15 @@
+# Alembic config for the Postgres cache schema.
+#
+# The database URL is NOT set here; env.py builds it from the same
+# CACHE_* environment variables as cx_common, so there's one source of
+# connection truth. To create a new revision during development:
+#
+#   cd 8Knot/cache_manager
+#   alembic revision -m "describe change"
+#
+# (the CACHE_*/AUGUR_* env vars cx_common reads must be set in your shell).
+# In production, db_init.py drives "alembic upgrade head" programmatically.
+
+[alembic]
+script_location = migrations
+prepend_sys_path = .

8Knot/cache_manager/cx_common.py

@@ -6,6 +6,8 @@
 import logging
 import time
 
+from psycopg2.extensions import make_dsn
+
 # credentials to access database from environment
 try:
     env_augur_user = os.environ["AUGUR_USERNAME"]
@@ -32,20 +34,28 @@
 
 # purely initial startup string
 # psycopg2 connection string for cache pg instance, initialization only
-init_cx_string = "dbname={} user={} password={} host={} port={}".format(
-    "postgres", env_user, env_password, env_host, env_port
+init_cx_string = make_dsn(
+    dbname="postgres",
+    user=env_user,
+    password=env_password,
+    host=env_host,
+    port=env_port,
 )
 
 # psycopg2 connection string for cache pg instance
-cache_cx_string = "dbname={} user={} password={} host={} port={}".format(
-    env_dbname, env_user, env_password, env_host, env_port
+cache_cx_string = make_dsn(
+    dbname=env_dbname,
+    user=env_user,
+    password=env_password,
+    host=env_host,
+    port=env_port,
 )
 
 # psycopg2 connection string for augur db
-db_cx_string = "dbname={} user={} password={} host={} port={}".format(
-    env_augur_database,
-    env_augur_user,
-    env_augur_password,
-    env_augur_host,
-    env_augur_port,
+db_cx_string = make_dsn(
+    dbname=env_augur_database,
+    user=env_augur_user,
+    password=env_augur_password,
+    host=env_augur_host,
+    port=env_augur_port,
 )