fix: on db & env init ch, check tables exist prior to sql select

ckan/config/environment.py

@@ -9,7 +9,7 @@
 
 from typing import Union, cast
 
-import sqlalchemy
+from sqlalchemy import engine_from_config, inspect
 import sqlalchemy.exc
 
 import ckan.model as model
@@ -220,7 +220,7 @@ def update_config() -> None:
     # to eliminate database errors due to stale pooled connections
     config.setdefault('sqlalchemy.pool_pre_ping', True)
     # Initialize SQLAlchemy
-    engine = sqlalchemy.engine_from_config(config)
+    engine = engine_from_config(config)
     model.init_model(engine)
 
     for plugin in p.PluginImplementations(p.IConfigurable):
@@ -232,14 +232,13 @@ def update_config() -> None:
     authz.clear_auth_functions_cache()
 
     # Here we create the site user if they are not already in the database
-    try:
-        logic.get_action('get_site_user')({'ignore_auth': True}, {})
-    except (sqlalchemy.exc.ProgrammingError, sqlalchemy.exc.OperationalError):
-        # The database is not yet initialised. It happens in `ckan db init`
-        pass
-    except sqlalchemy.exc.IntegrityError:
-        # Race condition, user already exists.
-        pass
+    db_inspect = inspect(engine)
+    if db_inspect.has_table("user"):
+        try:
+            logic.get_action('get_site_user')({'ignore_auth': True}, {})
+        except sqlalchemy.exc.IntegrityError:
+            # Race condition, user already exists.
+            pass
 
     # Close current session and open database connections to ensure a clean
     # clean environment even if an error occurs later on

ckan/model/__init__.py

@@ -8,8 +8,7 @@
 from time import sleep
 from typing import Any, Optional
 
-from sqlalchemy import MetaData, Table
-from sqlalchemy.exc import ProgrammingError
+from sqlalchemy import MetaData, Table, inspect
 
 from alembic.command import (
     upgrade as alembic_upgrade,
@@ -278,12 +277,13 @@ def setup_migration_version_control(self) -> None:
         alembic_config.set_main_option(
             "sqlalchemy.url", config.get("sqlalchemy.url")
         )
-        try:
+
+        sqlalchemy_migrate_version = 0
+        db_inspect = inspect(self.metadata.bind)
+        if db_inspect.has_table("migrate_version"):
             sqlalchemy_migrate_version = self.metadata.bind.execute(
                 u'select version from migrate_version'
             ).scalar()
-        except ProgrammingError:
-            sqlalchemy_migrate_version = 0
 
         # this value is used for graceful upgrade from
         # sqlalchemy-migrate to alembic