Add version table in preparation for future DB upgrades

src/ddns_service/models.py

@@ -19,6 +19,9 @@ from peewee import (
 # Database instance (initialized later)
 db = SqliteDatabase(None)
 
+# Current database schema version
+DATABASE_VERSION = 1
+
 
 class BaseModel(Model):
     """Base model with database binding."""
@@ -58,6 +61,15 @@ class Hostname(BaseModel):
         table_name = "hostnames"
 
 
+class Version(BaseModel):
+    """Database schema version for migrations."""
+
+    version = IntegerField()
+
+    class Meta:
+        table_name = "version"
+
+
 def init_database(config: dict):
     """
     Initialize database connection based on config.
@@ -91,6 +103,7 @@ def init_database(config: dict):
         # Re-bind models to new database
         User._meta.database = db
         Hostname._meta.database = db
+        Version._meta.database = db
         logging.info(f"Database backend: MariaDB db={config['database']['database']}")
 
     else:
@@ -101,7 +114,9 @@ def init_database(config: dict):
 
 def create_tables():
     """Create database tables if they don't exist."""
-    db.create_tables([User, Hostname])
+    db.create_tables([User, Hostname, Version])
+    if Version.select().count() == 0:
+        Version.create(version=DATABASE_VERSION)
     logging.info("Database tables created")
 
 
@@ -159,8 +174,10 @@ def get_hostname_for_user(hostname: str, user: User):
 # Re-export DoesNotExist for convenience
 __all__ = [
     'db',
+    'DATABASE_VERSION',
     'User',
     'Hostname',
+    'Version',
     'init_database',
     'create_tables',
     'get_user',