class Migrations(object):
"""
Migrations
Handle all migrations during application start.
"""
logger = None
database = None
def __init__(self, config):
unmanic_logging = unlogger.UnmanicLogger.__call__()
self.logger = unmanic_logging.get_logger(__class__.__name__)
# Based on configuration, select database to connect to.
if config['TYPE'] == 'SQLITE':
# Create SQLite directory if not exists
db_file_directory = os.path.dirname(config['FILE'])
if not os.path.exists(db_file_directory):
os.makedirs(db_file_directory)
self.database = SqliteDatabase(config['FILE'])
self.router = Router(database=self.database,
migrate_table='migratehistory_{}'.format(
config.get('MIGRATIONS_HISTORY_VERSION')),
migrate_dir=config.get('MIGRATIONS_DIR'),
logger=self.logger)
def __log(self, message, level='info'):
if self.logger:
getattr(self.logger, level)(message)
else:
print(message)
def __run_all_migrations(self):
"""
Run all new migrations.
Migrations that have already been run will be ignored.
:return:
"""
self.router.run()
def update_schema(self):
"""
Updates the Unmanic database schema.
Newly added tables/models and columns/fields will be automatically generated by this function.
This way we do not need to create a migration script unless we:
- rename a column/field
- delete a column/field
- delete a table/model
:return:
"""
# Fetch all model classes
all_models = []
all_base_models = []
for model in list_all_models():
imported_model = getattr(
importlib.import_module("unmanic.libs.unmodels"), model)
if inspect.isclass(imported_model) and issubclass(
imported_model, BaseModel):
# Add this model to both the 'all_models' list and our list of base models
all_models.append(imported_model)
all_base_models.append(imported_model)
elif inspect.isclass(imported_model) and issubclass(
imported_model, Model):
# If the model is not one of the base models, it is an in-build model from peewee.
# For, this list of models we will not run a migration, but we will still ensure that the
# table is created in the DB
all_models.append(imported_model)
pass
# Start by creating all models
self.__log("Initialising database tables")
try:
with self.database.transaction():
for model in all_models:
self.router.migrator.create_table(model)
self.router.migrator.run()
except Exception:
self.database.rollback()
self.__log("Initialising tables failed", level='exception')
raise
# Migrations will only be used for removing obsolete columns
self.__run_all_migrations()
# Newly added fields can be auto added with this function... no need for a migration script
# Ensure all files are also present for each of the model classes
self.__log("Updating database fields")
for model in all_base_models:
# Fetch all peewee fields for the model class
# https://stackoverflow.com/questions/22573558/peewee-determining-meta-data-about-model-at-run-time
fields = model._meta.fields
# loop over the fields and ensure each on exists in the table
field_keys = [f for f in fields]
for fk in field_keys:
field = fields.get(fk)
if isinstance(field, Field):
if not any(f for f in self.database.get_columns(
model._meta.name) if f.name == field.name):
# Field does not exist in DB table
self.__log("Adding missing column")
try:
with self.database.transaction():
self.router.migrator.add_columns(
model, **{field.name: field})
self.router.migrator.run()
except Exception:
self.database.rollback()
self.__log("Update failed", level='exception')
raise
