flypper-sqlalchemy

Flypper-sqlalchemy is a storage backend for the flypper package.

It is backed by a RDBMS through the SQL-Alchemy library so it an be used in a distributed environment and be persisted across restarts.

Installation

Use the package manager pip to install flypper-sqlalchemy.

pip install flypper-sqlalchemy

Usage

Build a storage backend:

from flypper_sqlalchemy.storage.sqla import SqlAlchemyStorage

# Create tables, make sure they are created, for instance with `create_all()`.
SqlAlchemyStorage.build_flags_table(sqla_metadata=metadata)
SqlAlchemyStorage.build_metadata_table(sqla_metadata=metadata)

storage = SqlAlchemyStorage(session=session_proxy)

# Or instead, depending on the use-case:
#
# storage = SqlAlchemyStorage(engine=engine)
)

Use it in the web UI:

from flypper.wsgi.web_ui import FlypperWebUI

web_ui = FlypperWebUI(storage=storage)

Use it in your code:

1. Build a client for your app
2. Use a context

from flypper.client import Client as FlypperClient

# Once per thread
flypper_client = FlypperClient(storage=storage, ttl=10)

# Once per request
flypper_context = FlypperContext(
    client=flypper_client,
    entries={"user_id": "42"},
)

# Every time you need
flypper_context.is_enabled("flag_name")
flypper_context.is_enabled(
    "other_flag_name",
    entries={"item_reference": "blue-shampoo"},
)

Q&A

How to use the ORM layer of SQL-Alchemy?

We can use the Hybrid Declarative mapping capability to build a mapped class from flypper's tables:

from sqlalchemy.ext.declarative import declarative_base

from flypper_sqlalchemy.storage.sqla import SqlAlchemyStorage

Base = declarative_base()

class FlypperFlag(Base):
    __table__ = SqlAlchemyStorage.build_flags_table(
        sqla_metadata=Base.metadata,
    )

class FlypperMetadata(Base):
    __table__ = SqlAlchemyStorage.build_metadata_table(
        sqla_metadata=Base.metadata,
    )

Contributing

Pull requests are welcome. For major changes, please open an issue first to discuss what you would like to change.

Please make sure to update tests as appropriate.

License

MIT