iky/nameko-autocrud

nameko-autocrud

An experimental (slightly magical) dependency to automatically add CRUD RPC (and possibly later HTTP) entrypoints to nameko microservices.
Based on Sqlalchemy models.
Aim is to reduce the amount of code required to implement common methods.
Uses sqlalchemy-filters.
Works in conjunction with sqlalchemy dependency providers such as nameko-sqlalchemy.
Each dependency also can be used in other methods to get/manipulate model instances.
Customisable components.

Usage

from nameko_sqlalchemy import DatabaseSession
from nameko_autocrud import AutoCrud

class MyService:

    name = 'my_service'
    session = DatabaseSession(models.Base)

    member_auto_crud = AutoCrud(session, model_cls=models.Member)
    payment_auto_crud = AutoCrud(session, model_cls=models.Payment)

    @rpc
    def my_entrypoint(self, value):
        return value + 1

This will automatically make the following additional RPC entrypoints available:

get_member(self, id_)
list_members(self, filters=None, offset=None, limit=None, order_by=None)
page_members(self, page_size, page_num, filters=None, order_by=None)
count_members(self, filters=None)
update_member(self, id_, data)
create_member(self, data)
delete_member(self, id_)
get_payment(self, id_)
list_payments(self, filters=None, offset=None, limit=None, order_by=None)
page_payments(self, page_size, page_num, filters=None, order_by=None)
count_payments(self, filters=None)
update_payment(self, id_, data)
create_payment(self, data)
delete_payment(self, id_)

The dependencies themselves can be used to manipulate sqlalchemy objects within other code E.g.

@rpc
def copy_member_name(self, from_id, to_id):
    member = self.member_auto_crud.get(from_id)
    self.member_auto_crud.update(to_id, {'name': member.name})

Customizing

Customizing method names

Specifying the entity_name will customize all generated method names. list, page and count methods all use a plural form. If adding "s" is not correct, entity_name_plural can be specified.

product_status_crud = AutoCrud(
    session, model_cls=models.ProductStatus,
    entity_name='product_status',
    entity_name_plural='product_statuses'
)

To customize individual methods-names, you can use the *_method_name kwargs. Setting this value to None will prevent the method from being generated.

cake_crud = AutoCrud(
    session, model_cls=models.Cake,
    delete_method_name='eat_cake',
    update_method_name=None,
)

Customizing serialization

TODO - marshmallow examples

Events

Nameko-autocrud includes an additional AutoCrudWithEvents DependencyProvider. This has the same behaviour as AutoCrud but will dispatch nameko events for create, update & delete actions.

from nameko.events import EventDispatcher
from nameko_sqlalchemy import DatabaseSession
from nameko_autocrud import AutoCrudWithEvents

class MyService:

    name = 'my_service'
    session = DatabaseSession(models.Base)
    dispatcher = EventDispatcher()

    payment_auto_crud = AutoCrudWithEvents(session, dispatcher, model_cls=models.Payment)

TODO - event formats - customizing event names Specifying event serializer

iky / nameko-autocrud