asyncio-RED (Redis Event Driven)
================================
Powers your microservices with event driven approach using redis as a backend.
Support both publishing and subscribing using lists, channels and streams.
`pydantic` is being used for events validation.
`s3` can be used for sharing event schemas between services.
Installation
------------
- `pip install asyncio-red`
Simple producer
---------------
```python
from aioredis import Redis
from asyncio_red import RED, Via, BaseEvent
from pydantic import Field
class EventV1List(BaseEvent):
key: str = Field(..., title='Key description')
class EventV1Channel(BaseEvent):
key: str = Field(..., title='Key description')
class EventV1Stream(BaseEvent):
key: str = Field(..., title='Key description')
redis_client = Redis()
red = RED(app_name=str('service_1'), redis_client=redis_client)
red.add_out(
event=EventV1List,
via=Via.LIST,
target_name='events_list'
)
red.add_out(
event=EventV1Channel,
via=Via.CHANNELS,
target_name='events_channel'
)
red.add_out(
event=EventV1Stream,
via=Via.STREAMS,
target_name='events_stream'
)
async def your_awesome_function():
# dispatch events
await EventV1List(key='value').dispatch() # this one will be put to a list
await EventV1Channel(key='value').dispatch() # this one will be pushed to a channel
await EventV1Stream(key='value').dispatch() # this one will be pushed to a stream
```
Simple consumer
--------------
```python
from aioredis import Redis
from asyncio_red import RED, Via, BaseEvent
from pydantic import Field
class EventV1List(BaseEvent):
key: str = Field(..., title='Key description')
class EventV1Channel(BaseEvent):
key: str = Field(..., title='Key description')
class EventV1Stream(BaseEvent):
key: str = Field(..., title='Key description')
redis_client = Redis()
red = RED(app_name=str('service_2'), redis_client=redis_client)
async def event_handler(event):
print(event)
red.add_in(
event=EventV1List,
via=Via.LIST,
handlers=(event_handler, ),
list_name="events_list",
)
red.add_in(
event=EventV1Channel,
via=Via.CHANNELS,
handlers=(event_handler, ),
error_handler=event_handler,
channel_name="events_channel"
)
red.add_in(
event=EventV1Stream,
via=Via.STREAMS,
handlers=(event_handler, event_handler),
stream_name="events_stream",
group_name="events_group",
consumer_name="consumer_name"
)
await red.run()
```
Shared events registry
----------------------
There is a possibility to keep event schemas registry on the S3 and share the schema across
different services. You'll need an AWS account and keys with access to S3.
- Go to app root dir and initialize asyncio-red:
```shell
asyncio_red init --app-name=<app name> --s3-bucket=<bucket name>
```
This will create an initial structure.
Define your events at `red/registry/<app name>.py`:
```python
from pydantic import Field
from asyncio_red.events import BaseEvent
class EventV1List(BaseEvent):
key: str = Field(..., title='Key description')
class EventV1Channel(BaseEvent):
key: str = Field(..., title='Key description')
class EventV1Stream(BaseEvent):
key: str = Field(..., title='Key description')
```
- push application events schemas to a registry: `asyncio-red push`
- on a different service you can pull shared schemas - do the same steps, e.g. init structure and run `asyncio-red pull`
