django-streams

Django application to produce/consume events from Kafka supported by kstreams

Installation

pip install django-streams

or with poetry

poetry add django-streams

and add it to INSTALLED_APPS:

INSTALLED_APPS = [
    ...
    "django_streams",
    ...
    "my_streams_app",
    # etc...
]

Documentation

https://kpn.github.io/django-streams/

Usage

create the engine:

# my_streams_app/engine.py
from django_streams import create_engine

from kstreams.backends import Kafka


stream_engine = create_engine(
    title="test-engine",
    backend=Kafka(),
)

To configure the backend follow the kstreams backend documentation

Consuming events

Define your streams:

# my_streams_app/streams.py
from kstreams import ConsumerRecord
from .engine import stream_engine


@stream_engine.stream("dev-kpn-des--hello-kpn", group_id="django-streams-principal-group-id")  # your consumer
async def consumer_task(cr: ConsumerRecord):
    async for cr in stream:
        logger.info(f"Event consumed: headers: {cr.headers}, value: {cr.value}")

and then in your apps.py you must import the python module or your coroutines

# my_streams_app/apps.py
from django.apps import AppConfig


class StreamingAppConfig(AppConfig):
    name = "streaming_app"

    def ready(self):
        from . import streams  # import the streams module

Now you can run the worker:

python manage.py worker

Producing events

Producing events can be sync or async. If you are in a sync context you must use stream_engine.sync_send, otherwise stream_engine.send. For both cases a RecordMetadata is returned.

# streaming_app/views.py
from django.http import HttpResponse
from django.views.generic import View

from .engine import stream_engine


class HelloWorldView(View):

    def get(self, request, *args, **kwargs):
        record_metadata = stream_engine.sync_send(
            "hello-kpn",
            value=b"hello world",
            key="hello",
            partition=None,
            timestamp_ms=None,
            headers=None,
        )

        return HttpResponse(f"Event metadata: {record_metadata}")

Benchmark

Producer:

Total produced events	Time (seconds)
1	0.004278898239135742
10	0.030963897705078125
100	0.07049298286437988
1000	0.6609988212585449
10000	6.501222133636475

Running tests

./scrtips/test

Code formating

./scrtips/format