Posting data to a Quix web app

You may have a web app, either hosted in Quix, or elsewhere (say on Glitch), that receives data that you want to process in Quix. In either case, data can be posted using HTTP POST methods (or other HTTP methods) to the web app, and then this data published to a Quix topic using Quix Streams.

The following example shows a Python Flask web app hosted in Quix. Data is received on an endpoint, in this case /data. The data is then published to an output topic. Of course you may have multiple endpoints receiving data, which you can publish to different streams, depending on your use case.

Note

When deploying this service in Quix, it's important to enable public access in the deployment dialog, and make a note of the service public URL.

The following shows the code for a simple web app that enables you to post data using HTTP, and then publish this to a Quix topic using Quix Streams:

from quixstreams import Application
from quixstreams.models.serializers.quix import JSONSerializer, SerializationContext
from flask import Flask, request
from datetime import datetime
from waitress import serve
import os, json

app = Application()

serializer = JSONSerializer()
output_topic = app.topic(os.environ["output"])
producer = app.get_producer()

flask_app = Flask("Post Data")

# this is unauthenticated, anyone could post anything to you!
@flask_app.route("/data", methods=['POST'])
def webhook():

    # publish data to output topic
    with producer:
        serialized_value = serializer(
            value=request.json, ctx=SerializationContext(topic=output_topic.name)
        )
        producer.produce(
            topic=output_topic.name,
            key="webapp-sample",
            value=serialized_value
        )

    return "OK", 200


print("CONNECTED!")

# use waitress for production
serve(flask_app, host='0.0.0.0', port = 80)

There may be various devices or apps posting data to your web app.

A simple test of your web app can be performed with Curl, as shown in the following example:

curl -X POST -H "Content-Type: application/json"  https://app-workspace-project-branch.deployments.quix.io/data -d @data.json

In this example, data.json contains your JSON data, such as:

{
  "id": "device-012-ABC",
  "temp": 123,
  "press": 456
}

Tip

You'll need to change the URL in the Curl example to the one provided in the deployment dialog for your service.

Quix can bring real-time web functionality to you client applications. The following types of applications are good candidates for using Quix as their data plane:

Dashboard and real-time monitoring applications that show updates as they happen to users like cloud/edge monitoring tools.
Applications that require data to be pushed from a backend at high frequency like games and simulations.
Social networking applications that require broadcasting updates to many users at high frequency like live sharing of Strava data.