Dapr Python SDK extensions on Dapr Docs

Getting started with the Dapr Python gRPC service extension

Mon, 01 Jan 0001 00:00:00 +0000

The Dapr Python SDK provides a built in gRPC server extension, dapr.ext.grpc, for creating Dapr services.

Installation

You can download and install the Dapr gRPC server extension with:

pip install dapr-ext-grpc

Note

The development package will contain features and behavior that will be compatible with the pre-release version of the Dapr runtime. Make sure to uninstall any stable versions of the Python SDK extension before installing the <code>dapr-dev</code> package.

pip3 install dapr-ext-grpc-dev

Examples

The App object can be used to create a server.

Dapr Python SDK integration with FastAPI

Mon, 01 Jan 0001 00:00:00 +0000

The Dapr Python SDK provides integration with FastAPI using the dapr-ext-fastapi extension.

Installation

You can download and install the Dapr FastAPI extension with:

pip install dapr-ext-fastapi

Note

The development package will contain features and behavior that will be compatible with the pre-release version of the Dapr runtime. Make sure to uninstall any stable versions of the Python SDK extension before installing the <code>dapr-dev</code> package.

pip install dapr-ext-fastapi-dev

Example

Subscribing to events of different types

import uvicorn
from fastapi import Body, FastAPI
from dapr.ext.fastapi import DaprApp
from pydantic import BaseModel

class RawEventModel(BaseModel):
 body: str

class User(BaseModel):
 id: int
 name: str

class CloudEventModel(BaseModel):
 data: User
 datacontenttype: str
 id: str
 pubsubname: str
 source: str
 specversion: str
 topic: str
 traceid: str
 traceparent: str
 tracestate: str
 type: str 
 
 
app = FastAPI()
dapr_app = DaprApp(app)

# Allow handling event with any structure (Easiest, but least robust)
# dapr publish --publish-app-id sample --topic any_topic --pubsub pubsub --data '{"id":"7", "desc": "good", "size":"small"}'
@dapr_app.subscribe(pubsub='pubsub', topic='any_topic')
def any_event_handler(event_data = Body()):
 print(event_data) 

# For robustness choose one of the below based on if publisher is using CloudEvents

# Handle events sent with CloudEvents
# dapr publish --publish-app-id sample --topic cloud_topic --pubsub pubsub --data '{"id":"7", "name":"Bob Jones"}'
@dapr_app.subscribe(pubsub='pubsub', topic='cloud_topic')
def cloud_event_handler(event_data: CloudEventModel):
 print(event_data) 

# Handle raw events sent without CloudEvents
# curl -X "POST" http://localhost:3500/v1.0/publish/pubsub/raw_topic?metadata.rawPayload=true -H "Content-Type: application/json" -d '{"body": "345"}'
@dapr_app.subscribe(pubsub='pubsub', topic='raw_topic')
def raw_event_handler(event_data: RawEventModel):
 print(event_data) 

 

if __name__ == "__main__":
 uvicorn.run(app, host="0.0.0.0", port=30212)

Creating an actor

from fastapi import FastAPI
from dapr.ext.fastapi import DaprActor
from demo_actor import DemoActor

app = FastAPI(title=f'{DemoActor.__name__}Service')

# Add Dapr Actor Extension
actor = DaprActor(app)

@app.on_event("startup")
async def startup_event():
 # Register DemoActor
 await actor.register_actor(DemoActor)

@app.get("/GetMyData")
def get_my_data():
 return "{'message': 'myData'}"

Dapr Python SDK integration with Flask

Mon, 01 Jan 0001 00:00:00 +0000

The Dapr Python SDK provides integration with Flask using the flask-dapr extension.

Installation

You can download and install the Dapr Flask extension with:

pip install flask-dapr

Note

The development package will contain features and behavior that will be compatible with the pre-release version of the Dapr runtime. Make sure to uninstall any stable versions of the Python SDK extension before installing the <code>dapr-dev</code> package.

pip install flask-dapr-dev

Example

from flask import Flask
from flask_dapr.actor import DaprActor

from dapr.conf import settings
from demo_actor import DemoActor

app = Flask(f'{DemoActor.__name__}Service')

# Enable DaprActor Flask extension
actor = DaprActor(app)

# Register DemoActor
actor.register_actor(DemoActor)

# Setup method route
@app.route('/GetMyData', methods=['GET'])
def get_my_data():
 return {'message': 'myData'}, 200

# Run application
if __name__ == '__main__':
 app.run(port=settings.HTTP_APP_PORT)