invoke-binding

Example - Dapr bindings

This example utilizes a publisher and a receiver for the InvokeBinding / OnBindingEvent / ListInputBindings functionality. It will create a gRPC server and bind the OnBindingEvent method, which gets called after a publisher sends a message to a kafka binding.

Note: Make sure to use the latest proto bindings

Pre-requisites

• Dapr CLI and initialized environment
• Install Python 3.7+

Install Dapr python-SDK

pip3 install dapr dapr-ext-grpc

Run example

Run the following commands in a terminal/command-prompt:

# 1. Start the kafka containers using docker-compose 
docker-compose -f ./docker-compose-single-kafka.yml up -d

# 2. Start Receiver (expose gRPC server receiver on port 50051) 
dapr run --app-id receiver --app-protocol grpc --app-port 50051 --components-path ./components python3 invoke-input-binding.py

In another terminal/command-prompt run:

# 3. Start Publisher
dapr run --app-id publisher --app-protocol grpc --components-path ./components python3 invoke-output-binding.py

Cleanup

The dapr apps can be stopped by calling stop or terminating the process. For kafka cleanup, run the following code:

docker-compose -f ./docker-compose-single-kafka.yml down