Echo app example

This echo app example shows how to use service invocation using gRPC API. You can learn how to create client-side gRPC server and call Dapr gRPC APIs.

Prerequsites

VSCode environment

Build echo app

Make sure that you reopen in container on VSCode
Open new bash terminal
Build echo_app

cd examples/echo_app

make

Run callee app

Open new bash terminal
Run callee app

dapr run --app-id callee --app-protocol grpc --app-port 6000  ./echo_app callee 6000

Run caller app

dapr run --app-id echo_app --app-protocol grpc --app-port 6100 ./echo_app caller 6100 callee

Check the logs From callee app:

...
== APP == OnInvoke() is called
== APP == Got the message: hello dapr
== APP == OnInvoke() is called
== APP == Got the message: hello dapr
...

From caller app:

...
== APP == Received [ack : hello dapr] from callee
== APP == Received [ack : hello dapr] from callee
...

Cleanup

dapr stop --app-id echo_app
dapr stop --app-id callee

gRPC Debug

Set the below environment variable to debug gRPC server and client.

export GRPC_VERBOSITY=debug 
export GRPC_TRACE=api,-timer_check,-timer