Dapr implements both an HTTP and a gRPC API for local calls. gRPC is useful for low-latency, high performance scenarios and has language integration using the proto clients.
You can find a list of auto-generated clients here.
The Dapr runtime implements a proto service that apps can communicate with via gRPC.
In addition to calling Dapr via gRPC, Dapr can communicate with an application via gRPC. To do that, the app needs to host a gRPC server and implements the Dapr appcallback service
When running in self hosted mode, use the --app-protocol
flag to tell Dapr to use gRPC to talk to the app:
dapr run --app-protocol grpc --app-port 5005 node app.js
This tells Dapr to communicate with your app via gRPC over port 5005
.
On Kubernetes, set the following annotations in your deployment YAML:
apiVersion: apps/v1
kind: Deployment
metadata:
name: myapp
namespace: default
labels:
app: myapp
spec:
replicas: 1
selector:
matchLabels:
app: myapp
template:
metadata:
labels:
app: myapp
annotations:
dapr.io/enabled: "true"
dapr.io/app-id: "myapp"
dapr.io/app-protocol: "grpc"
dapr.io/app-port: "5005"
...