Add example for Input and output Bindings

.github/workflows/validate-examples.yml

@@ -144,7 +144,7 @@ jobs:
       fail-fast: false
       matrix:
         examples:
-          [ "actors", "client", "configuration", "crypto", "invoke/grpc", "invoke/grpc-proxying", "pubsub", "query_state", "secrets-bulk" ]
+          [ "actors", "bindings", "client", "configuration", "crypto", "invoke/grpc", "invoke/grpc-proxying", "pubsub", "query_state", "secrets-bulk" ]
     steps:
       - name: Check out code
         uses: actions/checkout@v4

Cargo.toml

@@ -82,6 +82,14 @@ path = "examples/pubsub/publisher.rs"
 name = "subscriber"
 path = "examples/pubsub/subscriber.rs"
 
+[[example]]
+name = "output-bindings"
+path = "examples/bindings/output.rs"
+
+[[example]]
+name = "input-bindings"
+path = "examples/bindings/input.rs"
+
 [[example]]
 name = "query_state_q1"
 path = "examples/query_state/query1.rs"

examples/bindings/README.md

@@ -0,0 +1,70 @@
+# Input and Output Bindings Example
+
+This is a simple example that demonstrates Dapr's binding capabilities. To implement input bindings in your rust application, you need to implement `AppCallback` server for subscribing to events. Specifically, the following two methods need to be implemented for input bindings to work:
+
+1. `list_input_bindings` - Dapr runtime calls this method to get list of bindings the application is subscribed to.
+2. `on_binding_event` - Defines how the application handles the input binding event. 
+
+> **Note:** Make sure to use latest version of proto bindings.
+
+In order to have both examples working with the same binding configuration ServiceBus was used here. If you don't have it available you can change to a binding that works for both Input and Output from [this list](https://docs.dapr.io/reference/components-reference/supported-bindings/)
+
+
+## Running
+
+To run this example:
+
+1. Run a kafka container
+
+<!-- STEP
+name: Run kafka instance
+background: true
+sleep: 60
+timeout_seconds: 120
+expected_return_code:
+expected_stderr_lines:
+-->
+
+```bash
+docker run -p 9092:9092 apache/kafka:3.7.1
+```
+
+<!-- END_STEP -->
+
+2. Run the multi-app run template (`dapr.yaml`)
+
+<!-- STEP
+name: Run Multi-app Run
+output_match_mode: substring
+match_order: sequential
+expected_stdout_lines:
+  - '== APP - rust-input-b == Binding Name: binding-example'
+  - '== APP - rust-input-b == Message: 0 => hello from rust!'
+  - '== APP - rust-input-b == Binding Name: binding-example'
+  - '== APP - rust-input-b == Message: 1 => hello from rust!'
+  - '== APP - rust-input-b == Binding Name: binding-example'
+  - '== APP - rust-input-b == Message: 2 => hello from rust!'
+  - '== APP - rust-input-b == Binding Name: binding-example'
+  - '== APP - rust-input-b == Message: 3 => hello from rust!'
+  - '== APP - rust-input-b == Binding Name: binding-example'
+  - '== APP - rust-input-b == Message: 4 => hello from rust!'
+  - '== APP - rust-input-b == Binding Name: binding-example'
+  - '== APP - rust-input-b == Message: 5 => hello from rust!'
+  - '== APP - rust-input-b == Binding Name: binding-example'
+  - '== APP - rust-input-b == Message: 6 => hello from rust!'
+  - '== APP - rust-input-b == Binding Name: binding-example'
+  - '== APP - rust-input-b == Message: 7 => hello from rust!'
+  - '== APP - rust-input-b == Binding Name: binding-example'
+  - '== APP - rust-input-b == Message: 8 => hello from rust!'
+  - '== APP - rust-input-b == Binding Name: binding-example'
+  - '== APP - rust-input-b == Message: 9 => hello from rust!'
+background: true
+sleep: 30
+timeout_seconds: 90
+-->
+
+```bash
+dapr run -f .
+```
+
+<!-- END_STEP -->

examples/bindings/components/bindings.yml

@@ -0,0 +1,23 @@
+apiVersion: dapr.io/v1alpha1
+kind: Component
+metadata:
+  name: binding-example
+spec:
+  type: bindings.kafka
+  metadata:
+    - name: direction
+      value: "input, output"
+    # Kafka broker connection setting
+    - name: brokers
+      value: localhost:9092
+    # consumer configuration: topic and consumer group
+    - name: topics
+      value: sample
+    - name: consumerGroup
+      value: group1
+    # publisher configuration: topic
+    - name: publishTopic
+      value: sample
+    - name: authType
+      value: "none"
+

examples/bindings/dapr.yaml

@@ -0,0 +1,16 @@
+version: 1
+common:
+  resourcesPath: ./components/
+  daprdLogDestination: console
+apps:
+  - appID: rust-input-b
+    appDirPath: ./
+    appProtocol: grpc
+    appPort: 50051
+    logLevel: debug
+    command: ["cargo", "run", "--example", "input-bindings"]
+  - appID: rust-output-b
+    appDirPath: ./
+    appProtocol: grpc
+    logLevel: debug
+    command: ["cargo", "run", "--example", "output-bindings"]

examples/bindings/input.rs

@@ -0,0 +1,87 @@
+use tonic::{transport::Server, Request, Response, Status};
+
+use dapr::dapr::dapr::proto::common::v1::{InvokeRequest, InvokeResponse};
+use dapr::dapr::dapr::proto::runtime::v1::app_callback_server::{AppCallback, AppCallbackServer};
+use dapr::dapr::dapr::proto::runtime::v1::{
+    BindingEventRequest, BindingEventResponse, ListInputBindingsResponse,
+    ListTopicSubscriptionsResponse, TopicEventRequest, TopicEventResponse,
+};
+
+#[derive(Default)]
+pub struct AppCallbackService {}
+
+#[tonic::async_trait]
+impl AppCallback for AppCallbackService {
+    /// Invokes service method with InvokeRequest.
+    async fn on_invoke(
+        &self,
+        _request: Request<InvokeRequest>,
+    ) -> Result<Response<InvokeResponse>, Status> {
+        Ok(Response::new(InvokeResponse::default()))
+    }
+
+    /// Lists all topics subscribed by this app.
+    async fn list_topic_subscriptions(
+        &self,
+        _request: Request<()>,
+    ) -> Result<Response<ListTopicSubscriptionsResponse>, Status> {
+        Ok(Response::new(ListTopicSubscriptionsResponse::default()))
+    }
+
+    /// Subscribes events from Pubsub.
+    async fn on_topic_event(
+        &self,
+        _request: Request<TopicEventRequest>,
+    ) -> Result<Response<TopicEventResponse>, Status> {
+        Ok(Response::new(TopicEventResponse::default()))
+    }
+
+    /// Lists all input bindings subscribed by this app.
+    /// NOTE: Dapr runtime will call this method to get
+    /// the list of bindings the app wants to subscribe to.
+    /// In this example, the app is subscribing to a local pubsub binding named "binding-example"
+
+    async fn list_input_bindings(
+        &self,
+        _request: Request<()>,
+    ) -> Result<Response<ListInputBindingsResponse>, Status> {
+        let list_bindings = ListInputBindingsResponse {
+            bindings: vec![String::from("binding-example")],
+        };
+
+        Ok(Response::new(list_bindings))
+    }
+
+    /// Listens events from the input bindings.
+    async fn on_binding_event(
+        &self,
+        request: Request<BindingEventRequest>,
+    ) -> Result<Response<BindingEventResponse>, Status> {
+        let r = request.into_inner();
+        let name = &r.name;
+        let data = &r.data;
+
+        let message = String::from_utf8_lossy(&data);
+        println!("Binding Name: {}", &name);
+        println!("Message: {}", &message);
+
+        Ok(Response::new(BindingEventResponse::default()))
+    }
+}
+
+#[tokio::main]
+async fn main() -> Result<(), Box<dyn std::error::Error>> {
+    let addr = "[::]:50051".parse().unwrap();
+
+    let callback_service = AppCallbackService::default();
+
+    println!("AppCallback server listening on: {}", addr);
+
+    // Create a gRPC server with the callback_service.
+    Server::builder()
+        .add_service(AppCallbackServer::new(callback_service))
+        .serve(addr)
+        .await?;
+
+    Ok(())
+}

examples/bindings/output.rs

@@ -0,0 +1,35 @@
+use std::{collections::HashMap, thread, time::Duration};
+
+#[tokio::main]
+async fn main() -> Result<(), Box<dyn std::error::Error>> {
+    // TODO: Handle this issue in the sdk
+    // Introduce delay so that dapr grpc port is assigned before app tries to connect
+    thread::sleep(Duration::from_secs(2));
+
+    // Get the Dapr port and create a connection
+    let addr = "https://127.0.0.1".to_string();
+
+    // Create the client
+    let mut client = dapr::Client::<dapr::client::TonicClient>::connect(addr).await?;
+
+    // name of the component
+    let binding_name = "binding-example";
+
+    for count in 0..10 {
+        // message metadata
+        let mut metadata = HashMap::<String, String>::new();
+        metadata.insert("count".to_string(), count.to_string());
+
+        // message
+        let message = format!("{} => hello from rust!", &count).into_bytes();
+
+        client
+            .invoke_binding(binding_name, message, "create", Some(metadata))
+            .await?;
+
+        // sleep for 500ms to simulate delay b/w two events
+        tokio::time::sleep(Duration::from_millis(500)).await;
+    }
+
+    Ok(())
+}

src/appcallback.rs

@@ -66,6 +66,14 @@ impl TopicSubscription {
     }
 }
 
+impl ListInputBindingsResponse {
+    pub fn binding(binding_name: String) -> Self {
+        Self {
+            bindings: vec![binding_name],
+        }
+    }
+}
+
 pub struct AppCallbackService {
     handlers: Vec<Handler>,
 }

src/client.rs

@@ -70,15 +70,23 @@ impl<T: DaprInterface> Client<T> {
         &mut self,
         name: S,
         data: Vec<u8>,
+        operation: S,
+        metadata: Option<HashMap<String, String>>,
     ) -> Result<InvokeBindingResponse, Error>
     where
         S: Into<String>,
     {
+        let mut mdata = HashMap::<String, String>::new();
+        if let Some(m) = metadata {
+            mdata = m;
+        }
+
         self.0
             .invoke_binding(InvokeBindingRequest {
                 name: name.into(),
                 data,
-                ..Default::default()
+                operation: operation.into(),
+                metadata: mdata,
             })
             .await
     }

src/server/actor/runtime/mod.rs

@@ -168,7 +168,7 @@ impl ActorTypeRegistration {
     pub fn register_method<T>(
         mut self,
         method_name: &str,
-        handler: impl Handler<T, ActorState> + Send + Sync,
+        handler: impl Handler<T, ActorState> + Sync,
     ) -> Self
     where
         T: 'static,