feat: add HTTP invocation example

Signed-off-by: Vijay Karanjkar <vijaykaranjkar2003@gmail.com>

Author: Vijay-K-2003

examples/Cargo.toml

@@ -14,6 +14,7 @@ dapr = { path = "../dapr" }
 dapr-macros = { path = "../dapr-macros" }
 env_logger = "0.11"
 log = "0.4"
+reqwest = { version = "0.12", default-features = false }
 serde = { workspace = true, features = ["derive"] }
 serde_json = { workspace = true }
 tokio = { workspace = true, features = ["full"] }
@@ -74,8 +75,17 @@ path = "src/invoke/grpc-proxying/client.rs"
 name = "invoke-grpc-proxying-server"
 path = "src/invoke/grpc-proxying/server.rs"
 
+[[example]]
+name = "invoke-http-client"
+path = "src/invoke/http/client.rs"
+
+[[example]]
+name = "invoke-http-server"
+path = "src/invoke/http/server.rs"
+
 [[example]]
 name = "jobs"
+
 path = "src/jobs/jobs.rs"
 
 [[example]]

examples/src/invoke/http/README.md

@@ -0,0 +1,15 @@
+# Invoke HTTP Example
+
+This example demonstrates how to use the Dapr HTTP proxying feature to proxy HTTP requests sent via the Rust SDK (using `reqwest`) through Dapr to reach another application.
+
+1. Build the examples:
+```bash
+cargo build --examples
+```
+
+2. Run with Dapr in the example/invoke/http directory:
+```bash
+dapr run -f .
+```
+
+If everything worked, you should see the `invoke-http-client` successfully sending an HTTP request via the Dapr sidecar to the `invoke-http-server`, with `"Hello, test! (from HTTP server)"` printed to the stdout.

examples/src/invoke/http/client.rs

@@ -0,0 +1,53 @@
+use std::time::Duration;
+
+#[tokio::main]
+async fn main() -> Result<(), Box<dyn std::error::Error>> {
+    tokio::time::sleep(Duration::from_secs(5)).await;
+
+    let address = "https://127.0.0.1".to_string();
+
+    let client_result = dapr::Client::<dapr::client::TonicClient>::connect(address).await;
+    
+    let value = "test";
+    let method_to_call = format!("hello/{}", value);
+
+    match client_result {
+        Ok(mut _client) => {
+            let http_client = reqwest::Client::builder()
+                .timeout(Duration::from_secs(2))
+                .build()
+                .unwrap();
+
+            let target_app_id = "invoke-http-server";
+            let dapr_http_port: u16 = std::env::var("DAPR_HTTP_PORT")
+                .unwrap_or_else(|_| "3500".to_string())
+                .parse()?;
+
+            let url = format!("http://127.0.0.1:{}/{}", dapr_http_port, method_to_call);
+            let req = http_client.post(url).header("dapr-app-id", target_app_id);
+
+            let response_result = req.send().await;
+            match response_result {
+                Ok(response) => {
+                    let body_result = response.text().await;
+                    match body_result {
+                        Ok(body) => {
+                            println!("Response: {:?}", body);
+                        }
+                        Err(e) => {
+                            eprintln!("Error 1: {}", e);
+                        }
+                    }
+                }
+                Err(e) => {
+                    eprintln!("Error 2: {}", e);
+                }
+            }
+        }
+        Err(e) => {
+            eprintln!("Dapr client error: {}", e);
+        }
+    }
+
+    Ok(())
+}

examples/src/invoke/http/dapr.yaml

@@ -0,0 +1,15 @@
+version: 1
+common:
+  daprdLogDestination: console
+apps:
+  - appID: invoke-http-server
+    appDirPath: ./
+    appProtocol: http
+    appPort: 8080
+    logLevel: debug
+    command: ["cargo", "run", "--example", "invoke-http-server"]
+  - appID: invoke-http-client
+    appDirPath: ./
+    appProtocol: http
+    logLevel: debug
+    command: ["cargo", "run", "--example", "invoke-http-client"]

examples/src/invoke/http/server.rs

@@ -0,0 +1,43 @@
+use tokio::io::{AsyncReadExt, AsyncWriteExt};
+use tokio::net::TcpListener;
+
+#[tokio::main]
+async fn main() -> Result<(), Box<dyn std::error::Error>> {
+    let addr = "127.0.0.1:8080";
+    let listener = TcpListener::bind(&addr).await?;
+    println!("Server running on {}", addr);
+
+    loop {
+        let (mut stream, _) = listener.accept().await?;
+        
+        tokio::spawn(async move {
+            let mut buf = [0; 1024];
+            if let Ok(n) = stream.read(&mut buf).await {
+                if n > 0 {
+                    let request_str = String::from_utf8_lossy(&buf[..n]);
+                    
+                    if let Some(line) = request_str.lines().next() {
+                        let parts: Vec<&str> = line.split_whitespace().collect();
+                        if parts.len() >= 2 {
+                            let path = parts[1];
+                            
+                            if let Some(value) = path.strip_prefix("/hello/") {
+                                let body = format!("Hello, {}! (from HTTP server)", value);
+                                let response = format!(
+                                    "HTTP/1.1 200 OK\r\nContent-Type: text/plain\r\nContent-Length: {}\r\n\r\n{}",
+                                    body.len(),
+                                    body
+                                );
+                                let _ = stream.write_all(response.as_bytes()).await;
+                                return;
+                            }
+                        }
+                    }
+                    
+                    let response = "HTTP/1.1 404 Not Found\r\nContent-Length: 0\r\n\r\n";
+                    let _ = stream.write_all(response.as_bytes()).await;
+                }
+            }
+        });
+    }
+}