add binary file easytier-web-embed (#718)

* embed web dashboard into easytier-web
* add binary file easytier-web-embed

easytier-web/src/web/mod.rs

@@ -0,0 +1,39 @@
+use axum::Router;
+use easytier::common::scoped_task::ScopedTask;
+use rust_embed::RustEmbed;
+use std::net::SocketAddr;
+use axum_embed::ServeEmbed;
+use tokio::net::TcpListener;
+
+/// Embed assets for web dashboard, build frontend first
+#[derive(RustEmbed, Clone)]
+#[folder = "frontend/dist/"]
+struct Assets;
+
+pub struct WebServer {
+    bind_addr: SocketAddr,
+    serve_task: Option<ScopedTask<()>>,
+}
+
+impl WebServer {
+    pub async fn new(bind_addr: SocketAddr) -> anyhow::Result<Self> {
+        Ok(WebServer {
+            bind_addr,
+            serve_task: None,
+        })
+    }
+
+    pub async fn start(&mut self) -> Result<(), anyhow::Error> {
+        let listener = TcpListener::bind(self.bind_addr).await?;
+        let service = ServeEmbed::<Assets>::new();
+        let app = Router::new().fallback_service(service);
+
+        let task = tokio::spawn(async move {
+            axum::serve(listener, app).await.unwrap();
+        });
+
+        self.serve_task = Some(task.into());
+
+        Ok(())
+    }
+}