Supports customizing the API server address of the Web frontend through the --api-host parameter (#913)

easytier-web/src/web/mod.rs

@@ -1,8 +1,13 @@
-use axum::Router;
+use axum::{
+    extract::State,
+    http::header,
+    response::{IntoResponse, Response},
+    routing, Router,
+};
+use axum_embed::ServeEmbed;
 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
@@ -10,30 +15,72 @@ use tokio::net::TcpListener;
 #[folder = "frontend/dist/"]
 struct Assets;
 
+#[derive(Debug, serde::Deserialize, serde::Serialize)]
+struct ApiMetaResponse {
+    api_host: String,
+}
+
+async fn handle_api_meta(State(api_host): State<url::Url>) -> impl IntoResponse {
+    Response::builder()
+        .header(
+            header::CONTENT_TYPE,
+            "application/javascript; charset=utf-8",
+        )
+        .header(header::CACHE_CONTROL, "no-cache, no-store, must-revalidate")
+        .header(header::PRAGMA, "no-cache")
+        .header(header::EXPIRES, "0")
+        .body(format!(
+            "window.apiMeta = {}",
+            serde_json::to_string(&ApiMetaResponse {
+                api_host: api_host.to_string()
+            })
+            .unwrap(),
+        ))
+        .unwrap()
+}
+
+pub fn build_router(api_host: Option<url::Url>) -> Router {
+    let service = ServeEmbed::<Assets>::new();
+    let router = Router::new();
+
+    let router = if let Some(api_host) = api_host {
+        let sub_router = Router::new()
+            .route("/api_meta.js", routing::get(handle_api_meta))
+            .with_state(api_host);
+        router.merge(sub_router)
+    } else {
+        router
+    };
+
+    let router = router.fallback_service(service);
+
+    router
+}
+
 pub struct WebServer {
     bind_addr: SocketAddr,
+    router: Router,
     serve_task: Option<ScopedTask<()>>,
 }
 
 impl WebServer {
-    pub async fn new(bind_addr: SocketAddr) -> anyhow::Result<Self> {
+    pub async fn new(bind_addr: SocketAddr, router: Router) -> anyhow::Result<Self> {
         Ok(WebServer {
             bind_addr,
+            router,
             serve_task: None,
         })
     }
 
-    pub async fn start(&mut self) -> Result<(), anyhow::Error> {
+    pub async fn start(self) -> Result<ScopedTask<()>, anyhow::Error> {
         let listener = TcpListener::bind(self.bind_addr).await?;
-        let service = ServeEmbed::<Assets>::new();
-        let app = Router::new().fallback_service(service);
+        let app = self.router;
 
         let task = tokio::spawn(async move {
             axum::serve(listener, app).await.unwrap();
-        });
+        })
+        .into();
 
-        self.serve_task = Some(task.into());
-
-        Ok(())
+        Ok(task)
     }
 }