feat: LLM 服务可用性指示灯 (/llm/status 健康探测)

src/index.html

@@ -144,6 +144,9 @@ h1 {
 }
 
 .status-dot.connected { background: #a6e3a1; }
+.status-dot.online  { background: #a6e3a1; box-shadow: 0 0 6px #a6e3a1; }
+.status-dot.offline { background: #f38ba8; }
+.status-sep { color: #45475a; }
 
 .legend {
     display: flex;
@@ -175,6 +178,9 @@ h1 {
 <div class="status">
     <span class="status-dot" id="statusDot"></span>
     <span id="statusText">connecting...</span>
+    <span class="status-sep">·</span>
+    <span class="status-dot" id="llmDot"></span>
+    <span id="llmText">LLM ...</span>
 </div>
 
 <div class="legend">
@@ -295,8 +301,32 @@ function connectSSE() {
     };
 }
 
+const llmDot = document.getElementById('llmDot');
+const llmText = document.getElementById('llmText');
+
+async function pollLlm() {
+    try {
+        const res = await fetch('/llm/status');
+        const d = await res.json();
+        if (d.online) {
+            llmDot.className = 'status-dot online';
+            llmText.textContent = d.latency_ms != null
+                ? `LLM online · ${d.latency_ms}ms`
+                : 'LLM online';
+        } else {
+            llmDot.className = 'status-dot offline';
+            llmText.textContent = 'LLM offline';
+        }
+    } catch {
+        llmDot.className = 'status-dot offline';
+        llmText.textContent = 'LLM unknown';
+    }
+}
+
 loadHistory();
 connectSSE();
+pollLlm();
+setInterval(pollLlm, 15000);
 </script>
 
 </body>

src/main.rs

@@ -15,6 +15,9 @@ use sqlx::sqlite::SqlitePoolOptions;
 use sqlx::SqlitePool;
 use std::convert::Infallible;
 use std::sync::Arc;
+use std::sync::RwLock;
+use std::time::{Duration, Instant};
+use tokio::io::{AsyncReadExt, AsyncWriteExt};
 use tokio::sync::broadcast;
 use tokio_stream::StreamExt;
 use tokio_stream::wrappers::BroadcastStream;
@@ -33,10 +36,80 @@ struct Notification {
     created_at: String,
 }
 
+#[derive(Clone, Serialize, Default)]
+struct LlmStatus {
+    online: bool,
+    checked_at: Option<String>,
+    latency_ms: Option<u128>,
+}
+
 #[derive(Clone)]
 struct AppState {
     pool: SqlitePool,
     tx: broadcast::Sender<String>,
+    llm: Arc<RwLock<LlmStatus>>,
+}
+
+fn parse_http_url(url: &str) -> Option<(String, u16, String)> {
+    let rest = url.strip_prefix("http://")?;
+    let (authority, path) = match rest.find('/') {
+        Some(i) => (&rest[..i], &rest[i..]),
+        None => (rest, "/"),
+    };
+    let (host, port) = match authority.rsplit_once(':') {
+        Some((h, p)) => (h.to_string(), p.parse().ok()?),
+        None => (authority.to_string(), 80u16),
+    };
+    Some((host, port, path.to_string()))
+}
+
+/// 裸 HTTP GET，仅检查状态行是否为 200。
+/// 避免引入 HTTP client 依赖；目标为受信内网地址。
+async fn probe_llm(host: &str, port: u16, path: &str) -> bool {
+    let addr = format!("{host}:{port}");
+    let req = format!(
+        "GET {path} HTTP/1.1\r\nHost: {addr}\r\nUser-Agent: newsboard-health\r\nConnection: close\r\n\r\n"
+    );
+    let attempt = async {
+        let mut stream = tokio::net::TcpStream::connect(&addr).await?;
+        stream.write_all(req.as_bytes()).await?;
+        let mut buf = [0u8; 64];
+        let n = stream.read(&mut buf).await?;
+        let head = String::from_utf8_lossy(&buf[..n]);
+        Ok::<bool, std::io::Error>(
+            head.starts_with("HTTP/1.1 200") || head.starts_with("HTTP/1.0 200"),
+        )
+    };
+    matches!(
+        tokio::time::timeout(Duration::from_secs(5), attempt).await,
+        Ok(Ok(true))
+    )
+}
+
+fn spawn_llm_probe(status: Arc<RwLock<LlmStatus>>, url: String) {
+    tokio::spawn(async move {
+        let (host, port, path) = match parse_http_url(&url) {
+            Some(v) => v,
+            None => {
+                error!("Invalid LLM health URL: {url}");
+                return;
+            }
+        };
+        let mut ticker = tokio::time::interval(Duration::from_secs(15));
+        loop {
+            ticker.tick().await;
+            let start = Instant::now();
+            let online = probe_llm(&host, port, &path).await;
+            let snapshot = LlmStatus {
+                online,
+                checked_at: Some(Utc::now().to_rfc3339()),
+                latency_ms: Some(start.elapsed().as_millis()),
+            };
+            if let Ok(mut s) = status.write() {
+                *s = snapshot;
+            }
+        }
+    });
 }
 
 async fn init_db(pool: &SqlitePool) -> sqlx::Result<()> {
@@ -171,6 +244,11 @@ async fn handle_history(State(state): State<Arc<AppState>>) -> impl IntoResponse
     axum::Json(rows)
 }
 
+async fn handle_llm_status(State(state): State<Arc<AppState>>) -> impl IntoResponse {
+    let status = state.llm.read().map(|s| s.clone()).unwrap_or_default();
+    axum::Json(status)
+}
+
 async fn handle_events(
     State(state): State<Arc<AppState>>,
 ) -> Sse<impl tokio_stream::Stream<Item = Result<Event, Infallible>>> {
@@ -215,12 +293,23 @@ async fn main() {
 
     run_mqtt(pool.clone(), tx.clone()).await;
 
-    let state = Arc::new(AppState { pool, tx });
+    let llm_status = Arc::new(RwLock::new(LlmStatus::default()));
+    let llm_health_url = std::env::var("NEWSBOARD_LLM_HEALTH_URL")
+        .unwrap_or_else(|_| "http://192.168.0.4:8090/health".into());
+    info!("LLM health probe target: {llm_health_url}");
+    spawn_llm_probe(llm_status.clone(), llm_health_url);
+
+    let state = Arc::new(AppState {
+        pool,
+        tx,
+        llm: llm_status,
+    });
 
     let app = Router::new()
         .route("/", get(handle_root))
         .route("/events", get(handle_events))
         .route("/history", get(handle_history))
+        .route("/llm/status", get(handle_llm_status))
         .with_state(state);
 
     let port: u16 = std::env::var("NEWSBOARD_PORT")