huskies: merge 568_story_gateway_ui_connected_agents_dashboard

server/src/gateway.rs

@@ -65,6 +65,10 @@ pub struct JoinedAgent {
     pub address: String,
     /// Unix timestamp when the agent registered.
     pub registered_at: f64,
+    /// Unix timestamp of the last heartbeat from this agent. Defaults to `registered_at`
+    /// for agents loaded from persisted state that predate the heartbeat feature.
+    #[serde(default)]
+    pub last_seen: f64,
     /// Project this agent is assigned to, if any.
     #[serde(default, skip_serializing_if = "Option::is_none")]
     pub assigned_project: Option<String>,
@@ -691,11 +695,13 @@ pub async fn gateway_register_agent_handler(
     tokens.remove(&req.token);
     drop(tokens);
 
+    let now = chrono::Utc::now().timestamp() as f64;
     let agent = JoinedAgent {
         id: Uuid::new_v4().to_string(),
         label: req.label,
         address: req.address,
-        registered_at: chrono::Utc::now().timestamp() as f64,
+        registered_at: now,
+        last_seen: now,
         assigned_project: None,
     };
 
@@ -815,6 +821,38 @@ pub async fn gateway_assign_agent_handler(
     }
 }
 
+/// `POST /gateway/agents/:id/heartbeat` — update an agent's last-seen timestamp.
+///
+/// Build agents should call this periodically (e.g. every 30 s) so the gateway
+/// can distinguish live agents from disconnected ones.  Returns 204 No Content on
+/// success or 404 if the agent ID is not found.
+#[handler]
+pub async fn gateway_heartbeat_handler(
+    PoemPath(id): PoemPath<String>,
+    state: Data<&Arc<GatewayState>>,
+) -> Response {
+    let found = {
+        let mut agents = state.joined_agents.write().await;
+        match agents.iter_mut().find(|a| a.id == id) {
+            None => false,
+            Some(a) => {
+                a.last_seen = chrono::Utc::now().timestamp() as f64;
+                true
+            }
+        }
+    };
+
+    if found {
+        Response::builder()
+            .status(StatusCode::NO_CONTENT)
+            .body(Body::empty())
+    } else {
+        Response::builder()
+            .status(StatusCode::NOT_FOUND)
+            .body(Body::from("agent not found"))
+    }
+}
+
 // ── Health aggregation endpoint ──────────────────────────────────────
 
 /// HTTP GET `/health` handler for the gateway — aggregates health from all projects.
@@ -1620,6 +1658,10 @@ pub async fn run(config_path: &Path, port: u16) -> Result<(), std::io::Error> {
             "/gateway/agents/:id/assign",
             poem::post(gateway_assign_agent_handler),
         )
+        .at(
+            "/gateway/agents/:id/heartbeat",
+            poem::post(gateway_heartbeat_handler),
+        )
         // Serve the embedded React frontend so the gateway has a UI.
         .at(
             "/assets/*path",
@@ -2064,6 +2106,7 @@ enabled = false
             label: "agent-1".into(),
             address: "ws://a:3001/crdt-sync".into(),
             registered_at: 0.0,
+            last_seen: 0.0,
             assigned_project: None,
         });
         let app = poem::Route::new()
@@ -2085,6 +2128,7 @@ enabled = false
             label: "to-delete".into(),
             address: "ws://x:3001/crdt-sync".into(),
             registered_at: 0.0,
+            last_seen: 0.0,
             assigned_project: None,
         });
         let app = poem::Route::new()
@@ -2112,4 +2156,45 @@ enabled = false
         let resp = cli.delete("/gateway/agents/no-such-id").send().await;
         assert_eq!(resp.0.status(), StatusCode::NOT_FOUND);
     }
+
+    #[tokio::test]
+    async fn heartbeat_updates_last_seen() {
+        let state = make_test_state();
+        state.joined_agents.write().await.push(JoinedAgent {
+            id: "hb-id".into(),
+            label: "hb-agent".into(),
+            address: "ws://hb:3001/crdt-sync".into(),
+            registered_at: 0.0,
+            last_seen: 0.0,
+            assigned_project: None,
+        });
+        let app = poem::Route::new()
+            .at(
+                "/gateway/agents/:id/heartbeat",
+                poem::post(gateway_heartbeat_handler),
+            )
+            .data(state.clone());
+        let cli = poem::test::TestClient::new(app);
+        let resp = cli.post("/gateway/agents/hb-id/heartbeat").send().await;
+        assert_eq!(resp.0.status(), StatusCode::NO_CONTENT);
+        let agents = state.joined_agents.read().await;
+        assert!(agents[0].last_seen > 0.0);
+    }
+
+    #[tokio::test]
+    async fn heartbeat_unknown_id_returns_not_found() {
+        let state = make_test_state();
+        let app = poem::Route::new()
+            .at(
+                "/gateway/agents/:id/heartbeat",
+                poem::post(gateway_heartbeat_handler),
+            )
+            .data(state.clone());
+        let cli = poem::test::TestClient::new(app);
+        let resp = cli
+            .post("/gateway/agents/no-such-id/heartbeat")
+            .send()
+            .await;
+        assert_eq!(resp.0.status(), StatusCode::NOT_FOUND);
+    }
 }