chore: initial project import

backend/probe/src/Monitor.Probe/ProbeApp.cs

@@ -0,0 +1,154 @@
+using Fleet.Core;
+using Fleet.Hosting;
+using Fleet.Identity;
+using Monitor.Measurement;
+
+namespace Monitor.Probe;
+
+/// <summary>
+/// Probe 的组装点：Agent 列表 → 每个 Agent 一个连接（认证、重连、角色）。没有全局状态，测试可以在同一进程里启动多个。
+/// 列表变化时只调和连接：新增的建立，移除的断开，地址或证书指纹变化的重建，其余不受影响。
+/// </summary>
+public sealed class ProbeApp : IDisposable
+{
+    public const string Version = "0.1.0";
+
+    private readonly ConnectionEnv _env;
+    private readonly Dictionary<string, Running> _connections = [];
+    private readonly SemaphoreSlim _changed = new(0);
+    private readonly INodeLog _log;
+
+    public ProbeApp(ProbeFile file, string configDirectory, TimeProvider time, INodeLog log)
+    {
+        _log = log;
+        var directory = new AgentDirectory(new ConfigStore(configDirectory), configDirectory, file, log);
+        NodeIdentity identity = NodeIdentity.FromPkcs8(Convert.FromBase64String(file.PrivateKey));
+        _env = new ConnectionEnv(identity, file.ProbeId, file.Limits, directory, new MonoClock(time), time, log);
+        directory.Changed += () => _changed.Release();
+    }
+
+    public AgentDirectory Directory => _env.Directory;
+
+    /// <summary>某个 Agent 的会话是否已经建立（测试和状态查看用）。</summary>
+    public bool IsConnected(string agentId)
+    {
+        lock (_connections)
+        {
+            return _connections.TryGetValue(agentId, out Running? running) && running.Connection.IsConnected;
+        }
+    }
+
+    public AgentConnection? Connection(string agentId)
+    {
+        lock (_connections)
+        {
+            return _connections.TryGetValue(agentId, out Running? running) ? running.Connection : null;
+        }
+    }
+
+    public async Task RunAsync(CancellationToken ct)
+    {
+        if (_env.Directory.Agents.Count == 0)
+        {
+            _log.Warn("no agents known yet: probe.json has an empty bootstrap list");
+        }
+
+        try
+        {
+            while (!ct.IsCancellationRequested)
+            {
+                await ReconcileAsync(_env.Directory.Agents, ct);
+                await _changed.WaitAsync(ct);
+            }
+        }
+        catch (OperationCanceledException)
+        {
+            // 停止
+        }
+        finally
+        {
+            await ReconcileAsync([], CancellationToken.None);
+        }
+    }
+
+    public void Dispose()
+    {
+        _env.Identity.Dispose();
+        _changed.Dispose();
+    }
+
+    private async Task ReconcileAsync(IReadOnlyList<BootstrapAgent> agents, CancellationToken ct)
+    {
+        var wanted = agents.ToDictionary(a => a.AgentId);
+        var stopped = new List<Running>();
+        lock (_connections)
+        {
+            foreach ((string id, Running running) in _connections.ToList())
+            {
+                if (!wanted.TryGetValue(id, out BootstrapAgent? endpoint) || !AgentDirectory.Equal(endpoint, running.Connection.Endpoint))
+                {
+                    stopped.Add(running);
+                    _connections.Remove(id);
+                }
+            }
+        }
+
+        foreach (Running running in stopped)
+        {
+            await running.StopAsync();
+        }
+
+        if (ct.IsCancellationRequested)
+        {
+            return;
+        }
+
+        lock (_connections)
+        {
+            foreach ((string id, BootstrapAgent endpoint) in wanted)
+            {
+                if (!_connections.ContainsKey(id))
+                {
+                    _connections[id] = Running.Start(new AgentConnection(endpoint, _env));
+                }
+            }
+        }
+    }
+
+    private sealed class Running : IDisposable
+    {
+        private readonly CancellationTokenSource _cts = new();
+        private Task _run = Task.CompletedTask;
+
+        private Running(AgentConnection connection)
+        {
+            Connection = connection;
+        }
+
+        public AgentConnection Connection { get; }
+
+        public static Running Start(AgentConnection connection)
+        {
+            var running = new Running(connection);
+            running._run = Task.Run(() => connection.RunAsync(running._cts.Token), CancellationToken.None);
+            return running;
+        }
+
+        public async Task StopAsync()
+        {
+            await _cts.CancelAsync();
+            try
+            {
+                await _run.WaitAsync(TimeSpan.FromSeconds(10));
+            }
+            catch (Exception ex) when (ex is OperationCanceledException or TimeoutException)
+            {
+                // 没有及时退出：不再等
+            }
+
+            Dispose();
+        }
+
+        public void Dispose() => _cts.Dispose();
+    }
+}