feat: daily node restart controlled from the admin, connect timings as a default line task [CI]

Agents and Probes exit in order at a configured time (default 04:30 UTC+8, switch and time zone in the admin settings) and the service manager starts them again; a local restart_at or MOSHIRO_RESTART_AT wins. The connect kind (TCP connect and TLS handshake timings) is now a default continuous line template, with a section on the line page.

backend/fleet/src/Fleet.Hosting/Hosting.cs

@@ -126,7 +126,8 @@ public static class PlatformCheck
 /// <summary>处理 Ctrl+C 和 SIGTERM：取消令牌，让各个模块有序退出。</summary>
 public static class ServiceShell
 {
-    public static async Task RunAsync(Func<CancellationToken, Task> run, INodeLog log)
+    /// <param name="restart">每天定时有序退出一次（见 <see cref="RestartController"/>），重新拉起由服务管理器负责。</param>
+    public static async Task RunAsync(Func<CancellationToken, Task> run, INodeLog log, RestartController? restart = null, TimeProvider? time = null)
     {
         using var cts = new CancellationTokenSource();
         using PosixSignalRegistration term = PosixSignalRegistration.Create(PosixSignal.SIGTERM, context =>
@@ -156,6 +157,7 @@ public static class ServiceShell
             cts.Cancel();
         });
         Task trimmer = TrimHeapAsync(cts.Token);
+        Task scheduled = restart is null ? Task.CompletedTask : WaitForRestartAsync(restart, time ?? TimeProvider.System, log, cts);
         try
         {
             await run(cts.Token);
@@ -168,6 +170,38 @@ public static class ServiceShell
         {
             await cts.CancelAsync();
             await trimmer;
+            await scheduled;
+        }
+    }
+
+    private static async Task WaitForRestartAsync(RestartController restart, TimeProvider time, INodeLog log, CancellationTokenSource cts)
+    {
+        while (!cts.IsCancellationRequested)
+        {
+            // 先取令牌、再取设置：中间被改动的话令牌会被取消，下一轮重新排
+            CancellationToken changed = restart.ChangeToken;
+            RestartSchedule? schedule = restart.Current;
+            using CancellationTokenSource wait = CancellationTokenSource.CreateLinkedTokenSource(cts.Token, changed);
+            try
+            {
+                if (schedule is null)
+                {
+                    await Task.Delay(Timeout.Infinite, wait.Token);
+                    continue;
+                }
+
+                DateTimeOffset next = schedule.NextAfter(time.GetUtcNow() + RestartSchedule.MinimumUptime);
+                log.Info("restart scheduled", ("at", next.ToString("O", System.Globalization.CultureInfo.InvariantCulture)), ("source", restart.IsLocal ? "local" : "panel"));
+                await Task.Delay(next - time.GetUtcNow(), time, wait.Token);
+            }
+            catch (OperationCanceledException)
+            {
+                continue; // 进程在退出，或者设置被改了：循环条件和下一轮会处理
+            }
+
+            log.Info("stopping", ("result", "scheduled_restart"));
+            await cts.CancelAsync();
+            return;
         }
     }
 

backend/fleet/src/Fleet.Hosting/RestartController.cs

@@ -0,0 +1,73 @@
+namespace Fleet.Hosting;
+
+/// <summary>
+/// 当前生效的定时重启：节点本地的设置优先；本地没有写时用面板下发的，面板改了之后立即重新排下一次，不需要重启进程。
+/// </summary>
+public sealed class RestartController : IDisposable
+{
+    private readonly RestartSchedule? _local;
+    private readonly object _gate = new();
+    private RestartSchedule? _remote;
+    private CancellationTokenSource _changed = new();
+
+    public RestartController(RestartSchedule? local = null)
+    {
+        _local = local;
+    }
+
+    /// <summary>本地有设置时为 true：面板下发的不生效。</summary>
+    public bool IsLocal => _local is not null;
+
+    public RestartSchedule? Current
+    {
+        get
+        {
+            lock (_gate)
+            {
+                return _local ?? _remote;
+            }
+        }
+    }
+
+    /// <summary>当前设置被改动时会被取消的令牌；先取令牌、再取 <see cref="Current"/>，就不会漏掉中间的改动。</summary>
+    public CancellationToken ChangeToken
+    {
+        get
+        {
+            lock (_gate)
+            {
+                return _changed.Token;
+            }
+        }
+    }
+
+    /// <summary>面板下发的设置；为空表示面板关闭了定时重启。返回 false 表示文本不合法（节点忽略它）。</summary>
+    public bool SetRemote(string? text)
+    {
+        RestartSchedule? schedule = null;
+        if (!string.IsNullOrWhiteSpace(text) && !RestartSchedule.TryParse(text, out schedule))
+        {
+            return false;
+        }
+
+        CancellationTokenSource previous;
+        lock (_gate)
+        {
+            _remote = schedule;
+            previous = _changed;
+            _changed = new CancellationTokenSource();
+        }
+
+        previous.Cancel();
+        previous.Dispose();
+        return true;
+    }
+
+    public void Dispose()
+    {
+        lock (_gate)
+        {
+            _changed.Dispose();
+        }
+    }
+}

backend/fleet/src/Fleet.Hosting/RestartSchedule.cs

@@ -0,0 +1,105 @@
+using System.Globalization;
+
+namespace Fleet.Hosting;
+
+/// <summary>
+/// 每天固定时刻有序退出一次，由 systemd、容器引擎或 procd 的「总是重启」拉起。写法 <c>HH:mm</c>（按 UTC）、
+/// <c>HH:mm±hh:mm</c> 或 <c>HH:mm</c> 加 <c>Z</c>：容器里没有时区数据库，所以偏移要写明，例如 <c>04:00+08:00</c>。
+/// 进程自己退出，不需要任何执行外部命令的能力。
+/// </summary>
+public sealed class RestartSchedule
+{
+    /// <summary>环境变量，设置了就覆盖配置文件里的值。</summary>
+    public const string EnvironmentVariable = "MOSHIRO_RESTART_AT";
+
+    /// <summary>刚启动的一段时间内不会触发：重启之后不会因为时刻还没过去而再重启一次，也避免重启风暴。</summary>
+    public static readonly TimeSpan MinimumUptime = TimeSpan.FromMinutes(10);
+
+    private readonly TimeSpan _time;
+    private readonly TimeSpan _offset;
+
+    private RestartSchedule(TimeSpan time, TimeSpan offset)
+    {
+        _time = time;
+        _offset = offset;
+    }
+
+    public static bool TryParse(string? text, out RestartSchedule? schedule)
+    {
+        schedule = null;
+        string value = text?.Trim() ?? "";
+        // HH:mm，后面可以跟 Z 或 ±hh:mm
+        if (value.Length < 5 || value[2] != ':' ||
+            !TryTwoDigits(value, 0, out int hour) || !TryTwoDigits(value, 3, out int minute) || hour > 23 || minute > 59)
+        {
+            return false;
+        }
+
+        TimeSpan offset = TimeSpan.Zero;
+        string rest = value[5..];
+        if (rest.Length > 0 && rest != "Z")
+        {
+            if (rest.Length != 6 || rest[0] is not ('+' or '-') || rest[3] != ':' ||
+                !TryTwoDigits(rest, 1, out int offsetHours) || !TryTwoDigits(rest, 4, out int offsetMinutes) || offsetMinutes > 59)
+            {
+                return false;
+            }
+
+            offset = new TimeSpan(offsetHours, offsetMinutes, 0);
+            if (offset > TimeSpan.FromHours(14))
+            {
+                return false;
+            }
+
+            if (rest[0] == '-')
+            {
+                offset = -offset;
+            }
+        }
+
+        schedule = new RestartSchedule(new TimeSpan(hour, minute, 0), offset);
+        return true;
+    }
+
+    private static bool TryTwoDigits(string text, int start, out int value)
+    {
+        value = 0;
+        if (!char.IsAsciiDigit(text[start]) || !char.IsAsciiDigit(text[start + 1]))
+        {
+            return false;
+        }
+
+        value = (text[start] - '0') * 10 + (text[start + 1] - '0');
+        return true;
+    }
+
+    /// <summary>
+    /// 环境变量优先，其次配置文件的值；都没有就不定时重启。写错了抛 <see cref="InvalidOperationException"/>，
+    /// 启动时就能看到，而不是悄悄不生效。
+    /// </summary>
+    public static RestartSchedule? Resolve(string? configured)
+    {
+        string? text = Environment.GetEnvironmentVariable(EnvironmentVariable);
+        if (string.IsNullOrWhiteSpace(text))
+        {
+            text = configured;
+        }
+
+        if (string.IsNullOrWhiteSpace(text))
+        {
+            return null;
+        }
+
+        return TryParse(text, out RestartSchedule? schedule)
+            ? schedule
+            : throw new InvalidOperationException($"restart_at must look like 04:00, 04:00Z or 04:00+08:00 (got '{text}')");
+    }
+
+    /// <summary>严格晚于 <paramref name="now"/> 的下一个触发时刻。</summary>
+    public DateTimeOffset NextAfter(DateTimeOffset now)
+    {
+        DateTimeOffset local = now.ToOffset(_offset);
+        DateTimeOffset candidate = new DateTimeOffset(local.Year, local.Month, local.Day, 0, 0, 0, _offset) + _time;
+        return candidate <= local ? candidate.AddDays(1) : candidate;
+    }
+}