backend: require confirmation for signed channel updates [CI]

backend/src/MoShiro.Backend.Application/Updates/BackendUpdates.cs

@@ -0,0 +1,118 @@
+using Fleet.Core;
+using Microsoft.Extensions.Hosting;
+using MoShiro.Protocol;
+
+namespace MoShiro.Backend.Application;
+
+/// <summary>宿主机更新器的文件信箱端口。面板只写签名清单和确认的 seq，不执行命令。</summary>
+public interface IBackendUpdateFiles
+{
+    ValueTask WriteOfferAsync(string manifest, string signature, CancellationToken ct);
+
+    ValueTask<UpdateStatus?> ReadStatusAsync(CancellationToken ct);
+
+    ValueTask<long?> ReadRequestAsync(CancellationToken ct);
+
+    ValueTask RequestAsync(long seq, CancellationToken ct);
+}
+
+public sealed record BackendUpdateView(string Channel, bool Enabled, string State, string? CurrentTag, string? CurrentDigest, ReleaseOffer? Available, string? Error);
+
+/// <summary>Backend 的发布通知和确认。新清单只显示为可用更新，宿主机必须收到对应 seq 的确认才会重启。</summary>
+public sealed class BackendUpdates : IHostedService
+{
+    private readonly ReleaseService _releases;
+    private readonly IBackendUpdateFiles _files;
+    private readonly BackendOptions _options;
+
+    public BackendUpdates(ReleaseService releases, IBackendUpdateFiles files, BackendOptions options)
+    {
+        _releases = releases;
+        _files = files;
+        _options = options;
+    }
+
+    public static string ChannelOf(BackendOptions options)
+    {
+        if (options.UpdateChannel is "dev" or "release")
+        {
+            return options.UpdateChannel;
+        }
+
+        if (options.UpdateChannel != "auto")
+        {
+            throw new InvalidOperationException("UpdateChannel must be auto, dev or release");
+        }
+
+        string imageNamespace = options.ImageNamespace.Trim('/');
+        if (imageNamespace == "moshiro-dev" || imageNamespace.EndsWith("/moshiro-dev", StringComparison.Ordinal))
+        {
+            return "dev";
+        }
+
+        if (imageNamespace == "moshiro" || imageNamespace.EndsWith("/moshiro", StringComparison.Ordinal))
+        {
+            return "release";
+        }
+
+        return BuildInfo.Tag is { } tag && (tag.StartsWith("dev-", StringComparison.Ordinal) || tag.StartsWith("main-", StringComparison.Ordinal)) ? "dev" : "release";
+    }
+
+    public async ValueTask<BackendUpdateView> GetAsync(CancellationToken ct)
+    {
+        string channel = ChannelOf(_options);
+        ReleaseOffer? offer = await _releases.GetBackendAsync(channel, ct);
+        UpdateStatus? status = await _files.ReadStatusAsync(ct);
+        bool installed = offer is not null && (status?.Current == offer.Digest || BuildInfo.Tag == offer.Tag);
+        // 只有更新器确认过同一份清单才允许按钮执行；旧状态不能被套到新的清单上。
+        bool verified = offer is not null && status?.Available?.Seq == offer.Seq && status.Available.Digest == offer.Digest;
+        string state = status?.State ?? "unavailable";
+        if (installed)
+        {
+            state = "up_to_date";
+        }
+        else if (offer is not null && !verified && state is not ("invalid" or "failed" or "rolled_back"))
+        {
+            state = status is null ? "unavailable" : "checking";
+        }
+
+        if (verified && state == "available" && await _files.ReadRequestAsync(ct) == offer!.Seq)
+        {
+            state = "requested";
+        }
+
+        return new BackendUpdateView(channel, status is not null, state, BuildInfo.Tag, status?.Current, installed ? null : offer, status?.Error);
+    }
+
+    public async ValueTask<Result<bool>> ConfirmAsync(long seq, CancellationToken ct)
+    {
+        // 与 webhook 共用发布锁：确认之后即使又来了一个 tag，信箱中的请求仍只认本次确认的 seq。
+        await _releases.BackendGate.WaitAsync(ct);
+        try
+        {
+            BackendUpdateView view = await GetAsync(ct);
+            if (!view.Enabled || view.State != "available" || view.Available?.Seq != seq)
+            {
+                return Result<bool>.Fail(MoShiroErrors.PreconditionFailed, "the offered release changed or has not been verified by the host updater; refresh before confirming");
+            }
+
+            await _files.RequestAsync(seq, ct);
+            return Result<bool>.Ok(true);
+        }
+        finally
+        {
+            _releases.BackendGate.Release();
+        }
+    }
+
+    public async Task StartAsync(CancellationToken cancellationToken)
+    {
+        string channel = ChannelOf(_options);
+        if (await _releases.GetBackendAsync(channel, cancellationToken) is { } offer)
+        {
+            await _files.WriteOfferAsync(offer.Manifest, offer.Signature, cancellationToken);
+        }
+    }
+
+    public Task StopAsync(CancellationToken cancellationToken) => Task.CompletedTask;
+}

backend/src/MoShiro.Backend.Application/Updates/ReleaseService.cs

@@ -8,29 +8,38 @@ using MoShiro.Protocol;
 namespace MoShiro.Backend.Application;
 
 /// <summary>面板记下的、CI 签名的发布清单（只留每个组件最新的一份）。<c>Manifest</c> 是签名对象的原始文本，面板一个字节也不改。</summary>
-public sealed record ReleaseOffer(string Component, long Seq, string Tag, string Version, string Digest, string Manifest, string Signature);
+public sealed record ReleaseOffer(string Component, long Seq, string Tag, string Version, string Digest, string Manifest, string Signature, string Channel = "release");
 
 /// <summary>
 /// 发布清单的分发：CI 签名之后推给面板，面板存下来并原样转给在线的 Agent、Probe（节点连上时再补发一次）。
 /// <b>面板不验签、也不决定拉什么</b>：节点宿主机上的更新器用本机的发布公钥验签，并且只认本机配置的镜像仓库；
 /// 所以面板即使被攻破，也推不出一个能被装上的假镜像。面板只负责「通知」和「请求更新」，状态由节点随心跳报回来。
 /// </summary>
-public sealed partial class ReleaseService
+public sealed partial class ReleaseService : IDisposable
 {
     public const int MaxManifestBytes = 4096;
     public const int MaxSignatureBytes = 512;
-    private static readonly string[] s_components = [NodeKinds.Agent, NodeKinds.Probe];
+    public const string BackendComponent = "backend";
+    private static readonly string[] s_components = [NodeKinds.Agent, NodeKinds.Probe, BackendComponent];
 
     private readonly ISettingsStore _settings;
     private readonly IAgentGateway _gateway;
+    private readonly IBackendUpdateFiles _backendFiles;
+    private readonly BackendOptions _options;
     private readonly ConcurrentDictionary<string, UpdateStatus> _status = new();
 
-    public ReleaseService(ISettingsStore settings, IAgentGateway gateway)
+    public ReleaseService(ISettingsStore settings, IAgentGateway gateway, IBackendUpdateFiles backendFiles, BackendOptions options)
     {
         _settings = settings;
         _gateway = gateway;
+        _backendFiles = backendFiles;
+        _options = options;
     }
 
+    internal SemaphoreSlim BackendGate { get; } = new(1, 1);
+
+    public void Dispose() => BackendGate.Dispose();
+
     /// <summary>登记一份新清单并推给在线的同类节点。只要格式对、<c>seq</c> 比现有的新就收下（签名由节点验证）。</summary>
     public async ValueTask<Result<ReleaseOffer>> PublishAsync(string manifest, string signature, CancellationToken ct)
     {
@@ -39,20 +48,40 @@ public sealed partial class ReleaseService
             return ValidationError.Fail<ReleaseOffer>("manifest", problem);
         }
 
-        ReleaseOffer? current = await GetAsync(offer.Component, ct);
-        if (current is not null && offer.Seq <= current.Seq)
+        await BackendGate.WaitAsync(ct);
+        try
         {
-            return Result<ReleaseOffer>.Fail(MoShiroErrors.NameConflict, $"a release with seq {current.Seq} or newer is already registered");
-        }
+            bool backend = offer.Component == BackendComponent;
+            ReleaseOffer? current = backend ? await GetBackendAsync(offer.Channel, ct) : await GetAsync(offer.Component, ct);
+            if (current is not null && offer.Seq <= current.Seq)
+            {
+                return Result<ReleaseOffer>.Fail(MoShiroErrors.NameConflict, $"a release with seq {current.Seq} or newer is already registered");
+            }
 
-        await _settings.SetAsync(Key(offer.Component, "manifest"), offer.Manifest, ct);
-        await _settings.SetAsync(Key(offer.Component, "signature"), offer.Signature, ct);
-        foreach (NodeId node in OnlineOf(offer.Component))
+            string componentKey = backend ? BackendComponent + "." + offer.Channel : offer.Component;
+            await _settings.SetAsync(Key(componentKey, "manifest"), offer.Manifest, ct);
+            await _settings.SetAsync(Key(componentKey, "signature"), offer.Signature, ct);
+            if (backend)
+            {
+                if (offer.Channel == BackendUpdates.ChannelOf(_options))
+                {
+                    await _backendFiles.WriteOfferAsync(offer.Manifest, offer.Signature, ct);
+                }
+            }
+            else
+            {
+                foreach (NodeId node in OnlineOf(offer.Component))
+                {
+                    await _gateway.NotifyUpdateOfferAsync(node, offer.Manifest, offer.Signature, ct);
+                }
+            }
+
+            return Result<ReleaseOffer>.Ok(offer);
+        }
+        finally
         {
-            await _gateway.NotifyUpdateOfferAsync(node, offer.Manifest, offer.Signature, ct);
+            BackendGate.Release();
         }
-
-        return Result<ReleaseOffer>.Ok(offer);
     }
 
     public async ValueTask<ReleaseOffer?> GetAsync(string component, CancellationToken ct)
@@ -67,7 +96,8 @@ public sealed partial class ReleaseService
         var list = new List<ReleaseOffer>();
         foreach (string component in s_components)
         {
-            if (await GetAsync(component, ct) is { } offer)
+            ReleaseOffer? offer = component == BackendComponent ? await GetBackendAsync(BackendUpdates.ChannelOf(_options), ct) : await GetAsync(component, ct);
+            if (offer is not null)
             {
                 list.Add(offer);
             }
@@ -76,6 +106,15 @@ public sealed partial class ReleaseService
         return list;
     }
 
+    public async ValueTask<ReleaseOffer?> GetBackendAsync(string channel, CancellationToken ct)
+    {
+        string key = BackendComponent + "." + channel;
+        string? manifest = await _settings.GetAsync(Key(key, "manifest"), ct);
+        string? signature = await _settings.GetAsync(Key(key, "signature"), ct);
+        return manifest is not null && signature is not null && TryParse(manifest, signature, out ReleaseOffer? offer, out _)
+            && offer.Component == BackendComponent && offer.Channel == channel ? offer : null;
+    }
+
     /// <summary>节点刚连上：把它这个组件最新的清单补发一份（节点离线时发布的也不会错过）。</summary>
     public async ValueTask OfferToNodeAsync(NodeId node, CancellationToken ct)
     {
@@ -129,7 +168,14 @@ public sealed partial class ReleaseService
             JsonElement root = document.RootElement;
             string component = Text(root, "component");
             string digest = Text(root, "digest");
+            string channel = Text(root, "channel");
+            if (channel.Length == 0)
+            {
+                channel = "release"; // 老节点的清单没有 channel，保留原来的兼容性
+            }
+
             if (root.ValueKind != JsonValueKind.Object || Array.IndexOf(s_components, component) < 0
+                || channel is not ("dev" or "release")
                 || !root.TryGetProperty("seq", out JsonElement seq) || !seq.TryGetInt64(out long seqValue) || seqValue <= 0
                 || !Digest().IsMatch(digest) || Text(root, "image").Length is 0 or > 200)
             {
@@ -137,7 +183,7 @@ public sealed partial class ReleaseService
                 return false;
             }
 
-            offer = new ReleaseOffer(component, seqValue, Text(root, "tag"), Text(root, "version"), digest, manifest, signature);
+            offer = new ReleaseOffer(component, seqValue, Text(root, "tag"), Text(root, "version"), digest, manifest, signature, channel);
             return true;
         }
         catch (JsonException)