chore: initial project import

backend/fleet/src/Fleet.Server.Enrollment/FleetEnrollmentEndpoints.cs

@@ -0,0 +1,92 @@
+using System.Net;
+using System.Text.Json;
+using Fleet.Core;
+using Microsoft.AspNetCore.Builder;
+using Microsoft.AspNetCore.Http;
+using Microsoft.AspNetCore.Routing;
+using Microsoft.Extensions.DependencyInjection;
+
+namespace Fleet.Server;
+
+public static class FleetEnrollmentEndpoints
+{
+    private const int MaxBodyBytes = 64 * 1024;
+
+    /// <summary>注册端点：<c>POST {path}</c>，使用加入令牌认证。需要在 DI 中注册 <see cref="FleetEnrollmentService"/>。</summary>
+    public static IEndpointRouteBuilder MapFleetEnrollment(this IEndpointRouteBuilder app, string path)
+    {
+        app.MapPost(path, HandleAsync)
+            .WithName("fleet_enroll")
+            .WithTags("agent")
+            .WithSummary("Enroll a node with a join token")
+            .DisableAntiforgery();
+        return app;
+    }
+
+    private static async Task<IResult> HandleAsync(HttpContext http, FleetEnrollmentService service)
+    {
+        EnrollRequest? request;
+        try
+        {
+            request = await ReadBodyAsync(http, http.RequestAborted);
+        }
+        catch (JsonException)
+        {
+            request = null;
+        }
+
+        if (request is null)
+        {
+            return Problem(StatusCodes.Status400BadRequest, FleetErrors.InvalidParams, "request body is not valid");
+        }
+
+        Result<EnrollResponse> result = await service.EnrollAsync(request, http.Connection.RemoteIpAddress?.ToString(), http.RequestAborted);
+        if (result.TryGet(out EnrollResponse? response, out FleetError? error))
+        {
+            return Results.Json(response, EnrollmentJsonContext.Default.EnrollResponse, statusCode: StatusCodes.Status201Created);
+        }
+
+        int status = error.Code == FleetErrors.JoinTokenInvalid ? StatusCodes.Status401Unauthorized
+            : error.Code == FleetErrors.JoinTokenExpired ? StatusCodes.Status410Gone
+            : error.Code == FleetErrors.ProofInvalid ? StatusCodes.Status403Forbidden
+            : error.Code == FleetErrors.NameConflict ? StatusCodes.Status409Conflict
+            : error.Code == FleetErrors.InvalidParams ? StatusCodes.Status400BadRequest
+            : StatusCodes.Status500InternalServerError;
+        return Problem(status, error.Code, error.Message);
+    }
+
+    private static async Task<EnrollRequest?> ReadBodyAsync(HttpContext http, CancellationToken ct)
+    {
+        if (http.Request.ContentLength > MaxBodyBytes)
+        {
+            return null;
+        }
+
+        using var buffer = new MemoryStream();
+        byte[] chunk = new byte[4096];
+        int read;
+        while ((read = await http.Request.Body.ReadAsync(chunk, ct)) > 0)
+        {
+            buffer.Write(chunk, 0, read);
+            if (buffer.Length > MaxBodyBytes)
+            {
+                return null;
+            }
+        }
+
+        return JsonSerializer.Deserialize(buffer.ToArray(), EnrollmentJsonContext.Default.EnrollRequest);
+    }
+
+    private static IResult Problem(int status, ErrorCode code, string detail) =>
+        Results.Json(
+            new FleetProblem { Title = ((HttpStatusCode)status).ToString(), Status = status, Code = code.Value, Detail = detail },
+            EnrollmentJsonContext.Default.FleetProblem,
+            contentType: "application/problem+json",
+            statusCode: status);
+}
+
+public static class FleetEnrollmentServiceCollectionExtensions
+{
+    public static IServiceCollection AddFleetEnrollment(this IServiceCollection services) =>
+        services.AddSingleton<FleetEnrollmentService>();
+}