StopShopping/StopShopping.FileApi/Middlewares/InternalAccessOnlyMiddleware.cs

using System.Net;
using Microsoft.AspNetCore.Mvc;
using StopShopping.FileApi.Extensions;

namespace StopShopping.FileApi.Middlewares;

public class InternalAccessOnlyMiddleware
{
    public InternalAccessOnlyMiddleware(
        RequestDelegate next,
        IProblemDetailsService problemDetailsService,
        ILogger<InternalAccessOnlyMiddleware> logger)
    {
        _next = next;
        _problemService = problemDetailsService;
        _logger = logger;
    }

    private readonly RequestDelegate _next;
    private readonly IProblemDetailsService _problemService;
    private readonly ILogger<InternalAccessOnlyMiddleware> _logger;

    public async Task InvokeAsync(HttpContext httpContext)
    {
        var endpoint = httpContext.GetEndpoint();
        if (null != endpoint)
        {
            var internalOnlyMetadata = endpoint.Metadata.GetMetadata<InternalOnlyMetadata>();
            if (null != internalOnlyMetadata)
            {
                if (null == httpContext.Connection.RemoteIpAddress
                || !IPAddress.IsLoopback(httpContext.Connection.RemoteIpAddress))
                {
                    var problemDetails = new ProblemDetails
                    {
                        Detail = $"remote ip: {httpContext.Connection.RemoteIpAddress}",
                        Instance = httpContext.Request.Path,
                        Status = StatusCodes.Status403Forbidden,
                        Title = "access denied, local access only."
                    };

                    httpContext.Response.StatusCode = StatusCodes.Status403Forbidden;
                    httpContext.Response.ContentType = "application/problem+json";

                    await _problemService.WriteAsync(new ProblemDetailsContext
                    {
                        HttpContext = httpContext,
                        ProblemDetails = problemDetails,
                    });

                    _logger.LogInformation("denied access: {Ip}", httpContext.Connection.RemoteIpAddress);
                }
            }
        }

        await _next(httpContext);
    }
}