Host on edges

NostrStreamer/Config.cs

@@ -40,6 +40,10 @@ public class Config
     public S3BlobConfig S3Store { get; init; } = null!;
     
     public DateTime TosDate { get; init; }
+
+    public string GeoIpDatabase { get; init; } = null!;
+    
+    public List<EdgeLocation> Edges { get; init; } = new();
 }
 
 public class LndConfig
@@ -62,3 +66,11 @@ public sealed class S3BlobConfig
     public bool DisablePayloadSigning { get; init; }
     public Uri PublicHost { get; init; } = null!;
 }
+
+public sealed class EdgeLocation
+{
+    public string Name { get; init; } = null!;
+    public Uri Url { get; init; } = null!;
+    public double Latitude { get; init; }
+    public double Longitude { get; init; }
+}

NostrStreamer/Controllers/PlaylistController.cs

@@ -16,9 +16,10 @@ public class PlaylistController : Controller
     private readonly SrsApi _srsApi;
     private readonly ViewCounter _viewCounter;
     private readonly StreamManagerFactory _streamManagerFactory;
+    private readonly EdgeSteering _edgeSteering;
 
     public PlaylistController(Config config, ILogger<PlaylistController> logger,
-        HttpClient client, SrsApi srsApi, ViewCounter viewCounter, StreamManagerFactory streamManagerFactory)
+        HttpClient client, SrsApi srsApi, ViewCounter viewCounter, StreamManagerFactory streamManagerFactory, EdgeSteering edgeSteering)
     {
         _config = config;
         _logger = logger;
@@ -26,6 +27,7 @@ public class PlaylistController : Controller
         _srsApi = srsApi;
         _viewCounter = viewCounter;
         _streamManagerFactory = streamManagerFactory;
+        _edgeSteering = edgeSteering;
     }
 
     [ResponseCache(Duration = 1, Location = ResponseCacheLocation.Any)]
@@ -106,6 +108,7 @@ public class PlaylistController : Controller
     {
         try
         {
+            var edge = _edgeSteering.GetEdge(HttpContext);
             var streamManager = await _streamManagerFactory.ForStream(id);
             var userStream = streamManager.GetStream();
 
@@ -138,8 +141,17 @@ public class PlaylistController : Controller
                 await sw.WriteLineAsync(
                     $"#EXT-X-STREAM-INF:{string.Join(",", allArgs)}");
 
-                var u = $"../{variant.SourceName}/{userStream.Id}.m3u8{(!string.IsNullOrEmpty(hlsCtx) ? $"?hls_ctx={hlsCtx}" : "")}";
-                await sw.WriteLineAsync(u);
+                var path = $"{variant.SourceName}/{userStream.Id}.m3u8{(!string.IsNullOrEmpty(hlsCtx) ? $"?hls_ctx={hlsCtx}" : "")}";
+                if (edge != default)
+                {
+                    var u = new Uri(edge.Url, path);
+                    await sw.WriteLineAsync(u.ToString());
+                }
+                else
+                {
+                    var u = $"../{path}";
+                    await sw.WriteLineAsync(u);
+                }
             }
         }
         catch (Exception ex)

NostrStreamer/Extensions.cs

@@ -1,6 +1,7 @@
 using Amazon;
 using Amazon.Runtime;
 using Amazon.S3;
+using MaxMind.GeoIP2;
 using Newtonsoft.Json;
 using Nostr.Client.Json;
 using Nostr.Client.Keys;
@@ -50,6 +51,46 @@ public static class Extensions
         return !string.IsNullOrEmpty(user.Tags) ?
             user.Tags.Split(",", StringSplitOptions.RemoveEmptyEntries | StringSplitOptions.TrimEntries) : Array.Empty<string>();
     }
+
+    public static (double lat, double lon)? GetLocation(this HttpContext ctx, IGeoIP2DatabaseReader db)
+    {
+        var ip = ctx.GetRealIp();
+        var loc = db.TryCity(ip, out var city) ? city?.Location : default;
+        if ((loc?.Latitude.HasValue ?? false) && loc.Longitude.HasValue)
+        {
+            return (loc.Latitude.Value, loc.Longitude.Value);
+        }
+
+        return default;
+    }
+
+    public static string GetRealIp(this HttpContext ctx)
+    {
+        var cci = ctx.Request.Headers.TryGetValue("CF-Connecting-IP", out var xx) ? xx.ToString() : null;
+        if (!string.IsNullOrEmpty(cci))
+        {
+            return cci;
+        }
+
+        var xff = ctx.Request.Headers.TryGetValue("X-Forwarded-For", out var x) ? x.ToString() : null;
+        if (!string.IsNullOrEmpty(xff))
+        {
+            return xff.Split(",", StringSplitOptions.RemoveEmptyEntries).First();
+        }
+
+        return ctx.Connection.RemoteIpAddress!.ToString();
+    }
+
+    public static double GetDistance(double longitude, double latitude, double otherLongitude, double otherLatitude)
+    {
+        var d1 = latitude * (Math.PI / 180.0);
+        var num1 = longitude * (Math.PI / 180.0);
+        var d2 = otherLatitude * (Math.PI / 180.0);
+        var num2 = otherLongitude * (Math.PI / 180.0) - num1;
+        var d3 = Math.Pow(Math.Sin((d2 - d1) / 2.0), 2.0) + Math.Cos(d1) * Math.Cos(d2) * Math.Pow(Math.Sin(num2 / 2.0), 2.0);
+
+        return 6376500.0 * (2.0 * Math.Atan2(Math.Sqrt(d3), Math.Sqrt(1.0 - d3)));
+    }
 }
 
 public class Variant

NostrStreamer/NostrStreamer.csproj

@@ -38,6 +38,7 @@
         <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
       </PackageReference>
       <PackageReference Include="LNURL" Version="0.0.30" />
+      <PackageReference Include="MaxMind.GeoIP2" Version="5.1.0" />
       <PackageReference Include="MediaFormatLibrary.Lib" Version="1.0.0" />
       <PackageReference Include="Microsoft.AspNetCore.Mvc.NewtonsoftJson" Version="6.0.19" />
       <PackageReference Include="Microsoft.EntityFrameworkCore" Version="7.0.8" />

NostrStreamer/Program.cs

@@ -1,4 +1,5 @@
 using System.Security.Claims;
+using MaxMind.GeoIP2;
 using Microsoft.AspNetCore.Authorization;
 using Microsoft.AspNetCore.Authorization.Infrastructure;
 using Microsoft.EntityFrameworkCore;
@@ -29,6 +30,10 @@ internal static class Program
         services.AddControllers().AddNewtonsoftJson();
         services.AddSingleton(config);
         
+        // GeoIP
+        services.AddSingleton<IGeoIP2DatabaseReader>(_ => new DatabaseReader(config.GeoIpDatabase));
+        services.AddTransient<EdgeSteering>();
+        
         // nostr auth
         services.AddTransient<NostrAuthHandler>();
         services.AddAuthentication(o =>

NostrStreamer/Services/EdgeSteering.cs

@@ -0,0 +1,35 @@
+using System.Diagnostics;
+using MaxMind.GeoIP2;
+
+namespace NostrStreamer.Services;
+
+public class EdgeSteering
+{
+    private readonly Config _config;
+    private readonly IGeoIP2DatabaseReader _db;
+    private readonly ILogger<EdgeSteering> _logger;
+
+    public EdgeSteering(Config config, IGeoIP2DatabaseReader db, ILogger<EdgeSteering> logger)
+    {
+        _config = config;
+        _db = db;
+        _logger = logger;
+    }
+
+    public EdgeLocation? GetEdge(HttpContext ctx)
+    {
+        var sw = Stopwatch.StartNew();
+        var loc = ctx.GetLocation(_db);
+        if (loc != default)
+        {
+            var ret = _config.Edges.MinBy(a => Extensions.GetDistance(a.Longitude, a.Latitude, loc.Value.lon, loc.Value.lat));
+            sw.Stop();
+            _logger.LogTrace("Found edge in {n:#,##0.#}ms", sw.Elapsed.TotalMilliseconds);
+            return ret;
+        }
+        
+        sw.Stop();
+        _logger.LogTrace("Found no edge in {n:#,##0.#}ms", sw.Elapsed.TotalMilliseconds);
+        return default;
+    }
+}

NostrStreamer/appsettings.json

@@ -32,6 +32,21 @@
       "AccessKey": "TQcxug1ZAXfnZ5bvc9n5",
       "SecretKey": "p7EK4qew6DBkBPqrpRPuJgTOc6ChUlfIcEdAwE7K",
       "PublicHost": "http://localhost:9010"
-    }
+    },
+    "GeoIpDatabase": "/Users/kieran/Downloads/GeoLite2-City_20230801/GeoLite2-City.mmdb",
+    "Edges": [
+      {
+        "Name": "US0",
+        "Url": "https://us0.edge.zap.stream/",
+        "Longitude": -73.8024,
+        "Latitude": 45.4616
+      },
+      {
+        "Name": "Origin",
+        "Url": "https://data.zap.stream/",
+        "Longitude": 2.12664,
+        "Latitude": 50.98515
+      }
+    ]
   }
 }