Adding support for YARP native configuration

AppServiceProxy.Tests/ProxiesJsonReaderTests.cs

@@ -1,4 +1,4 @@
-using AppServiceProxy.Configuration;
+using AppServiceProxy.Configuration.Proxies;
 
 using Xunit;
 

AppServiceProxy.Tests/ProxiesJsonTransformTests.cs

@@ -1,6 +1,6 @@
 using System;
 
-using AppServiceProxy.Configuration;
+using AppServiceProxy.Configuration.Proxies;
 
 using Xunit;
 

AppServiceProxy.Tests/YarpJsonReaderTests.cs

@@ -0,0 +1,39 @@
+using AppServiceProxy.Configuration.Yarp;
+
+using Xunit;
+
+namespace AppServiceProxy.Tests;
+
+public class YarpJsonReaderTests
+{
+    [Fact]
+    public void Basic()
+    {
+        var json = @"
+{
+  ""Routes"": {
+    ""route1"": {
+      ""ClusterId"": ""cluster1"",
+      ""Match"": {
+        ""Path"": ""{**catch-all}""
+      }
+    }
+  },
+  ""Clusters"": {
+    ""cluster1"": {
+      ""Destinations"": {
+        ""cluster1/destination1"": {
+          ""Address"": ""https://shibayan.jp/""
+        }
+      }
+    }
+  }
+}
+";
+
+        var yarp = YarpJsonReader.ParseJson(json);
+
+        Assert.Single(yarp.Routes);
+        Assert.Single(yarp.Clusters);
+    }
+}

AppServiceProxy/Configuration/FileBaseProxyConfigProvider.cs

@@ -0,0 +1,77 @@
+using System.Diagnostics.CodeAnalysis;
+
+using AppServiceProxy.Configuration.Yarp;
+
+using Microsoft.Extensions.FileProviders;
+using Microsoft.Extensions.Primitives;
+
+using Yarp.ReverseProxy.Configuration;
+
+namespace AppServiceProxy.Configuration;
+
+internal class FileBaseProxyConfigProvider : IProxyConfigProvider
+{
+    public FileBaseProxyConfigProvider(IEnumerable<IConfigFileLoader> configFileLoaders)
+    {
+        _configFileLoaders = configFileLoaders;
+
+        var json = System.Text.Json.JsonSerializer.Deserialize<YarpJson>(File.ReadAllText(@"C:\Users\shibayan\Documents\yarp.json"));
+
+        _fileProvider = new PhysicalFileProvider(s_wwwroot)
+        {
+            UseActivePolling = true,
+            UsePollingFileWatcher = true
+        };
+    }
+
+    private readonly IEnumerable<IConfigFileLoader> _configFileLoaders;
+    private readonly PhysicalFileProvider _fileProvider;
+
+    private static readonly string s_wwwroot = Environment.ExpandEnvironmentVariables(@"%HOME%\site\wwwroot");
+
+    public IProxyConfig GetConfig()
+    {
+        if (TryGetConfigFileLoader(out var configFileLoader))
+        {
+            var contents = File.ReadAllText(Path.Combine(s_wwwroot, configFileLoader.ConfigFileName));
+
+            var (routes, clusters) = configFileLoader.LoadConfig(contents);
+
+            var changeToken = _fileProvider.Watch(configFileLoader.ConfigFileName);
+
+            return new FileBaseProxyConfig
+            {
+                Routes = routes,
+                Clusters = clusters,
+                ChangeToken = changeToken
+            };
+        }
+        else
+        {
+            var changeToken = _fileProvider.Watch("*.*");
+
+            return new FileBaseProxyConfig
+            {
+                Routes = Array.Empty<RouteConfig>(),
+                Clusters = Array.Empty<ClusterConfig>(),
+                ChangeToken = changeToken
+            };
+        }
+    }
+
+    private bool TryGetConfigFileLoader([NotNullWhen(true)] out IConfigFileLoader? configFileLoader)
+    {
+        configFileLoader = _configFileLoaders.FirstOrDefault(x => File.Exists(Path.Combine(s_wwwroot, x.ConfigFileName)));
+
+        return configFileLoader is not null;
+    }
+
+    private class FileBaseProxyConfig : IProxyConfig
+    {
+        public IReadOnlyList<RouteConfig> Routes { get; init; } = null!;
+
+        public IReadOnlyList<ClusterConfig> Clusters { get; init; } = null!;
+
+        public IChangeToken ChangeToken { get; init; } = null!;
+    }
+}

AppServiceProxy/Configuration/IConfigFileLoader.cs

@@ -0,0 +1,10 @@
+using Yarp.ReverseProxy.Configuration;
+
+namespace AppServiceProxy.Configuration;
+
+internal interface IConfigFileLoader
+{
+    string ConfigFileName { get; }
+
+    (IReadOnlyList<RouteConfig>, IReadOnlyList<ClusterConfig>) LoadConfig(string contents);
+}

AppServiceProxy/Configuration/ProxiesJson.cs → AppServiceProxy/Configuration/Proxies/ProxiesJson.cs

@@ -1,4 +1,4 @@
-namespace AppServiceProxy.Configuration;
+namespace AppServiceProxy.Configuration.Proxies;
 
 internal class ProxiesJson
 {
@@ -27,14 +27,18 @@ internal class MatchConditionConfig
     internal class RequestOverridesConfig
     {
         public string? Method { get; init; }
+
         public IReadOnlyDictionary<string, string> QueryString { get; init; } = null!;
+
         public IReadOnlyDictionary<string, string> Headers { get; init; } = null!;
     }
 
     internal class ResponseOverridesConfig
     {
         public int? StatusCode { get; init; }
+
         public string? StatusReason { get; init; }
+
         public IReadOnlyDictionary<string, string> Headers { get; init; } = null!;
     }
 }

AppServiceProxy/Configuration/Proxies/ProxiesJsonConfigFileLoader.cs

@@ -0,0 +1,24 @@
+
+using Yarp.ReverseProxy.Configuration;
+
+namespace AppServiceProxy.Configuration.Proxies;
+
+internal class ProxiesJsonConfigFileLoader : IConfigFileLoader
+{
+    public string ConfigFileName => "proxies.json";
+
+    public (IReadOnlyList<RouteConfig>, IReadOnlyList<ClusterConfig>) LoadConfig(string contents)
+    {
+        try
+        {
+            var proxies = ProxiesJsonReader.ParseJson(contents);
+            var (routes, clusters) = ProxiesJsonTransform.Apply(proxies);
+
+            return (routes, clusters);
+        }
+        catch
+        {
+            return (Array.Empty<RouteConfig>(), Array.Empty<ClusterConfig>());
+        }
+    }
+}

AppServiceProxy/Configuration/ProxiesJsonReader.cs → AppServiceProxy/Configuration/Proxies/ProxiesJsonReader.cs

@@ -1,8 +1,8 @@
 using System.Text.Json;
 
-using static AppServiceProxy.Configuration.ProxiesJson;
+using static AppServiceProxy.Configuration.Proxies.ProxiesJson;
 
-namespace AppServiceProxy.Configuration;
+namespace AppServiceProxy.Configuration.Proxies;
 
 internal class ProxiesJsonReader
 {
@@ -57,8 +57,8 @@ private static ProxyConfig ParseProxyConfig(JsonProperty proxy)
         var requestOverridesConfig = new RequestOverridesConfig
         {
             Method = requestOverrides.TryGetProperty("method", out var method) ? method.GetString() : null,
-            QueryString = requestOverrides.EnumerateObject().Where(x => x.Name.StartsWith("backend.request.querystring.")).ToDictionary(x => x.Name.Substring(28), x => x.Value.GetString()!),
-            Headers = requestOverrides.EnumerateObject().Where(x => x.Name.StartsWith("backend.request.headers.")).ToDictionary(x => x.Name.Substring(24), x => x.Value.GetString()!)
+            QueryString = requestOverrides.EnumerateObject().Where(x => x.Name.StartsWith("backend.request.querystring.")).ToDictionary(x => x.Name[28..], x => x.Value.GetString()!),
+            Headers = requestOverrides.EnumerateObject().Where(x => x.Name.StartsWith("backend.request.headers.")).ToDictionary(x => x.Name[24..], x => x.Value.GetString()!)
         };
 
         return requestOverridesConfig;
@@ -75,7 +75,7 @@ private static ProxyConfig ParseProxyConfig(JsonProperty proxy)
         {
             StatusCode = responseOverrides.TryGetProperty("response.statusCode", out var statusCode) ? statusCode.GetInt32() : null,
             StatusReason = responseOverrides.TryGetProperty("response.statusReason", out var statusReason) ? statusReason.GetString() : null,
-            Headers = responseOverrides.EnumerateObject().Where(x => x.Name.StartsWith("response.headers.")).ToDictionary(x => x.Name.Substring(17), x => x.Value.GetString()!)
+            Headers = responseOverrides.EnumerateObject().Where(x => x.Name.StartsWith("response.headers.")).ToDictionary(x => x.Name[17..], x => x.Value.GetString()!)
         };
 
         return responseOverridesConfig;

AppServiceProxy/Configuration/ProxiesJsonTransform.cs → AppServiceProxy/Configuration/Proxies/ProxiesJsonTransform.cs

@@ -2,13 +2,13 @@
 
 using Yarp.ReverseProxy.Configuration;
 
-using static AppServiceProxy.Configuration.ProxiesJson;
+using static AppServiceProxy.Configuration.Proxies.ProxiesJson;
 
-namespace AppServiceProxy.Configuration;
+namespace AppServiceProxy.Configuration.Proxies;
 
-internal static class ProxiesJsonTransform
+internal static partial class ProxiesJsonTransform
 {
-    private static readonly Regex s_templateRegex = new(@"\{([^\{\}]+)\}", RegexOptions.Compiled);
+    private static readonly Regex s_templateRegex = TemplateRegex();
 
     public static (IReadOnlyList<RouteConfig>, IReadOnlyList<ClusterConfig>) Apply(IReadOnlyList<ProxyConfig> proxies)
     {
@@ -126,4 +126,7 @@ private static (string, string?) SplitBackendUri(string backendUri)
 
         return (destinationAddress, absolutePath);
     }
+
+    [GeneratedRegex(@"\{([^\{\}]+)\}", RegexOptions.Compiled)]
+    private static partial Regex TemplateRegex();
 }

AppServiceProxy/Configuration/Yarp/YarpJson.cs

@@ -0,0 +1,11 @@
+
+using Yarp.ReverseProxy.Configuration;
+
+namespace AppServiceProxy.Configuration.Yarp;
+
+internal class YarpJson
+{
+    public IReadOnlyList<RouteConfig> Routes { get; set; } = null!;
+
+    public IReadOnlyList<ClusterConfig> Clusters { get; set; } = null!;
+}

AppServiceProxy/Configuration/Yarp/YarpJsonConfigFileLoader.cs

@@ -0,0 +1,23 @@
+
+using Yarp.ReverseProxy.Configuration;
+
+namespace AppServiceProxy.Configuration.Yarp;
+
+internal class YarpJsonConfigFileLoader : IConfigFileLoader
+{
+    public string ConfigFileName => "yarp.json";
+
+    public (IReadOnlyList<RouteConfig>, IReadOnlyList<ClusterConfig>) LoadConfig(string contents)
+    {
+        try
+        {
+            var yarp = YarpJsonReader.ParseJson(contents);
+
+            return (yarp.Routes, yarp.Clusters);
+        }
+        catch
+        {
+            return (Array.Empty<RouteConfig>(), Array.Empty<ClusterConfig>());
+        }
+    }
+}

AppServiceProxy/Configuration/Yarp/YarpJsonReader.cs

@@ -0,0 +1,53 @@
+using System.Text.Json;
+
+using Yarp.ReverseProxy.Configuration;
+
+namespace AppServiceProxy.Configuration.Yarp;
+
+internal class YarpJsonReader
+{
+    public static YarpJson ParseJson(string json)
+    {
+        var document = JsonDocument.Parse(json);
+
+        var routes = document.RootElement.GetProperty("Routes");
+        var clusters = document.RootElement.GetProperty("Clusters");
+
+        return new YarpJson { };
+    }
+
+    private static RouteConfig ParseRouteConfig(JsonProperty route)
+    {
+        return new RouteConfig
+        {
+            RouteId = route.Name,
+            Order = route.Value.TryGetProperty(nameof(RouteConfig.Order), out var order) ? order.GetInt32() : null,
+            ClusterId = route.Value.TryGetProperty(nameof(RouteConfig.ClusterId), out var clusterId) ? clusterId.GetString() : null,
+            AuthorizationPolicy = route.Value.TryGetProperty(nameof(RouteConfig.AuthorizationPolicy), out var authorizationPolicy) ? authorizationPolicy.GetString() : null,
+            CorsPolicy = route.Value.TryGetProperty(nameof(RouteConfig.CorsPolicy), out var corsPolicy) ? corsPolicy.GetString() : null,
+            Metadata = route.Value.TryGetProperty(nameof(RouteConfig.Metadata), out var metadata) ? metadata.Deserialize<Dictionary<string, string>>() : null,
+            Transforms = route.Value.TryGetProperty(nameof(RouteConfig.Transforms), out var transforms) ? ParseTransforms(transforms) : null
+        };
+    }
+
+    private static ClusterConfig ParseClusterConfig(JsonProperty cluster)
+    {
+        return new ClusterConfig
+        {
+            ClusterId = cluster.Name,
+            LoadBalancingPolicy = cluster.Value.TryGetProperty(nameof(ClusterConfig.LoadBalancingPolicy), out var loadBalancingPolicy) ? loadBalancingPolicy.GetString() : null,
+        };
+    }
+
+    private static IReadOnlyList<IReadOnlyDictionary<string, string>>? ParseTransforms(JsonElement transforms)
+    {
+        if (transforms.GetArrayLength() == 0)
+        {
+            return null;
+        }
+
+        return transforms.EnumerateArray()
+                         .Select(x => x.EnumerateObject().ToDictionary(xs => xs.Name, xs => xs.Value.GetString()!, StringComparer.OrdinalIgnoreCase))
+                         .ToList();
+    }
+}