feat(apiv2): basic error handling

PluralKit.API/Errors.cs

@@ -0,0 +1,51 @@
+using System;
+
+using Newtonsoft.Json.Linq;
+
+namespace PluralKit.API
+{
+    public class PKError: Exception
+    {
+        public int ResponseCode { get; init; }
+        public int JsonCode { get; init; }
+        public PKError(int code, int json_code, string message) : base(message)
+        {
+            ResponseCode = code;
+            JsonCode = json_code;
+        }
+
+        public JObject ToJson()
+        {
+            var j = new JObject();
+            j.Add("message", this.Message);
+            j.Add("code", this.JsonCode);
+            return j;
+        }
+    }
+
+    public class ModelParseError: PKError
+    {
+        public ModelParseError() : base(400, 0, "Error parsing JSON model")
+        {
+            // todo
+        }
+
+        public new JObject ToJson()
+        {
+            var j = base.ToJson();
+
+            return j;
+        }
+    }
+
+    public static class APIErrors
+    {
+        public static PKError GenericBadRequest = new(400, 0, "400: Bad Request");
+        public static PKError SystemNotFound = new(404, 20001, "System not found.");
+        public static PKError MemberNotFound = new(404, 20002, "Member not found.");
+        public static PKError GroupNotFound = new(404, 20003, "Group not found.");
+        public static PKError UnauthorizedMemberList = new(403, 30001, "Unauthorized to view member list");
+        public static PKError UnauthorizedGroupList = new(403, 30002, "Unauthorized to view group list");
+        public static PKError Unimplemented = new(501, 50001, "Unimplemented");
+    }
+}

PluralKit.API/Startup.cs

@@ -7,7 +7,9 @@ using Autofac;
 using Microsoft.AspNetCore.Authentication;
 using Microsoft.AspNetCore.Authorization;
 using Microsoft.AspNetCore.Builder;
+using Microsoft.AspNetCore.Diagnostics;
 using Microsoft.AspNetCore.Hosting;
+using Microsoft.AspNetCore.Http;
 using Microsoft.AspNetCore.Mvc;
 using Microsoft.AspNetCore.Mvc.Versioning;
 using Microsoft.Extensions.Configuration;
@@ -15,6 +17,10 @@ using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Hosting;
 using Microsoft.OpenApi.Models;
 
+using Newtonsoft.Json;
+
+using Serilog;
+
 using PluralKit.Core;
 
 namespace PluralKit.API
@@ -91,7 +97,7 @@ namespace PluralKit.API
             builder.RegisterInstance(InitUtils.BuildConfiguration(Environment.GetCommandLineArgs()).Build())
                 .As<IConfiguration>();
             builder.RegisterModule(new ConfigModule<ApiConfig>("API"));
-            builder.RegisterModule(new LoggingModule("api"));
+            builder.RegisterModule(new LoggingModule("api", cfg: new LoggerConfiguration().Filter.ByExcluding(exc => exc.Exception is PKError)));
             builder.RegisterModule(new MetricsModule("API"));
             builder.RegisterModule<DataStoreModule>();
             builder.RegisterModule<APIModule>();
@@ -124,6 +130,23 @@ namespace PluralKit.API
                 return next();
             });
 
+            app.UseExceptionHandler(handler => handler.Run(async ctx =>
+            {
+                var exc = ctx.Features.Get<IExceptionHandlerPathFeature>();
+                if (exc.Error is not PKError)
+                {
+                    ctx.Response.StatusCode = 500;
+                    await ctx.Response.WriteAsync("{\"message\":\"500: Internal Server Error\",\"code\":0}");
+                    return;
+                }
+
+                var err = (PKError)exc.Error;
+                ctx.Response.StatusCode = err.ResponseCode;
+
+                var json = JsonConvert.SerializeObject(err.ToJson());
+                await ctx.Response.WriteAsync(json);
+            }));
+
             app.UseMiddleware<AuthorizationTokenHandlerMiddleware>();
 
             //app.UseHttpsRedirection();

PluralKit.Core/Modules/LoggingModule.cs

@@ -17,11 +17,13 @@ namespace PluralKit.Core
     {
         private readonly string _component;
         private readonly Action<LoggerConfiguration> _fn;
+        private LoggerConfiguration _cfg { get; init; }
 
-        public LoggingModule(string component, Action<LoggerConfiguration> fn = null)
+        public LoggingModule(string component, Action<LoggerConfiguration> fn = null, LoggerConfiguration cfg = null)
         {
             _component = component;
             _fn = fn ?? (_ => { });
+            _cfg = cfg ?? new LoggerConfiguration();
         }
 
         protected override void Load(ContainerBuilder builder)
@@ -44,7 +46,7 @@ namespace PluralKit.Core
             var consoleTemplate = "[{Timestamp:HH:mm:ss.fff}] {Level:u3} {Message:lj}{NewLine}{Exception}";
             var outputTemplate = "[{Timestamp:yyyy-MM-dd HH:mm:ss.ffffff}] {Level:u3} {Message:lj}{NewLine}{Exception}";
 
-            var logCfg = new LoggerConfiguration()
+            var logCfg = _cfg
                 .Enrich.FromLogContext()
                 .ConfigureForNodaTime(DateTimeZoneProviders.Tzdb)
                 .Enrich.WithProperty("Component", _component)
@@ -53,6 +55,9 @@ namespace PluralKit.Core
                 // Don't want App.Metrics/D#+ spam
                 .MinimumLevel.Override("App.Metrics", LogEventLevel.Information)
 
+                // nor ASP.NET spam
+                .MinimumLevel.Override("Microsoft", LogEventLevel.Information)
+
                 // Actual formatting for these is handled in ScalarFormatting
                 .Destructure.AsScalar<SystemId>()
                 .Destructure.AsScalar<MemberId>()