fix(api): actually run metrics reporters

create MetricsRunner.cs

PluralKit.API/MetricsRunner.cs

@@ -0,0 +1,48 @@
+using App.Metrics;
+
+using NodaTime;
+
+namespace PluralKit.API;
+
+public class MetricsRunner : IHostedService, IDisposable
+{
+    private readonly Serilog.ILogger _logger;
+    private readonly IMetrics _metrics;
+
+    private Timer? _periodicTask = null;
+
+    public MetricsRunner(Serilog.ILogger logger, IMetrics metrics)
+    {
+        _logger = logger;
+        _metrics = metrics;
+    }
+
+    public Task StartAsync(CancellationToken stoppingToken)
+    {
+        var timeNow = SystemClock.Instance.GetCurrentInstant();
+        var timeTillNextWholeMinute = TimeSpan.FromMilliseconds(60000 - timeNow.ToUnixTimeMilliseconds() % 60000 + 250);
+        _periodicTask = new Timer(_ =>
+        {
+            var __ = ReportMetrics();
+        }, null, timeTillNextWholeMinute, TimeSpan.FromMinutes(1));
+
+        return Task.CompletedTask;
+    }
+
+    private async Task ReportMetrics()
+    {
+        await Task.WhenAll(((IMetricsRoot)_metrics).ReportRunner.RunAllAsync());
+        _logger.Debug("Submitted metrics to backend");
+    }
+
+    public Task StopAsync(CancellationToken stoppingToken)
+    {
+        _periodicTask.Change(Timeout.Infinite, 0);
+        return Task.CompletedTask;
+    }
+
+    public void Dispose()
+    {
+        _periodicTask?.Dispose();
+    }
+}

PluralKit.API/Startup.cs

@@ -26,6 +26,8 @@ public class Startup
                 options.InvalidModelStateResponseFactory = context =>
                     throw Errors.GenericBadRequest
             );
+        
+        services.AddHostedService<MetricsRunner>();
     }
 
     public void ConfigureContainer(ContainerBuilder builder)