add otel support

README.md

@@ -32,9 +32,6 @@ There is a full description of section that is needed in appsettings.json.
          },
          "EnableMetrics": true,
          "Metrics": {
-            "MapPath": "/metrics",
-            "Port": 82,
-            "UseDefaultCollectors": false,
             "LogsWriteFailCounterName": "logs_write_fail_counter",
             "LogsWriteSuccessCounterName": "logs_write_success_counter",
             "LogsSizeKbCounterName": "logs_size_kb_counter"
@@ -107,11 +104,9 @@ There is a full description of section that is needed in appsettings.json.
 ---
 
 If you need to enable metrics provide the additional section.
+You already need to add OpenTelemetry nuget packages and register services in Startup.cs.
 - `EnableMetrics` (default = false) - if `true` turn on metrics exporting
 - `Metrics` - could be fulfilled if `EnableMetrics: true`
-- `MapPath` (default = "/metrics") - endpoint for exporting metrics
-- `Port` (default = null) - port for exporting metrics
-- `UseDefaultCollectors` (default = false) - if `true` use default Prometheus collectors in addition
 - `LogsWriteFailCounterName` (default = 'logs_write_fail_counter') - metric counter name for exporting (broken logs)
 - `LogsWriteSuccessCounterName` (default = 'logs_write_success_counter') - metric counter name for exporting (correct logs)
 - `LogsSizeKbCounterName` (default = 'logs_size_kb_counter') - metric counter name for exporting (correct logs size in kb)
@@ -156,9 +151,19 @@ services.AddDirectToLokiLogging(configuration, c =>
    c.BaseAddress = new Uri("http://loki.net:3100"));
 ```
 
-3) `Optional`: if it is needed to skip logs in your RequestResponseLoggingMiddleware use
+3) `Optional (1)`: if it is needed to skip logs in your RequestResponseLoggingMiddleware use
 `RequestResponseLoggingFilter(httpContext)` method like an aid in determining which logs should be skipped.
 
+4) `Optional (2)` if you need to export logs metrics, you should add 
+```
+services.AddOpenTelemetry()
+   .WithMetrics(builder => builder
+        .AddPrometheusExporter(...)
+        .AddDirectLokiLoggingMeter();
+   );
+   ```
+in startup.cs file.
+
 
 
 ## Usage

samples/AspNetCore.WebApi/MetricsStartup.cs

@@ -0,0 +1,24 @@
+using System;
+using Microsoft.AspNetCore.Builder;
+using Microsoft.AspNetCore.Hosting;
+
+namespace WebApi;
+
+internal sealed class MetricsStartup : IStartupFilter
+{
+    private readonly IServiceProvider _serviceProvider;
+
+    public MetricsStartup(IServiceProvider serviceProvider)
+    {
+        _serviceProvider = serviceProvider;
+    }
+
+    public Action<IApplicationBuilder> Configure(Action<IApplicationBuilder> next)
+    {
+        return app =>
+        {
+            app.UseOpenTelemetryPrometheusScrapingEndpoint();
+            next(app);
+        };
+    }
+}

samples/AspNetCore.WebApi/Program.cs

@@ -3,9 +3,13 @@
 using Aerx.Serilog.Sinks.Loki.Extensions;
 using Microsoft.AspNetCore.Builder;
 using Microsoft.AspNetCore.Diagnostics;
+using Microsoft.AspNetCore.Hosting;
 using Microsoft.AspNetCore.Http;
 using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.DependencyInjection.Extensions;
+using OpenTelemetry.Metrics;
+using OpenTelemetry.Resources;
 using WebApi;
 using WebApi.Models;
 
@@ -17,6 +21,15 @@
     c.Timeout = TimeSpan.FromSeconds(5);
 });
 
+builder.Services.AddMetrics();
+builder.Services.AddOpenTelemetry()
+    .WithMetrics(b =>
+    {
+        b.AddPrometheusExporter(options => options.ScrapeEndpointPath = "/metrics")
+            .AddDirectLokiLoggingMeter();
+    });
+
+builder.Services.TryAddEnumerable(ServiceDescriptor.Transient<IStartupFilter, MetricsStartup>());
 builder.Services.AddSwaggerGen();
 builder.Services.AddControllers();
 

samples/AspNetCore.WebApi/WebApi.csproj

@@ -6,11 +6,19 @@
     </PropertyGroup>
 
     <ItemGroup>
+      <PackageReference Include="Microsoft.Extensions.DependencyInjection" Version="8.0.0" />
+      <PackageReference Include="Microsoft.Extensions.Diagnostics" Version="8.0.0" />
       <PackageReference Include="Microsoft.IO.RecyclableMemoryStream" Version="2.3.2" />
+      <PackageReference Include="OpenTelemetry.Exporter.Console" Version="1.7.0" />
+      <PackageReference Include="OpenTelemetry.Exporter.OpenTelemetryProtocol" Version="1.7.0" />
+      <PackageReference Include="OpenTelemetry.Exporter.Prometheus.AspNetCore" Version="1.7.0-rc.1" />
+      <PackageReference Include="OpenTelemetry.Extensions.Hosting" Version="1.7.0" />
+      <PackageReference Include="OpenTelemetry.Instrumentation.AspNetCore" Version="1.7.0" />
+      <PackageReference Include="OpenTelemetry.Instrumentation.Process" Version="0.5.0-beta.4" />
+      <PackageReference Include="OpenTelemetry.Instrumentation.Runtime" Version="1.7.0" />
       <PackageReference Include="Serilog" Version="3.0.1" />
       <PackageReference Include="Serilog.Sinks.Async" Version="1.5.0" />
       <PackageReference Include="Newtonsoft.Json" Version="13.0.2" />
-      <PackageReference Include="Prometheus.Client" Version="5.2.0" />
       <PackageReference Include="Serilog.AspNetCore" Version="7.0.0" />
       <PackageReference Include="Swashbuckle.AspNetCore.Swagger" Version="6.5.0" />
       <PackageReference Include="Swashbuckle.AspNetCore.SwaggerGen" Version="6.5.0" />

samples/AspNetCore.WebApi/appsettings.Prod.json

@@ -11,8 +11,8 @@
   },
   "Loki": {
     "AppName": "web-app",
-    "BatchPostingLimit": 100,
-    "ParallelismFactor": 4,
+    "BatchPostingLimit": 10,
+    "ParallelismFactor": 1,
     "Labels": {
       "app": "web-app"
     },

src/Aerx.Serilog.Sinks.Loki/Aerx.Serilog.Sinks.Loki.csproj

@@ -19,17 +19,18 @@
         <PackageReference Include="Microsoft.Extensions.Hosting" Version="6.0.0" />
         <PackageReference Include="Microsoft.Extensions.Http" Version="6.0.0" />
         <PackageReference Include="Microsoft.Extensions.Logging" Version="6.0.0" />
+        <PackageReference Include="OpenTelemetry.Api" Version="1.7.0" />
+        <PackageReference Include="OpenTelemetry.Instrumentation.Runtime" Version="1.7.0" />
         <PackageReference Include="Serilog.Extensions.Logging" Version="3.1.0" />
         <PackageReference Include="Microsoft.Extensions.ObjectPool" Version="6.0.0" />
         <PackageReference Include="Microsoft.Extensions.Options.ConfigurationExtensions" Version="6.0.0" />
         <PackageReference Include="Microsoft.Extensions.Options.DataAnnotations" Version="6.0.0" />
         <PackageReference Include="Newtonsoft.Json" Version="13.0.2" />
-        <PackageReference Include="Prometheus.Client" Version="5.2.0" />
-        <PackageReference Include="Prometheus.Client.Abstractions" Version="5.2.0" />
         <PackageReference Include="Serilog" Version="3.0.1" />
         <PackageReference Include="Serilog.Sinks.Async" Version="1.5.0" />
         <PackageReference Include="Serilog.Sinks.Console" Version="4.0.1" />
         <PackageReference Include="Microsoft.IO.RecyclableMemoryStream" Version="2.3.2" />
+        <PackageReference Include="System.Diagnostics.DiagnosticSource" Version="8.0.0" />
     </ItemGroup>
 
     <ItemGroup>

src/Aerx.Serilog.Sinks.Loki/Extensions/DependencyInjection.cs

@@ -4,15 +4,13 @@
 using Aerx.Serilog.Sinks.Loki.Logger;
 using Aerx.Serilog.Sinks.Loki.Metrics;
 using Aerx.Serilog.Sinks.Loki.Options;
-using Microsoft.AspNetCore.Hosting;
 using Microsoft.AspNetCore.Http;
 using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.DependencyInjection.Extensions;
 using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.Options;
-using Prometheus.Client;
-using Prometheus.Client.Collectors;
+using OpenTelemetry.Metrics;
 using Serilog.Formatting;
 using Serilog.Formatting.Json;
 
@@ -82,23 +80,19 @@ public static IServiceCollection AddDirectToLokiLogging(this IServiceCollection
         services.TryAddSingleton<LokiHttpClientPooledObjectPolicy>();
         services.TryAddSingleton<LokiSink>();
         services.TryAddSingleton<ILoggerProvider, DirectLogToLokiLoggerProvider>();
-
-        var registry = new CollectorRegistry();
-        var factory = new MetricFactory(registry);
-
-        services.TryAddSingleton<ICollectorRegistry>(registry);
-        services.TryAddSingleton<IMetricFactory>(factory);
-        services.TryAddSingleton<IMetricService, MetricService>();
-
-        var enableMetrics = configuration.GetValue<bool>($"{Constants.Loki}:{Constants.EnableMetrics}");
-        if (enableMetrics)
-        {
-            services.TryAddEnumerable(ServiceDescriptor.Transient<IStartupFilter, MetricsStartup>());
-        }
+        services.TryAddSingleton<IMeterService, MeterService>();
 
         return services;
     }
 
+    /// <summary>
+    /// Add metrics for open telemetry
+    /// </summary>
+    /// <param name="builder">Meter provider from OpenTelemetry lib</param>
+    /// <returns></returns>
+    public static MeterProviderBuilder AddDirectLokiLoggingMeter(this MeterProviderBuilder builder) => 
+        builder.AddMeter(MeterService.MeterName);
+
     /// <summary>
     /// Add direct to loki logging
     /// Required properties in configuration

src/Aerx.Serilog.Sinks.Loki/HttpClient/LokiGzipHttpClient.cs

@@ -7,7 +7,7 @@
 
 namespace Aerx.Serilog.Sinks.Loki.HttpClient;
 
-public class LokiGzipHttpClient : ILokiHttpClient
+public sealed class LokiGzipHttpClient : ILokiHttpClient
 {
     private static readonly MediaTypeHeaderValue ContentType = MediaTypeHeaderValue.Parse(Constants.JsonContentType);
     private static readonly JsonSerializerSettings CamelCase = new()
@@ -58,7 +58,7 @@ public async Task<LokiPushResponse> Push(LokiBatch batch)
         return result;
     }
 
-    public virtual ILokiHttpClient SetTenantId(string tenantId)
+    public ILokiHttpClient SetTenantId(string tenantId)
     {
         if (string.IsNullOrEmpty(tenantId) || _httpClient.DefaultRequestHeaders.Contains(Constants.TenantIdHeader))
         {

src/Aerx.Serilog.Sinks.Loki/Logger/LokiSink.cs

@@ -27,7 +27,7 @@ public LokiSink(
         ITextFormatter textFormatter,
         ILokiBatchFormatter batchFormatter,
         LokiHttpClientPooledObjectPolicy pooledObjectPolicy, 
-        IMetricService metricService)
+        IMeterService meterService)
     {
         var pool = new DefaultObjectPoolProvider
         {
@@ -60,7 +60,7 @@ public LokiSink(
                 }
                 catch (Exception e)
                 {
-                    metricService.ObserveOnLogsWriteFail(messages.Length);
+                    meterService.ObserveOnLogsWriteFail(messages.Length);
                     SelfLog.WriteLine($"Transformation block exception: {e}");
                     return new LokiBatch();
                 }
@@ -93,13 +93,13 @@ public LokiSink(
                         }
                         else
                         {
-                            metricService.ObserveOnLogsWriteSuccess(batchSize);
-                            metricService.ObserveOnLogsBatchSize(result.ContentSizeInKb);
+                            meterService.ObserveOnLogsWriteSuccess(batchSize);
+                            meterService.ObserveOnLogsBatchSize(result.ContentSizeInKb);
                         }
                     }
                     catch (Exception)
                     {
-                        metricService.ObserveOnLogsWriteFail(batchSize);
+                        meterService.ObserveOnLogsWriteFail(batchSize);
                     }
                     finally
                     {

src/Aerx.Serilog.Sinks.Loki/Metrics/IMetricService.cs → src/Aerx.Serilog.Sinks.Loki/Metrics/IMeterService.cs

@@ -1,6 +1,6 @@
 namespace Aerx.Serilog.Sinks.Loki.Metrics;
 
-public interface IMetricService
+public interface IMeterService
 {
     void ObserveOnLogsWriteFail(int failLogsCount);