CSharpEssentials.LoggerHelper 5.0.3

CSharpEssentials.LoggerHelper

Route Serilog sinks by log level — zero boilerplate, native ILogger<T> support.

Install the NuGet, add 5 lines of JSON, and every ILogger<T> in your app automatically routes logs to Console, File, Email, Telegram, PostgreSQL, SQL Server, Elasticsearch, and Seq — each sink receiving only the levels you want.

dotnet add package CSharpEssentials.LoggerHelper
dotnet add package CSharpEssentials.LoggerHelper.Sink.Console
dotnet add package CSharpEssentials.LoggerHelper.Sink.File
dotnet add package CSharpEssentials.LoggerHelper.Sink.Email   # add only what you need

Why LoggerHelper?

Quick Start — 30 seconds

Option A — JSON config (recommended)

Program.cs

builder.Services.AddLoggerHelper(builder.Configuration);
app.UseLoggerHelper();

appsettings.LoggerHelper.json

{
  "LoggerHelper": {
    "ApplicationName": "MyApp",
    "Routes": [
      { "Sink": "Console", "Levels": ["Information", "Warning"] },
      { "Sink": "File",    "Levels": ["Information", "Warning", "Error", "Fatal"] },
      { "Sink": "Email",   "Levels": ["Error", "Fatal"] }
    ],
    "Sinks": {
      "File":  { "Path": "C:\\Logs\\MyApp", "RollingInterval": "Day" },
      "Email": { "To": "ops@example.com", "Host": "smtp.example.com", "Port": 587 }
    },
    "General": { "EnableRequestResponseLogging": true }
  }
}

That's it. Every ILogger<T> in your app now routes through LoggerHelper.

Option B — Fluent API

builder.Services.AddLoggerHelper(b => b
    .WithApplicationName("MyApp")
    .AddRoute("Console", LogEventLevel.Information, LogEventLevel.Warning)
    .AddRoute("File",    LogEventLevel.Information, LogEventLevel.Warning, LogEventLevel.Error, LogEventLevel.Fatal)
    .AddRoute("Email",   LogEventLevel.Error, LogEventLevel.Fatal)
    .ConfigureFile(f => { f.Path = "C:\\Logs\\MyApp"; f.RollingInterval = "Day"; })
    .EnableRequestResponseLogging()
);

Option C — JSON base + fluent overrides (merge)

// JSON defines shared config across environments.
// Fluent adds Development-only extras without touching JSON.
builder.Services.AddLoggerHelper(builder.Configuration, b => b
    .AddRoute("Console", LogEventLevel.Debug)  // extra sink only in code
);

Option D — Via ILoggingBuilder (respects Logging:LogLevel filters)

builder.Logging.ClearProviders();
builder.Logging.AddLoggerHelper(builder.Configuration);

Zero code changes for existing apps

If your app already uses ILogger<T>, you change nothing. LoggerHelper plugs in as a standard ILoggerProvider:

// Your existing service — not a single line changes
public class OrderService(ILogger<OrderService> logger) {
    public void Process(int orderId) {
        logger.LogInformation("Processing order {OrderId}", orderId);  // → Console + File
        logger.LogError("Payment failed for {OrderId}", orderId);      // → File + Email
    }
}

Named parameters like {OrderId} are preserved as structured Serilog properties — not flattened into strings.

BeginScope — context that travels with your logs

Add business properties once. Every log in that block carries them automatically, including logs inside methods you call:

using (_logger.BeginScope(new Dictionary<string, object?> {
    ["OrderId"] = orderId,
    ["UserId"]  = userId
}))
{
    _logger.LogInformation("Validation started");   // OrderId + UserId are here
    await ValidateStock();                           // logs inside also carry them
    _logger.LogInformation("Order confirmed");       // OrderId + UserId are here
}
// Outside the using: properties removed automatically

Scope nesting — properties accumulate layer by layer:

using (_logger.BeginScope(new Dictionary<string, object?> { ["OrderId"] = 123 }))
{
    using (_logger.BeginScope(new Dictionary<string, object?> { ["Provider"] = "Stripe" }))
    {
        _logger.LogInformation("Charging card");
        // OrderId=123, Provider="Stripe"
    }
    _logger.LogInformation("Order complete");
    // OrderId=123  (Provider removed)
}

Automatic enrichment on every log

Without any extra code, every log event carries:

Available sinks

Each sink is a separate NuGet — install only what you need:

Sinks self-register via a plugin mechanism — the core package has zero dependency on them.

Per-level routing — real-world example

"Routes": [
  { "Sink": "Console",       "Levels": ["Debug", "Information", "Warning"] },
  { "Sink": "File",          "Levels": ["Information", "Warning", "Error", "Fatal"] },
  { "Sink": "Telegram",      "Levels": ["Error", "Fatal"] },
  { "Sink": "Email",         "Levels": ["Fatal"] },
  { "Sink": "Elasticsearch", "Levels": ["Information", "Warning", "Error", "Fatal"] }
]

• Developers see everything on Console during development
• File captures all non-debug logs for auditing
• Telegram pings the team on every error
• Email sends a full report only for fatal crashes
• Elasticsearch indexes everything for Kibana dashboards

Migrating from v2/v4 (legacy JSON)

See gap analysis for feature parity details.

Benchmarks

See docs/benchmarks.md for LoggerHelper v5 vs Serilog vs NLog comparisons.

Environment-aware configuration

LoggerHelper automatically picks the right file based on the current environment:

Internal diagnostics

If a sink fails to configure (wrong connection string, unreachable SMTP server), LoggerHelper captures the error silently and exposes it — your app keeps running:

app.MapGet("/health/logging", (ILogErrorStore errors) =>
    errors.Count == 0
        ? Results.Ok("All sinks healthy")
        : Results.Problem(string.Join("\n", errors.GetAll().Select(e => $"{e.SinkName}: {e.ErrorMessage}")))
);

Request / Response logging middleware

Enable HTTP request/response logging with a single setting:

"General": { "EnableRequestResponseLogging": true }

Then activate in the pipeline:

app.UseLoggerHelper();

Building a custom sink

1. Create a project CSharpEssentials.LoggerHelper.Sink.MyTarget
2. Implement ISinkPlugin:

internal sealed class MyTargetSinkPlugin : ISinkPlugin {
    public bool CanHandle(string sinkName) =>
        sinkName.Equals("MyTarget", StringComparison.OrdinalIgnoreCase);

    public void Configure(LoggerConfiguration loggerConfig, SinkRouting routing, LoggerHelperOptions options) {
        var opts = options.GetSinkConfig<MyTargetOptions>("MyTarget")
                   ?? options.BindSinkSection<MyTargetOptions>("MyTarget")
                   ?? new MyTargetOptions();

        loggerConfig.WriteTo.Conditional(
            evt => routing.Matches(evt.Level),
            wt => wt.MySink(opts.ConnectionString)
        );
    }
}

public static class PluginInitializer {
    [ModuleInitializer]
    public static void Init() => SinkPluginRegistry.Register(new MyTargetSinkPlugin());
}

3. Reference CSharpEssentials.LoggerHelper as a NuGet — not a project reference.
4. The sink auto-registers at startup with no changes to the core.

Performance

LoggerHelper v5 is built on Serilog, adding a thin MEL-compatible routing layer. Overhead vs raw Serilog is kept minimal — no reflection at log time, level checks short-circuit before routing evaluation.

Full benchmark results (auto-updated on each release) → docs/benchmarks.md

Benchmarks run with BenchmarkDotNet on .NET 9, comparing LoggerHelper v5 against Serilog (baseline) and NLog using no-op sinks to measure framework overhead independently of I/O.

Target frameworks

TODO

Planned for upcoming releases — contributions welcome.

• Source Generator — replace runtime reflection for sink loading with a compile-time source generator: faster startup, AOT-compatible, trimming-safe
• BenchmarkDotNet suite — published performance comparisons vs Serilog pure, NLog, and Microsoft.Extensions.Logging default provider
• dotnet new template — dotnet new loggerhelper-api scaffolds a pre-configured project with zero friction
• Dashboard sink — embedded real-time UI showing active sinks, routing rules, and recent sink errors
• xUnit sink — forwards log output to xUnit test runner for integration test visibility
• AI extension — natural language log queries, anomaly detection, and incident summarization via LLM
• Telemetry extension — OpenTelemetry metrics export (log counters per sink, error rates, latency)
• Interactive playground — browser-based editor to test JSON routing config and see live output

License

MIT — © Alessandro Chiodo

Documentation · GitHub · NuGet