Overview

Silky integrates Serilog as its structured logging framework via the Silky.Logging.Serilog module. Serilog provides a rich Sink ecosystem for writing logs to console, file, Elasticsearch, Seq, and more, with deep SkyAPM integration (automatic TraceId injection into every log entry).

Installation

<PackageReference Include="Silky.Logging.Serilog" Version="3.9.2" />

Silky.Logging.Serilog is already included in Silky.Agent.Host — no separate installation needed if you use that package.

Quick Start

Enable Serilog with a single method call in Program.cs:

var hostBuilder = Host.CreateDefaultBuilder(args)
    .ConfigureSilkyGeneralHostDefaults()
    .UseSerilogDefault();  // enable Serilog (default: Console + File)

await hostBuilder.Build().RunAsync();

UseSerilogDefault() behavior:

1. Reads the Serilog config section from appsettings.json / appsettings.yaml if present.
2. If Serilog:WriteTo is not configured, automatically enables:
   • Console: format [HH:mm:ss LVL] Message {Properties}
   • File: rolling file logs/application.log, daily rotation, UTF-8

Configuration File

Serilog:
  MinimumLevel:
    Default: Information
    Override:
      Microsoft: Warning
      Microsoft.Hosting.Lifetime: Information
      System: Warning
  WriteTo:
    - Name: Console
      Args:
        outputTemplate: "[{Timestamp:HH:mm:ss} {Level:u3}] {Message:lj} {Properties:j}{NewLine}{Exception}"
    - Name: File
      Args:
        path: logs/application.log
        rollingInterval: Day
        retainedFileCountLimit: 30
        outputTemplate: "[{Timestamp:yyyy-MM-dd HH:mm:ss.fff zzz} {Level:u3}] {Message:lj} {Properties:j}{NewLine}{Exception}"
  Enrich:
    - FromLogContext

When Serilog:WriteTo is present in configuration, UseSerilogDefault() uses only the configured sinks — no automatic Console/File.

Custom Configuration (Code)

.UseSerilogDefault(config =>
{
    config
        .WriteTo.Console()
        .WriteTo.File("logs/app.log", rollingInterval: RollingInterval.Day)
        .WriteTo.Seq("http://localhost:5341");
});

Elasticsearch Integration

Serilog:
  WriteTo:
    - Name: Elasticsearch
      Args:
        nodeUris: "http://localhost:9200"
        indexFormat: "silky-logs-{0:yyyy.MM}"
        autoRegisterTemplate: true

Structured Logging Best Practices

// ✅ Correct — structured, searchable in Seq/ELK
_logger.LogInformation("RPC call starting for {ServiceId} with timeout {Timeout}ms", serviceId, timeout);

// ❌ Wrong — destroys structure, incompatible with Seq/ELK
_logger.LogInformation($"RPC call starting for {serviceId} with timeout {timeout}ms");

Log Levels

SkyAPM TraceId Integration

When Silky.SkyApm.Agent is installed, every log entry automatically includes the current TraceId and SpanId. This correlates log entries with distributed traces in SkyWalking:

[2026-04-23 10:15:00 INF] Order created {OrderId: 1001, TraceId: "abc123", SpanId: "1.1"}