Serilog Skill
VanDaemon uses Serilog 8.x for structured logging with console and file sinks. Logs use semantic message templates with named properties for queryability. The API layer configures Serilog in Program.cs with rolling file output to logs/vandaemon-{Date}.txt.
Quick Start
Basic Structured Logging
csharp
// Inject ILogger<T> via constructor
private readonly ILogger<TankService> _logger;
public TankService(ILogger<TankService> logger)
{
_logger = logger;
}
// Use semantic message templates - property names in braces
_logger.LogInformation("Tank {TankId} updated to {Level}%", tankId, level);
_logger.LogWarning("Tank {TankName} below threshold: {CurrentLevel}% < {Threshold}%",
tank.Name, tank.CurrentLevel, tank.AlertLevel);
Exception Logging
csharp
try
{
await plugin.SetStateAsync(controlId, state, ct);
}
catch (Exception ex)
{
// Exception as FIRST parameter, then message template
_logger.LogError(ex, "Failed to set state for control {ControlId}", controlId);
throw;
}
Key Concepts
| Concept | Usage | Example |
|---|---|---|
| Message Template | Named placeholders for structured data | "Processing {TankId}" |
| Log Level | Severity filtering | LogInformation, LogWarning, LogError |
| Enrichment | Automatic context properties | Enrich.FromLogContext() |
| Sink | Output destination | Console, File, Seq |
Common Patterns
Service Layer Logging
When: Logging business operations with context
csharp
public async Task<Tank> UpdateTankAsync(Tank tank, CancellationToken ct)
{
_logger.LogDebug("Updating tank {TankId}: {TankName}", tank.Id, tank.Name);
// Business logic...
_logger.LogInformation("Tank {TankId} saved successfully", tank.Id);
return tank;
}
Plugin Lifecycle Logging
When: Tracking plugin initialization and disposal
csharp
public async Task InitializeAsync(Dictionary<string, object> config, CancellationToken ct)
{
_logger.LogInformation("Initializing {PluginName} v{Version}", Name, Version);
if (!config.TryGetValue("MqttBroker", out var broker))
{
_logger.LogWarning("{PluginName} missing MqttBroker config, using default", Name);
}
}
See Also
- •patterns - Structured logging patterns and enrichment
- •workflows - Configuration and debugging workflows
Related Skills
- •See the aspnet-core skill for middleware logging configuration
- •See the dotnet skill for DI registration patterns
- •See the docker skill for viewing container logs