ServiceStack.Logging is a collection of logging integration providers that adapt external .NET logging frameworks to ServiceStack's core logging abstractions (ILogFactory and ILog).

It enables ServiceStack applications to route internal framework logs and application diagnostic messages to their preferred logging destination:

• Serilog (ServiceStack.Logging.Serilog): Structured logging adapter forwarding to Serilog sink pipelines.
• NLog (ServiceStack.Logging.NLog): Adapter for NLog targets and layout renderers.
• Log4Net (ServiceStack.Logging.Log4Net): Adapter for Apache log4net repositories.
• Slack (ServiceStack.Logging.Slack): Webhook logger publishing error notifications directly to Slack channels.
• EventLog (ServiceStack.Logging.EventLog): Windows Event Log integration.
• ELMAH (ServiceStack.Logging.Elmah): Intercepting logger signaling errors into ELMAH pipelines.

Target frameworks: net472;net6.0;net8.0;net10.0 (varying per provider package)

ServiceStack.Interfaces (ILogFactory, ILog, LogManager)
                         │
                         ▼
               ServiceStack.Logging
                         │
    ┌────────────┬───────┴────┬───────────┬────────────┐
    ▼            ▼            ▼           ▼            ▼
 Serilog        NLog       Log4Net      Slack       EventLog

• Depends on: ServiceStack.Interfaces, external logging SDKs (Serilog, NLog, log4net, etc.).
• Depended on by: ServiceStack applications requiring external log aggregation and monitoring.
• Registration: Initialized early in application startup (before AppHost.Init()) by setting LogManager.LogFactory.

Setting LogManager.LogFactory = new SerilogFactory() transparently redirects all ServiceStack framework logging across the entire process without modifying service code.

Logging adapters wrap external framework dispatches in defensive try/catch blocks so failures in logging destinations (e.g., Slack webhook downtime, ELMAH configuration issues) never crash the calling application or suppress secondary loggers.

Sourced from SECURITY_CHANGES.md. Follow these precautions:

• URLs pointing to http://hooks.slack.com must be automatically upgraded to https:// to prevent plaintext transmission of secret webhook tokens over the wire.
• Fire-and-forget webhook tasks must observe faults via .ContinueWith(..., TaskContinuationOptions.OnlyOnFaulted) to prevent unobserved task exceptions.
• Limit inner exception traversal to a fixed depth (e.g. 20) to prevent infinite loops on circular exceptions.

• EventLog instances must be wrapped in using blocks to prevent unmanaged handle leaks.
• Windows Event Log entry text must be truncated to 31,839 characters to avoid buffer overflow ArgumentException crashes.
• Guard source verification calls against SecurityException on unprivileged accounts.

• In SerilogFactory.GetLogger(string typeName), fall back to ForContext("SourceContext", typeName) when Type.GetType(typeName) returns null. Handle null message payloads gracefully.

• Use Assembly.GetEntryAssembly() ?? Assembly.GetExecutingAssembly() to avoid ArgumentNullException in web/worker hosts where GetEntryAssembly() is null.

1. Configuring a Logging Provider at Startup

   LogManager.LogFactory = new SerilogFactory();

2. Creating a Custom Log Provider

   • Implement ILogFactory and ILog.
   • Ensure ILog.Error methods safely handle null messages and null exceptions.