How to use Serilog ForContext

.net, logging, serilog

Solution

Not all properties attached to a log event will be rendered by all sinks attached to the logger; the file sink used here only includes the timestamp, level, message and so-on.

To get the report ID into the file, include it in the sink's `outputTemplate`:

var logger = new LoggerConfiguration()
  .WriteTo.File(@"C:\Log.txt",
    outputTemplate: "{Timestamp:u} [{Level}] ({ReportId}) {Message}{NewLine}{Exception}")
  .CreateLogger()
  .ForContext("ReportId", 10);

logger.Information("Test");

This will include the report ID in each message.

`ForContext` is usually used to create a short temporary scope; if you want the same property on all messages you can use `Enrich.WithProperty()`:

var logger = new LoggerConfiguration()
  .Enrich.WithProperty("ReportId", 10);
  .WriteTo.File(@"C:\Log.txt",
    outputTemplate: "{Timestamp:u} [{Level}] ({ReportId}) {Message}{NewLine}{Exception}")
  .CreateLogger()

Flat files are a great way to get up and running quickly with structured logs, but using a data store more suited to structured storage, e.g. `CouchDB`, `RavenDB` or `Seq`, will make it much nicer to view and correlate events based on property values.

Problem

I am new to Serilog and I am having a hard time figuring out how to use the context functionality. When I run the code below the output file does not include the the report id. Any ideas what I am missing? ``` var logger = new LoggerConfiguration() .WriteTo .File(@"C:\Log.txt") .CreateLogger() .ForContext("Report ID", 10); logger.Information("Test"); ```

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