How to add custom file name to serilog file sink generated logs file

Question

I would like to add hostname to the log files which is generated by Serilog file sink.

I tried below, but my file name appears as log-{fileName}-20210910.txt for below code,

  vservices.AddLogging(logging => logging.AddSerilog(
            new LoggerConfiguration()
                .WriteTo.RollingFile(Path.Combine(Environment.CurrentDirectory, $"log-{fileName}.txt"),
                    outputTemplate: "{Timestamp:yyyy-MM-dd HH:mm:ss.fff zzz} [{Level:u3}] {fileName}, {Message:lj}{NewLine}{Exception}")
                .CreateLogger()));

How to access fileName variable while defining serilog configuration?

Answer 1

you are missing the $ symbol

var fileName = Environment.GetEnvironmentVariable("HOSTNAME") ?? "add-on";
    services.AddLogging(logging => logging.AddSerilog(new LoggerConfiguration()
        .WriteTo.RollingFile(Path.Combine(Environment.CurrentDirectory, $"log-{fileName}.txt"))
        .CreateLogger()));

other option is:

var fileName = Environment.GetEnvironmentVariable("HOSTNAME") ?? "add-on";
    services.AddLogging(logging => logging.AddSerilog(new LoggerConfiguration()
        .WriteTo.RollingFile(Path.Combine(Environment.CurrentDirectory, "log-" + fileName + ".txt"))
        .CreateLogger()));