How to configure log4net programmatically from scratch (no config)

Question

This is a Bad Idea, I know, but... I want to configure log4net programmatically from scratch with no config file. I'm working on a simple logging application for me and my team to use for a bunch of relatively small departmental applications we're responsible for. I want them to all log to the same database. The logging application is just a wrapper around log4net with the AdoNetAppender preconfigured.

All of the applications are ClickOnce deployed, which presents a small problem with deploying the config file. If the config file were part of the core project, I could set its properties to deploy with the assembly. But it's part of a linked application, so I don't have the option of deploying it with the main application. (If that's not true, somebody please let me know).

Probably because it's a Bad Idea, there doesn't seem to be much sample code available for programmatically configruating log4net from scratch. Here's what I have so far.

Dim apndr As New AdoNetAppender()
apndr.CommandText = "INSERT INTO LOG_ENTRY (LOG_DTM, LOG_LEVEL, LOGGER, MESSAGE, PROGRAM, USER_ID, MACHINE, EXCEPTION) VALUES (@log_date, @log_level, @logger, @message, @program, @user, @machine, @exception)"
apndr.ConnectionString = connectionString
apndr.ConnectionType = "System.Data.SqlClient.SqlConnection, System.Data, Version=1.0.3300.0, Culture=neutral, PublicKeyToken=b77a5c561934e089"
apndr.CommandType = CommandType.Text
Dim logDate As New AdoNetAppenderParameter()
logDate.ParameterName = "@log_date"
logDate.DbType = DbType.DateTime
logDate.Layout = New RawTimeStampLayout()
apndr.AddParameter(logDate)
Dim logLevel As New AdoNetAppenderParameter()
logLevel.ParameterName = "@log_level"
'And so forth...

After configuring all the parameters for apndr, I at first tried this...

Dim hier As Hierarchy = DirectCast(LogManager.GetRepository(), Hierarchy)
hier.Root.AddAppender(apndr)

It didn't work. Then, as a shot in the dark, I tried this instead.

BasicConfigurator.Configure(apndr)

That didn't work either. Does anybody have any good references on how to configure log4net programmatically from scratch with no config file?

Answer 1

Here's an example class that creates log4net config completely in code. I should mention that creating a logger via a static method is generally viewed as bad, but in my context, this is what I wanted. Regardless, you can carve up the code to meet your needs.

using log4net;
using log4net.Repository.Hierarchy;
using log4net.Core;
using log4net.Appender;
using log4net.Layout;

namespace dnservices.logging
{
public class Logger
{
    private PatternLayout _layout = new PatternLayout();
    private const string LOG_PATTERN = "%d [%t] %-5p %m%n";

    public string DefaultPattern
    {
        get { return LOG_PATTERN; }
    }

    public Logger()
    {
        _layout.ConversionPattern = DefaultPattern;
        _layout.ActivateOptions();
    }

    public PatternLayout DefaultLayout
    {
        get { return _layout; }
    }

    public void AddAppender(IAppender appender)
    {
        Hierarchy hierarchy = 
            (Hierarchy)LogManager.GetRepository();

        hierarchy.Root.AddAppender(appender);
    }

    static Logger()
    {
        Hierarchy hierarchy = (Hierarchy)LogManager.GetRepository();
        TraceAppender tracer = new TraceAppender();
        PatternLayout patternLayout = new PatternLayout();

        patternLayout.ConversionPattern = LOG_PATTERN;
        patternLayout.ActivateOptions();

        tracer.Layout = patternLayout;
        tracer.ActivateOptions();
        hierarchy.Root.AddAppender(tracer);

        RollingFileAppender roller = new RollingFileAppender();
        roller.Layout = patternLayout;
        roller.AppendToFile = true;
        roller.RollingStyle = RollingFileAppender.RollingMode.Size;
        roller.MaxSizeRollBackups = 4;
        roller.MaximumFileSize = "100KB";
        roller.StaticLogFileName = true;
        roller.File = "dnservices.txt";
        roller.ActivateOptions();
        hierarchy.Root.AddAppender(roller);

        hierarchy.Root.Level = Level.All;
        hierarchy.Configured = true;
    }

    public static ILog Create()
    {
        return LogManager.GetLogger("dnservices");
    }
}

}