How to configure log4net programmatically from scr

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

I ended up using this:

http://www.mikebevers.be/blog/2010/09/log4net-custom-adonetappender/

After 4 hours fiddling with the config and getting progressively more frustrated.

Hope it helps someone.

Answer 2

'Solution for Vb.Net

Private Shared EscanerLog As log4net.ILog = log4net.LogManager.GetLogger("Log4Net.Config")

Public Sub New(ByVal sIDSesion As String)
    Dim sStream As Stream
    Dim JsText As String
    Using reader As New StreamReader((GetType(ClsGestorLogsTraza).Assembly).GetManifestResourceStream("Comun.Log4Net.Config"))
        JsText = reader.ReadToEnd()
        sStream = GenerateStreamFromString(JsText)
        log4net.Config.XmlConfigurator.Configure(sStream)
    End Using
End Sub

Public Function GenerateStreamFromString(ByVal s As String) As Stream
    Dim stream = New MemoryStream()
    Dim writer = New StreamWriter(stream)
    writer.Write(s)
    writer.Flush()
    stream.Position = 0
    Return stream
End Function

Public Function StreamFromResource(ByVal sFilename As String) As Stream
    Dim nAssembly As System.Reflection.Assembly = System.Reflection.Assembly.GetExecutingAssembly()
    Dim s As Stream = nAssembly.GetManifestResourceStream(System.Reflection.MethodBase.GetCurrentMethod.DeclaringType, sFilename)
    Return s
End Function

Answer 3

// I've embedded three config files as an Embedded Resource and access them like this:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Resources;
using System.IO;

namespace Loader
{
  class Program
  {
    private static log4net.ILog CustomerLog = log4net.LogManager.GetLogger("CustomerLogging");
    private static log4net.ILog OrderLog = log4net.LogManager.GetLogger("OrderLogging");
    private static log4net.ILog DetailsLog = log4net.LogManager.GetLogger("OrderDetailLogging");


    static void Main(string[] args)
    {
      // array of embedded log4net config files
      string[] configs = { "Customer.config", "Order.config", "Detail.config"};

      foreach (var config in configs)
      {
        // build path to assembly config
        StringBuilder sb = new StringBuilder();
        sb.Append(System.Reflection.Assembly.GetExecutingAssembly().GetName().Name);
        sb.Append(".");
        sb.Append(config);

        // convert to a stream
        Stream configStream = System.Reflection.Assembly.GetExecutingAssembly().GetManifestResourceStream(sb.ToString());

        // configure logger with ocnfig stream
        log4net.Config.XmlConfigurator.Configure(configStream);

        // test logging
        CustomerLog.Info("Begin logging with: " + config);
        OrderLog.Info("Begin logging with: " + config);
        DetailsLog.Info("Begin logging with: " + config);
        for (int iX = 0; iX < 10; iX++)
        {
          CustomerLog.Info("iX=" + iX);
          OrderLog.Info("iX=" + iX);
          DetailsLog.Info("iX=" + iX);
        }
        CustomerLog.Info("Ending logging with: " + config);
        OrderLog.Info("Ending logging with: " + config);
        DetailsLog.Info("Ending logging with: " + config);
      }

    }
  }
}

Answer 4

More concise solution:

var layout = new PatternLayout("%-4timestamp [%thread] %-5level %logger %ndc - %message%newline");
var appender = new RollingFileAppender {
    File = "my.log",
    Layout = layout
};
layout.ActivateOptions();
appender.ActivateOptions();
BasicConfigurator.Configure(appender);

Don't forget to call ActivateOptions method:

The ActivateOptions method must be called on this object after the configuration properties have been set. Until ActivateOptions is called this object is in an undefined state and must not be used.

Answer 5

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");
    }
}

}

Answer 6

I can't tell in the question's code snippet if the "'And so forth..." includes the very important apndr.ActivateOptions() which is indicated in Todd Stout's answer. Without ActivateOptions() the Appender is inactive and will not do anything which could explain why it is failing.