NConfig is a .Net library that allows using multi-file, host-based configurations in .Net

This is thing you are really missing during staged deployments and with developer dependent environments.

All Original Software is licensed under the MIT License (see LICENSE.txt) and does not apply to any other 3rd party tools, utilities or code which may be used to develop this application.

Please inform me if anyone is aware of any license violations that this code may be making.

The easiest way to build NConfig from source is to clone the git repository on GitHub and build the NConfig solution.

git clone git://github.com/Yegoroff/NConfig.git

The solution file NConfig.sln is located in the root of the repo.

You can find NConfig in NuGet Gallery or just install it using VS NuGet Packages Manager.
Or just type Install-Package NConfig in Package Manager Console.

Also you can create NuGet package and put it to your local NuGet hive. To do this please run NuGet.bat, newly created package will be put to NuGet subfolder.

To enable NConfig in your code, you need only one code line in your application startup section:

NConfigurator.UsingFiles("Config\\Custom.config", "Config\\Connections.config").SetAsSystemDefault();

As result configurations from files {HostName}.Custom.config and {HostName}.Connections.config in Config subfolder will be merged and used in ConfigurationManager instead of default configuration.

Where {HostName} is the current machine name.

In case {HostName}.Custom.config do not exist, Custom.config file will be used. Moreover if Custom.config is missing too, App.config (or Web.config) will be used.

NOTE:
You should set Copy To Output Directory = Copy Always for all your custom configuration files, otherwise they will not be copied to Bin folder and NConfig will not find them.

	// Setup NConfigurator to use Custom.config file from Config subfolder.
	NConfigurator.UsingFile(@"Config\Custom.config").SetAsSystemDefault();


        var configManagerTestSection = ConfigurationManager.GetSection("TestConfigSection") as TestConfigSection;

        var testSection = NConfigurator.Default.GetSection<TestConfigSection>();

	var namedTestSection = NConfigurator.UsingFile(@"Config\Custom.config").GetSection<TestConfigSection>("NamedSection");

	Console.WriteLine("NConfig Default : " + testSection.TestValue);
	Console.WriteLine("ConfigurationManager : " + configManagerTestSection.TestValue);
	Console.WriteLine("NConfig named section : " + namedTestSection.TestValue);

	Console.WriteLine("Merged APP Settings : ");
	foreach(var key in ConfigurationManager.AppSettings.AllKeys)
	{
		Console.WriteLine(key + " : " +  ConfigurationManager.AppSettings[key]);
	}

For more complex examples please refer to Samples subfolder.

In most cases this very popular logging library uses direct access to App.config(Web.config) XML, ignoring ConfigurationManager and therefore ignoring NConfig.

So, how can I configure it?
There are several ways:

First: If you just need to split log4net configuration from App.config.

Use log4net.Config setting in appSettings:

        <appSettings>
            <add key="log4net.Config" value="Config\separate-log4net.config"/>
        </appSettings>

Or use [assembly: log4net.Config.XmlConfigurator(ConfigFile = @"Config\separate-log4net.config")] attribute.
Or specify configuration file programmatically

        var fullPath = Path.Combine(AppDomain.CurrentDomain.BaseDirectory, @"\Config\separate-log4net.config");
        log4net.Config.XmlConfigurator.Configure(new FileInfo(fullPath));

More details [here] (http://logging.apache.org/log4net/release/manual/configuration.html)

Second: If you need machine/host dependent log4net configurations.

One of the issue there is that usually log4net initialized earlier than NConfig, because of static field initialization.
private static log4net.ILog log = log4net.LogManager.GetLogger(...);

One way is to use log4net.Config setting with current config file path in your custom configuration file,
and delay logger setup till NConfig initialized.

File Config\Custom.config

      <?xml version="1.0"?>
      <configuration>
        <configSections>
            <section name="log4net" type="System.Configuration.IgnoreSectionHandler" />
        </configSections>

        <appSettings>
            <!-- This will override any previous log4net.Config settings in app.config and 
                 forces log4net to use this file as configuration. -->
            <add key="log4net.Config" value="Config\Custom.config"/>
        </appSettings>
        
        <log4net>
            <!-- log4net configuration here -->
            ...
        </log4net>
        
     </configuration>

Program code:

   private static log4net.ILog log;

   static void Main() {
   
	// Setup NConfigurator to use Custom.config file from Config subfolder.
	NConfigurator.UsingFile(@"Config\Custom.config").SetAsSystemDefault();
	
	//Delayed log setup, this will configure log4net using current appSettings from Custom.config.
	log = log4net.LogManager.GetLogger(System.Reflection.MethodBase.GetCurrentMethod().DeclaringType);
	...

Another way is to use explicit log4net.Config.XmlConfigurator.Configure(); call after NConfig initialization and declare log4net section as Log4NetConfigurationSectionHandler. This will allow us not to specify any additional configuration file paths in appSettings and will provide smooth NConfig experience.

File Config\Custom.config

      <?xml version="1.0"?>
      <configuration>
        <configSections>
            <!-- NOTE that we use Log4NetConfigurationSectionHandler to make log4net use ConfigurationManager -->
            <section name="log4net" type="log4net.Config.Log4NetConfigurationSectionHandler, log4net" />
        </configSections>
        
        <log4net>
            <!-- log4net configuration here -->
            ...
        </log4net>
        
     </configuration>

Program code:

   private static log4net.ILog log = log4net.LogManager.GetLogger(System.Reflection.MethodBase.GetCurrentMethod().DeclaringType);

   static void Main() {
   
	// Setup NConfigurator to use Custom.config file from Config subfolder.
	NConfigurator.UsingFile(@"Config\Custom.config").SetAsSystemDefault();
	
	// Configure log4net using host-based Custom.config configuration file.
	log4net.Config.XmlConfigurator.Configure();
	...

Feel free to contact me if you have any other questions related to NConfig integrations.

Currently NConfig was tested against ASP.Net, ASP.Net MVC, WinServices, WinForms/WPF, Console apps. Other environments are supposed to be supported too, but I haven't tested them yet.

If you do everything as described before, but no custom configuration applied, please check that settings
Copy To Output Directory = Copy Always
for all your configuration files.

If you encounter any issues please do not hesitate to inform me using GitHub direct messages or raising issue on GitHub.

I would like to thank my colleagues for helping me testing and fixing this tool. Also thanks to TLK for his help in this file creation. Also I would like to thank the guys at 31337 chat for their support.