Exclude app.config from source control?

Question

What's the best way to allow team members to customize their own app.config, but keep an authoritative version in version control? Is it best to exclude all *.config files from source control, and use an app.config.template file in version control?

Answer 1

The template method is the best method I've seen. If you can automatically determine what it should contain (such as by running a script to check for the appropriate values), then you can include that in your build process and automatically create the file from the template. If you can't automatically determine what it needs to contain, be sure that your build process will check for the config file and provide the developer with useful guidance as to what he should configure before the build will work.

You'll want your scm to ignore the config file itself so that your devs don't accidentally commit it to the repository.

Answer 2

For a long time I'd always thought that Microsoft made configuration management a complete pain in the ass.

Luckily now you can externalise settings in the appSettings and connectionStrings sections etc. by using the file property for appSettings and the configSource property for other sections.

The documentation for configSource is hidden away in MSDN unfortunately, which is why I assume it isn't more widely known. The documentation provided is also rather bland, but there's a much better explanation here:

Best Practices for Configuring ASP.NET ConnectionStrings and AppSettings in Web.Config

To paraphrase, you can do stuff like this:

<appSettings file="webAppSettings.config">
  <add key="UseCache" value="True"/>
  <add key="MapsKey" value="1234567890-AA"/>
  <add key="SMTPServer" value="smtp.peterkellner.net"/>
</appSettings>

<connectionStrings configSource="WebConnectionString.config">
</connectionStrings>

You can use this method in conjunction with the template method to handle settings for different environments too.