Managing complex Web.Config files between deployment environments.

Question

Does anyone know of any good tools/utilities for managing Web.Config files between different build/deployment environments?

For example, I have a WCF project that in development I don't want to enable SSL, but I do want it enabled in production. I want different logging settings, different DB connection strings, different error handling, different file paths... Even some different Unity framework bindings (wire up mocks for unit testing instead of the real objects for deployment).

Maintaining individual copies of the Web.Config is a pain, because adding a new web service means editing multiple files and keeping them in sync.

I've also noticed that if you muck with the Web.Config too much by hand, Visual Studio will choke if you try to use the "add item" wizard to, say, add a new Web Service for WCF, since it has to modify the Web.Config to add the endpoint,a nd can't parse it any more. So I have to be careful not to invalidate the existing Web.Config.

I also thought about just using some regex to do replacements and just building a new Web.Config in a pre-build command. That seems like the best option so far...

Any other ideas? It seems like this should be a very common issue, since the Web.Config should probably never be the same between development and production deployments.

---

Update:

I decided to write a quick console app that will take all the xml files in a given directory and merge them into one, and only include certain files based on the name.

So I can make in a directory:

WebConfig_All

<configuration>
  <configSections>
    ...
  </configSections>
  <system.web>
    ...
  </system.web>
</configuration>

connectionStrings_Debug

<configuration>
  <connectionStrings>
    <add name="connstr" connectionString="...dev..." />
  </connectionStrings>
</configuration>

connectionStrings_Release

<configuration>
  <connectionStrings>
    <add name="connstr" connectionString="...prod..." />
  </connectionStrings>
</configuration>

Then run my command line tool, and pass in the configuration (Debug, Release, custom...) And it will merge all the files that end in "All" or "<configuration>".

So now I have 80% of my Web.Config in a single WebConfig_All file,a nd the 20% custom stuff in seperate files per build configuration. I can then run my command line tool as a pre-build task in VisualStudio, or from NAnt, or wherever I want...

I also made my XML merge logic good enough to handle stuff like:

<x>
  <y a="1">
    <z a="1"/>
  </y>
</x>

merge with

<x>
  <y a="1">
    <z a="2"/>
  </y>
  <y a="2"/>
</x>

results in:

<x>
  <y a="1">
    <z a="1"/>
    <z a="2"/>
  </y>
  <y a="2"/>
</x>

Looking good so far... :)

Answer 1

I have traditionally used the multiple web.configs as you mentioned. It can be a pain but it is mitigated by file compare tools such as BeyoneComapare2 or KDIff...

Answer 2

You could use Build Events to manage your web configs. Hanselman has a good article about it.

Basically you have all your different web.configs in the solution you then create (some) new build types. Depending on the build type you run a web.config is copied over the referenced one!

Answer 3

I like to use a build task to automate changing the config file for the desired environment.

Answer 4

I use the method explained by Scott Hanselman (he explains it much better than I can reproduce this so follow the link :) ) It has worked fine for me...

Answer 5

We split out all region specific settings into thier own config file. Under the root of the web app we create a config folder and place the region specific settings there. So whatever files are living under the root of config will get picked up.

our web.config looks something like:

.
.
.
<appSettings configSource="config\appSettings.config"/>
<nlog configSource="config\nlog.config"/>
<applicationSettings>
 <MyApp.UI.Properties.Settings configSource="config\Settings.APGUI.config"/>
 <MyApp.BusinessServices.Properties.Settings configSource="config\Settings.Business.config"/>
 <MyApp.Auditing.Properties.Settings configSource="config\Settings.Auditing.config"/>
</applicationSettings>
.
.
.

So if we are deploying to the release region the build tool will just have an action to replace the files in the root of config with the files from the appropriate region folder. The file structure looks something like:

ADDED: This is how the source control structure looks, the deployed app would just have the config dir with no sub folders or course

\Root
   web.config    
   \Config    
       appsettings.config    
       services.config    
       logging.config    
       \release    
          appsettings.config    
          services.config    
          logging.config    
       \debug
          appsettings.config    
          services.config    
          logging.config

It is pretty clean and supported by any automated build tool(copying/replacing files). The nice side affect is that developers can create different flavors and keep them under source control without affecting the "real" configs.

Answer 6

Annoyance:

I mentioned my little cmd line app to merge XML docs in my 1st update... Well to do that I just use XmlDocument, and eventually just .Save() it to an FileStream.

Unfortuantely, the nodes aren't really in any particular order, and apparently, .NET requires the <configSections> element be the 1st child of the document.

I thought all these fancy tools were supposed to make programming life easier?

Answer 7

I use this tool: xmlpreprocess

we maintain separate 'property' files for each environment that are merged in by the deployment script.

Answer 8

We use tags in our config files, that are replaced at build time to reflect the intended deployment environment. I've been inspired by Lavablast blog

It's nice to have only one template config file to manage.

The drawback is that you can't easily have custom "sections".

Answer 9

You want the XmlMassUpdate task in MSBuildCommunityTasks (does what you're trying to do with your xml console app)

http://msbuildtasks.tigris.org/

use it like this

  <XmlMassUpdate Condition=" '@(ConfigTemplateFile)'!='' And '@(ConfigSubstitutionsFile)'!=''"
    ContentFile="@(ConfigTemplateFile)"
    SubstitutionsFile="@(ConfigSubstitutionsFile)"
    MergedFile="@(ConfigFile)"
    ContentRoot="/configuration"
    SubstitutionsRoot="/configuration/substitutions/$(Configuration)"/>