External Config Files with elmah - web-config

Question

I am using elmah (v1.1.11517.0) and am trying to move the config to an external source.
My config currently looks like this:
<?xml version="1.0"?>
<configuration>
<configSections>
<sectionGroup name="elmah">
<section name="security" requirePermission="false" type="Elmah.SecuritySectionHandler, Elmah"/>
<section name="errorLog" requirePermission="false" type="Elmah.ErrorLogSectionHandler, Elmah" />
<section name="errorMail" requirePermission="false" type="Elmah.ErrorMailSectionHandler, Elmah" />
<section name="errorFilter" requirePermission="false" type="Elmah.ErrorFilterSectionHandler, Elmah"/>
<section name="errorTweet" requirePermission="false" type="Elmah.ErrorTweetSectionHandler, Elmah"/>
</sectionGroup>
<section name="log4net" type="log4net.Config.Log4NetConfigurationSectionHandler, log4net"/>
</configSections>
<log4net configSource="Settings\RobDev\log4net.config" />
<elmah configSource="Settings\RobDev\ELMAH.config" />
</configuration>
log4net is happy and runs fine, however for elmah I get the error
Parser Error Message: The attribute 'configSource' cannot be specified because its name starts with the reserved prefix 'config' or 'lock'.
Which is a pain, the elmah file is definitely there, but something isn't happy.
What might be causing this?

Answer 1

The reason why you can't use the configSource element for elmah is because elmah is defined as a sectionGroup. You can use the configSource on Sections. That is why it works on log4net.
If you need the seperate config-file for web-deployment like Dan Atkinson you could do the following:
<?xml version="1.0"?>
<configuration>
<configSections>
<sectionGroup name="elmah">
<section name="security" requirePermission="false" type="Elmah.SecuritySectionHandler, Elmah"/>
<section name="errorLog" requirePermission="false" type="Elmah.ErrorLogSectionHandler, Elmah" />
<section name="errorMail" requirePermission="false" type="Elmah.ErrorMailSectionHandler, Elmah" />
<section name="errorFilter" requirePermission="false" type="Elmah.ErrorFilterSectionHandler, Elmah"/>
<section name="errorTweet" requirePermission="false" type="Elmah.ErrorTweetSectionHandler, Elmah"/>
</sectionGroup>
<section name="log4net" type="log4net.Config.Log4NetConfigurationSectionHandler, log4net"/>
</configSections>
<log4net configSource="Settings\RobDev\log4net.config" />
<elmah>
<errorLog configSource="Settings\RobDev\errorLog.config" />
<errorMail configSource="Settings\RobDev\errorMail.config" />
<errorFilter configSource="Settings\RobDev\errorFilter.config" />
<errorTweet configSource="Settings\RobDev\errorTweet.config" />
<security configSource="Settings\RobDev\security.config" />
</elmah>
</configuration>
The downside is that you need a config file for each section. But you often do that for web deployment projects.

Answer 2

I've added a bounty to this question as I'd also like to know the answer to this.
I need it because I use Web Deployment functionality which replaces files by their configSource attribute.
In the meantime, you could move the contents of elmah.config into your web.config, replacing the <elmah configSource="..." />.