grails - subdomain based projects and links

I am trying to develop a grails application that has "root" content (www.mydomain.com/about for example) but will also support "projects" based upon the subdomain开发者_开发问答 of the request; for example myproject.mydomain.com > www.mydomain.com/myproject. As a first pass, i have the URL configuration below:

"/$controller/$action?/$id?" {
 ...
}

"/$project/$controller/$action?/$id?" {
    constraints {
    }
}

The main drawback so far is that the $project variable must be injected manually into every link (tedious and not DRY):

<g:link controller="foo" action="bar" params="${[project: params.project]}">link</g:link>

Is there a way to automatically inject the $project parameter into all links if it is present, or is there a better way to approach this problem?

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Basically you can create a grails plugin that will inject into the controller a new project param with a value based on a custom TagLib <g:project bean="myproject"/> (for instance)

It will force you to define this tagLib on each gsp page of your project but it is still DRYer than each link.

Hope it helps,

Fabien.

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I can think of a couple of things.

a) You can place a proxy (Apache or something else) in front of your app-server and do some url-rewriting. Bonus: This would also allow you to do some caching of static resources.

b) This solution is a little more technically interesting. You can look up the project based on the http host header (the subdomain part). This will save you from rewriting all urls, all Grails conventions will still apply so you shouldn't run into any problems with third party plugins and so on.