--- /usr/share/foreman/extras/puppet/foreman/files/foreman-report.rb    2010-06-07 02:37:59.000000000 -0500
+++ files/foreman.rb    2010-09-30 13:40:07.000000000 -0500
@@ -3,8 +3,6 @@
 # reports=log, foreman # (or any other reports you want)

 # URL of your Foreman installation
-$foreman_url="http://foreman:3000" 
-
 require 'puppet'
 require 'net/http'
 require 'uri'
@@ -15,17 +13,18 @@

     def process
       begin
-        uri = URI.parse($foreman_url)
+        uri = URI.parse(Puppet[:foremanurl])
         http = Net::HTTP.new(uri.host, uri.port)
         if uri.scheme == 'https' then
           http.use_ssl = true
           http.verify_mode = OpenSSL::SSL::VERIFY_NONE
         end
-        req = Net::HTTP::Post.new("/reports/create?format=yml")
+        req = Net::HTTP::Post.new(Puppet[:foremanurl]+
+          "/reports/create?format=yml")
         req.set_form_data({'report' => to_yaml})
         response = http.request(req)
       rescue Exception => e
-        raise Puppet::Error, "Could not send report to Foreman at #{$foreman_url}/reports/create?format=yml: #{e}" 
+        raise Puppet::Error, "Could not send report to Foreman at #{Puppet[:foremanurl]}/reports/create?format=yml: #{e}" 
       end
     end
 end

Changes also made to /usr/lib/ruby/1.8/puppet/defaults.rb though I can't say if these are necessary. After line 634 reporturl: "The URL used by the http reports processor to send reports"]
Put a ',' at the end of that line and add something like:

    :foremanurl => ["http://localhost:3000/reports",
      "The URL used by the http reports processor to send reports"]

I didn't do anything more, but add this to my puppet master config section.

    foremanurl = http://commestnik.local/foreman

Rather I added this to a template:

    foremanurl = http://<%= puppetserver rescue "commestnik.local" 
                %>/foreman