add supervisord export engine

data/export/supervisord/master.conf.erb

@@ -1,3 +1,9 @@
+<% 
+engine.procfile.entries.each do |process|
+  next if (conc = self.concurrency[process.name]) < 1 
+  1.upto(self.concurrency[process.name]) do |num| 
+    port = engine.port_for(process, num, self.port)
+%>  
 [program:<%= app %>-<%= process.name %>]
 command=<%= process.command %>
 autostart=true
@@ -7,4 +13,8 @@ stdout_logfile=<%= log_root %>/<%=process.name%>-<%=num%>.log
 stderr_logfile=<%= log_root %>/<%=process.name%>-<%=num%>err.log
 user=<%= user %>
 directory=<%= engine.directory %>
-environment=<% engine.environment.each_pair { |var,env| "#{var.upcase}=#{env}" }.join(',') %>
+environment=<% engine.environment.each_pair { |var,env| "#{var.upcase}=#{env}" }.join(',') %>,<%= "PORT=#{port}" %>
+<% 
+  end
+end 
+%>

lib/foreman/export/supervisord.rb

@@ -0,0 +1,26 @@
+require "erb"
+require "foreman/export"
+
+class Foreman::Export::Supervisord < Foreman::Export::Base
+
+  def export
+    error("Must specify a location") unless location
+
+    FileUtils.mkdir_p location
+
+    app = self.app || File.basename(engine.directory)
+    user = self.user || app
+    log_root = self.log || "/var/log/#{app}"
+    template_root = self.template
+
+    Dir["#{location}/#{app}*.conf"].each do |file|
+      say "cleaning up: #{file}"
+      FileUtils.rm(file)
+    end
+
+    master_template = export_template("supervisord", "master.conf.erb", template_root)
+    master_config   = ERB.new(master_template).result(binding)
+    write_file "#{location}/#{app}.conf", master_config
+  end
+
+end