database.yml

<%

require 'cgi'
require 'uri'

begin
  uri = URI.parse(ENV["DATABASE_URL"])
rescue URI::InvalidURIError
  raise "Invalid DATABASE_URL"
end

raise "No RACK_ENV or RAILS_ENV found" unless ENV["RAILS_ENV"] || ENV["RACK_ENV"]

def attribute(name, value)
  value ? "#{name}: #{value}" : ""
end

adapter = uri.scheme
adapter = "postgresql" if adapter == "postgres"

adapter = nil if adapter == 'mongo'

database = (uri.path || "").split("/")[1]

username = uri.user
password = uri.password

host = uri.host
port = uri.port

params = CGI.parse(uri.query || "")
%>

<%= ENV["RAILS_ENV"] || ENV["RACK_ENV"] %>:
  <%= attribute("adapter",  adapter) if adapter %>
  <%= attribute("database", database) if database %>
  <%= attribute("username", username) if username %>
  <%= attribute("password", password) if password %>
  <%= attribute("host",     host) if host %>
  <%= attribute("port",     port) if port %>

<% params.each do |key, value| %>
  <%= key %>: <%= value.first %>
<% end %>