instance method database_configuration

# File railties/lib/rails/application/configuration.rb, line 165
      def database_configuration
        path = paths["config/database"].existent.first
        yaml = Pathname.new(path) if path

        config = if yaml && yaml.exist?
          require "yaml"
          require "erb"
          loaded_yaml = YAML.load(ERB.new(yaml.read).result) || {}
          shared = loaded_yaml.delete("shared")
          if shared
            loaded_yaml.each do |_k, values|
              values.reverse_merge!(shared)
            end
          end
          Hash.new(shared).merge(loaded_yaml)
        elsif ENV["DATABASE_URL"]
          # Value from ENV['DATABASE_URL'] is set to default database connection
          # by Active Record.
          {}
        else
          raise "Could not load database configuration. No such file - #{paths["config/database"].instance_variable_get(:@paths)}"
        end

        config
      rescue Psych::SyntaxError => e
        raise "YAML syntax error occurred while parsing #{paths["config/database"].first}. " \
              "Please note that YAML must be consistently indented using spaces. Tabs are not allowed. " \
              "Error: #{e.message}"
      rescue => e
        raise e, "Cannot load database configuration:\n#{e.message}", e.backtrace
      end