ha-handler/lib/ha_handler/web/controller.ex

defmodule HAHandler.Web.Controller do
  import Plug.Conn

  alias HAHandler.{HAProxy, PGSQL}

  @template_dir "lib/ha_handler/web/templates"
  @index_template EEx.compile_file(Path.join(@template_dir, "index.html.eex"))

  defp render(conn, template, assigns) do
    {body, _binding} = Code.eval_quoted(template, assigns)

    conn
    |> put_resp_content_type("text/html")
    |> send_resp(200, body)
  end

  def index(conn) do
    {:ok, hostname} = :net_adm.dns_hostname(:net_adm.localhost())

    haproxy_stats = HAProxy.get_stats(hide_error: true)
    pgsql_stats = PGSQL.get_stats()

    assigns = [
      haproxy_stats: haproxy_stats,
      pgsql_status: pgsql_stats,
      hostname: hostname,
      otp_app: HAHandler.otp_app(),
      version: HAHandler.version(),
      env: HAHandler.env()
    ]

    render(conn, @index_template, assigns)
  end
end