fix dns request failures at boot

config/target/dev.exs

@@ -41,12 +41,15 @@ config :farmbot, :init, [
   # Wait for time time come up.
   Farmbot.Target.Network.WaitForTime,
 
+  # Wait for DNS resolution
+  Farmbot.Target.Network.DnsTask,
 
   # Stops the disk from getting full.
   Farmbot.Target.Network.TzdataTask,
 
   # Reports SOC temperature to BotState.
   Farmbot.Target.SocTempWorker,
+  
   # Reports Wifi info to BotState.
   Farmbot.Target.Network.InfoSupervisor,
 

config/target/prod.exs

@@ -41,6 +41,9 @@ config :farmbot, :init, [
   # Wait for time time come up.
   Farmbot.Target.Network.WaitForTime,
 
+  # Wait for DNS resolution
+  Farmbot.Target.Network.DnsTask,
+
   # Stops the disk from getting full.
   Farmbot.Target.Network.TzdataTask,
 

platform/target/network/dns_task.ex

@@ -0,0 +1,60 @@
+defmodule Farmbot.Target.Network.DnsTask do
+  use Farmbot.Logger
+  use GenServer
+  import Farmbot.Target.Network, only: [test_dns: 0]
+  import Farmbot.System.ConfigStorage, only: [get_config_value: 3]
+
+  def start_link(args, opts) do
+    GenServer.start_link(__MODULE__, args, opts)
+  end
+
+  def init([]) do
+    # Block and reset if after 10 tries
+    # resolution doesn't  work.
+    block_check(true)
+    {:ok, %{timer: start_timer()}}
+  end
+
+  def handle_info(:checkup, state) do
+    # Block and don't reset if after 10 tries
+    # resolution doesn't work.
+    block_check()
+    {:noreply, %{state | timer: start_timer()}}
+  end
+
+  defp block_check(reset \\ false, tries \\ 10)
+
+  defp block_check(false, 0) do
+    server = get_config_value(:string, "authorization", "server")
+    Logger.error 1, "Could not resolve #{server} after 10 tries."
+  end
+
+  defp block_check(true, 0) do
+    server = get_config_value(:string, "authorization", "server")
+    Logger.error 1, "Tried 10 times to resolve DNS requests."
+    msg = """
+    FarmBot is unable to make DNS requests to #{server} after
+    10 tries. It is possible your network has a firewall blocking this
+    url, or your FarmBot is configured incorrectly.
+    """
+    Farmbot.System.factory_reset(msg)
+  end
+
+  defp block_check(reset, tries) do
+    server = get_config_value(:string, "authorization", "server")
+    case test_dns() do
+      {:ok, _} -> :ok
+      {:error, :nxdomain} ->
+        Process.sleep(10_000)
+        Logger.error 1, "Trying to resolve #{server} #{tries - 1} more times."
+        block_check(reset, tries - 1)
+      err ->
+        Logger.error 1, "Failed to resolve #{server}: #{inspect err}"
+        block_check(reset, tries)
+    end
+  end
+
+  defp start_timer do
+    Process.send_after(self(), :checkup, 45_000)
+  end
+end

platform/target/network/manager.ex

@@ -150,20 +150,11 @@ defmodule Farmbot.Target.Network.Manager do
       reconnect_timer: reconnect_timer
     }
     {:noreply, new_state}
-    # if state.connected do
-    #   NotFoundTimer.start()
-    #   Nerves.Network.IFSupervisor.teardown(state.interface)
-    #   Process.sleep(5000)
-    #   {:stop, :reconnect_timer, state}
-    # else
-    #   # This event can come in for a brief moment while connecting.
-    #   {:noreply, state}
-    # end
   end
 
   def handle_info({Nerves.WpaSupplicant, info, infoa}, state) do
     # :"CTRL-EVENT-SSID-TEMP-DISABLED id=0 ssid=\"Rory's Phone\" auth_failures=2 duration=20 reason=CONN_FAILED"
-    case to_string(info) do
+    case is_atom(info) && to_string(info) do
       <<"CTRL-EVENT-SSID-TEMP-DISABLED" <> _>> = msg ->
         if String.contains?(msg, "duration=20") do
           reconnect_timer = if state.connected, do: restart_connection_timer(state)
@@ -189,8 +180,6 @@ defmodule Farmbot.Target.Network.Manager do
 
   def handle_info(:reconnect_timer, %{ap_connected: false} = state) do
     Logger.warn 1, "Wireless network not found still. Trying again."
-    # new_state = %{state | reconnect_timer: restart_connection_timer(state)}
-    # {:noreply, new_state}
     {:stop, :reconnect_timer, state}
   end
 

platform/target/network/network.ex

@@ -120,6 +120,7 @@ defmodule Farmbot.Target.Network do
   end
 
   def test_dns(hostname) do
+    :ok = :inet_db.clear_cache()
     # IO.puts "testing dns: #{hostname}"
     case :inet.parse_ipv4_address(hostname) do
       {:ok, addr} -> {:ok, {:hostent, hostname, [], :inet, 4, [addr]}}

platform/target/network/ntp.ex

@@ -1,96 +0,0 @@
-defmodule Farmbot.Target.Network.Ntp do
-  @moduledoc """
-  Sets time.
-  """
-
-  use Farmbot.Logger
-  import Farmbot.Target.Network, only: [test_dns: 1]
-  import Farmbot.System.ConfigStorage, only: [get_config_value: 3]
-
-  @doc """
-  Tries to set the time from ntp.
-  This will try 3 times to set the time. if it fails the thrid time,
-  it will return an error
-  """
-  def set_time(tries \\ 0)
-  def set_time(tries) when tries < 4 do
-    Process.sleep(1000 * tries)
-    case test_dns(to_charlist(ntp_server_1())) do
-      {:ok, {:hostent, _url, _, _, _, _}} ->
-        do_try_set_time(tries)
-      {:error, err} ->
-        Logger.error 1, "Failed to set time (#{tries}): DNS Lookup: #{inspect err}"
-        set_time(tries + 1)
-    end
-  end
-
-  def set_time(_), do: {:error, :timeout}
-
-  defp do_try_set_time(tries) when tries < 4 do
-    # we try to set ntp time 3 times before giving up.
-    # Logger.busy 3, "Trying to set time (try #{tries})"
-    IO.puts "Trying to set time (try #{tries})"
-    :os.cmd('ntpd -q -p #{ntp_server_1()} -p #{ntp_server_2()}')
-    wait_for_time(tries)
-  end
-
-  defp wait_for_time(tries, loops \\ 0)
-
-  defp wait_for_time(tries, loops) when loops > 5 do
-    :os.cmd('killall ntpd')
-    set_time(tries)
-  end
-
-  defp wait_for_time(tries, loops) do
-    case :os.system_time(:seconds) do
-      t when t > 1_474_929 ->
-        # Logger.success 2, "Time is set."
-        # Logger.busy 2, "Updating tzdata."
-        update_tzdata()
-      _ ->
-        Process.sleep(1_000 * loops)
-        wait_for_time(tries, loops + 1)
-    end
-  end
-
-  defp update_tzdata(retries \\ 0)
-
-  defp update_tzdata(retries) when retries > 5 do
-    Logger.error 1, "Failed too update tzdata!"
-    {:error, :failed_to_update_tzdata}
-  end
-
-  defp update_tzdata(retries) do
-    maybe_hack_tzdata()
-    case Tzdata.DataLoader.download_new() do
-      {:ok, _, _, _, _} ->
-        # Logger.success 3, "Successfully updated tzdata."
-        :ok
-      _ -> update_tzdata(retries + 1)
-    end
-  end
-
-  @fb_data_dir Application.get_env(:farmbot, :data_path)
-  @tzdata_dir Application.app_dir(:tzdata, "priv")
-  def maybe_hack_tzdata do
-    case Tzdata.Util.data_dir() do
-      @fb_data_dir -> :ok
-      _ ->
-        Logger.warn 3, "Hacking tzdata."
-        objs_to_cp = Path.wildcard(Path.join(@tzdata_dir, "*"))
-        for obj <- objs_to_cp do
-          File.cp_r obj, @fb_data_dir
-        end
-        Application.put_env(:tzdata, :data_dir, @fb_data_dir)
-        :ok
-    end
-  end
-
-  defp ntp_server_1 do
-    get_config_value(:string, "settings", "default_ntp_server_1")
-  end
-
-  defp ntp_server_2 do
-    get_config_value(:string, "settings", "default_ntp_server_2")
-  end
-end

platform/target/network/wait_for_time.ex

@@ -8,7 +8,7 @@ defmodule Farmbot.Target.Network.WaitForTime do
 
   defp wait_for_time do
     case :os.system_time(:seconds) do
-      t when t > 1_474_929 ->
+      t when t > 1534459652 ->
         :ok
 
       _ ->