Tau - set OTP application config in config/runtime.exs

This was previously set via Erlang in the pre-Elixir releases. Now trying to make things more idiomatic for Elixir developers.

Author: samaaron

app/server/beam/tau/config/runtime.exs

@@ -6,12 +6,29 @@ import Config
 # and secrets from environment variables or elsewhere. Do not define
 # any compile-time configuration in here, as it won't be applied.
 
-log_path = case System.fetch_env("TAU_LOG_PATH") do
-             {:ok, log_path} ->
-               log_path
-             _error ->
-               "log/tau.log"
-           end
+extract_env = fn name, kind, default ->
+  env_val = System.get_env(name)
+
+  if !env_val do
+    default
+  else
+    extracted =
+      case kind do
+        :int ->
+          {val, ""} = Integer.parse(env_val)
+          val
+
+        :bool ->
+          dc_val = env_val |> String.downcase() |> String.trim()
+          dc_val != "false" and dc_val != "0"
+
+        :string ->
+          env_val
+      end
+
+    extracted
+  end
+end
 
 config :tau,
   handle_otp_reports: true,
@@ -26,7 +43,7 @@ else
 end
 
 config :logger, :tau_file_log,
-  path: log_path,
+  path: extract_env.("TAU_LOG_PATH", :string, "log/tau.log"),
   level: :info
 
 # ## Using releases
@@ -39,18 +56,22 @@ config :logger, :tau_file_log,
 # Then you can assemble a release by calling `mix release`.
 # See `mix help release` for more information.
 
-phx_port_default = 8001
-phx_port = case System.fetch_env("TAU_PHX_PORT") do
-             {:ok, port_str} ->
-               case Integer.parse(port_str) do
-                 {port, ""} ->
-                   port
-                 _other ->
-                   phx_port_default
-               end
-             _error ->
-               phx_port_default
-           end
+phx_port = extract_env.("TAU_PHX_PORT", :int, 8002)
+
+config :tau,
+  midi_on: extract_env.("TAU_MIDI_ON", :bool, false),
+  midi_enabled: extract_env.("TAU_MIDI_ENABLED", :bool, false),
+  link_enabled: extract_env.("TAU_LINK_ENABLED", :bool, false),
+  cues_on: extract_env.("TAU_CUES_ON", :bool, true),
+  osc_in_udp_loopback_restricted: extract_env.("TAU_OSC_IN_UDP_LOOPBACK_RESTRICTED", :bool, true),
+  link_on: extract_env.("TAU_LINK_ON", :bool, false),
+  osc_in_udp_port: extract_env.("TAU_OSC_IN_UDP_PORT", :int, 5000),
+  api_port: extract_env.("TAU_API_PORT", :int, 5001),
+  spider_port: extract_env.("TAU_SPIDER_PORT", :int, 5002),
+  daemon_port: extract_env.("TAU_DAEMON_PORT", :int, -1),
+  daemon_token: extract_env.("TAU_DAEMON_TOKEN", :int, -1),
+  daemon_host: {127, 0, 0, 1},
+  phx_port: phx_port
 
 config :tau, TauWeb.Endpoint,
   server: true,

app/server/beam/tau/lib/tau/application.ex

@@ -10,19 +10,8 @@ defmodule Tau.Application do
   def start(_type, _args) do
     Logger.info("All systems booting....")
 
-    _tau_env                       = extract_env("TAU_ENV",                            :string, "prod")
-    midi_enabled                   = extract_env("TAU_MIDI_ENABLED",                   :bool, false)
-    link_enabled                   = extract_env("TAU_LINK_ENABLED",                   :bool, false)
-    cues_on                        = extract_env("TAU_CUES_ON",                        :bool, true)
-    osc_in_udp_loopback_restricted = extract_env("TAU_OSC_IN_UDP_LOOPBACK_RESTRICTED", :bool, true)
-    midi_on                        = extract_env("TAU_MIDI_ON",                        :bool, false)
-    link_on                        = extract_env("TAU_LINK_ON",                        :bool, false)
-    osc_in_udp_port                = extract_env("TAU_OSC_IN_UDP_PORT",                :int,  5000)
-    api_port                       = extract_env("TAU_API_PORT",                       :int,  5001)
-    spider_port                    = extract_env("TAU_SPIDER_PORT",                    :int,  5002)
-    daemon_port                    = extract_env("TAU_DAEMON_PORT",                    :int,  -1)
-    daemon_token                   = extract_env("TAU_DAEMON_TOKEN",                   :int,  -1)
-    daemon_host = {127,0,0,1}
+    midi_enabled = Application.get_env(:tau, :midi_enabled, false)
+    link_enabled = Application.get_env(:tau, :link_enabled, false)
 
     if midi_enabled do
       Logger.info("Initialising MIDI native interface")
@@ -38,21 +27,6 @@ defmodule Tau.Application do
       Logger.info("Starting without Link native interface")
     end
 
-    :tau_server_sup.set_application_env(
-      midi_enabled,
-      link_enabled,
-      cues_on,
-      osc_in_udp_loopback_restricted,
-      midi_on,
-      link_on,
-      osc_in_udp_port,
-      api_port,
-      spider_port,
-      daemon_port,
-      daemon_token,
-      daemon_host
-    )
-
     Logger.info("Starting Phoenix server")
 
     children = [
@@ -83,31 +57,4 @@ defmodule Tau.Application do
     TauWeb.Endpoint.config_change(changed, removed)
     :ok
   end
-
-  defp extract_env(name, kind, default) do
-    env_val = System.get_env(name)
-
-    if !env_val do
-      Logger.info("No env variable supplied for #{name} using default: #{default}")
-      default
-    else
-      extracted = extract_env(env_val, kind)
-      Logger.info("Extracting env #{name} #{kind}: #{extracted}")
-      extracted
-    end
-  end
-
-  defp extract_env(env_val, :int) do
-    {val, ""} = Integer.parse(env_val)
-    val
-  end
-
-  defp extract_env(env_val, :bool) do
-    dc_val = env_val |> String.downcase() |> String.trim()
-    (dc_val != "false") and (dc_val != "0")
-  end
-
-  defp extract_env(env_val, :string) do
-    env_val
-  end
 end

app/server/beam/tau/src/tau_server/tau_server_sup.erl

@@ -8,7 +8,6 @@
 
 %% API
 -export([start_link/0, child_spec/1]).
--export([set_application_env/12]).
 
 %% Supervisor callbacks
 -export([init/1]).
@@ -42,32 +41,6 @@ start_link() ->
 %% NOTE: it is important that this code cannot fail, because that
 %% would prevent the application from even being started.
 
-set_application_env(MIDIEnabled,
-                    LinkEnabled,
-                    CuesOn,
-                    OSCInUDPLoopbackRestricted,
-                    MidiOn,
-                    LinkOn,
-                    OSCInUDPPort,
-                    ApiPort,
-                    SpiderPort,
-                    DaemonPort,
-                    DaemonToken,
-                    DaemonHost) ->
-
-    application:set_env(?APPLICATION, midi_enabled, MIDIEnabled),
-    application:set_env(?APPLICATION, link_enabled, LinkEnabled),
-    application:set_env(?APPLICATION, cues_on, CuesOn),
-    application:set_env(?APPLICATION, osc_in_udp_loopback_restricted, OSCInUDPLoopbackRestricted),
-    application:set_env(?APPLICATION, midi_on, MidiOn),
-    application:set_env(?APPLICATION, link_on, LinkOn),
-    application:set_env(?APPLICATION, osc_in_udp_port, OSCInUDPPort),
-    application:set_env(?APPLICATION, api_port, ApiPort),
-    application:set_env(?APPLICATION, spider_port, SpiderPort),
-    application:set_env(?APPLICATION, daemon_port, DaemonPort),
-    application:set_env(?APPLICATION, daemon_token, DaemonToken),
-    application:set_env(?APPLICATION, daemon_host, DaemonHost).
-
 init(_Args) ->
     CueServer = tau_server_cue:server_name(),
     MIDIServer = tau_server_midi:server_name(),