fix: wait before startup to prevent race condition

More informations: bitwalker/distillery#593

lib/imager.ex

@@ -37,8 +37,7 @@ defmodule Imager do
 
     Instrumenter.Processing.command(commands)
 
-    Logger.metadata(input: file_name, commands: inspect(commands))
-    Logger.debug(inspect(args))
+    Logger.metadata(input: file_name)
 
     with :error <- Store.retrieve(cache, result_name, opts),
          {:ok, {_, _, in_stream}} <- Store.retrieve(store, file_name, opts) do

lib/imager/application.ex

@@ -18,7 +18,7 @@ defmodule Imager.Application do
     {:ok, _} = Logger.add_backend(Sentry.LoggerBackend)
     _ = Application.ensure_all_started(:sentry)
 
-    prometheus()
+    Imager.Instrumenter.setup()
 
     JOSE.json_module(Imager.JOSE.Jason)
 
@@ -44,12 +44,4 @@ defmodule Imager.Application do
 
     %{id: :exec_app, start: {:exec, :start_link, [opts]}}
   end
-
-  defp prometheus do
-    :prometheus_registry.register_collector(:prometheus_process_collector)
-
-    Imager.Instrumenter.Cache.setup()
-    Imager.Instrumenter.Processing.setup()
-    Imager.Instrumenter.Storage.setup()
-  end
 end

rel/config.exs

@@ -16,6 +16,7 @@ environment :prod do
   set commands: [
     config: "rel/commands/config.sh"
   ]
+  set post_configure_hooks: "rel/hooks/post_configure"
   set include_erts: true
   set include_src: false
   set cookie: :"1u[<S!I(rduF/Rzy8)&A<,$D{;y:&av9?V],2S/37FKidw5JKpq|j17^D2Gz]N=m"

rel/hooks/post_configure/wait.sh

@@ -0,0 +1,4 @@
+#!/usr/bin/env sh
+
+echo "Wait 1s to mitigate race condition in Distillery config"
+sleep 1