From 7b44caeae4d108c4707ec69af0a4515ebcfd843f Mon Sep 17 00:00:00 2001
From: ieQu1 <99872536+ieQu1@users.noreply.github.com>
Date: Wed, 16 Aug 2023 15:48:18 +0200
Subject: [PATCH] fix(emqx_machine_boot): Fix excluded_apps

---
 apps/emqx_machine/src/emqx_machine_boot.erl | 17 ++++++++++++-----
 1 file changed, 12 insertions(+), 5 deletions(-)

diff --git a/apps/emqx_machine/src/emqx_machine_boot.erl b/apps/emqx_machine/src/emqx_machine_boot.erl
index 82b909b4f..481927765 100644
--- a/apps/emqx_machine/src/emqx_machine_boot.erl
+++ b/apps/emqx_machine/src/emqx_machine_boot.erl
@@ -30,12 +30,19 @@
 -export([sorted_reboot_apps/1, reboot_apps/0]).
 -endif.
 
-%% these apps are always (re)started by emqx_machine
+%% These apps are always (re)started by emqx_machine:
 -define(BASIC_REBOOT_APPS, [gproc, esockd, ranch, cowboy, emqx]).
 
-%% If any of these applications crash, the entire EMQX node shuts down
+%% If any of these applications crash, the entire EMQX node shuts down:
 -define(BASIC_PERMANENT_APPS, [mria, ekka, esockd, emqx]).
 
+%% These apps should NOT be (re)started automatically:
+-define(EXCLUDED_APPS, [system_monitor, observer_cli, jq]).
+
+%% These apps are optional, they may or may not be present in the
+%% release, depending on the build flags:
+-define(OPTIONAL_APPS, [bcrypt, observer]).
+
 post_boot() ->
     ok = ensure_apps_started(),
     ok = print_vsn(),
@@ -148,9 +155,9 @@ basic_reboot_apps() ->
     ?BASIC_REBOOT_APPS ++ (BusinessApps -- excluded_apps()).
 
 excluded_apps() ->
-    OptionalApps = [bcrypt, jq, observer],
-    [system_monitor, observer_cli] ++
-        [App || App <- OptionalApps, not is_app(App)].
+    %% Optional apps _should_ be (re)started automatically, but only
+    %% when they are found in the release:
+    ?EXCLUDED_APPS ++ [App || App <- ?OPTIONAL_APPS, not is_app(App)].
 
 is_app(Name) ->
     case application:load(Name) of