feat: Restart salt-master on config changes

Automatically restart salt-master when config changes are detected.

assets/runtime/env-defaults.sh

@@ -11,6 +11,7 @@ SALT_LOG_ROTATE_FREQUENCY=${SALT_LOG_ROTATE_FREQUENCY:-weekly}
 SALT_LOG_ROTATE_RETENTION=${SALT_LOG_ROTATE_RETENTION:-52}
 
 # https://docs.saltstack.com/en/latest/ref/configuration/master.html
+SALT_RESTART_MASTER_ON_CONFIG_CHANGE=${SALT_RESTART_MASTER_ON_CONFIG_CHANGE:-false}
 
 #####         Logging settings       #####
 # https://docs.saltstack.com/en/latest/ref/configuration/master.html#master-logging-settings

assets/runtime/functions.sh

@@ -432,6 +432,27 @@ EOF
 
 }
 
+function configure_config_reloader()
+{
+  rm -f /etc/supervisor/conf.d/config-reloader.conf
+  [ "${SALT_RESTART_MASTER_ON_CONFIG_CHANGE}" == true ] || return 0
+
+  echo "Configuring config reloader ..."
+
+  # configure supervisord to start config-reloader
+  cat > /etc/supervisor/conf.d/config-reloader.conf <<EOF
+[program:config-reloader]
+priority=20
+directory=/tmp
+command=/usr/local/sbin/config-reloader
+user=root
+autostart=true
+autorestart=true
+stdout_logfile=${SALT_LOGS_DIR}/supervisor/%(program_name)s.log
+stderr_logfile=${SALT_LOGS_DIR}/supervisor/%(program_name)s.log
+EOF
+}
+
 #---  FUNCTION  -------------------------------------------------------------------------------------------------------
 #          NAME:  initialize_system
 #   DESCRIPTION:  Initialize the system.
@@ -445,6 +466,7 @@ function initialize_system()
   configure_salt_master
   configure_salt_api
   configure_salt_formulas
+  configure_config_reloader
   setup_salt_keys
   setup_ssh_keys
   rm -rf /var/run/supervisor.sock

assets/sbin/config-reloader

@@ -0,0 +1,17 @@
+#!/bin/bash
+
+# shellcheck source=assets/runtime/functions.sh
+FUNCTIONS_FILE="${SALT_RUNTIME_DIR}/functions.sh"
+source "${FUNCTIONS_FILE}"
+
+function check_for_config_changes()
+{
+  inotifywait -qq --recursive \
+    --event modify,move,create,delete \
+    "${SALT_CONFS_DIR}"
+}
+
+while check_for_config_changes; do
+  log_info "Configuration changes detected. Reloading salt-master ..."
+  supervisorctl restart salt-master
+done