op-mode: T5514: Allow safe reboots to config defaults when config.boot is deleted

* Added flag to vyos.config_mgmt.unsaved_commits() that will tolerate missing config.boot for specific circumstances
* Shutdown/reboot uses this flag; config will regenerate from defaults after a reboot

Author: talmakion

python/vyos/config_mgmt.py

@@ -81,9 +81,11 @@ def save_config(target, json_out=None):
     if rc != 0:
         logger.critical(f'save config failed: {out}')
 
-def unsaved_commits() -> bool:
+def unsaved_commits(allow_missing_config=False) -> bool:
     if get_full_version_data()['boot_via'] == 'livecd':
         return False
+    if allow_missing_config and not os.path.exists(config_file):
+        return True
     tmp_save = '/tmp/config.running'
     save_config(tmp_save)
     ret = not cmp(tmp_save, config_file, shallow=False)

src/op_mode/powerctrl.py

@@ -110,7 +110,7 @@ def check_unsaved_config():
     from vyos.config_mgmt import unsaved_commits
     from vyos.utils.boot import boot_configuration_success
 
-    if unsaved_commits() and boot_configuration_success():
+    if unsaved_commits(allow_missing_config=True) and boot_configuration_success():
         print("Warning: there are unsaved configuration changes!")
         print("Run 'save' command if you do not want to lose those changes after reboot/shutdown.")
     else: