Fix: ui_node: prevent traceback on node standby

[freishutz]

Crm throws traceback on crm node standby if cluster (corosync/pacemaker) stopped.

[root@es-3-virt1 ~]# rpm -qa | grep crmsh
crmsh-4.5.1-1.el8.noarch
crmsh-scripts-4.5.1-1.el8.noarch
crmsh-test-4.5.1-1.el8.noarch

[root@es-3-virt1 ~]# crm cluster stop
WARNING: crmsh configuration is inconsistent in cluster.
INFO: The cluster stack already stopped on es-3-virt1

[root@es-3-virt1 ~]# crm node standby
WARNING: crmsh configuration is inconsistent in cluster.
ERROR: running cibadmin -Ql: Could not connect to the CIB: Transport endpoint is not connected
Init failed, could not perform requested operations

Traceback (most recent call last):
  File "/usr/sbin/crm", line 53, in <module>
    rc = main.run()
  File "/usr/lib/python3.6/site-packages/crmsh/main.py", line 369, in run
    return main_input_loop(context, user_args)
  File "/usr/lib/python3.6/site-packages/crmsh/main.py", line 247, in main_input_loop
    rc = handle_noninteractive_use(context, user_args)
  File "/usr/lib/python3.6/site-packages/crmsh/main.py", line 204, in handle_noninteractive_use
    if context.run(' '.join(l)):
  File "/usr/lib/python3.6/site-packages/crmsh/ui_context.py", line 86, in run
    rv = self.execute_command() is not False
  File "/usr/lib/python3.6/site-packages/crmsh/ui_context.py", line 271, in execute_command
    rv = self.command_info.function(*arglist)
  File "/usr/lib/python3.6/site-packages/crmsh/ui_node.py", line 397, in do_standby
    xml_item_list = cib.xpath(xml_path)
AttributeError: 'NoneType' object has no attribute 'xpath'

[root@es-3-virt1 ~]# echo $?
1

[root@es-3-virt1 ~]# cp /usr/lib/python3.6/site-packages/crmsh/ui_node.py{,.orig}
[root@es-3-virt1 ~]# vim /usr/lib/python3.6/site-packages/crmsh/ui_node.py
[root@es-3-virt1 ~]# diff -Naru /usr/lib/python3.6/site-packages/crmsh/ui_node.py.orig /usr/lib/python3.6/site-packages/crmsh/ui_node.py
--- /usr/lib/python3.6/site-packages/crmsh/ui_node.py.orig      2024-01-08 14:43:49.166728433 +0000
+++ /usr/lib/python3.6/site-packages/crmsh/ui_node.py   2024-01-08 14:44:50.942622070 +0000
@@ -376,6 +376,8 @@
             xml_query_path_oppsite = constants.XML_NODE_QUERY_STANDBY_PATH

         cib = xmlutil.cibdump2elem()
+        if cib is None:
+            return False
         # IMPORTANT:
         # Do NOT call cibdump2elem twice, or you risk a race where the
         # resulting diff will contain more changes than the values for

[root@es-3-virt1 ~]# crm node standby ; echo $?
WARNING: crmsh configuration is inconsistent in cluster.
ERROR: running cibadmin -Ql: Could not connect to the CIB: Transport endpoint is not connected
Init failed, could not perform requested operations

1

[liangxin1300]

@freishutz Good catch!

Could you please fix the same issue on crm node online?

Thanks!

[codecov]

Codecov Report

Attention: 2 lines in your changes are missing coverage. Please review.

Comparison is base (d797e04) 52.95% compared to head (72f6851) 52.95%.

Files	Patch %	Lines
crmsh/ui_node.py	50.00%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #1299      +/-   ##
==========================================
- Coverage   52.95%   52.95%   -0.01%     
==========================================
  Files          79       79              
  Lines       25055    25059       +4     
==========================================
+ Hits        13268    13270       +2     
- Misses      11787    11789       +2     

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[freishutz]

@freishutz Good catch!

Could you please fix the same issue on crm node online?

Thanks!

Done.