During overcloud node delete to delete a compute node, we assume the that nova-compute is enabled on the node and is working as expected. However, the node scale down
fails in cases where the node being scaled is not correctly
behaving as a compute node (nova containers not running/reporting
to the overcloud). This patch includes a check to only disable
and stop nova services if they are running.
When running /var/lib/mistral/overcloud/scale_steps_tasks.yaml for scale down, we see
TASK [Disable nova-compute service] ********************************************
Thursday 23 January 2020 15:20:58 +0000 (0:00:00.087) 0:01:52.056 ******
fatal: [overcloud-r630compute-0]: FAILED! => {"msg": "The task includes an option with an undefined variable. The error was: list object has no element 0\n\nThe error appears to be in '/var/lib/mistral/overcloud/scale_steps_tasks.yaml': line 24, column 5, but may\nbe elsewhere in the file depending on the exact syntax problem.\n\nThe offending line appears to be:\n\n - (nova_compute_service | length) > 1\n - check_mode: false\n ^ here\n"}
due to compute service not properly running on the node we are trying to remove.
We need better handling of this case.
Fix proposed to branch: master
Review: https:/