[dhclient] dhclient resolvconf exit hooks returns non zero exit status

[gpunathilell]

Description

This issue occurs during statistically when there is a dhclient packet being transmitted or received, the resolvconf entry hooks for dhclient fails and returns an exit code of 1. The issue is seen multiple times in 202311 images and 202405 images on mellanox switches.The entry hooks for resolvconf internally calls /sbin/resolvconf - this file is a generated file and looks similar to this. Parallely this /sbin/resolvconf is also invoked by resolv-config.sh script. Some of the reasons why resolvconf returns an exit code of 1 is:

• File lock is held by another process for longer than 10 seconds (This case is seen multiple times, but since we do not have information on the other process which crashed/exited while holding the lock)
• Some cases due to the ENABLE_UPDATES_FLAGFILE as well

Due to the entry hooks failing we get the following error log in the logs:
ERR root: /etc/dhcp/dhclient-enter-hooks.d/resolvconf returned non-zero exit status 1

Steps to reproduce the issue:

Unable to reproduce issue as it is a statistical issue, There are multiple occurences fo the bug, but I couldn't reproduce it manually

Describe the results you received:

Presence of ERR root: /etc/dhcp/dhclient-enter-hooks.d/resolvconf returned non-zero exit status 1 in the logs

Describe the results you expected:

No error logs related to dhclient entry hooks