Automating Periodic SSH Login Checks with Jenkins and Expect

Background: The goal is to periodically batch‑login to remote virtual machines, perform specified operations, and support users adding new hostnames.

Requirements: automatic periodic execution, clear login test result output, ability to add hostnames to the check list, and user notification after execution, all using Jenkins without additional web pages.

Implementation steps: maintain a hostname list in a file, use a Jenkins job to add new hostnames (grep to avoid duplicates), commit the updated file to a Git repository, and schedule the script for regular runs.

Key techniques:

Use expect to automate interactive SSH login; install it with sudo yum install expect .

Utilize Bash arrays to read the file, perform logins, record failures, and display results.

When pushing new hostnames, set the remote URL to https://${USERNAME}:${PASSWORD}@git.company.com/scm/vmm.git or [email protected]:scm/vmm.git , with an SSH key pre‑configured on the execution machine.

The script archives results; an example output is shown below:

#####################################################
######### VM login check via SSH results ############
#####################################################
#                                                   #
# Compelted (success) 14/16 (total) login vm check. #
#                                                   #
# Below 2 host(s) login faied, need to check.       #
#                                                   #
abc.company.com
xyz.company.com
#                                                   #
#####################################################

Conclusion emphasizes the importance of understanding underlying principles rather than merely mastering tools, encouraging deep learning of operating systems, shell scripting, and programming languages for sustainable DevOps practice.