It seems every other organization is using Jenkins these days. Jenkins is a continuous integration and continuous delivery server that can be used to automate building, testing, and delivering or deploying software. 

Many organizations also use Puppet for their configuration management needs. Puppet is, if not the de facto configuration management solution, at least one of the most mature and field tested ones. It consists of several server components, agents, a declarative programming language, amongst others. Puppet can be used to install, set up and manage large number of all kinds of resources.

Jenkins is a continuous integration (CI) / continuous delivery (CD) platform consisting of a Jenkins master - essentially a controller - which launches jobs on Jenkins slaves. Often slaves are controlled via SSH.

Recently I ran into an issue with a legacy Jenkins slave where the “jenkins” where Puppet tried to enforce the home directory of “jenkins” to be /home/jenkins instead of /var/lib/jenkins:

Error: Could not set home on user[jenkins]: Execution of '/usr/sbin/usermod -d /home/jenkins jenkins' returned 8: usermod: user jenkins is currently used by p rocess 802  

The usermod command failed because several Jenkins processes (ssh-agent, Java) locked the user from modification. The solution was relatively straightforward: