I have created the below unit file to create a systemd service on linux. This file launches jenkins agent on the machine. I have a stage in my pipeline in which the slave machine will be rebooted. Creating a service that starts after reboot was the solution that I was able to come up with, so that my pipeline execution can continue after reboot.
[Unit]
Description=Run jenkinsAgent at startup
After=network.target
[Service]
WorkingDirectory=/home/qatest/jenkins
Type=simple
ExecStart=/bin/bash /home/qatest/jenkins/jenkinsAgent.sh
StandardOutput=journal+console
[Install]
WantedBy=multi-user.target
My pipeline (groovy) uses hostName = sh(script: "hostname", returnStdout: true). But when the jenkins agent is started as a systemd service and the job is run, hostName is returned as empty.
If I start the jenkins agent manually in a shell using sudo ./jenkinsAgent.sh, then the sh works fine for the job run. ( my user is in the sudoers list ).
I initially thought that the std out of the systemd service was not directed properly, so I tried StandardOutput=journal+console in the unit file, but to no avail.
What am I missing here ?
I modified the unit file as shown below and the issue got resolved.
[Unit]
Description=Run jenkinsAgent at startup
After=network.target
[Service]
Type=simple
ExecStart=/usr/bin/java -jar /home/qatest/jenkins/agent.jar -jnlpUrl http://.../slave-agent.jnlp -secret ... -workDir "/home/qatest/jenkins"
[Install]
WantedBy=multi-user.target