Systemd One-Shot Services Lab

Overview

This lab teaches participants how to create and manage systemd one-shot services through a practical database backup scenario at the fictitious Super-Business company.

Learning Objectives

Participants will learn to:

• Understand the difference between daemon and one-shot systemd services

• Create systemd one-shot service units for task automation

• Configure service dependencies and ordering with Requires= and After=

• Use systemd timers to schedule one-shot services

• Implement a production-ready database backup solution

Lab Scenario

At Super-Business, Manager Scott has attempted to implement database backups with…​ creative results. Participants will work with Senior Sysadmin Nate to build a proper backup system using systemd one-shot services and timers.

The lab progresses through four modules:

1. Introduction - Understanding one-shot services and the lab environment

2. Creating a One-Shot Service - Building a backup script and service unit

3. Dependencies and Ordering - Ensuring the database is running before backups

4. Automation with Timers - Scheduling backups with systemd timers

Technical Details

• Platform: RHEL 10

• Services: MariaDB database server

• Tools: systemd, systemctl, journalctl, mysqldump

Lab Structure

zt-systemd-oneshot/
├── config/                     # VM and network configuration
├── content/                    # Lab documentation
│   └── modules/ROOT/pages/     # Module content files
├── setup-automation/           # Initial provisioning
│   └── setup-rhel.sh          # Sets up MariaDB with test data
├── runtime-automation/         # Per-module automation
│   ├── module-01/             # Introduction (validation only)
│   ├── module-02/             # One-shot service creation
│   ├── module-03/             # Dependencies and ordering
│   └── module-04/             # Timers and scheduling
└── utilities/                  # Development helper scripts

Real-World Applications

The skills learned in this lab apply to:

• Database backups and maintenance

• Log rotation and cleanup

• System initialization tasks

• Certificate renewal automation

• Data synchronization jobs

• Report generation

• Pre/post deployment scripts

Development

To build and preview the lab locally:

./utilities/lab-build
./utilities/lab-serve

Access the preview at http://localhost:8080

To stop the local server:

./utilities/lab-stop

Notes

• All backup files are stored in /var/backups/mariadb/

• The backup script automatically maintains only the 5 most recent backups

• All service actions are logged to the systemd journal

• Progress is tracked in /tmp/progress.log for debugging