Systemd Timer

Description

This role configures a systemd timer to periodically start a corresponding service. It uses a Jinja2 template to create a timer unit file that specifies the scheduling parameters (such as OnCalendar and RandomizedDelaySec) and then restarts the timer service accordingly.

Overview

Optimized for automated task scheduling in a systemd environment, this role:

  • Generates a timer unit file for a given service (using the system_service_timer_service variable).

  • Reloads and restarts the timer using systemd to ensure that changes take effect.

  • Supports dynamic configuration of scheduling parameters via variables like system_service_on_calendar and RANDOMIZED_DELAY_SEC.

Cosmos

The diagram places Systemd Timer in the Infinito.Nexus cosmos: the components it deploys (capabilities), the central services it consumes (dependencies), and its outward reach (federation and bridged external networks).

flowchart LR
    subgraph role [sys-timer 💻]
        svc_timer["timer"]
    end

Solid 1:1 edges are fixed relationships; dashed 0..1 edges are conditional (enabled only in matching deployments); red 0..0 edges are turned off in this role. Node markers show the role’s deploy modes (💻 host, 🐳 compose, 🐝 swarm); ❌ marks a service that is explicitly turned off, and ⚙️ an Ansible role dependency declared in meta/main.yml.

Purpose

The primary purpose of this role is to provide a reusable mechanism for scheduling recurring tasks on a system. By creating and managing a systemd timer unit, the role ensures that specified services are automatically started at defined intervals, enhancing system automation and reliability.

Features

  • Dynamic Timer Configuration: Uses a Jinja2 template to create a timer unit file based on provided variables.

  • Automated Service Management: Automatically reloads the systemd daemon and restarts the timer when changes are detected.

  • Flexible Scheduling: Supports configuration of parameters such as OnCalendar and RandomizedDelaySec for precise control over task timing.

  • Persistent Timers: Optionally enables persistent timer behavior to ensure missed activations are handled.

Credits

Implemented by Kevin Veen-Birkenbach. Part of the Infinito.Nexus Project and maintained by Kevin Veen-Birkenbach. Licensed under the Infinito.Nexus Community License (Non-Commercial).