Files
mkdocs-etz/mkdocs/site/basics/Automatisierung mit cron und systemd/index.html
2025-12-04 07:57:14 +01:00

1013 lines
25 KiB
HTML
Raw Blame History

This file contains invisible Unicode characters
This file contains invisible Unicode characters that are indistinguishable to humans but may be processed differently by a computer. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.
<!doctype html>
<html lang="en" class="no-js">
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width,initial-scale=1">
<link rel="prev" href="../Windows-Freigabe%20mit%20Samba/">
<link rel="next" href="../../Linux_Unternehmen/ubuntu-ad-dc/">
<link rel="icon" href="../../assets/images/favicon.png">
<meta name="generator" content="mkdocs-1.6.1, mkdocs-material-9.7.0">
<title>Automatisierung mit cron und systemd - Linux Grundlagen MK-IT</title>
<link rel="stylesheet" href="../../assets/stylesheets/main.618322db.min.css">
<link rel="stylesheet" href="../../assets/stylesheets/palette.ab4e12ef.min.css">
<link rel="preconnect" href="https://fonts.gstatic.com" crossorigin>
<link rel="stylesheet" href="https://fonts.googleapis.com/css?family=Roboto:300,300i,400,400i,700,700i%7CRoboto+Mono:400,400i,700,700i&display=fallback">
<style>:root{--md-text-font:"Roboto";--md-code-font:"Roboto Mono"}</style>
<script>__md_scope=new URL("../..",location),__md_hash=e=>[...e].reduce(((e,_)=>(e<<5)-e+_.charCodeAt(0)),0),__md_get=(e,_=localStorage,t=__md_scope)=>JSON.parse(_.getItem(t.pathname+"."+e)),__md_set=(e,_,t=localStorage,a=__md_scope)=>{try{t.setItem(a.pathname+"."+e,JSON.stringify(_))}catch(e){}}</script>
</head>
<body dir="ltr" data-md-color-scheme="default" data-md-color-primary="indigo" data-md-color-accent="indigo">
<input class="md-toggle" data-md-toggle="drawer" type="checkbox" id="__drawer" autocomplete="off">
<input class="md-toggle" data-md-toggle="search" type="checkbox" id="__search" autocomplete="off">
<label class="md-overlay" for="__drawer"></label>
<div data-md-component="skip">
<a href="#automatisierung-mit-cron-und-systemd" class="md-skip">
Skip to content
</a>
</div>
<div data-md-component="announce">
</div>
<header class="md-header md-header--shadow" data-md-component="header">
<nav class="md-header__inner md-grid" aria-label="Header">
<a href="../.." title="Linux Grundlagen MK-IT" class="md-header__button md-logo" aria-label="Linux Grundlagen MK-IT" data-md-component="logo">
<img src="../../assets/Logo.png" alt="logo">
</a>
<label class="md-header__button md-icon" for="__drawer">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M3 6h18v2H3zm0 5h18v2H3zm0 5h18v2H3z"/></svg>
</label>
<div class="md-header__title" data-md-component="header-title">
<div class="md-header__ellipsis">
<div class="md-header__topic">
<span class="md-ellipsis">
Linux Grundlagen MK-IT
</span>
</div>
<div class="md-header__topic" data-md-component="header-topic">
<span class="md-ellipsis">
Automatisierung mit cron und systemd
</span>
</div>
</div>
</div>
<form class="md-header__option" data-md-component="palette">
<input class="md-option" data-md-color-media="(prefers-color-scheme)" data-md-color-scheme="default" data-md-color-primary="indigo" data-md-color-accent="indigo" aria-label="Switch to light mode" type="radio" name="__palette" id="__palette_0">
<label class="md-header__button md-icon" title="Switch to light mode" for="__palette_1" hidden>
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="m14.3 16-.7-2h-3.2l-.7 2H7.8L11 7h2l3.2 9zM20 8.69V4h-4.69L12 .69 8.69 4H4v4.69L.69 12 4 15.31V20h4.69L12 23.31 15.31 20H20v-4.69L23.31 12zm-9.15 3.96h2.3L12 9z"/></svg>
</label>
<input class="md-option" data-md-color-media="(prefers-color-scheme: light)" data-md-color-scheme="default" data-md-color-primary="blue-grey" data-md-color-accent="orange" aria-label="Switch to dark mode" type="radio" name="__palette" id="__palette_1">
<label class="md-header__button md-icon" title="Switch to dark mode" for="__palette_2" hidden>
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M12 8a4 4 0 0 0-4 4 4 4 0 0 0 4 4 4 4 0 0 0 4-4 4 4 0 0 0-4-4m0 10a6 6 0 0 1-6-6 6 6 0 0 1 6-6 6 6 0 0 1 6 6 6 6 0 0 1-6 6m8-9.31V4h-4.69L12 .69 8.69 4H4v4.69L.69 12 4 15.31V20h4.69L12 23.31 15.31 20H20v-4.69L23.31 12z"/></svg>
</label>
<input class="md-option" data-md-color-media="(prefers-color-scheme: dark)" data-md-color-scheme="slate" data-md-color-primary="blue-grey" data-md-color-accent="yellow" aria-label="Switch to system preference" type="radio" name="__palette" id="__palette_2">
<label class="md-header__button md-icon" title="Switch to system preference" for="__palette_0" hidden>
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M12 18c-.89 0-1.74-.2-2.5-.55C11.56 16.5 13 14.42 13 12s-1.44-4.5-3.5-5.45C10.26 6.2 11.11 6 12 6a6 6 0 0 1 6 6 6 6 0 0 1-6 6m8-9.31V4h-4.69L12 .69 8.69 4H4v4.69L.69 12 4 15.31V20h4.69L12 23.31 15.31 20H20v-4.69L23.31 12z"/></svg>
</label>
</form>
<script>var palette=__md_get("__palette");if(palette&&palette.color){if("(prefers-color-scheme)"===palette.color.media){var media=matchMedia("(prefers-color-scheme: light)"),input=document.querySelector(media.matches?"[data-md-color-media='(prefers-color-scheme: light)']":"[data-md-color-media='(prefers-color-scheme: dark)']");palette.color.media=input.getAttribute("data-md-color-media"),palette.color.scheme=input.getAttribute("data-md-color-scheme"),palette.color.primary=input.getAttribute("data-md-color-primary"),palette.color.accent=input.getAttribute("data-md-color-accent")}for(var[key,value]of Object.entries(palette.color))document.body.setAttribute("data-md-color-"+key,value)}</script>
<label class="md-header__button md-icon" for="__search">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M9.5 3A6.5 6.5 0 0 1 16 9.5c0 1.61-.59 3.09-1.56 4.23l.27.27h.79l5 5-1.5 1.5-5-5v-.79l-.27-.27A6.52 6.52 0 0 1 9.5 16 6.5 6.5 0 0 1 3 9.5 6.5 6.5 0 0 1 9.5 3m0 2C7 5 5 7 5 9.5S7 14 9.5 14 14 12 14 9.5 12 5 9.5 5"/></svg>
</label>
<div class="md-search" data-md-component="search" role="dialog">
<label class="md-search__overlay" for="__search"></label>
<div class="md-search__inner" role="search">
<form class="md-search__form" name="search">
<input type="text" class="md-search__input" name="query" aria-label="Search" placeholder="Search" autocapitalize="off" autocorrect="off" autocomplete="off" spellcheck="false" data-md-component="search-query" required>
<label class="md-search__icon md-icon" for="__search">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M9.5 3A6.5 6.5 0 0 1 16 9.5c0 1.61-.59 3.09-1.56 4.23l.27.27h.79l5 5-1.5 1.5-5-5v-.79l-.27-.27A6.52 6.52 0 0 1 9.5 16 6.5 6.5 0 0 1 3 9.5 6.5 6.5 0 0 1 9.5 3m0 2C7 5 5 7 5 9.5S7 14 9.5 14 14 12 14 9.5 12 5 9.5 5"/></svg>
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M20 11v2H8l5.5 5.5-1.42 1.42L4.16 12l7.92-7.92L13.5 5.5 8 11z"/></svg>
</label>
<nav class="md-search__options" aria-label="Search">
<button type="reset" class="md-search__icon md-icon" title="Clear" aria-label="Clear" tabindex="-1">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24"><path d="M19 6.41 17.59 5 12 10.59 6.41 5 5 6.41 10.59 12 5 17.59 6.41 19 12 13.41 17.59 19 19 17.59 13.41 12z"/></svg>
</button>
</nav>
</form>
<div class="md-search__output">
<div class="md-search__scrollwrap" tabindex="0" data-md-scrollfix>
<div class="md-search-result" data-md-component="search-result">
<div class="md-search-result__meta">
Initializing search
</div>
<ol class="md-search-result__list" role="presentation"></ol>
</div>
</div>
</div>
</div>
</div>
</nav>
</header>
<div class="md-container" data-md-component="container">
<main class="md-main" data-md-component="main">
<div class="md-main__inner md-grid">
<div class="md-sidebar md-sidebar--primary" data-md-component="sidebar" data-md-type="navigation" >
<div class="md-sidebar__scrollwrap">
<div class="md-sidebar__inner">
<nav class="md-nav md-nav--primary" aria-label="Navigation" data-md-level="0">
<label class="md-nav__title" for="__drawer">
<a href="../.." title="Linux Grundlagen MK-IT" class="md-nav__button md-logo" aria-label="Linux Grundlagen MK-IT" data-md-component="logo">
<img src="../../assets/Logo.png" alt="logo">
</a>
Linux Grundlagen MK-IT
</label>
<ul class="md-nav__list" data-md-scrollfix>
<li class="md-nav__item">
<a href="../.." class="md-nav__link">
<span class="md-ellipsis">
Home
</span>
</a>
</li>
<li class="md-nav__item md-nav__item--active md-nav__item--section md-nav__item--nested">
<input class="md-nav__toggle md-toggle " type="checkbox" id="__nav_2" checked>
<label class="md-nav__link" for="__nav_2" id="__nav_2_label" tabindex="">
<span class="md-ellipsis">
Grundlagen
</span>
<span class="md-nav__icon md-icon"></span>
</label>
<nav class="md-nav" data-md-level="1" aria-labelledby="__nav_2_label" aria-expanded="true">
<label class="md-nav__title" for="__nav_2">
<span class="md-nav__icon md-icon"></span>
Grundlagen
</label>
<ul class="md-nav__list" data-md-scrollfix>
<li class="md-nav__item">
<a href="../Einstieg%20in%20Linux-Desktop/" class="md-nav__link">
<span class="md-ellipsis">
Einstieg in Linux-Desktop
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../Grundlagen%20der%20Konsole/" class="md-nav__link">
<span class="md-ellipsis">
Grundlagen der Konsole
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../Windows-Freigabe%20mit%20Samba/" class="md-nav__link">
<span class="md-ellipsis">
Windows-Freigabe mit Samba
</span>
</a>
</li>
<li class="md-nav__item md-nav__item--active">
<input class="md-nav__toggle md-toggle" type="checkbox" id="__toc">
<a href="./" class="md-nav__link md-nav__link--active">
<span class="md-ellipsis">
Automatisierung mit cron und systemd
</span>
</a>
</li>
</ul>
</nav>
</li>
<li class="md-nav__item md-nav__item--section md-nav__item--nested">
<input class="md-nav__toggle md-toggle " type="checkbox" id="__nav_3" >
<label class="md-nav__link" for="__nav_3" id="__nav_3_label" tabindex="">
<span class="md-ellipsis">
Linux im Unternehmen
</span>
<span class="md-nav__icon md-icon"></span>
</label>
<nav class="md-nav" data-md-level="1" aria-labelledby="__nav_3_label" aria-expanded="false">
<label class="md-nav__title" for="__nav_3">
<span class="md-nav__icon md-icon"></span>
Linux im Unternehmen
</label>
<ul class="md-nav__list" data-md-scrollfix>
<li class="md-nav__item">
<a href="../../Linux_Unternehmen/ubuntu-ad-dc/" class="md-nav__link">
<span class="md-ellipsis">
Ubuntu Servr als Active Directory Domain Controller
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../Linux_Unternehmen/linux-als-ad-client/" class="md-nav__link">
<span class="md-ellipsis">
Linux als Client in Active Directory
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../Linux_Unternehmen/nextcloud-ldap/" class="md-nav__link">
<span class="md-ellipsis">
Nextcloud mit LDAP-Anbindung
</span>
</a>
</li>
</ul>
</nav>
</li>
<li class="md-nav__item md-nav__item--section md-nav__item--nested">
<input class="md-nav__toggle md-toggle " type="checkbox" id="__nav_4" >
<label class="md-nav__link" for="__nav_4" id="__nav_4_label" tabindex="">
<span class="md-ellipsis">
Bonuskapitel
</span>
<span class="md-nav__icon md-icon"></span>
</label>
<nav class="md-nav" data-md-level="1" aria-labelledby="__nav_4_label" aria-expanded="false">
<label class="md-nav__title" for="__nav_4">
<span class="md-nav__icon md-icon"></span>
Bonuskapitel
</label>
<ul class="md-nav__list" data-md-scrollfix>
<li class="md-nav__item">
<a href="../../bonus/docker-grundlagen.md" class="md-nav__link">
<span class="md-ellipsis">
Docker-Grundlagen
</span>
</a>
</li>
<li class="md-nav__item md-nav__item--nested">
<input class="md-nav__toggle md-toggle " type="checkbox" id="__nav_4_2" >
<label class="md-nav__link" for="__nav_4_2" id="__nav_4_2_label" tabindex="0">
<span class="md-ellipsis">
Docker-Projekte
</span>
<span class="md-nav__icon md-icon"></span>
</label>
<nav class="md-nav" data-md-level="2" aria-labelledby="__nav_4_2_label" aria-expanded="false">
<label class="md-nav__title" for="__nav_4_2">
<span class="md-nav__icon md-icon"></span>
Docker-Projekte
</label>
<ul class="md-nav__list" data-md-scrollfix>
<li class="md-nav__item">
<a href="../../bonus/docker-pi-hole.md" class="md-nav__link">
<span class="md-ellipsis">
Pi-Hole
</span>
</a>
</li>
<li class="md-nav__item">
<a href="../../bonus/docker-backuppc.md" class="md-nav__link">
<span class="md-ellipsis">
BackupPC
</span>
</a>
</li>
</ul>
</nav>
</li>
</ul>
</nav>
</li>
</ul>
</nav>
</div>
</div>
</div>
<div class="md-sidebar md-sidebar--secondary" data-md-component="sidebar" data-md-type="toc" >
<div class="md-sidebar__scrollwrap">
<div class="md-sidebar__inner">
<nav class="md-nav md-nav--secondary" aria-label="Table of contents">
</nav>
</div>
</div>
</div>
<div class="md-content" data-md-component="content">
<article class="md-content__inner md-typeset">
<h1 id="automatisierung-mit-cron-und-systemd">Automatisierung mit cron und systemd</h1>
<p>Stellen Sie sich vor, Sie betreiben einen Server oder eine Anwendung, die rund um die Uhr laufen muss. Als IT-Meister möchten Sie jederzeit nachvollziehen können, ob Ihr System aktiv ist und wann es zuletzt gestartet wurde. Dafür können Sie zwei klassische Linux-Automatisierungswerkzeuge nutzen:</p>
<ul>
<li><strong>Cronjob:</strong> Führt regelmäßig Aufgaben aus, z.B. jede Minute, jede Stunde oder einmal täglich.</li>
<li><strong>systemd-Unit:</strong> Startet Aufgaben beim Systemstart oder zu bestimmten Ereignissen.</li>
</ul>
<p>Mit diesen Werkzeugen können Sie z.B. eine Datei anlegen oder aktualisieren, um so einen „Herzschlag" (Heartbeat) Ihres Systems zu dokumentieren.</p>
<h1 id="cron-job-jede-minute-eine-datei-aktualisieren">Cron-Job: Jede Minute eine Datei aktualisieren</h1>
<blockquote>
<p>Praxisbeispiel: Heartbeat-File</p>
</blockquote>
<p>Sie möchten, dass jede Minute der Zeitstempel einer Datei (/tmp/heartbeat.txt) aktualisiert wird. Das ist nützlich, um zu prüfen, ob Cron und das System laufen.</p>
<p><strong>So geht's:</strong></p>
<p>Öffnen Sie die Crontab des aktuellen Benutzers:</p>
<div class="highlight"><pre><span></span><code>crontab -e
</code></pre></div>
<p>Fügen Sie folgende Zeile hinzu:</p>
<div class="highlight"><pre><span></span><code>* * * * * /usr/bin/touch /tmp/heartbeat.txt
</code></pre></div>
<p>Jetzt wird jede Minute die Datei /tmp/heartbeat.txt neu angelegt oder ihr Zeitstempel aktualisiert.</p>
<p>\newpage</p>
<h1 id="crontab-syntax-erklart">Crontab-Syntax erklärt:</h1>
<table>
<thead>
<tr>
<th>Feld</th>
<th>Bedeutung</th>
<th>Wert im Beispiel</th>
<th>Bedeutung</th>
</tr>
</thead>
<tbody>
<tr>
<td>Minute</td>
<td>0-59</td>
<td>*</td>
<td>jede Minute</td>
</tr>
<tr>
<td>Stunde</td>
<td>0-23</td>
<td>*</td>
<td>jede Stunde</td>
</tr>
<tr>
<td>Tag (Monat)</td>
<td>1-31</td>
<td>*</td>
<td>jeder Tag</td>
</tr>
<tr>
<td>Monat</td>
<td>1-12</td>
<td>*</td>
<td>jeder Monat</td>
</tr>
<tr>
<td>Tag (Woche)</td>
<td>0-7 (0/7 = Son)</td>
<td>*</td>
<td>jeder Wochentag</td>
</tr>
<tr>
<td>Befehl</td>
<td>Befehl</td>
<td>/usr/bin/touch /tmp/heartbeat.txt</td>
<td>Was wird ausgeführt</td>
</tr>
</tbody>
</table>
<p><strong>Beispiel:</strong></p>
<div class="highlight"><pre><span></span><code>* * * * * /usr/bin/touch /tmp/heartbeat.txt
</code></pre></div>
<p>→ Jede Minute wird die Datei angefasst („touched").</p>
<p><strong>Weitere Beispiele:</strong></p>
<div class="highlight"><pre><span></span><code>0 0 * * * /usr/bin/touch /tmp/midnight.txt
</code></pre></div>
<ul>
<li>&#x20;jeden Tag um Mitternacht</li>
</ul>
<div class="highlight"><pre><span></span><code>1/5 * * * * /usr/bin/touch /tmp/every5min.txt
</code></pre></div>
<ul>
<li>alle 5 Minuten beginnend 5 Minuten nach 1 also 6,11,16,...</li>
</ul>
<h1 id="systemd-unit-datei-beim-systemstart-aktualisieren">systemd-Unit: Datei beim Systemstart aktualisieren</h1>
<h2 id="praxisbeispiel-boot-marker"><strong>Praxisbeispiel: Boot-Marker</strong></h2>
<p>Sie möchten beim Systemstart eine Datei (/tmp/boot.txt) anlegen oder deren Zeitstempel aktualisieren, um den letzten Bootvorgang zu protokollieren.</p>
<p><strong>So geht's:</strong></p>
<p>Erstellen Sie eine neue systemd-Service-Datei:</p>
<div class="highlight"><pre><span></span><code>sudo nano /etc/systemd/system/touch-at-boot.service
</code></pre></div>
<p>Fügen Sie folgenden Inhalt ein:</p>
<div class="highlight"><pre><span></span><code><span class="k">[Unit]</span>
<span class="na">Description</span><span class="o">=</span><span class="s">Touch file at boot</span>
<span class="k">[Service]</span>
<span class="na">Type</span><span class="o">=</span><span class="s">oneshot</span>
<span class="na">ExecStart</span><span class="o">=</span><span class="s">/usr/bin/touch /tmp/boot.txt</span>
<span class="k">[Install]</span>
<span class="na">WantedBy</span><span class="o">=</span><span class="s">multi-user.target</span>
</code></pre></div>
<ol>
<li>Datei speichern und schließen.</li>
<li>Service aktivieren und testen:</li>
</ol>
<div class="highlight"><pre><span></span><code>sudo systemctl daemon-reload
sudo systemctl enable touch-at-boot.service
sudo systemctl start touch-at-boot.service
</code></pre></div>
<p>Nach jedem Neustart wird /tmp/boot.txt aktualisiert.</p>
<p><strong>systemd-Unit erklärt:</strong></p>
<div class="highlight"><pre><span></span><code><span class="na">[Unit]</span><span class="o">:</span><span class="w"> </span><span class="s">Metadaten und Abhängigkeiten</span>
<span class="na">Description</span><span class="o">:</span><span class="w"> </span><span class="s">Kurze Beschreibung</span>
<span class="na">[Service]</span><span class="o">:</span><span class="w"> </span><span class="s">Was soll gemacht werden?</span>
<span class="na">Type</span><span class="o">=</span><span class="s">oneshot: Einmaliger Befehl, kein dauerhafter Prozess der überwacht werden könnte</span>
<span class="na">ExecStart</span><span class="o">:</span><span class="w"> </span><span class="s">Der auszuführende Befehl</span>
<span class="na">[Install]</span><span class="o">:</span><span class="w"> </span><span class="s">Wann/wo soll der Service gestartet werden?</span>
<span class="na">WantedBy</span><span class="o">=</span><span class="s">multi-user.target: Startet beim normalen Systemstart</span>
</code></pre></div>
<p><strong>systemd-Kommandos:</strong></p>
<div class="highlight"><pre><span></span><code>sudo systemctl start &lt;service&gt; # Service sofort starten
sudo systemctl enable &lt;service&gt; # Service beim Boot aktivieren
sudo systemctl status &lt;service&gt; # Status anzeigen
sudo systemctl stop &lt;service&gt; # Service stoppen
</code></pre></div>
<p><strong>Wann nutze ich was?</strong></p>
<ul>
<li><strong>Cronjob</strong>: Für wiederkehrende Aufgaben (regelmäßig, z.B. jede Minute, stündlich, täglich)</li>
<li><strong>systemd-Unit</strong>: Für Aufgaben beim Systemstart, beim Herunterfahren oder bei bestimmten Ereignissen</li>
</ul>
<p><a class="md-button" href="../Automatisierung_mit_cron_und_systemd.pdf">PDF herunterladen</a></p>
</article>
</div>
<script>var target=document.getElementById(location.hash.slice(1));target&&target.name&&(target.checked=target.name.startsWith("__tabbed_"))</script>
</div>
</main>
<footer class="md-footer">
<div class="md-footer-meta md-typeset">
<div class="md-footer-meta__inner md-grid">
<div class="md-copyright">
Made with
<a href="https://squidfunk.github.io/mkdocs-material/" target="_blank" rel="noopener">
Material for MkDocs
</a>
</div>
</div>
</div>
</footer>
</div>
<div class="md-dialog" data-md-component="dialog">
<div class="md-dialog__inner md-typeset"></div>
</div>
<script id="__config" type="application/json">{"annotate": null, "base": "../..", "features": ["navigation.sections"], "search": "../../assets/javascripts/workers/search.7a47a382.min.js", "tags": null, "translations": {"clipboard.copied": "Copied to clipboard", "clipboard.copy": "Copy to clipboard", "search.result.more.one": "1 more on this page", "search.result.more.other": "# more on this page", "search.result.none": "No matching documents", "search.result.one": "1 matching document", "search.result.other": "# matching documents", "search.result.placeholder": "Type to start searching", "search.result.term.missing": "Missing", "select.version": "Select version"}, "version": null}</script>
<script src="../../assets/javascripts/bundle.e71a0d61.min.js"></script>
</body>
</html>