cdist-web/src/extra/manual/beta/cdist-explorer.html

286 lines
11 KiB
HTML

<!DOCTYPE html>
<!--[if IE 8]><html class="no-js lt-ie9" lang="en" > <![endif]-->
<!--[if gt IE 8]><!--> <html class="no-js" lang="en" > <!--<![endif]-->
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>17. Explorer &mdash; cdist 6.8.0 documentation</title>
<script type="text/javascript" src="_static/js/modernizr.min.js"></script>
<script type="text/javascript" id="documentation_options" data-url_root="./" src="_static/documentation_options.js"></script>
<script src="_static/jquery.js"></script>
<script src="_static/underscore.js"></script>
<script src="_static/doctools.js"></script>
<script src="_static/language_data.js"></script>
<script type="text/javascript" src="_static/js/theme.js"></script>
<link rel="stylesheet" href="_static/css/theme.css" type="text/css" />
<link rel="stylesheet" href="_static/pygments.css" type="text/css" />
<link rel="index" title="Index" href="genindex.html" />
<link rel="search" title="Search" href="search.html" />
<link rel="next" title="18. Messaging" href="cdist-messaging.html" />
<link rel="prev" title="16.162. cdist-type__zypper_service(7)" href="man7/cdist-type__zypper_service.html" />
</head>
<body class="wy-body-for-nav">
<div class="wy-grid-for-nav">
<nav data-toggle="wy-nav-shift" class="wy-nav-side">
<div class="wy-side-scroll">
<div class="wy-side-nav-search" >
<a href="index.html" class="icon icon-home"> cdist
<img src="_static/cdist-logo.jpeg" class="logo" alt="Logo"/>
</a>
<div class="version">
6.8.0
</div>
<div role="search">
<form id="rtd-search-form" class="wy-form" action="search.html" method="get">
<input type="text" name="q" placeholder="Search docs" />
<input type="hidden" name="check_keywords" value="yes" />
<input type="hidden" name="area" value="default" />
</form>
</div>
</div>
<div class="wy-menu wy-menu-vertical" data-spy="affix" role="navigation" aria-label="main navigation">
<ul class="current">
<li class="toctree-l1"><a class="reference internal" href="cdist-why.html">1. Why should I use cdist?</a></li>
<li class="toctree-l1"><a class="reference internal" href="cdist-features.html">2. Features</a></li>
<li class="toctree-l1"><a class="reference internal" href="cdist-os.html">3. Supported operating systems</a></li>
<li class="toctree-l1"><a class="reference internal" href="cdist-install.html">4. How to install cdist</a></li>
<li class="toctree-l1"><a class="reference internal" href="cdist-upgrade.html">5. How to upgrade cdist</a></li>
<li class="toctree-l1"><a class="reference internal" href="cdist-support.html">6. Support</a></li>
<li class="toctree-l1"><a class="reference internal" href="cdist-quickstart.html">7. Quickstart</a></li>
<li class="toctree-l1"><a class="reference internal" href="cdist-real-world.html">8. Dive into real world cdist</a></li>
<li class="toctree-l1"><a class="reference internal" href="man1/cdist.html">9. cdist(1)</a></li>
<li class="toctree-l1"><a class="reference internal" href="man1/cdist-dump.html">10. cdist-dump(1)</a></li>
<li class="toctree-l1"><a class="reference internal" href="man1/cdist-new-type.html">11. cdist-new-type(1)</a></li>
<li class="toctree-l1"><a class="reference internal" href="cdist-bootstrap.html">12. Bootstrap</a></li>
<li class="toctree-l1"><a class="reference internal" href="cdist-configuration.html">13. Configuration</a></li>
<li class="toctree-l1"><a class="reference internal" href="cdist-manifest.html">14. Manifest</a></li>
<li class="toctree-l1"><a class="reference internal" href="cdist-type.html">15. cdist type</a></li>
<li class="toctree-l1"><a class="reference internal" href="cdist-types.html">16. cdist types</a></li>
<li class="toctree-l1 current"><a class="current reference internal" href="#">17. Explorer</a><ul>
<li class="toctree-l2"><a class="reference internal" href="#description">17.1. Description</a></li>
<li class="toctree-l2"><a class="reference internal" href="#examples">17.2. Examples</a></li>
</ul>
</li>
<li class="toctree-l1"><a class="reference internal" href="cdist-messaging.html">18. Messaging</a></li>
<li class="toctree-l1"><a class="reference internal" href="cdist-parallelization.html">19. Parallelization</a></li>
<li class="toctree-l1"><a class="reference internal" href="cdist-inventory.html">20. Inventory</a></li>
<li class="toctree-l1"><a class="reference internal" href="cdist-trigger.html">21. Trigger</a></li>
<li class="toctree-l1"><a class="reference internal" href="cdist-preos.html">22. PreOS</a></li>
<li class="toctree-l1"><a class="reference internal" href="cdist-integration.html">23. cdist integration / using cdist as library</a></li>
<li class="toctree-l1"><a class="reference internal" href="cdist-reference.html">24. Reference</a></li>
<li class="toctree-l1"><a class="reference internal" href="cdist-best-practice.html">25. Best practice</a></li>
<li class="toctree-l1"><a class="reference internal" href="cdist-stages.html">26. Execution stages</a></li>
<li class="toctree-l1"><a class="reference internal" href="cdist-cache.html">27. Local cache overview</a></li>
<li class="toctree-l1"><a class="reference internal" href="cdist-saving-output-streams.html">28. Saving output streams</a></li>
<li class="toctree-l1"><a class="reference internal" href="cdist-remote-exec-copy.html">29. Remote exec and copy commands</a></li>
<li class="toctree-l1"><a class="reference internal" href="cdist-hacker.html">30. Hacking</a></li>
<li class="toctree-l1"><a class="reference internal" href="cdist-troubleshooting.html">31. Troubleshooting</a></li>
</ul>
</div>
</div>
</nav>
<section data-toggle="wy-nav-shift" class="wy-nav-content-wrap">
<nav class="wy-nav-top" aria-label="top navigation">
<i data-toggle="wy-nav-top" class="fa fa-bars"></i>
<a href="index.html">cdist</a>
</nav>
<div class="wy-nav-content">
<div class="rst-content">
<div role="navigation" aria-label="breadcrumbs navigation">
<ul class="wy-breadcrumbs">
<li><a href="index.html">Docs</a> &raquo;</li>
<li><span class="section-number">17. </span>Explorer</li>
<li class="wy-breadcrumbs-aside">
<a href="_sources/cdist-explorer.rst.txt" rel="nofollow"> View page source</a>
</li>
</ul>
<hr/>
</div>
<div role="main" class="document" itemscope="itemscope" itemtype="http://schema.org/Article">
<div itemprop="articleBody">
<div class="section" id="explorer">
<h1><span class="section-number">17. </span>Explorer<a class="headerlink" href="#explorer" title="Permalink to this headline"></a></h1>
<div class="section" id="description">
<h2><span class="section-number">17.1. </span>Description<a class="headerlink" href="#description" title="Permalink to this headline"></a></h2>
<p>Explorers are small shell scripts, which will be executed on the target
host. The aim of each explorer is to give hints to types on how to act on the
target system. An explorer outputs the result to stdout, which is usually
a one liner, but may be empty or multi line especially in the case of
type explorers.</p>
<p>There are general explorers, which are run in an early stage, and
type explorers. Both work almost exactly the same way, with the difference
that the values of the general explorers are stored in a general location and
the type specific below the object.</p>
<p>Explorers can reuse other explorers on the target system by calling</p>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span>$__explorer/&lt;explorer_name&gt; (general and type explorer)
</pre></div>
</div>
<p>or</p>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span>$__type_explorer/&lt;explorer name&gt; (type explorer).
</pre></div>
</div>
<p>In case of significant errors, the explorer may exit non-zero and return an
error message on stderr, which will cause cdist to abort.</p>
<p>You can also use stderr for debugging purposes while developing a new
explorer.</p>
</div>
<div class="section" id="examples">
<h2><span class="section-number">17.2. </span>Examples<a class="headerlink" href="#examples" title="Permalink to this headline"></a></h2>
<p>A very simple explorer may look like this:</p>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="n">hostname</span>
</pre></div>
</div>
<p>Which is in practise the <strong>hostname</strong> explorer.</p>
<p>A type explorer, which could check for the status of a package may look like this:</p>
<div class="highlight-sh notranslate"><div class="highlight"><pre><span></span><span class="k">if</span> <span class="o">[</span> -f <span class="s2">&quot;</span><span class="nv">$__object</span><span class="s2">/parameter/name&quot;</span> <span class="o">]</span><span class="p">;</span> <span class="k">then</span>
<span class="nv">name</span><span class="o">=</span><span class="s2">&quot;</span><span class="k">$(</span>cat <span class="s2">&quot;</span><span class="nv">$__object</span><span class="s2">/parameter/name&quot;</span><span class="k">)</span><span class="s2">&quot;</span>
<span class="k">else</span>
<span class="nv">name</span><span class="o">=</span><span class="s2">&quot;</span><span class="nv">$__object_id</span><span class="s2">&quot;</span>
<span class="k">fi</span>
<span class="c1"># Expect dpkg failing, if package is not known / installed</span>
dpkg -s <span class="s2">&quot;</span><span class="nv">$name</span><span class="s2">&quot;</span> <span class="m">2</span>&gt;/dev/null <span class="o">||</span> <span class="nb">exit</span> <span class="m">0</span>
</pre></div>
</div>
</div>
</div>
</div>
</div>
<footer>
<div class="rst-footer-buttons" role="navigation" aria-label="footer navigation">
<a href="cdist-messaging.html" class="btn btn-neutral float-right" title="18. Messaging" accesskey="n" rel="next">Next <span class="fa fa-arrow-circle-right"></span></a>
<a href="man7/cdist-type__zypper_service.html" class="btn btn-neutral float-left" title="16.162. cdist-type__zypper_service(7)" accesskey="p" rel="prev"><span class="fa fa-arrow-circle-left"></span> Previous</a>
</div>
<hr/>
<div role="contentinfo">
<p>
&copy; Copyright ungleich GmbH 2020
</p>
</div>
Built with <a href="http://sphinx-doc.org/">Sphinx</a> using a <a href="https://github.com/rtfd/sphinx_rtd_theme">theme</a> provided by <a href="https://readthedocs.org">Read the Docs</a>.
</footer>
</div>
</div>
</section>
</div>
<script type="text/javascript">
jQuery(function () {
SphinxRtdTheme.Navigation.enable(true);
});
</script>
</body>
</html>