luet/docs/concepts/index.xml

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    <title>Luet – Concepts</title>
    <link>https://luet.io/docs/concepts/</link>
    <description>Recent content in Concepts on Luet</description>
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    <item>
      <title>Docs: Overview</title>
      <link>https://luet.io/docs/concepts/overview/</link>
      <pubDate>Mon, 01 Jan 0001 00:00:00 +0000</pubDate>
      
      <guid>https://luet.io/docs/concepts/overview/</guid>
      <description>
        
        
        &lt;p&gt;Luet provides an abstraction layer on top of the container image layer to make the package a first class construct. A package definition and all its dependencies are translated by Luet to Dockerfiles which can then be built anywhere that docker runs.&lt;/p&gt;
&lt;p&gt;Luet is written entirely in Go and comes as a single static binary. This has a few advantages:&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;Easy to recover. You can use luet to bootstrap the system entirely from the ground-up.&lt;/li&gt;
&lt;li&gt;Package manager has no dependencies on the packages that it installs. There is no chance of breaking the package manager by installing a conflicting package, or uninstalling one.&lt;/li&gt;
&lt;li&gt;Portable - it can run on any architecture&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;Luet brings the containers ecosystem to standard software package management and delivery. It is fully built around the container concept, and leverages the huge catalog already present in the wild. It lets you use container images from &lt;a href=&#34;https://hub.docker.com/&#34;&gt;Docker Hub&lt;/a&gt;, or from private registries to build packages, and helps you to redistribute them.&lt;/p&gt;
&lt;p&gt;Systems that are using luet as a package manager can consume Luet repositories with only luet itself. No dependency is required by the Package manager, giving you the full control on what you install or not in the system. It can be used to generate &lt;em&gt;Linux from Scratch&lt;/em&gt; distributions,  also to build Docker images, or to simply build standalone packages that you might want to redistribute.&lt;/p&gt;
&lt;p&gt;The syntax proposed aims to be &lt;a href=&#34;https://en.wikipedia.org/wiki/KISS_principle&#34;&gt;KISS&lt;/a&gt; - you define a set of steps that need to be run to build your image, and a set of constraints denoting the requirements or conflicts of your package.&lt;/p&gt;
&lt;h2 id=&#34;why-another-package-manager&#34;&gt;Why another Package manager?&lt;/h2&gt;
&lt;p&gt;There is no known package manager with 0-dependency that fully leverages the container ecosystem. This gap forces current package managers to depend on a specific system layout as base of the building process and the corresponding depencies. This can cause situations leading to a broken system. We want to fix that by empowering the user, by building their own packages, and redistribute them.
Luet allows also to create packages entirely from Docker images content. In this way the user can actually bundle all the files of an image into a package and deliver part of it, or entirely as a layer. All of that, without the package manager depending on a single bit from it.&lt;/p&gt;
&lt;h2 id=&#34;package-definitions&#34;&gt;Package definitions&lt;/h2&gt;
&lt;p&gt;Luet uses &lt;a href=&#34;https://en.wikipedia.org/wiki/YAML&#34;&gt;YAML&lt;/a&gt; for the package specification format, Luet parses the &lt;a href=&#34;https://luet.io/docs/concepts/overview/constraints&#34;&gt;requirements&lt;/a&gt; to build &lt;a href=&#34;https://luet.io/docs/concepts/packages&#34;&gt;packages&lt;/a&gt;, so Luet can consume them.&lt;/p&gt;
&lt;p&gt;Below you can find links to tutorials on how to build packages, images and repositories.&lt;/p&gt;

      </description>
    </item>
    
    <item>
      <title>Docs: Packages</title>
      <link>https://luet.io/docs/concepts/packages/</link>
      <pubDate>Mon, 01 Jan 0001 00:00:00 +0000</pubDate>
      
      <guid>https://luet.io/docs/concepts/packages/</guid>
      <description>
        
        
        &lt;p&gt;A Package in Luet is denoted by a triple (&lt;code&gt;name&lt;/code&gt;, &lt;code&gt;category&lt;/code&gt; and &lt;code&gt;version&lt;/code&gt;), here called &lt;em&gt;package form&lt;/em&gt; in a &lt;code&gt;definition.yaml&lt;/code&gt; file in YAML:&lt;/p&gt;
&lt;div class=&#34;highlight&#34;&gt;&lt;pre tabindex=&#34;0&#34; style=&#34;background-color:#f8f8f8;-moz-tab-size:4;-o-tab-size:4;tab-size:4&#34;&gt;&lt;code class=&#34;language-yaml&#34; data-lang=&#34;yaml&#34;&gt;&lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;name&lt;/span&gt;&lt;span style=&#34;color:#000;font-weight:bold&#34;&gt;:&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt; &lt;/span&gt;&lt;span style=&#34;color:#4e9a06&#34;&gt;&amp;#34;awesome&amp;#34;&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;&lt;/span&gt;&lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;version&lt;/span&gt;&lt;span style=&#34;color:#000;font-weight:bold&#34;&gt;:&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt; &lt;/span&gt;&lt;span style=&#34;color:#4e9a06&#34;&gt;&amp;#34;0.1&amp;#34;&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;&lt;/span&gt;&lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;category&lt;/span&gt;&lt;span style=&#34;color:#000;font-weight:bold&#34;&gt;:&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt; &lt;/span&gt;&lt;span style=&#34;color:#4e9a06&#34;&gt;&amp;#34;foo&amp;#34;&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;p&gt;While &lt;code&gt;category&lt;/code&gt; and &lt;code&gt;version&lt;/code&gt; can be omitted, the name is required. Note that when refering to a package, the triplet is always present:&lt;/p&gt;
&lt;div class=&#34;highlight&#34;&gt;&lt;pre tabindex=&#34;0&#34; style=&#34;background-color:#f8f8f8;-moz-tab-size:4;-o-tab-size:4;tab-size:4&#34;&gt;&lt;code class=&#34;language-yaml&#34; data-lang=&#34;yaml&#34;&gt;&lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;requires&lt;/span&gt;&lt;span style=&#34;color:#000;font-weight:bold&#34;&gt;:&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;&lt;/span&gt;- &lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;name&lt;/span&gt;&lt;span style=&#34;color:#000;font-weight:bold&#34;&gt;:&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt; &lt;/span&gt;&lt;span style=&#34;color:#4e9a06&#34;&gt;&amp;#34;awesome&amp;#34;&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;  &lt;/span&gt;&lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;version&lt;/span&gt;&lt;span style=&#34;color:#000;font-weight:bold&#34;&gt;:&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt; &lt;/span&gt;&lt;span style=&#34;color:#4e9a06&#34;&gt;&amp;#34;0.1&amp;#34;&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;  &lt;/span&gt;&lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;category&lt;/span&gt;&lt;span style=&#34;color:#000;font-weight:bold&#34;&gt;:&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt; &lt;/span&gt;&lt;span style=&#34;color:#4e9a06&#34;&gt;&amp;#34;foo&amp;#34;&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;&lt;/span&gt;- &lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;name&lt;/span&gt;&lt;span style=&#34;color:#000;font-weight:bold&#34;&gt;:&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt; &lt;/span&gt;&lt;span style=&#34;color:#4e9a06&#34;&gt;&amp;#34;bar&amp;#34;&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;  &lt;/span&gt;&lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;version&lt;/span&gt;&lt;span style=&#34;color:#000;font-weight:bold&#34;&gt;:&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt; &lt;/span&gt;&lt;span style=&#34;color:#4e9a06&#34;&gt;&amp;#34;0.1&amp;#34;&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;  &lt;/span&gt;&lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;category&lt;/span&gt;&lt;span style=&#34;color:#000;font-weight:bold&#34;&gt;:&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt; &lt;/span&gt;&lt;span style=&#34;color:#4e9a06&#34;&gt;&amp;#34;foo&amp;#34;&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;h2 id=&#34;building-process&#34;&gt;Building process&lt;/h2&gt;
&lt;p&gt;When a package is required to be built, Luet resolves the dependency trees and orders the spec files to satisfy the given contraints.&lt;/p&gt;
&lt;p&gt;Each package build context is where the spec files are found (&lt;code&gt;definition.yaml&lt;/code&gt; and &lt;code&gt;build.yaml&lt;/code&gt;). This means that in the container, which is running the build process, the resources inside the package folder are accessible, as normally in Docker.&lt;/p&gt;
&lt;pre tabindex=&#34;0&#34;&gt;&lt;code&gt;❯ tree distro/raspbian/buster
distro/raspbian/buster
├── build.sh
├── build.yaml
├── definition.yaml
└── finalize.yaml
&lt;/code&gt;&lt;/pre&gt;&lt;p&gt;In the example above, &lt;code&gt;build.sh&lt;/code&gt; is accessible in build time and can be invoked easily in build time in &lt;code&gt;build.yaml&lt;/code&gt;:&lt;/p&gt;
&lt;div class=&#34;highlight&#34;&gt;&lt;pre tabindex=&#34;0&#34; style=&#34;background-color:#f8f8f8;-moz-tab-size:4;-o-tab-size:4;tab-size:4&#34;&gt;&lt;code class=&#34;language-yaml&#34; data-lang=&#34;yaml&#34;&gt;&lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;steps&lt;/span&gt;&lt;span style=&#34;color:#000;font-weight:bold&#34;&gt;:&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;&lt;/span&gt;- &lt;span style=&#34;color:#000&#34;&gt;sh build.sh&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;h2 id=&#34;package-provides&#34;&gt;Package provides&lt;/h2&gt;
&lt;p&gt;Packages can specify a list of &lt;code&gt;provides&lt;/code&gt;. This is a list of packages in &lt;em&gt;package form&lt;/em&gt;, which indicates that the current definition &lt;em&gt;replaces&lt;/em&gt; every occurrence of the packages in the list (both at &lt;em&gt;build&lt;/em&gt; and &lt;em&gt;runtime&lt;/em&gt;). This mechanism is particularly helpful for handling package moves or for enabling virtual packages (e.g., &lt;a href=&#34;https://packages.gentoo.org/categories/virtual&#34;&gt;gentoo virtual packages&lt;/a&gt;).&lt;/p&gt;
&lt;p&gt;&lt;em&gt;Note: packages in the &lt;code&gt;provides&lt;/code&gt; list don&amp;rsquo;t need to exist or have a valid build definition either.&lt;/em&gt;&lt;/p&gt;
&lt;h2 id=&#34;package-types&#34;&gt;Package types&lt;/h2&gt;
&lt;p&gt;By a combination of keywords in &lt;code&gt;build.yaml&lt;/code&gt;, you end up with categories of packages that can be built:&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;Seed packages&lt;/li&gt;
&lt;li&gt;Packages deltas&lt;/li&gt;
&lt;li&gt;Package layers&lt;/li&gt;
&lt;li&gt;Package with includes&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;Check the &lt;a href=&#34;https://luet.io/docs/concepts/packages/specfile&#34;&gt;Specfile concept&lt;/a&gt; page for a full overview of the available keywords in the Luet specfile format.&lt;/p&gt;
&lt;h3 id=&#34;seed-packages&#34;&gt;Seed packages&lt;/h3&gt;
&lt;p&gt;Seed packages denote a parent package (or root) that can be used by other packages as a dependency. Normally, seed packages include just an image (preferably tagged) used as a base for other packages to depend on.&lt;/p&gt;
&lt;p&gt;It is useful to pin to specific image versions, and to write down in a tree where packages are coming from. There can be as many seed packages as you like in a tree.&lt;/p&gt;
&lt;p&gt;A seed package &lt;code&gt;build.yaml&lt;/code&gt; example is the following:&lt;/p&gt;
&lt;div class=&#34;highlight&#34;&gt;&lt;pre tabindex=&#34;0&#34; style=&#34;background-color:#f8f8f8;-moz-tab-size:4;-o-tab-size:4;tab-size:4&#34;&gt;&lt;code class=&#34;language-yaml&#34; data-lang=&#34;yaml&#34;&gt;&lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;image&lt;/span&gt;&lt;span style=&#34;color:#000;font-weight:bold&#34;&gt;:&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt; &lt;/span&gt;&lt;span style=&#34;color:#4e9a06&#34;&gt;&amp;#34;alpine:3.1&amp;#34;&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;p&gt;Every other package that depends on it will inherit the layers from it.&lt;/p&gt;
&lt;p&gt;If you want to extract the content of the seed package in a separate packages (splitting), you can just create as many package as you wish depending on that one, and extract its content, for example:&lt;/p&gt;
&lt;p&gt;&lt;strong&gt;alpine/build.yaml&lt;/strong&gt;&lt;/p&gt;
&lt;div class=&#34;highlight&#34;&gt;&lt;pre tabindex=&#34;0&#34; style=&#34;background-color:#f8f8f8;-moz-tab-size:4;-o-tab-size:4;tab-size:4&#34;&gt;&lt;code class=&#34;language-yaml&#34; data-lang=&#34;yaml&#34;&gt;&lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;image&lt;/span&gt;&lt;span style=&#34;color:#000;font-weight:bold&#34;&gt;:&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt; &lt;/span&gt;&lt;span style=&#34;color:#4e9a06&#34;&gt;&amp;#34;alpine:3.1&amp;#34;&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;p&gt;&lt;strong&gt;alpine/definition.yaml&lt;/strong&gt;&lt;/p&gt;
&lt;div class=&#34;highlight&#34;&gt;&lt;pre tabindex=&#34;0&#34; style=&#34;background-color:#f8f8f8;-moz-tab-size:4;-o-tab-size:4;tab-size:4&#34;&gt;&lt;code class=&#34;language-yaml&#34; data-lang=&#34;yaml&#34;&gt;&lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;name&lt;/span&gt;&lt;span style=&#34;color:#000;font-weight:bold&#34;&gt;:&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt; &lt;/span&gt;&lt;span style=&#34;color:#4e9a06&#34;&gt;&amp;#34;alpine&amp;#34;&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;&lt;/span&gt;&lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;version&lt;/span&gt;&lt;span style=&#34;color:#000;font-weight:bold&#34;&gt;:&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt; &lt;/span&gt;&lt;span style=&#34;color:#4e9a06&#34;&gt;&amp;#34;3.1&amp;#34;&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;&lt;/span&gt;&lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;category&lt;/span&gt;&lt;span style=&#34;color:#000;font-weight:bold&#34;&gt;:&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt; &lt;/span&gt;&lt;span style=&#34;color:#4e9a06&#34;&gt;&amp;#34;seed&amp;#34;&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;p&gt;&lt;strong&gt;sh/build.yaml&lt;/strong&gt;&lt;/p&gt;
&lt;div class=&#34;highlight&#34;&gt;&lt;pre tabindex=&#34;0&#34; style=&#34;background-color:#f8f8f8;-moz-tab-size:4;-o-tab-size:4;tab-size:4&#34;&gt;&lt;code class=&#34;language-yaml&#34; data-lang=&#34;yaml&#34;&gt;&lt;span style=&#34;color:#8f5902;font-style:italic&#34;&gt;# List of build-time dependencies&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;&lt;/span&gt;&lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;requires&lt;/span&gt;&lt;span style=&#34;color:#000;font-weight:bold&#34;&gt;:&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;&lt;/span&gt;- &lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;name&lt;/span&gt;&lt;span style=&#34;color:#000;font-weight:bold&#34;&gt;:&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt; &lt;/span&gt;&lt;span style=&#34;color:#4e9a06&#34;&gt;&amp;#34;alpine&amp;#34;&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;  &lt;/span&gt;&lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;version&lt;/span&gt;&lt;span style=&#34;color:#000;font-weight:bold&#34;&gt;:&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt; &lt;/span&gt;&lt;span style=&#34;color:#4e9a06&#34;&gt;&amp;#34;3.1&amp;#34;&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;  &lt;/span&gt;&lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;category&lt;/span&gt;&lt;span style=&#34;color:#000;font-weight:bold&#34;&gt;:&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt; &lt;/span&gt;&lt;span style=&#34;color:#4e9a06&#34;&gt;&amp;#34;seed&amp;#34;&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;&lt;/span&gt;&lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;unpack&lt;/span&gt;&lt;span style=&#34;color:#000;font-weight:bold&#34;&gt;:&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt; &lt;/span&gt;&lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;true&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt; &lt;/span&gt;&lt;span style=&#34;color:#8f5902;font-style:italic&#34;&gt;# Tells luet to use the image content by unpacking it&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;&lt;/span&gt;&lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;includes&lt;/span&gt;&lt;span style=&#34;color:#000;font-weight:bold&#34;&gt;:&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt; 
&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;&lt;/span&gt;- &lt;span style=&#34;color:#000&#34;&gt;/bin/sh&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;p&gt;&lt;strong&gt;sh/definition.yaml&lt;/strong&gt;&lt;/p&gt;
&lt;div class=&#34;highlight&#34;&gt;&lt;pre tabindex=&#34;0&#34; style=&#34;background-color:#f8f8f8;-moz-tab-size:4;-o-tab-size:4;tab-size:4&#34;&gt;&lt;code class=&#34;language-yaml&#34; data-lang=&#34;yaml&#34;&gt;&lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;name&lt;/span&gt;&lt;span style=&#34;color:#000;font-weight:bold&#34;&gt;:&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt; &lt;/span&gt;&lt;span style=&#34;color:#4e9a06&#34;&gt;&amp;#34;sh&amp;#34;&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;&lt;/span&gt;&lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;category&lt;/span&gt;&lt;span style=&#34;color:#000;font-weight:bold&#34;&gt;:&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt; &lt;/span&gt;&lt;span style=&#34;color:#4e9a06&#34;&gt;&amp;#34;utils&amp;#34;&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;&lt;/span&gt;&lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;version&lt;/span&gt;&lt;span style=&#34;color:#000;font-weight:bold&#34;&gt;:&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt; &lt;/span&gt;&lt;span style=&#34;color:#4e9a06&#34;&gt;&amp;#34;1.0&amp;#34;&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;p&gt;In this example, there are two packages being specified:&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;One is the &lt;code&gt;seed&lt;/code&gt; package, which is the base image employed to later extract packages. It has no installable content, and it is just virtually used during build phase.&lt;/li&gt;
&lt;li&gt;&lt;code&gt;sh&lt;/code&gt; is the package which contains &lt;code&gt;/bin/sh&lt;/code&gt;, extracted from the seed image and packaged. This can be consumed by Luet clients in order to install &lt;code&gt;sh&lt;/code&gt; in their system.&lt;/li&gt;
&lt;/ul&gt;
&lt;h3 id=&#34;packages-delta&#34;&gt;Packages delta&lt;/h3&gt;
&lt;p&gt;Luet, by default, will try to calculate the delta of the package that is meant to be built. This means that it tracks &lt;strong&gt;incrementally&lt;/strong&gt; the changes in the packages, to ease the build definition. Let&amp;rsquo;s see an example.&lt;/p&gt;
&lt;p&gt;Given the root package:
&lt;strong&gt;alpine/build.yaml&lt;/strong&gt;&lt;/p&gt;
&lt;div class=&#34;highlight&#34;&gt;&lt;pre tabindex=&#34;0&#34; style=&#34;background-color:#f8f8f8;-moz-tab-size:4;-o-tab-size:4;tab-size:4&#34;&gt;&lt;code class=&#34;language-yaml&#34; data-lang=&#34;yaml&#34;&gt;&lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;image&lt;/span&gt;&lt;span style=&#34;color:#000;font-weight:bold&#34;&gt;:&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt; &lt;/span&gt;&lt;span style=&#34;color:#4e9a06&#34;&gt;&amp;#34;alpine:3.1&amp;#34;&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;p&gt;&lt;strong&gt;alpine/definition.yaml&lt;/strong&gt;&lt;/p&gt;
&lt;div class=&#34;highlight&#34;&gt;&lt;pre tabindex=&#34;0&#34; style=&#34;background-color:#f8f8f8;-moz-tab-size:4;-o-tab-size:4;tab-size:4&#34;&gt;&lt;code class=&#34;language-yaml&#34; data-lang=&#34;yaml&#34;&gt;&lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;name&lt;/span&gt;&lt;span style=&#34;color:#000;font-weight:bold&#34;&gt;:&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt; &lt;/span&gt;&lt;span style=&#34;color:#4e9a06&#34;&gt;&amp;#34;alpine&amp;#34;&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;&lt;/span&gt;&lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;version&lt;/span&gt;&lt;span style=&#34;color:#000;font-weight:bold&#34;&gt;:&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt; &lt;/span&gt;&lt;span style=&#34;color:#4e9a06&#34;&gt;&amp;#34;3.1&amp;#34;&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;&lt;/span&gt;&lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;category&lt;/span&gt;&lt;span style=&#34;color:#000;font-weight:bold&#34;&gt;:&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt; &lt;/span&gt;&lt;span style=&#34;color:#4e9a06&#34;&gt;&amp;#34;seed&amp;#34;&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;p&gt;We can generate any file, and include it in our package by defining this simple package:&lt;/p&gt;
&lt;p&gt;&lt;strong&gt;foo/build.yaml&lt;/strong&gt;&lt;/p&gt;
&lt;div class=&#34;highlight&#34;&gt;&lt;pre tabindex=&#34;0&#34; style=&#34;background-color:#f8f8f8;-moz-tab-size:4;-o-tab-size:4;tab-size:4&#34;&gt;&lt;code class=&#34;language-yaml&#34; data-lang=&#34;yaml&#34;&gt;&lt;span style=&#34;color:#8f5902;font-style:italic&#34;&gt;# List of build-time dependencies&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;&lt;/span&gt;&lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;requires&lt;/span&gt;&lt;span style=&#34;color:#000;font-weight:bold&#34;&gt;:&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;&lt;/span&gt;- &lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;name&lt;/span&gt;&lt;span style=&#34;color:#000;font-weight:bold&#34;&gt;:&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt; &lt;/span&gt;&lt;span style=&#34;color:#4e9a06&#34;&gt;&amp;#34;alpine&amp;#34;&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;  &lt;/span&gt;&lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;version&lt;/span&gt;&lt;span style=&#34;color:#000;font-weight:bold&#34;&gt;:&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt; &lt;/span&gt;&lt;span style=&#34;color:#4e9a06&#34;&gt;&amp;#34;3.1&amp;#34;&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;  &lt;/span&gt;&lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;category&lt;/span&gt;&lt;span style=&#34;color:#000;font-weight:bold&#34;&gt;:&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt; &lt;/span&gt;&lt;span style=&#34;color:#4e9a06&#34;&gt;&amp;#34;seed&amp;#34;&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;&lt;/span&gt;&lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;steps&lt;/span&gt;&lt;span style=&#34;color:#000;font-weight:bold&#34;&gt;:&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;&lt;/span&gt;- &lt;span style=&#34;color:#000&#34;&gt;echo &amp;#34;Awesome&amp;#34; &amp;gt; /foo&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;p&gt;&lt;strong&gt;foo/definition.yaml&lt;/strong&gt;&lt;/p&gt;
&lt;div class=&#34;highlight&#34;&gt;&lt;pre tabindex=&#34;0&#34; style=&#34;background-color:#f8f8f8;-moz-tab-size:4;-o-tab-size:4;tab-size:4&#34;&gt;&lt;code class=&#34;language-yaml&#34; data-lang=&#34;yaml&#34;&gt;&lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;name&lt;/span&gt;&lt;span style=&#34;color:#000;font-weight:bold&#34;&gt;:&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt; &lt;/span&gt;&lt;span style=&#34;color:#4e9a06&#34;&gt;&amp;#34;foo&amp;#34;&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;&lt;/span&gt;&lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;category&lt;/span&gt;&lt;span style=&#34;color:#000;font-weight:bold&#34;&gt;:&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt; &lt;/span&gt;&lt;span style=&#34;color:#4e9a06&#34;&gt;&amp;#34;utils&amp;#34;&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;&lt;/span&gt;&lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;version&lt;/span&gt;&lt;span style=&#34;color:#000;font-weight:bold&#34;&gt;:&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt; &lt;/span&gt;&lt;span style=&#34;color:#4e9a06&#34;&gt;&amp;#34;1.0&amp;#34;&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;p&gt;By analyzing the difference between the two packages, Luet will automatically track and package &lt;code&gt;/foo&lt;/code&gt; as part of the &lt;code&gt;foo&lt;/code&gt; package.&lt;/p&gt;
&lt;p&gt;To allow operations that must not be accounted in to the final package, you can use the &lt;code&gt;prelude&lt;/code&gt; keyword:&lt;/p&gt;
&lt;p&gt;&lt;strong&gt;foo/build.yaml&lt;/strong&gt;&lt;/p&gt;
&lt;div class=&#34;highlight&#34;&gt;&lt;pre tabindex=&#34;0&#34; style=&#34;background-color:#f8f8f8;-moz-tab-size:4;-o-tab-size:4;tab-size:4&#34;&gt;&lt;code class=&#34;language-yaml&#34; data-lang=&#34;yaml&#34;&gt;&lt;span style=&#34;color:#8f5902;font-style:italic&#34;&gt;# List of build-time dependencies&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;&lt;/span&gt;&lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;requires&lt;/span&gt;&lt;span style=&#34;color:#000;font-weight:bold&#34;&gt;:&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;&lt;/span&gt;- &lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;name&lt;/span&gt;&lt;span style=&#34;color:#000;font-weight:bold&#34;&gt;:&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt; &lt;/span&gt;&lt;span style=&#34;color:#4e9a06&#34;&gt;&amp;#34;alpine&amp;#34;&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;  &lt;/span&gt;&lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;version&lt;/span&gt;&lt;span style=&#34;color:#000;font-weight:bold&#34;&gt;:&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt; &lt;/span&gt;&lt;span style=&#34;color:#4e9a06&#34;&gt;&amp;#34;3.1&amp;#34;&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;  &lt;/span&gt;&lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;category&lt;/span&gt;&lt;span style=&#34;color:#000;font-weight:bold&#34;&gt;:&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt; &lt;/span&gt;&lt;span style=&#34;color:#4e9a06&#34;&gt;&amp;#34;seed&amp;#34;&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;&lt;/span&gt;&lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;prelude&lt;/span&gt;&lt;span style=&#34;color:#000;font-weight:bold&#34;&gt;:&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;&lt;/span&gt;- &lt;span style=&#34;color:#000&#34;&gt;echo &amp;#34;Not packaged&amp;#34; &amp;gt; /invisible&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;&lt;/span&gt;&lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;steps&lt;/span&gt;&lt;span style=&#34;color:#000;font-weight:bold&#34;&gt;:&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;&lt;/span&gt;- &lt;span style=&#34;color:#000&#34;&gt;echo &amp;#34;Awesome&amp;#34; &amp;gt; /foo&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;p&gt;&lt;strong&gt;foo/definition.yaml&lt;/strong&gt;&lt;/p&gt;
&lt;div class=&#34;highlight&#34;&gt;&lt;pre tabindex=&#34;0&#34; style=&#34;background-color:#f8f8f8;-moz-tab-size:4;-o-tab-size:4;tab-size:4&#34;&gt;&lt;code class=&#34;language-yaml&#34; data-lang=&#34;yaml&#34;&gt;&lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;name&lt;/span&gt;&lt;span style=&#34;color:#000;font-weight:bold&#34;&gt;:&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt; &lt;/span&gt;&lt;span style=&#34;color:#4e9a06&#34;&gt;&amp;#34;foo&amp;#34;&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;&lt;/span&gt;&lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;category&lt;/span&gt;&lt;span style=&#34;color:#000;font-weight:bold&#34;&gt;:&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt; &lt;/span&gt;&lt;span style=&#34;color:#4e9a06&#34;&gt;&amp;#34;utils&amp;#34;&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;&lt;/span&gt;&lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;version&lt;/span&gt;&lt;span style=&#34;color:#000;font-weight:bold&#34;&gt;:&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt; &lt;/span&gt;&lt;span style=&#34;color:#4e9a06&#34;&gt;&amp;#34;1.0&amp;#34;&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;p&gt;The list of commands inside &lt;code&gt;prelude&lt;/code&gt; that would produce artifacts, are not accounted to the final package. In this example, only &lt;code&gt;/foo&lt;/code&gt; would be packaged (which output is equivalent to the example above).&lt;/p&gt;
&lt;p&gt;This can be used, for instance, to fetch sources that must not be part of the package.&lt;/p&gt;
&lt;p&gt;You can apply restrictions anytime and use the &lt;code&gt;includes&lt;/code&gt; keyword to specifically pin to the files you wish in your package.&lt;/p&gt;
&lt;h3 id=&#34;package-layers&#34;&gt;Package layers&lt;/h3&gt;
&lt;p&gt;Luet can be used to track entire layers and make them installable by Luet clients.&lt;/p&gt;
&lt;p&gt;Given the examples above:&lt;/p&gt;
&lt;p&gt;&lt;strong&gt;alpine/build.yaml&lt;/strong&gt;&lt;/p&gt;
&lt;div class=&#34;highlight&#34;&gt;&lt;pre tabindex=&#34;0&#34; style=&#34;background-color:#f8f8f8;-moz-tab-size:4;-o-tab-size:4;tab-size:4&#34;&gt;&lt;code class=&#34;language-yaml&#34; data-lang=&#34;yaml&#34;&gt;&lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;image&lt;/span&gt;&lt;span style=&#34;color:#000;font-weight:bold&#34;&gt;:&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt; &lt;/span&gt;&lt;span style=&#34;color:#4e9a06&#34;&gt;&amp;#34;alpine:3.1&amp;#34;&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;p&gt;&lt;strong&gt;alpine/definition.yaml&lt;/strong&gt;&lt;/p&gt;
&lt;div class=&#34;highlight&#34;&gt;&lt;pre tabindex=&#34;0&#34; style=&#34;background-color:#f8f8f8;-moz-tab-size:4;-o-tab-size:4;tab-size:4&#34;&gt;&lt;code class=&#34;language-yaml&#34; data-lang=&#34;yaml&#34;&gt;&lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;name&lt;/span&gt;&lt;span style=&#34;color:#000;font-weight:bold&#34;&gt;:&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt; &lt;/span&gt;&lt;span style=&#34;color:#4e9a06&#34;&gt;&amp;#34;alpine&amp;#34;&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;&lt;/span&gt;&lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;version&lt;/span&gt;&lt;span style=&#34;color:#000;font-weight:bold&#34;&gt;:&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt; &lt;/span&gt;&lt;span style=&#34;color:#4e9a06&#34;&gt;&amp;#34;3.1&amp;#34;&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;&lt;/span&gt;&lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;category&lt;/span&gt;&lt;span style=&#34;color:#000;font-weight:bold&#34;&gt;:&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt; &lt;/span&gt;&lt;span style=&#34;color:#4e9a06&#34;&gt;&amp;#34;seed&amp;#34;&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;p&gt;An installable package derived by the seed, with the actual full content of the layer can be composed as follows:&lt;/p&gt;
&lt;p&gt;&lt;strong&gt;foo/build.yaml&lt;/strong&gt;&lt;/p&gt;
&lt;div class=&#34;highlight&#34;&gt;&lt;pre tabindex=&#34;0&#34; style=&#34;background-color:#f8f8f8;-moz-tab-size:4;-o-tab-size:4;tab-size:4&#34;&gt;&lt;code class=&#34;language-yaml&#34; data-lang=&#34;yaml&#34;&gt;&lt;span style=&#34;color:#8f5902;font-style:italic&#34;&gt;# List of build-time dependencies&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;&lt;/span&gt;&lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;requires&lt;/span&gt;&lt;span style=&#34;color:#000;font-weight:bold&#34;&gt;:&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;&lt;/span&gt;- &lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;name&lt;/span&gt;&lt;span style=&#34;color:#000;font-weight:bold&#34;&gt;:&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt; &lt;/span&gt;&lt;span style=&#34;color:#4e9a06&#34;&gt;&amp;#34;alpine&amp;#34;&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;  &lt;/span&gt;&lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;version&lt;/span&gt;&lt;span style=&#34;color:#000;font-weight:bold&#34;&gt;:&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt; &lt;/span&gt;&lt;span style=&#34;color:#4e9a06&#34;&gt;&amp;#34;3.1&amp;#34;&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;  &lt;/span&gt;&lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;category&lt;/span&gt;&lt;span style=&#34;color:#000;font-weight:bold&#34;&gt;:&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt; &lt;/span&gt;&lt;span style=&#34;color:#4e9a06&#34;&gt;&amp;#34;seed&amp;#34;&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;&lt;/span&gt;&lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;unpack&lt;/span&gt;&lt;span style=&#34;color:#000;font-weight:bold&#34;&gt;:&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt; &lt;/span&gt;&lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;true&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt; &lt;/span&gt;&lt;span style=&#34;color:#8f5902;font-style:italic&#34;&gt;# It advertize Luet to consume the package as is&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;p&gt;&lt;strong&gt;foo/definition.yaml&lt;/strong&gt;&lt;/p&gt;
&lt;div class=&#34;highlight&#34;&gt;&lt;pre tabindex=&#34;0&#34; style=&#34;background-color:#f8f8f8;-moz-tab-size:4;-o-tab-size:4;tab-size:4&#34;&gt;&lt;code class=&#34;language-yaml&#34; data-lang=&#34;yaml&#34;&gt;&lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;name&lt;/span&gt;&lt;span style=&#34;color:#000;font-weight:bold&#34;&gt;:&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt; &lt;/span&gt;&lt;span style=&#34;color:#4e9a06&#34;&gt;&amp;#34;foo&amp;#34;&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;&lt;/span&gt;&lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;category&lt;/span&gt;&lt;span style=&#34;color:#000;font-weight:bold&#34;&gt;:&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt; &lt;/span&gt;&lt;span style=&#34;color:#4e9a06&#34;&gt;&amp;#34;utils&amp;#34;&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;&lt;/span&gt;&lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;version&lt;/span&gt;&lt;span style=&#34;color:#000;font-weight:bold&#34;&gt;:&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt; &lt;/span&gt;&lt;span style=&#34;color:#4e9a06&#34;&gt;&amp;#34;1.0&amp;#34;&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;p&gt;This can be combined with other keywords to manipulate the resulting package (layer), for example:&lt;/p&gt;
&lt;p&gt;&lt;strong&gt;foo/build.yaml&lt;/strong&gt;&lt;/p&gt;
&lt;div class=&#34;highlight&#34;&gt;&lt;pre tabindex=&#34;0&#34; style=&#34;background-color:#f8f8f8;-moz-tab-size:4;-o-tab-size:4;tab-size:4&#34;&gt;&lt;code class=&#34;language-yaml&#34; data-lang=&#34;yaml&#34;&gt;&lt;span style=&#34;color:#8f5902;font-style:italic&#34;&gt;# List of build-time dependencies&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;&lt;/span&gt;&lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;requires&lt;/span&gt;&lt;span style=&#34;color:#000;font-weight:bold&#34;&gt;:&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;&lt;/span&gt;- &lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;name&lt;/span&gt;&lt;span style=&#34;color:#000;font-weight:bold&#34;&gt;:&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt; &lt;/span&gt;&lt;span style=&#34;color:#4e9a06&#34;&gt;&amp;#34;alpine&amp;#34;&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;  &lt;/span&gt;&lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;version&lt;/span&gt;&lt;span style=&#34;color:#000;font-weight:bold&#34;&gt;:&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt; &lt;/span&gt;&lt;span style=&#34;color:#4e9a06&#34;&gt;&amp;#34;3.1&amp;#34;&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;  &lt;/span&gt;&lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;category&lt;/span&gt;&lt;span style=&#34;color:#000;font-weight:bold&#34;&gt;:&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt; &lt;/span&gt;&lt;span style=&#34;color:#4e9a06&#34;&gt;&amp;#34;seed&amp;#34;&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;&lt;/span&gt;&lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;unpack&lt;/span&gt;&lt;span style=&#34;color:#000;font-weight:bold&#34;&gt;:&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt; &lt;/span&gt;&lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;true&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt; &lt;/span&gt;&lt;span style=&#34;color:#8f5902;font-style:italic&#34;&gt;# It advertize Luet to consume the package as is&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;&lt;/span&gt;&lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;steps&lt;/span&gt;&lt;span style=&#34;color:#000;font-weight:bold&#34;&gt;:&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;&lt;/span&gt;- &lt;span style=&#34;color:#000&#34;&gt;apk update&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;&lt;/span&gt;- &lt;span style=&#34;color:#000&#34;&gt;apk add git&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;&lt;/span&gt;- &lt;span style=&#34;color:#000&#34;&gt;apk add ..&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;p&gt;&lt;strong&gt;foo/definition.yaml&lt;/strong&gt;&lt;/p&gt;
&lt;div class=&#34;highlight&#34;&gt;&lt;pre tabindex=&#34;0&#34; style=&#34;background-color:#f8f8f8;-moz-tab-size:4;-o-tab-size:4;tab-size:4&#34;&gt;&lt;code class=&#34;language-yaml&#34; data-lang=&#34;yaml&#34;&gt;&lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;name&lt;/span&gt;&lt;span style=&#34;color:#000;font-weight:bold&#34;&gt;:&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt; &lt;/span&gt;&lt;span style=&#34;color:#4e9a06&#34;&gt;&amp;#34;foo&amp;#34;&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;&lt;/span&gt;&lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;category&lt;/span&gt;&lt;span style=&#34;color:#000;font-weight:bold&#34;&gt;:&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt; &lt;/span&gt;&lt;span style=&#34;color:#4e9a06&#34;&gt;&amp;#34;utils&amp;#34;&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;&lt;/span&gt;&lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;version&lt;/span&gt;&lt;span style=&#34;color:#000;font-weight:bold&#34;&gt;:&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt; &lt;/span&gt;&lt;span style=&#34;color:#4e9a06&#34;&gt;&amp;#34;1.0&amp;#34;&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;h3 id=&#34;package-includes&#34;&gt;Package includes&lt;/h3&gt;
&lt;p&gt;In addition, the &lt;code&gt;includes&lt;/code&gt; keyword can be set in order to extract portions from the package image.&lt;/p&gt;
&lt;p&gt;&lt;strong&gt;git/build.yaml&lt;/strong&gt;&lt;/p&gt;
&lt;div class=&#34;highlight&#34;&gt;&lt;pre tabindex=&#34;0&#34; style=&#34;background-color:#f8f8f8;-moz-tab-size:4;-o-tab-size:4;tab-size:4&#34;&gt;&lt;code class=&#34;language-yaml&#34; data-lang=&#34;yaml&#34;&gt;&lt;span style=&#34;color:#8f5902;font-style:italic&#34;&gt;# List of build-time dependencies&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;&lt;/span&gt;&lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;requires&lt;/span&gt;&lt;span style=&#34;color:#000;font-weight:bold&#34;&gt;:&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;&lt;/span&gt;- &lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;name&lt;/span&gt;&lt;span style=&#34;color:#000;font-weight:bold&#34;&gt;:&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt; &lt;/span&gt;&lt;span style=&#34;color:#4e9a06&#34;&gt;&amp;#34;alpine&amp;#34;&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;  &lt;/span&gt;&lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;version&lt;/span&gt;&lt;span style=&#34;color:#000;font-weight:bold&#34;&gt;:&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt; &lt;/span&gt;&lt;span style=&#34;color:#4e9a06&#34;&gt;&amp;#34;3.1&amp;#34;&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;  &lt;/span&gt;&lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;category&lt;/span&gt;&lt;span style=&#34;color:#000;font-weight:bold&#34;&gt;:&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt; &lt;/span&gt;&lt;span style=&#34;color:#4e9a06&#34;&gt;&amp;#34;seed&amp;#34;&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;&lt;/span&gt;&lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;unpack&lt;/span&gt;&lt;span style=&#34;color:#000;font-weight:bold&#34;&gt;:&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt; &lt;/span&gt;&lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;true&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt; &lt;/span&gt;&lt;span style=&#34;color:#8f5902;font-style:italic&#34;&gt;# It advertize Luet to consume the package as is&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;&lt;/span&gt;&lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;steps&lt;/span&gt;&lt;span style=&#34;color:#000;font-weight:bold&#34;&gt;:&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;&lt;/span&gt;- &lt;span style=&#34;color:#000&#34;&gt;apk update&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;&lt;/span&gt;- &lt;span style=&#34;color:#000&#34;&gt;apk add git&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;&lt;/span&gt;&lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;includes&lt;/span&gt;&lt;span style=&#34;color:#000;font-weight:bold&#34;&gt;:&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;&lt;/span&gt;- &lt;span style=&#34;color:#000&#34;&gt;/usr/bin/git&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;p&gt;&lt;strong&gt;foo/definition.yaml&lt;/strong&gt;&lt;/p&gt;
&lt;div class=&#34;highlight&#34;&gt;&lt;pre tabindex=&#34;0&#34; style=&#34;background-color:#f8f8f8;-moz-tab-size:4;-o-tab-size:4;tab-size:4&#34;&gt;&lt;code class=&#34;language-yaml&#34; data-lang=&#34;yaml&#34;&gt;&lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;name&lt;/span&gt;&lt;span style=&#34;color:#000;font-weight:bold&#34;&gt;:&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt; &lt;/span&gt;&lt;span style=&#34;color:#4e9a06&#34;&gt;&amp;#34;git&amp;#34;&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;&lt;/span&gt;&lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;category&lt;/span&gt;&lt;span style=&#34;color:#000;font-weight:bold&#34;&gt;:&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt; &lt;/span&gt;&lt;span style=&#34;color:#4e9a06&#34;&gt;&amp;#34;utils&amp;#34;&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;&lt;/span&gt;&lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;version&lt;/span&gt;&lt;span style=&#34;color:#000;font-weight:bold&#34;&gt;:&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt; &lt;/span&gt;&lt;span style=&#34;color:#4e9a06&#34;&gt;&amp;#34;1.0&amp;#34;&lt;/span&gt;&lt;span style=&#34;color:#f8f8f8;text-decoration:underline&#34;&gt;
&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;p&gt;As a reminder, the &lt;code&gt;includes&lt;/code&gt; keywords accepts regular expressions in the Golang format. Any criteria expressed by means of Golang regular expressions, and matching the file name (absolute path), will be part of the final package.&lt;/p&gt;

      </description>
    </item>
    
    <item>
      <title>Docs: Plugins and Extensions</title>
      <link>https://luet.io/docs/concepts/plugins-and-extensions/</link>
      <pubDate>Mon, 01 Jan 0001 00:00:00 +0000</pubDate>
      
      <guid>https://luet.io/docs/concepts/plugins-and-extensions/</guid>
      <description>
        
        
        &lt;p&gt;Luet can be extended in 2 ways by extensions and plugins.&lt;/p&gt;
&lt;h1 id=&#34;before-you-begin&#34;&gt;Before you begin&lt;/h1&gt;
&lt;p&gt;You need to have a working &lt;code&gt;luet&lt;/code&gt; binary installed.&lt;/p&gt;
&lt;h2 id=&#34;extensions&#34;&gt;Extensions&lt;/h2&gt;
&lt;p&gt;Extensions expand Luet featureset horizontally, so for example, “luet geniso” will allow you to build an iso using luet, without this needing to be part of the luet core.&lt;/p&gt;
&lt;p&gt;An Extension is nothing more than a standalone executable file, whose name begins with &lt;code&gt;luet-&lt;/code&gt;. To install an extension, simply move its executable file to anywhere on your system &lt;code&gt;PATH&lt;/code&gt;.&lt;/p&gt;
&lt;p&gt;All the plugins will be accessible to luet as &lt;code&gt;luet pluginname&lt;/code&gt;&lt;/p&gt;
&lt;h3 id=&#34;writing-an-extension&#34;&gt;Writing an Extension&lt;/h3&gt;
&lt;p&gt;You can write an extension in any programming language or script that allows you to write command-line commands.&lt;/p&gt;
&lt;p&gt;Executables receive the inherited environment from luet. An extension determines which command path it wishes to implement based on its name. For example, a plugin wanting to provide a new command luet foo, would simply be named luet-foo, and live somewhere in your PATH.&lt;/p&gt;
&lt;h4 id=&#34;example-extension&#34;&gt;Example Extension&lt;/h4&gt;
&lt;div class=&#34;highlight&#34;&gt;&lt;pre tabindex=&#34;0&#34; style=&#34;background-color:#f8f8f8;-moz-tab-size:4;-o-tab-size:4;tab-size:4&#34;&gt;&lt;code class=&#34;language-bash&#34; data-lang=&#34;bash&#34;&gt;&lt;span style=&#34;color:#8f5902;font-style:italic&#34;&gt;#!/bin/bash
&lt;/span&gt;&lt;span style=&#34;color:#8f5902;font-style:italic&#34;&gt;&lt;/span&gt;
&lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;if&lt;/span&gt; &lt;span style=&#34;color:#ce5c00;font-weight:bold&#34;&gt;[[&lt;/span&gt; &lt;span style=&#34;color:#4e9a06&#34;&gt;&amp;#34;&lt;/span&gt;&lt;span style=&#34;color:#000&#34;&gt;$1&lt;/span&gt;&lt;span style=&#34;color:#4e9a06&#34;&gt;&amp;#34;&lt;/span&gt; &lt;span style=&#34;color:#ce5c00;font-weight:bold&#34;&gt;==&lt;/span&gt; &lt;span style=&#34;color:#4e9a06&#34;&gt;&amp;#34;help&amp;#34;&lt;/span&gt; &lt;span style=&#34;color:#ce5c00;font-weight:bold&#34;&gt;]]&lt;/span&gt;
&lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;then&lt;/span&gt;
    &lt;span style=&#34;color:#204a87&#34;&gt;echo&lt;/span&gt; &lt;span style=&#34;color:#4e9a06&#34;&gt;&amp;#34;Extension help&amp;#34;&lt;/span&gt;
    &lt;span style=&#34;color:#204a87&#34;&gt;exit&lt;/span&gt; &lt;span style=&#34;color:#0000cf;font-weight:bold&#34;&gt;0&lt;/span&gt;
&lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;fi&lt;/span&gt;

&lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;if&lt;/span&gt; &lt;span style=&#34;color:#ce5c00;font-weight:bold&#34;&gt;[[&lt;/span&gt; &lt;span style=&#34;color:#4e9a06&#34;&gt;&amp;#34;&lt;/span&gt;&lt;span style=&#34;color:#000&#34;&gt;$1&lt;/span&gt;&lt;span style=&#34;color:#4e9a06&#34;&gt;&amp;#34;&lt;/span&gt; &lt;span style=&#34;color:#ce5c00;font-weight:bold&#34;&gt;==&lt;/span&gt; &lt;span style=&#34;color:#4e9a06&#34;&gt;&amp;#34;run&amp;#34;&lt;/span&gt; &lt;span style=&#34;color:#ce5c00;font-weight:bold&#34;&gt;]]&lt;/span&gt;
&lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;then&lt;/span&gt;
    &lt;span style=&#34;color:#8f5902;font-style:italic&#34;&gt;# do something interesting&lt;/span&gt;
&lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;fi&lt;/span&gt;

&lt;span style=&#34;color:#204a87&#34;&gt;echo&lt;/span&gt; &lt;span style=&#34;color:#4e9a06&#34;&gt;&amp;#34;I am an Extension named luet-foo&amp;#34;&lt;/span&gt;

&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;h3 id=&#34;using-an-extension&#34;&gt;Using an Extension&lt;/h3&gt;
&lt;p&gt;To use the above extension, simply make it executable:&lt;/p&gt;
&lt;div class=&#34;highlight&#34;&gt;&lt;pre tabindex=&#34;0&#34; style=&#34;background-color:#f8f8f8;-moz-tab-size:4;-o-tab-size:4;tab-size:4&#34;&gt;&lt;code class=&#34;language-bash&#34; data-lang=&#34;bash&#34;&gt;$ sudo chmod +x ./luet-foo
&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;p&gt;and place it anywhere in your PATH:&lt;/p&gt;
&lt;div class=&#34;highlight&#34;&gt;&lt;pre tabindex=&#34;0&#34; style=&#34;background-color:#f8f8f8;-moz-tab-size:4;-o-tab-size:4;tab-size:4&#34;&gt;&lt;code class=&#34;language-bash&#34; data-lang=&#34;bash&#34;&gt;$ sudo mv ./luet-foo /usr/local/bin
&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;p&gt;You may now invoke your extension as a luet command:&lt;/p&gt;
&lt;div class=&#34;highlight&#34;&gt;&lt;pre tabindex=&#34;0&#34; style=&#34;background-color:#f8f8f8;-moz-tab-size:4;-o-tab-size:4;tab-size:4&#34;&gt;&lt;code class=&#34;language-bash&#34; data-lang=&#34;bash&#34;&gt;$ luet foo
I am an Extension named luet-foo
&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;p&gt;All args and flags are passed as-is to the executable:&lt;/p&gt;
&lt;div class=&#34;highlight&#34;&gt;&lt;pre tabindex=&#34;0&#34; style=&#34;background-color:#f8f8f8;-moz-tab-size:4;-o-tab-size:4;tab-size:4&#34;&gt;&lt;code class=&#34;language-bash&#34; data-lang=&#34;bash&#34;&gt;$ luet foo &lt;span style=&#34;color:#204a87&#34;&gt;help&lt;/span&gt;

Extension &lt;span style=&#34;color:#204a87&#34;&gt;help&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;h2 id=&#34;plugins&#34;&gt;Plugins&lt;/h2&gt;
&lt;p&gt;Plugins instead are expanding Luet vertically by hooking into internal events. Plugins and Extensions can be written in any language, bash included! Luet uses &lt;a href=&#34;https://github.com/mudler/go-pluggable&#34;&gt;go-pluggable&lt;/a&gt; so it can dispatch events to external binaries.&lt;/p&gt;
&lt;p&gt;Similarly to &lt;strong&gt;Extensions&lt;/strong&gt;, a &lt;strong&gt;Plugin&lt;/strong&gt; is nothing more than a standalone executable file, but without any special prefix. To install a plugin, simply move its executable file to anywhere on your system &lt;code&gt;PATH&lt;/code&gt;.&lt;/p&gt;
&lt;p&gt;Differently from &lt;strong&gt;Extensions&lt;/strong&gt;, they are not available from the &lt;strong&gt;CLI&lt;/strong&gt; and cannot be invoked directly by the user, instead they are called by Luet during its lifecycle.&lt;/p&gt;
&lt;h3 id=&#34;writing-a-plugin&#34;&gt;Writing a Plugin&lt;/h3&gt;
&lt;p&gt;You can write a plugin in any programming language or script.&lt;/p&gt;
&lt;p&gt;The first argument that is passed to a plugin will always be the event that was emitted by Luet in its lifecycle. You can see all the &lt;a href=&#34;https://github.com/mudler/luet/blob/master/pkg/bus/events.go&#34;&gt;events available here&lt;/a&gt;. The second argument, is a &lt;code&gt;JSON&lt;/code&gt; encoded payload of the object that Luet is emitting with the event. The object(s) may vary depending on the emitted event.&lt;/p&gt;
&lt;p&gt;The output of the plugin (&lt;code&gt;stdout&lt;/code&gt;) will be parsed as JSON. Every plugin must return a valid JSON at the end of its execution, or it will be marked as failed and stops &lt;code&gt;luet&lt;/code&gt; further execution. &lt;a href=&#34;https://github.com/mudler/go-pluggable#plugin-processed-data&#34;&gt;See also the go-pluggable README&lt;/a&gt;.&lt;/p&gt;
&lt;p&gt;The returning payload should be in the following form:&lt;/p&gt;
&lt;div class=&#34;highlight&#34;&gt;&lt;pre tabindex=&#34;0&#34; style=&#34;background-color:#f8f8f8;-moz-tab-size:4;-o-tab-size:4;tab-size:4&#34;&gt;&lt;code class=&#34;language-json&#34; data-lang=&#34;json&#34;&gt;&lt;span style=&#34;color:#000;font-weight:bold&#34;&gt;{&lt;/span&gt; &lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;&amp;#34;state&amp;#34;&lt;/span&gt;&lt;span style=&#34;color:#000;font-weight:bold&#34;&gt;:&lt;/span&gt; &lt;span style=&#34;color:#4e9a06&#34;&gt;&amp;#34;&amp;#34;&lt;/span&gt;&lt;span style=&#34;color:#000;font-weight:bold&#34;&gt;,&lt;/span&gt; &lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;&amp;#34;data&amp;#34;&lt;/span&gt;&lt;span style=&#34;color:#000;font-weight:bold&#34;&gt;:&lt;/span&gt; &lt;span style=&#34;color:#4e9a06&#34;&gt;&amp;#34;data&amp;#34;&lt;/span&gt;&lt;span style=&#34;color:#000;font-weight:bold&#34;&gt;,&lt;/span&gt; &lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;&amp;#34;error&amp;#34;&lt;/span&gt;&lt;span style=&#34;color:#000;font-weight:bold&#34;&gt;:&lt;/span&gt; &lt;span style=&#34;color:#4e9a06&#34;&gt;&amp;#34;&amp;#34;&lt;/span&gt;&lt;span style=&#34;color:#000;font-weight:bold&#34;&gt;}&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;p&gt;By returning a json with the error field not empty, it will make fail the overall execution.&lt;/p&gt;
&lt;h4 id=&#34;example-plugin&#34;&gt;Example Plugin&lt;/h4&gt;
&lt;div class=&#34;highlight&#34;&gt;&lt;pre tabindex=&#34;0&#34; style=&#34;background-color:#f8f8f8;-moz-tab-size:4;-o-tab-size:4;tab-size:4&#34;&gt;&lt;code class=&#34;language-bash&#34; data-lang=&#34;bash&#34;&gt;&lt;span style=&#34;color:#8f5902;font-style:italic&#34;&gt;#!/bin/bash
&lt;/span&gt;&lt;span style=&#34;color:#8f5902;font-style:italic&#34;&gt;&lt;/span&gt;&lt;span style=&#34;color:#204a87&#34;&gt;echo&lt;/span&gt; &lt;span style=&#34;color:#4e9a06&#34;&gt;&amp;#34;&lt;/span&gt;&lt;span style=&#34;color:#000&#34;&gt;$1&lt;/span&gt;&lt;span style=&#34;color:#4e9a06&#34;&gt;&amp;#34;&lt;/span&gt; &amp;gt;&amp;gt; /tmp/event.txt
&lt;span style=&#34;color:#204a87&#34;&gt;echo&lt;/span&gt; &lt;span style=&#34;color:#4e9a06&#34;&gt;&amp;#34;&lt;/span&gt;&lt;span style=&#34;color:#000&#34;&gt;$2&lt;/span&gt;&lt;span style=&#34;color:#4e9a06&#34;&gt;&amp;#34;&lt;/span&gt; &amp;gt;&amp;gt; /tmp/payload.txt

&lt;span style=&#34;color:#204a87&#34;&gt;echo&lt;/span&gt; &lt;span style=&#34;color:#4e9a06&#34;&gt;&amp;#34;{}&amp;#34;&lt;/span&gt;

&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;h3 id=&#34;using-a-plugin&#34;&gt;Using a plugin&lt;/h3&gt;
&lt;p&gt;To use the above plugin, simply make it executable:&lt;/p&gt;
&lt;div class=&#34;highlight&#34;&gt;&lt;pre tabindex=&#34;0&#34; style=&#34;background-color:#f8f8f8;-moz-tab-size:4;-o-tab-size:4;tab-size:4&#34;&gt;&lt;code class=&#34;language-bash&#34; data-lang=&#34;bash&#34;&gt;$ sudo chmod +x ./test-foo
&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;p&gt;and place it anywhere in your PATH:&lt;/p&gt;
&lt;div class=&#34;highlight&#34;&gt;&lt;pre tabindex=&#34;0&#34; style=&#34;background-color:#f8f8f8;-moz-tab-size:4;-o-tab-size:4;tab-size:4&#34;&gt;&lt;code class=&#34;language-bash&#34; data-lang=&#34;bash&#34;&gt;$ sudo mv ./test-foo /usr/local/bin
&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;p&gt;Now, when running luet, add &lt;code&gt;--plugin test-foo&lt;/code&gt;:&lt;/p&gt;
&lt;div class=&#34;highlight&#34;&gt;&lt;pre tabindex=&#34;0&#34; style=&#34;background-color:#f8f8f8;-moz-tab-size:4;-o-tab-size:4;tab-size:4&#34;&gt;&lt;code class=&#34;language-bash&#34; data-lang=&#34;bash&#34;&gt;
$ luet --plugin test-foo install -y foopackage

&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;&lt;p&gt;And check &lt;code&gt;/tmp/event.txt&lt;/code&gt; to see the event fired and &lt;code&gt;/tmp/payload.txt&lt;/code&gt; to check the payloads that were emitted by Luet.&lt;/p&gt;
&lt;h3 id=&#34;concrete-example&#34;&gt;Concrete example&lt;/h3&gt;
&lt;p&gt;A plugin that prints the images that are being built in &lt;code&gt;/tmp/exec.log&lt;/code&gt;:&lt;/p&gt;
&lt;div class=&#34;highlight&#34;&gt;&lt;pre tabindex=&#34;0&#34; style=&#34;background-color:#f8f8f8;-moz-tab-size:4;-o-tab-size:4;tab-size:4&#34;&gt;&lt;code class=&#34;language-bash&#34; data-lang=&#34;bash&#34;&gt;&lt;span style=&#34;color:#8f5902;font-style:italic&#34;&gt;#!/bin/bash
&lt;/span&gt;&lt;span style=&#34;color:#8f5902;font-style:italic&#34;&gt;&lt;/span&gt;&lt;span style=&#34;color:#204a87&#34;&gt;exec&lt;/span&gt; &amp;gt;&amp;gt; /tmp/exec.log
&lt;span style=&#34;color:#204a87&#34;&gt;exec&lt;/span&gt; 2&amp;gt;&lt;span style=&#34;color:#000;font-weight:bold&#34;&gt;&amp;amp;&lt;/span&gt;&lt;span style=&#34;color:#0000cf;font-weight:bold&#34;&gt;1&lt;/span&gt;
&lt;span style=&#34;color:#000&#34;&gt;event&lt;/span&gt;&lt;span style=&#34;color:#ce5c00;font-weight:bold&#34;&gt;=&lt;/span&gt;&lt;span style=&#34;color:#4e9a06&#34;&gt;&amp;#34;&lt;/span&gt;&lt;span style=&#34;color:#000&#34;&gt;$1&lt;/span&gt;&lt;span style=&#34;color:#4e9a06&#34;&gt;&amp;#34;&lt;/span&gt;
&lt;span style=&#34;color:#000&#34;&gt;payload&lt;/span&gt;&lt;span style=&#34;color:#ce5c00;font-weight:bold&#34;&gt;=&lt;/span&gt;&lt;span style=&#34;color:#4e9a06&#34;&gt;&amp;#34;&lt;/span&gt;&lt;span style=&#34;color:#000&#34;&gt;$2&lt;/span&gt;&lt;span style=&#34;color:#4e9a06&#34;&gt;&amp;#34;&lt;/span&gt;
&lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;if&lt;/span&gt; &lt;span style=&#34;color:#ce5c00;font-weight:bold&#34;&gt;[&lt;/span&gt; &lt;span style=&#34;color:#4e9a06&#34;&gt;&amp;#34;&lt;/span&gt;&lt;span style=&#34;color:#000&#34;&gt;$event&lt;/span&gt;&lt;span style=&#34;color:#4e9a06&#34;&gt;&amp;#34;&lt;/span&gt; &lt;span style=&#34;color:#ce5c00;font-weight:bold&#34;&gt;==&lt;/span&gt; &lt;span style=&#34;color:#4e9a06&#34;&gt;&amp;#34;image.post.build&amp;#34;&lt;/span&gt; &lt;span style=&#34;color:#ce5c00;font-weight:bold&#34;&gt;]&lt;/span&gt;&lt;span style=&#34;color:#000;font-weight:bold&#34;&gt;;&lt;/span&gt; &lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;then&lt;/span&gt;
  &lt;span style=&#34;color:#000&#34;&gt;image&lt;/span&gt;&lt;span style=&#34;color:#ce5c00;font-weight:bold&#34;&gt;=&lt;/span&gt;&lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;$(&lt;/span&gt;&lt;span style=&#34;color:#204a87&#34;&gt;echo&lt;/span&gt; &lt;span style=&#34;color:#4e9a06&#34;&gt;&amp;#34;&lt;/span&gt;&lt;span style=&#34;color:#000&#34;&gt;$payload&lt;/span&gt;&lt;span style=&#34;color:#4e9a06&#34;&gt;&amp;#34;&lt;/span&gt; &lt;span style=&#34;color:#000;font-weight:bold&#34;&gt;|&lt;/span&gt; jq -r .data &lt;span style=&#34;color:#000;font-weight:bold&#34;&gt;|&lt;/span&gt; jq -r .ImageName &lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;)&lt;/span&gt;
    &lt;span style=&#34;color:#204a87&#34;&gt;echo&lt;/span&gt; &lt;span style=&#34;color:#4e9a06&#34;&gt;&amp;#34;{ \&amp;#34;data\&amp;#34;: \&amp;#34;&lt;/span&gt;&lt;span style=&#34;color:#000&#34;&gt;$image&lt;/span&gt;&lt;span style=&#34;color:#4e9a06&#34;&gt; built\&amp;#34; }&amp;#34;&lt;/span&gt;
&lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;else&lt;/span&gt;
    &lt;span style=&#34;color:#204a87&#34;&gt;echo&lt;/span&gt; &lt;span style=&#34;color:#4e9a06&#34;&gt;&amp;#34;{}&amp;#34;&lt;/span&gt;
&lt;span style=&#34;color:#204a87;font-weight:bold&#34;&gt;fi&lt;/span&gt;

&lt;/code&gt;&lt;/pre&gt;&lt;/div&gt;
      </description>
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