Adding upstream version 252.22.upstream/252.22upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 565 insertions, 0 deletions

diff --git a/man/os-release.xml b/man/os-release.xml
new file mode 100644
index 0000000..c1819ff
--- /dev/null
+++ b/man/os-release.xml
@@ -0,0 +1,565 @@
+<?xml version='1.0'?> <!--*-nxml-*-->
+<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
+  "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
+<!-- SPDX-License-Identifier: LGPL-2.1-or-later -->
+
+<refentry id="os-release" xmlns:xi="http://www.w3.org/2001/XInclude">
+  <refentryinfo>
+    <title>os-release</title>
+    <productname>systemd</productname>
+  </refentryinfo>
+
+  <refmeta>
+    <refentrytitle>os-release</refentrytitle>
+    <manvolnum>5</manvolnum>
+  </refmeta>
+
+  <refnamediv>
+    <refname>os-release</refname>
+    <refname>initrd-release</refname>
+    <refname>extension-release</refname>
+    <refpurpose>Operating system identification</refpurpose>
+  </refnamediv>
+
+  <refsynopsisdiv>
+    <para><filename>/etc/os-release</filename></para>
+    <para><filename>/usr/lib/os-release</filename></para>
+    <para><filename>/etc/initrd-release</filename></para>
+    <para><filename>/usr/lib/extension-release.d/extension-release.<replaceable>IMAGE</replaceable></filename></para>
+  </refsynopsisdiv>
+
+  <refsect1>
+    <title>Description</title>
+
+    <para>The <filename>/etc/os-release</filename> and
+    <filename>/usr/lib/os-release</filename> files contain operating
+    system identification data.</para>
+
+    <para>The format of <filename>os-release</filename> is a newline-separated list of
+    environment-like shell-compatible variable assignments. It is possible to source the configuration from
+    Bourne shell scripts, however, beyond mere variable assignments, no shell features are supported (this
+    means variable expansion is explicitly not supported), allowing applications to read the file without
+    implementing a shell compatible execution engine. Variable assignment values must be enclosed in double
+    or single quotes if they include spaces, semicolons or other special characters outside of A–Z, a–z,
+    0–9. (Assignments that do not include these special characters may be enclosed in quotes too, but this is
+    optional.) Shell special characters ("$", quotes, backslash, backtick) must be escaped with backslashes,
+    following shell style. All strings should be in UTF-8 encoding, and non-printable characters should not
+    be used. Concatenation of multiple individually quoted strings is not supported. Lines beginning with "#"
+    are treated as comments. Blank lines are permitted and ignored.</para>
+
+    <para>The file <filename>/etc/os-release</filename> takes
+    precedence over <filename>/usr/lib/os-release</filename>.
+    Applications should check for the former, and exclusively use its
+    data if it exists, and only fall back to
+    <filename>/usr/lib/os-release</filename> if it is missing.
+    Applications should not read data from both files at the same
+    time. <filename>/usr/lib/os-release</filename> is the recommended
+    place to store OS release information as part of vendor trees.
+    <filename>/etc/os-release</filename> should be a relative symlink
+    to <filename>/usr/lib/os-release</filename>, to provide
+    compatibility with applications only looking at
+    <filename>/etc/</filename>. A relative symlink instead of an
+    absolute symlink is necessary to avoid breaking the link in a
+    chroot or initrd environment such as dracut.</para>
+
+    <para><filename>os-release</filename> contains data that is
+    defined by the operating system vendor and should generally not be
+    changed by the administrator.</para>
+
+    <para>As this file only encodes names and identifiers it should
+    not be localized.</para>
+
+    <para>The <filename>/etc/os-release</filename> and
+    <filename>/usr/lib/os-release</filename> files might be symlinks
+    to other files, but it is important that the file is available
+    from earliest boot on, and hence must be located on the root file
+    system.</para>
+
+    <para><filename>os-release</filename> must not contain repeating keys. Nevertheless, readers should pick
+    the entries later in the file in case of repeats, similarly to how a shell sourcing the file would. A
+    reader may warn about repeating entries.</para>
+
+    <para>For a longer rationale for <filename>os-release</filename>
+    please refer to the <ulink
+    url="https://0pointer.de/blog/projects/os-release">Announcement of <filename>/etc/os-release</filename></ulink>.</para>
+
+    <refsect2>
+      <title><filename>/etc/initrd-release</filename></title>
+
+      <para>In the <ulink
+      url="https://docs.kernel.org/admin-guide/initrd.html">initrd</ulink>,
+      <filename>/etc/initrd-release</filename> plays the same role as <filename>os-release</filename> in the
+      main system. Additionally, the presence of that file means that the system is in the initrd phase.
+      <filename>/etc/os-release</filename> should be symlinked to <filename>/etc/initrd-release</filename>
+      (or vice versa), so programs that only look for <filename>/etc/os-release</filename> (as described
+      above) work correctly.</para>
+
+      <para>The rest of this document that talks about <filename>os-release</filename> should be understood
+      to apply to <filename>initrd-release</filename> too.</para>
+    </refsect2>
+
+    <refsect2>
+      <title><filename>/usr/lib/extension-release.d/extension-release.<replaceable>IMAGE</replaceable></filename></title>
+
+      <para><filename>/usr/lib/extension-release.d/extension-release.<replaceable>IMAGE</replaceable></filename>
+      plays the same role for extension images as <filename>os-release</filename> for the main system, and
+      follows the syntax and rules as described in the <ulink
+      url="https://systemd.io/PORTABLE_SERVICES">Portable Services Documentation</ulink>. The purpose of this
+      file is to identify the extension and to allow the operating system to verify that the extension image
+      matches the base OS. This is typically implemented by checking that the <varname>ID=</varname> options
+      match, and either <varname>SYSEXT_LEVEL=</varname> exists and matches too, or if it is not present,
+      <varname>VERSION_ID=</varname> exists and matches. This ensures ABI/API compatibility between the
+      layers and prevents merging of an incompatible image in an overlay.</para>
+
+      <para>In the <filename>extension-release.<replaceable>IMAGE</replaceable></filename> filename, the
+      <replaceable>IMAGE</replaceable> part must exactly match the file name of the containing image with the
+      suffix removed. In case it is not possible to guarantee that an image file name is stable and doesn't
+      change between the build and the deployment phases, it is possible to relax this check: if exactly one
+      file whose name matches <literal><filename>extension-release.*</filename></literal> is present in this
+      directory, and the file is tagged with a <varname>user.extension-release.strict</varname>
+      <citerefentry project='man-pages'><refentrytitle>xattr</refentrytitle><manvolnum>7</manvolnum></citerefentry> set to the
+      string <literal>0</literal>, it will be used instead.</para>
+
+      <para>The rest of this document that talks about <filename>os-release</filename> should be understood
+      to apply to <filename>extension-release</filename> too.</para>
+    </refsect2>
+  </refsect1>
+
+  <refsect1>
+    <title>Options</title>
+
+    <para>The following OS identifications parameters may be set using
+    <filename>os-release</filename>:</para>
+
+    <refsect2>
+      <title>General information identifying the operating system</title>
+
+      <variablelist class='environment-variables'>
+        <varlistentry>
+          <term><varname>NAME=</varname></term>
+
+          <listitem><para>A string identifying the operating system, without a version component, and
+          suitable for presentation to the user. If not set, a default of <literal>NAME=Linux</literal> may
+          be used.</para>
+
+          <para>Examples: <literal>NAME=Fedora</literal>, <literal>NAME="Debian GNU/Linux"</literal>.
+          </para></listitem>
+        </varlistentry>
+
+        <varlistentry>
+          <term><varname>ID=</varname></term>
+
+          <listitem><para>A lower-case string (no spaces or other characters outside of 0–9, a–z, ".", "_"
+          and "-") identifying the operating system, excluding any version information and suitable for
+          processing by scripts or usage in generated filenames. If not set, a default of
+          <literal>ID=linux</literal> may be used. Note that even though this string may not include
+          characters that require shell quoting, quoting may nevertheless be used.</para>
+
+          <para>Examples: <literal>ID=fedora</literal>, <literal>ID=debian</literal>.</para></listitem>
+        </varlistentry>
+
+        <varlistentry>
+          <term><varname>ID_LIKE=</varname></term>
+
+          <listitem><para>A space-separated list of operating system identifiers in the same syntax as the
+          <varname>ID=</varname> setting. It should list identifiers of operating systems that are closely
+          related to the local operating system in regards to packaging and programming interfaces, for
+          example listing one or more OS identifiers the local OS is a derivative from.  An OS should
+          generally only list other OS identifiers it itself is a derivative of, and not any OSes that are
+          derived from it, though symmetric relationships are possible. Build scripts and similar should
+          check this variable if they need to identify the local operating system and the value of
+          <varname>ID=</varname> is not recognized. Operating systems should be listed in order of how
+          closely the local operating system relates to the listed ones, starting with the closest. This
+          field is optional.</para>
+
+          <para>Examples: for an operating system with <literal>ID=centos</literal>, an assignment of
+          <literal>ID_LIKE="rhel fedora"</literal> would be appropriate. For an operating system with
+          <literal>ID=ubuntu</literal>, an assignment of <literal>ID_LIKE=debian</literal> is appropriate.
+          </para></listitem>
+        </varlistentry>
+
+        <varlistentry>
+          <term><varname>PRETTY_NAME=</varname></term>
+
+          <listitem><para>A pretty operating system name in a format suitable for presentation to the
+          user. May or may not contain a release code name or OS version of some kind, as suitable. If not
+          set, a default of <literal>PRETTY_NAME="Linux"</literal> may be used</para>
+
+          <para>Example: <literal>PRETTY_NAME="Fedora 17 (Beefy Miracle)"</literal>.</para></listitem>
+        </varlistentry>
+
+        <varlistentry>
+          <term><varname>CPE_NAME=</varname></term>
+
+          <listitem><para>A CPE name for the operating system, in URI binding syntax, following the <ulink
+          url="http://scap.nist.gov/specifications/cpe/">Common Platform Enumeration Specification</ulink> as
+          proposed by the NIST. This field is optional.</para>
+
+          <para>Example: <literal>CPE_NAME="cpe:/o:fedoraproject:fedora:17"</literal></para></listitem>
+        </varlistentry>
+
+        <varlistentry>
+          <term><varname>VARIANT=</varname></term>
+
+          <listitem><para>A string identifying a specific variant or edition of the operating system suitable
+          for presentation to the user. This field may be used to inform the user that the configuration of
+          this system is subject to a specific divergent set of rules or default configuration settings. This
+          field is optional and may not be implemented on all systems.</para>
+
+          <para>Examples: <literal>VARIANT="Server Edition"</literal>, <literal>VARIANT="Smart Refrigerator
+          Edition"</literal>.</para>
+
+          <para>Note: this field is for display purposes only. The <varname>VARIANT_ID</varname> field should
+          be used for making programmatic decisions.</para></listitem>
+        </varlistentry>
+
+        <varlistentry>
+          <term><varname>VARIANT_ID=</varname></term>
+
+          <listitem><para>A lower-case string (no spaces or other characters outside of 0–9, a–z, ".", "_" and
+          "-"), identifying a specific variant or edition of the operating system. This may be interpreted by
+          other packages in order to determine a divergent default configuration. This field is optional and
+          may not be implemented on all systems.</para>
+
+          <para>Examples: <literal>VARIANT_ID=server</literal>, <literal>VARIANT_ID=embedded</literal>.
+          </para></listitem>
+        </varlistentry>
+      </variablelist>
+    </refsect2>
+
+    <refsect2>
+      <title>Information about the version of the operating system</title>
+
+      <variablelist class='environment-variables'>
+        <varlistentry>
+          <term><varname>VERSION=</varname></term>
+
+          <listitem><para>A string identifying the operating system version, excluding any OS name
+          information, possibly including a release code name, and suitable for presentation to the
+          user. This field is optional.</para>
+
+          <para>Examples: <literal>VERSION=17</literal>, <literal>VERSION="17 (Beefy Miracle)"</literal>.
+          </para></listitem>
+        </varlistentry>
+
+        <varlistentry>
+          <term><varname>VERSION_ID=</varname></term>
+
+          <listitem><para>A lower-case string (mostly numeric, no spaces or other characters outside of 0–9,
+          a–z, ".", "_" and "-") identifying the operating system version, excluding any OS name information
+          or release code name, and suitable for processing by scripts or usage in generated filenames. This
+          field is optional.</para>
+
+          <para>Examples: <literal>VERSION_ID=17</literal>, <literal>VERSION_ID=11.04</literal>.
+          </para></listitem>
+        </varlistentry>
+
+        <varlistentry>
+          <term><varname>VERSION_CODENAME=</varname></term>
+
+          <listitem><para>A lower-case string (no spaces or other characters outside of 0–9, a–z, ".", "_"
+          and "-") identifying the operating system release code name, excluding any OS name information or
+          release version, and suitable for processing by scripts or usage in generated filenames. This field
+          is optional and may not be implemented on all systems.</para>
+
+          <para>Examples: <literal>VERSION_CODENAME=buster</literal>,
+          <literal>VERSION_CODENAME=xenial</literal>.</para></listitem>
+        </varlistentry>
+
+        <varlistentry>
+          <term><varname>BUILD_ID=</varname></term>
+
+          <listitem><para>A string uniquely identifying the system image originally used as the installation
+          base. In most cases, <varname>VERSION_ID</varname> or
+          <varname>IMAGE_ID</varname>+<varname>IMAGE_VERSION</varname> are updated when the entire system
+          image is replaced during an update. <varname>BUILD_ID</varname> may be used in distributions where
+          the original installation image version is important: <varname>VERSION_ID</varname> would change
+          during incremental system updates, but <varname>BUILD_ID</varname> would not. This field is
+          optional.</para>
+
+          <para>Examples: <literal>BUILD_ID="2013-03-20.3"</literal>, <literal>BUILD_ID=201303203</literal>.
+          </para></listitem>
+        </varlistentry>
+
+        <varlistentry>
+          <term><varname>IMAGE_ID=</varname></term>
+
+          <listitem><para> A lower-case string (no spaces or other characters outside of 0–9, a–z, ".", "_"
+          and "-"), identifying a specific image of the operating system. This is supposed to be used for
+          environments where OS images are prepared, built, shipped and updated as comprehensive, consistent
+          OS images. This field is optional and may not be implemented on all systems, in particularly not on
+          those that are not managed via images but put together and updated from individual packages and on
+          the local system.</para>
+
+          <para>Examples: <literal>IMAGE_ID=vendorx-cashier-system</literal>,
+          <literal>IMAGE_ID=netbook-image</literal>.</para></listitem>
+        </varlistentry>
+
+        <varlistentry>
+          <term><varname>IMAGE_VERSION=</varname></term>
+
+          <listitem><para>A lower-case string (mostly numeric, no spaces or other characters outside of 0–9,
+          a–z, ".", "_" and "-") identifying the OS image version. This is supposed to be used together with
+          <varname>IMAGE_ID</varname> described above, to discern different versions of the same image.
+          </para>
+
+          <para>Examples: <literal>IMAGE_VERSION=33</literal>, <literal>IMAGE_VERSION=47.1rc1</literal>.
+          </para></listitem>
+        </varlistentry>
+      </variablelist>
+
+      <para>To summarize: if the image updates are built and shipped as comprehensive units,
+      <varname>IMAGE_ID</varname>+<varname>IMAGE_VERSION</varname> is the best fit. Otherwise, if updates
+      eventually completely replace previously installed contents, as in a typical binary distribution,
+      <varname>VERSION_ID</varname> should be used to identify major releases of the operating system.
+      <varname>BUILD_ID</varname> may be used instead or in addition to <varname>VERSION_ID</varname> when
+      the original system image version is important.</para>
+    </refsect2>
+
+    <refsect2>
+      <title>Presentation information and links</title>
+
+      <variablelist class='environment-variables'>
+        <varlistentry>
+          <term><varname>HOME_URL=</varname></term>
+          <term><varname>DOCUMENTATION_URL=</varname></term>
+          <term><varname>SUPPORT_URL=</varname></term>
+          <term><varname>BUG_REPORT_URL=</varname></term>
+          <term><varname>PRIVACY_POLICY_URL=</varname></term>
+
+          <listitem><para>Links to resources on the Internet related to the operating system.
+          <varname>HOME_URL=</varname> should refer to the homepage of the operating system, or alternatively
+          some homepage of the specific version of the operating system.
+          <varname>DOCUMENTATION_URL=</varname> should refer to the main documentation page for this
+          operating system.  <varname>SUPPORT_URL=</varname> should refer to the main support page for the
+          operating system, if there is any. This is primarily intended for operating systems which vendors
+          provide support for. <varname>BUG_REPORT_URL=</varname> should refer to the main bug reporting page
+          for the operating system, if there is any. This is primarily intended for operating systems that
+          rely on community QA. <varname>PRIVACY_POLICY_URL=</varname> should refer to the main privacy
+          policy page for the operating system, if there is any. These settings are optional, and providing
+          only some of these settings is common. These URLs are intended to be exposed in "About this system"
+          UIs behind links with captions such as "About this Operating System", "Obtain Support", "Report a
+          Bug", or "Privacy Policy". The values should be in <ulink
+          url="https://tools.ietf.org/html/rfc3986">RFC3986 format</ulink>, and should be
+          <literal>http:</literal> or <literal>https:</literal> URLs, and possibly <literal>mailto:</literal>
+          or <literal>tel:</literal>. Only one URL shall be listed in each setting. If multiple resources
+          need to be referenced, it is recommended to provide an online landing page linking all available
+          resources.</para>
+
+          <para>Examples: <literal>HOME_URL="https://fedoraproject.org/"</literal>,
+          <literal>BUG_REPORT_URL="https://bugzilla.redhat.com/"</literal>.</para></listitem>
+        </varlistentry>
+
+        <varlistentry>
+          <term><varname>SUPPORT_END=</varname></term>
+
+          <listitem><para>The date at which support for this version of the OS ends. (What exactly "lack of
+          support" means varies between vendors, but generally users should assume that updates, including
+          security fixes, will not be provided.) The value is a date in the ISO 8601 format
+          <literal>YYYY-MM-DD</literal>, and specifies the first day on which support <emphasis>is
+          not</emphasis> provided.</para>
+
+          <para>For example, <literal>SUPPORT_END=2001-01-01</literal> means that the system was supported
+          until the end of the last day of the previous millennium.</para></listitem>
+        </varlistentry>
+
+        <varlistentry>
+          <term><varname>LOGO=</varname></term>
+
+          <listitem><para>A string, specifying the name of an icon as defined by <ulink
+          url="https://standards.freedesktop.org/icon-theme-spec/latest">freedesktop.org Icon Theme
+          Specification</ulink>. This can be used by graphical applications to display an operating system's
+          or distributor's logo. This field is optional and may not necessarily be implemented on all
+          systems.</para>
+
+          <para>Examples: <literal>LOGO=fedora-logo</literal>, <literal>LOGO=distributor-logo-opensuse</literal>
+          </para></listitem>
+        </varlistentry>
+
+        <varlistentry>
+          <term><varname>ANSI_COLOR=</varname></term>
+
+          <listitem><para>A suggested presentation color when showing the OS name on the console. This should
+          be specified as string suitable for inclusion in the ESC [ m ANSI/ECMA-48 escape code for setting
+          graphical rendition. This field is optional.</para>
+
+          <para>Examples: <literal>ANSI_COLOR="0;31"</literal> for red, <literal>ANSI_COLOR="1;34"</literal>
+          for light blue, or <literal>ANSI_COLOR="0;38;2;60;110;180"</literal> for Fedora blue.
+          </para></listitem>
+        </varlistentry>
+      </variablelist>
+    </refsect2>
+
+    <refsect2>
+      <title>Distribution-level defaults and metadata</title>
+
+      <variablelist class='environment-variables'>
+        <varlistentry>
+          <term><varname>DEFAULT_HOSTNAME=</varname></term>
+
+          <listitem><para>A string specifying the hostname if
+          <citerefentry><refentrytitle>hostname</refentrytitle><manvolnum>5</manvolnum></citerefentry> is not
+          present and no other configuration source specifies the hostname. Must be either a single DNS label
+          (a string composed of 7-bit ASCII lower-case characters and no spaces or dots, limited to the
+          format allowed for DNS domain name labels), or a sequence of such labels separated by single dots
+          that forms a valid DNS FQDN. The hostname must be at most 64 characters, which is a Linux
+          limitation (DNS allows longer names).</para>
+
+          <para>See <citerefentry><refentrytitle>org.freedesktop.hostname1</refentrytitle><manvolnum>5</manvolnum></citerefentry>
+          for a description of how
+          <citerefentry><refentrytitle>systemd-hostnamed.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>
+          determines the fallback hostname.</para></listitem>
+        </varlistentry>
+
+        <varlistentry>
+          <term><varname>ARCHITECTURE=</varname></term>
+          <listitem><para>A string that specifies which CPU architecture the userspace binaries require.
+          The architecture identifiers are the same as for <varname>ConditionArchitecture=</varname>
+          described in <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
+          The field is optional and should only be used when just single architecture is supported.
+          It may provide redundant information when used in a GPT partition with a GUID type that already
+          encodes the architecture. If this is not the case, the architecture should be specified in
+          e.g., an extension image, to prevent an incompatible host from loading it.
+          </para></listitem>
+        </varlistentry>
+
+        <varlistentry>
+          <term><varname>SYSEXT_LEVEL=</varname></term>
+
+          <listitem><para>A lower-case string (mostly numeric, no spaces or other characters outside of 0–9,
+          a–z, ".", "_" and "-") identifying the operating system extensions support level, to indicate which
+          extension images are supported. See <filename>/usr/lib/extension-release.d/extension-release.<replaceable>IMAGE</replaceable></filename>,
+          <ulink url="https://docs.kernel.org/admin-guide/initrd.html">initrd</ulink> and
+          <citerefentry><refentrytitle>systemd-sysext</refentrytitle><manvolnum>8</manvolnum></citerefentry>)
+          for more information.</para>
+
+          <para>Examples: <literal>SYSEXT_LEVEL=2</literal>, <literal>SYSEXT_LEVEL=15.14</literal>.
+          </para></listitem>
+        </varlistentry>
+
+        <varlistentry>
+          <term><varname>SYSEXT_SCOPE=</varname></term>
+          <listitem><para>Takes a space-separated list of one or more of the strings
+          <literal>system</literal>, <literal>initrd</literal> and <literal>portable</literal>. This field is
+          only supported in <filename>extension-release.d/</filename> files and indicates what environments
+          the system extension is applicable to: i.e. to regular systems, to initrds, or to portable service
+          images. If unspecified, <literal>SYSEXT_SCOPE=system portable</literal> is implied, i.e. any system
+          extension without this field is applicable to regular systems and to portable service environments,
+          but not to initrd environments.</para></listitem>
+        </varlistentry>
+
+        <varlistentry>
+          <term><varname>PORTABLE_PREFIXES=</varname></term>
+          <listitem><para>Takes a space-separated list of one or more valid prefix match strings for the
+          <ulink url="https://systemd.io/PORTABLE_SERVICES">Portable Services</ulink> logic. This field
+          serves two purposes: it is informational, identifying portable service images as such (and thus
+          allowing them to be distinguished from other OS images, such as bootable system images). It is also
+          used when a portable service image is attached: the specified or implied portable service prefix is
+          checked against the list specified here, to enforce restrictions how images may be attached to a
+          system.</para></listitem>
+        </varlistentry>
+      </variablelist>
+    </refsect2>
+
+    <refsect2>
+      <title>Notes</title>
+
+      <para>If you are using this file to determine the OS or a specific version of it, use the
+      <varname>ID</varname> and <varname>VERSION_ID</varname> fields, possibly with
+      <varname>ID_LIKE</varname> as fallback for <varname>ID</varname>. When looking for an OS identification
+      string for presentation to the user use the <varname>PRETTY_NAME</varname> field.</para>
+
+      <para>Note that operating system vendors may choose not to provide version information, for example to
+      accommodate for rolling releases. In this case, <varname>VERSION</varname> and
+      <varname>VERSION_ID</varname> may be unset. Applications should not rely on these fields to be
+      set.</para>
+
+      <para>Operating system vendors may extend the file format and introduce new fields. It is highly
+      recommended to prefix new fields with an OS specific name in order to avoid name clashes. Applications
+      reading this file must ignore unknown fields.</para>
+
+      <para>Example: <literal>DEBIAN_BTS="debbugs://bugs.debian.org/"</literal>.</para>
+
+      <para>Container and sandbox runtime managers may make the host's identification data available to
+      applications by providing the host's <filename>/etc/os-release</filename> (if available, otherwise
+      <filename>/usr/lib/os-release</filename> as a fallback) as
+      <filename>/run/host/os-release</filename>.</para>
+    </refsect2>
+  </refsect1>
+
+  <refsect1>
+    <title>Examples</title>
+
+    <example>
+      <title><filename>os-release</filename> file for Fedora Workstation</title>
+
+      <programlisting>NAME=Fedora
+VERSION="32 (Workstation Edition)"
+ID=fedora
+VERSION_ID=32
+PRETTY_NAME="Fedora 32 (Workstation Edition)"
+ANSI_COLOR="0;38;2;60;110;180"
+LOGO=fedora-logo-icon
+CPE_NAME="cpe:/o:fedoraproject:fedora:32"
+HOME_URL="https://fedoraproject.org/"
+DOCUMENTATION_URL="https://docs.fedoraproject.org/en-US/fedora/f32/system-administrators-guide/"
+SUPPORT_URL="https://fedoraproject.org/wiki/Communicating_and_getting_help"
+BUG_REPORT_URL="https://bugzilla.redhat.com/"
+REDHAT_BUGZILLA_PRODUCT="Fedora"
+REDHAT_BUGZILLA_PRODUCT_VERSION=32
+REDHAT_SUPPORT_PRODUCT="Fedora"
+REDHAT_SUPPORT_PRODUCT_VERSION=32
+PRIVACY_POLICY_URL="https://fedoraproject.org/wiki/Legal:PrivacyPolicy"
+VARIANT="Workstation Edition"
+VARIANT_ID=workstation</programlisting>
+    </example>
+
+    <example>
+      <title><filename>extension-release</filename> file for an extension for Fedora Workstation 32</title>
+
+      <programlisting>ID=fedora
+VERSION_ID=32</programlisting>
+    </example>
+
+    <example>
+      <title>Reading <filename>os-release</filename> in
+      <citerefentry project='man-pages'><refentrytitle>sh</refentrytitle><manvolnum>1</manvolnum></citerefentry></title>
+
+      <programlisting><xi:include href="check-os-release.sh" parse="text" /></programlisting>
+    </example>
+
+    <example>
+      <title>Reading <filename>os-release</filename> in
+      <citerefentry project='die-net'><refentrytitle>python</refentrytitle><manvolnum>1</manvolnum></citerefentry> (versions &gt;= 3.10)</title>
+
+      <programlisting><xi:include href="check-os-release-simple.py" parse="text" /></programlisting>
+
+      <para>See docs for <ulink url="https://docs.python.org/3/library/platform.html#platform.freedesktop_os_release">
+      <function>platform.freedesktop_os_release</function></ulink> for more details.
+      </para>
+    </example>
+
+    <example>
+      <title>Reading <filename>os-release</filename> in
+      <citerefentry project='die-net'><refentrytitle>python</refentrytitle><manvolnum>1</manvolnum></citerefentry> (any version)</title>
+
+      <programlisting><xi:include href="check-os-release.py" parse="text" /></programlisting>
+
+      <para>Note that the above version that uses the built-in implementation is preferred
+      in most cases, and the open-coded version here is provided for reference.</para>
+    </example>
+
+  </refsect1>
+
+  <refsect1>
+      <title>See Also</title>
+      <para>
+        <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
+        <citerefentry project='die-net'><refentrytitle>lsb_release</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
+        <citerefentry><refentrytitle>hostname</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
+        <citerefentry><refentrytitle>machine-id</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
+        <citerefentry><refentrytitle>machine-info</refentrytitle><manvolnum>5</manvolnum></citerefentry>
+      </para>
+  </refsect1>
+
+</refentry>