SYSUPDATE.FEATURES(5) sysupdate.features SYSUPDATE.FEATURES(5)
NAME
sysupdate.features - Definition Files for Optional Features
SYNOPSIS
/etc/sysupdate.d/*.feature
/run/sysupdate.d/*.feature
/usr/local/lib/sysupdate.d/*.feature
/usr/lib/sysupdate.d/*.feature
DESCRIPTION
"Optional Features" are functionality provided by systemd-sysupdate(8),
that allow a distribution to define sets of sysupdate.d(5) transfer
definitions that are intended to be enabled or disabled by the system
administrator.
When a feature is enabled, transfers belonging to it will be considered
when checking for and downloading updates, when vacuuming, and in all
other situations. In effect, transfers belonging to a feature will
always be updated in lock-step with the rest of their target. This is
the primary difference an Optional Feature and a systemd-sysupdate(8)
component. When a feature is disabled, its transfers will not be
considered when checking for and downloading updates, but
systemd-sysupdate will still consider them while vacuuming and in other
situations where it needs to determine ownership over previously
downloaded system resources. systemd-sysupdate will clean up all
instances of the feature's transfers whenever it is disabled,
effectively uninstalling it.
Optional Features are described by sysupdate.d/*.feature files, which
are defined below. Transfers can declare that they belong to a feature
via the Features= setting. Feature definitions support drop-in files,
which are most commonly used to override the Enabled= setting. They can
also be masked to hide the availability of the feature entirely.
Each *.feature file contains one section: [Feature].
[FEATURE] SECTION OPTIONS
This section defines general properties of this feature.
Description=
A short human readable description of this feature. This may be used
as a label for this feature, so the string should meaningfully
identify the feature among the features available in sysupdate.d/.
Added in version 257.
Documentation=
A user-presentable URL to documentation about this feature. This
setting supports specifier expansion; see below for details on
supported specifiers.
Added in version 257.
AppStream=
A URL to an AppStream catalog[1] XML file. This may be used by
software centers (such as GNOME Software or KDE Discover) to present
rich metadata about this feature. This includes display names,
chagnelogs, icons, and more. This setting supports specifier
expansion; see below for details on supported specifiers.
Added in version 257.
Enabled=
Whether or not this feature is enabled. If unspecified, the feature
is disabled by default.
Added in version 257.
SPECIFIERS
Specifiers may be used in the Documentation= and AppStream= settings.
The following expansions are understood:
Table 1. Specifiers available
┌───────────┬──────────────────────┬────────────────────────┐
│ Specifier │ Meaning │ Details │
├───────────┼──────────────────────┼────────────────────────┤
│ "%a" │ Architecture │ A short string │
│ │ │ identifying the │
│ │ │ architecture of the │
│ │ │ local system. A │
│ │ │ string such as x86, │
│ │ │ x86-64 or arm64. See │
│ │ │ the architectures │
│ │ │ defined for │
│ │ │ ConditionArchitecture= │
│ │ │ in systemd.unit(5) │
│ │ │ for a full list. │
├───────────┼──────────────────────┼────────────────────────┤
│ "%A" │ Operating system │ The operating system │
│ │ image version │ image version │
│ │ │ identifier of the │
│ │ │ running system, as │
│ │ │ read from the │
│ │ │ IMAGE_VERSION= field │
│ │ │ of /etc/os-release. If │
│ │ │ not set, resolves to │
│ │ │ an empty string. See │
│ │ │ os-release(5) for more │
│ │ │ information. │
├───────────┼──────────────────────┼────────────────────────┤
│ "%b" │ Boot ID │ The boot ID of the │
│ │ │ running system, │
│ │ │ formatted as string. │
│ │ │ See random(4) for more │
│ │ │ information. │
├───────────┼──────────────────────┼────────────────────────┤
│ "%B" │ Operating system │ The operating system │
│ │ build ID │ build identifier of │
│ │ │ the running system, as │
│ │ │ read from the │
│ │ │ BUILD_ID= field of │
│ │ │ /etc/os-release. If │
│ │ │ not set, resolves to │
│ │ │ an empty string. See │
│ │ │ os-release(5) for more │
│ │ │ information. │
├───────────┼──────────────────────┼────────────────────────┤
│ "%H" │ Host name │ The hostname of the │
│ │ │ running system. │
├───────────┼──────────────────────┼────────────────────────┤
│ "%l" │ Short host name │ The hostname of the │
│ │ │ running system, │
│ │ │ truncated at the first │
│ │ │ dot to remove any │
│ │ │ domain component. │
├───────────┼──────────────────────┼────────────────────────┤
│ "%m" │ Machine ID │ The machine ID of the │
│ │ │ running system, │
│ │ │ formatted as string. │
│ │ │ See machine-id(5) for │
│ │ │ more information. │
├───────────┼──────────────────────┼────────────────────────┤
│ "%M" │ Operating system │ The operating system │
│ │ image identifier │ image identifier of │
│ │ │ the running system, as │
│ │ │ read from the │
│ │ │ IMAGE_ID= field of │
│ │ │ /etc/os-release. If │
│ │ │ not set, resolves to │
│ │ │ an empty string. See │
│ │ │ os-release(5) for more │
│ │ │ information. │
├───────────┼──────────────────────┼────────────────────────┤
│ "%o" │ Operating system ID │ The operating system │
│ │ │ identifier of the │
│ │ │ running system, as │
│ │ │ read from the ID= │
│ │ │ field of │
│ │ │ /etc/os-release. See │
│ │ │ os-release(5) for more │
│ │ │ information. │
├───────────┼──────────────────────┼────────────────────────┤
│ "%v" │ Kernel release │ Identical to uname -r │
│ │ │ output. │
├───────────┼──────────────────────┼────────────────────────┤
│ "%w" │ Operating system │ The operating system │
│ │ version ID │ version identifier of │
│ │ │ the running system, as │
│ │ │ read from the │
│ │ │ VERSION_ID= field of │
│ │ │ /etc/os-release. If │
│ │ │ not set, resolves to │
│ │ │ an empty string. See │
│ │ │ os-release(5) for more │
│ │ │ information. │
├───────────┼──────────────────────┼────────────────────────┤
│ "%W" │ Operating system │ The operating system │
│ │ variant ID │ variant identifier of │
│ │ │ the running system, as │
│ │ │ read from the │
│ │ │ VARIANT_ID= field of │
│ │ │ /etc/os-release. If │
│ │ │ not set, resolves to │
│ │ │ an empty string. See │
│ │ │ os-release(5) for more │
│ │ │ information. │
├───────────┼──────────────────────┼────────────────────────┤
│ "%T" │ Directory for │ This is either /tmp or │
│ │ temporary files │ the path "$TMPDIR", │
│ │ │ "$TEMP" or "$TMP" are │
│ │ │ set to. (Note that the │
│ │ │ directory may be │
│ │ │ specified without a │
│ │ │ trailing slash.) │
├───────────┼──────────────────────┼────────────────────────┤
│ "%V" │ Directory for larger │ This is either │
│ │ and persistent │ /var/tmp or the path │
│ │ temporary files │ "$TMPDIR", "$TEMP" or │
│ │ │ "$TMP" are set to. │
│ │ │ (Note that the │
│ │ │ directory may be │
│ │ │ specified without a │
│ │ │ trailing slash.) │
├───────────┼──────────────────────┼────────────────────────┤
│ "%%" │ Single percent sign │ Use "%%" in place of │
│ │ │ "%" to specify a │
│ │ │ single percent sign. │
└───────────┴──────────────────────┴────────────────────────┘
EXAMPLES
Example 1. Development Tools for Image-Based OS
We'll use the hypothetical "foobarOS" described in sysupdate.d(5) as our
example base OS. The vast majority of foobarOS's users have no need for
a compiler, build system, debugger, and other such development tools to
be part of their OS. However, the developers of foobarOS itself need
this build tooling to be available. So, foobarOS needs to provide a
system extension image (see systemd-sysext(8)) containing these
development tools, and this image must be updated in lock-step with the
underlying base OS. This is a great use case for an optional OS feature,
so let's define one:
# /usr/lib/sysupdate.d/devel.feature
[Feature]
Description=Development Tools
Documentation=https://developer.example.com/foobarOS/getting-started
Enabled=false
The above defines the "devel" feature, and disables it by default. Now
let's a define a transfer that's associated with this feature:
# /usr/lib/sysupdate.d/50-devel.transfer
[Transfer]
Features=devel
ProtectVersion=%A
[Source]
Type=url-file
Path=https://download.example.com/
MatchPattern=foobarOS_@v_devel.raw.xz
[Target]
Type=regular-file
Path=/var/lib/extensions
MatchPattern=foobarOS_@v_devel.raw
Mode=0444
InstancesMax=2
With these two files, we have created a feature called "devel" that,
when enabled, will download and decompress the appropriate version of
"https://download.example.com/foobarOS_@v_devel.raw.xz" into
"/var/lib/extensions/foobarOS_@v_devel.raw" during each OS update.
The developers of foobarOS can enable the "devel" feature on their
workstations by creating the following drop-in:
# /etc/sysupdate.d/devel.feature.d/enable.conf
[Feature]
Enabled=true
Example 2. Proprietary Drivers
Suppose that many of foobarOS's users have a GPU manufactured by the
MVISUAL corporation. Due to lack of documentation and difficulty in
reverse-engineering the hardware, the open-source drivers for MVISUAL
GPUs are unable to make proper use of available graphics and compute
performance. MVISUAL provides a redistributable proprietary driver for
their cards, and foobarOS's developers distribute them to address their
users' needs.
MVISUAL's driver has a couple different parts that must be installed for
it to function: a UKI addon to configure the kernel command-line, an
initrd system extension image to add the MVISUAL kernel module into the
initrd, and a regular system extension image to add the proprietary
OpenGL and Vulkan userspace drivers. All of these should be
version-locked to the core OS.
Let's start by defining an optional feature named "mvisual-driver":
# /usr/lib/sysupdate.d/mvisual-driver.feature
[Feature]
Description=MVISUAL Proprietary GPU Driver
Documentation=https://support.example.com/foobarOS/mvisual
AppStream=https://metadata.example.com/mvisual-driver-%A.xml.gz
Note that we define AppStream metadata for this feature, because we want
software centers to present it to end-users. Next, let's define the
corresponding transfers:
# /usr/lib/sysupdate.d/50-mvisual-userspace.transfer
[Transfer]
Features=mvisual-driver
ProtectVersion=%A
[Source]
Type=url-file
Path=https://download.example.com/
MatchPattern=foobarOS_@v_mvisual_userspace.raw.xz
[Target]
Type=regular-file
Path=/var/lib/extensions
MatchPattern=foobarOS_@v_mvisual.raw
Mode=0444
InstancesMax=2
# /usr/lib/sysupdate.d/70-mvisual-initrd.transfer
[Transfer]
Features=mvisual-driver
ProtectVersion=%A
[Source]
Type=url-file
Path=https://download.example.com/
MatchPattern=foobarOS_@v_mvisual_initrd.raw.xz
[Target]
Type=regular-file
Path=/EFI/Linux
PathRelativeTo=boot
MatchPattern=foobarOS_@v.efi.extra.d/foobarOS_mvisual.raw
Mode=0444
InstancesMax=2
# /usr/lib/sysupdate.d/90-mvisual-addon.transfer
[Transfer]
Features=mvisual-driver
ProtectVersion=%A
[Source]
Type=url-file
Path=https://download.example.com/
MatchPattern=foobarOS_@v_mvisual_addon.efi.xz
[Target]
Type=regular-file
Path=/EFI/Linux
PathRelativeTo=boot
MatchPattern=foobarOS_@v.efi.extra.d/foobarOS_mvisual.addon.efi
Mode=0444
InstancesMax=2
Example 3. Intersecting Features
Suppose that MVISUAL releases special tooling to help a distribution
developer troubleshoot crashes in their proprietary driver. Let's define
a transfer:
# /usr/lib/sysupdate.d/50-mvisual-debugger.transfer
[Transfer]
RequisiteFeatures=devel mvisual-driver
ProtectVersion=%A
[Source]
Type=url-file
Path=https://download.example.com/
MatchPattern=foobarOS_@v_devel.raw.xz
[Target]
Type=regular-file
Path=/var/lib/extensions
MatchPattern=foobarOS_@v_devel.raw
Mode=0444
InstancesMax=2
This transfer will be used only if both the "devel" and "mvisual-driver"
features are enabled.
SEE ALSO
systemd(1), systemd-sysupdate(8), sysupdate.d(5)
NOTES
1. AppStream catalog
https://www.freedesktop.org/software/appstream/docs/chap-CatalogData.html
systemd 257.9 SYSUPDATE.FEATURES(5)
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