1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
|
<?xml version='1.0'?>
<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
"http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd">
<!-- SPDX-License-Identifier: LGPL-2.1-or-later -->
<refentry id="sysupdate.features" conditional='ENABLE_SYSUPDATE'
xmlns:xi="http://www.w3.org/2001/XInclude">
<refentryinfo>
<title>sysupdate.features</title>
<productname>systemd</productname>
</refentryinfo>
<refmeta>
<refentrytitle>sysupdate.features</refentrytitle>
<manvolnum>5</manvolnum>
</refmeta>
<refnamediv>
<refname>sysupdate.features</refname>
<refpurpose>Definition Files for Optional Features</refpurpose>
</refnamediv>
<refsynopsisdiv>
<para><simplelist>
<member><filename>/etc/sysupdate.d/*.feature</filename></member>
<member><filename>/run/sysupdate.d/*.feature</filename></member>
<member><filename>/usr/local/lib/sysupdate.d/*.feature</filename></member>
<member><filename>/usr/lib/sysupdate.d/*.feature</filename></member>
</simplelist></para>
</refsynopsisdiv>
<refsect1>
<title>Description</title>
<para>"Optional Features" are functionality provided by
<citerefentry><refentrytitle>systemd-sysupdate</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
that allow a distribution to define sets of
<citerefentry><refentrytitle>sysupdate.d</refentrytitle><manvolnum>5</manvolnum></citerefentry>
transfer definitions that are intended to be enabled or disabled by the system administrator.</para>
<para>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
<citerefentry><refentrytitle>systemd-sysupdate</refentrytitle><manvolnum>8</manvolnum></citerefentry>
component.
When a feature is disabled, its transfers will not be considered when checking for and downloading updates,
but <command>systemd-sysupdate</command> will still consider them while vacuuming and in other situations
where it needs to determine ownership over previously downloaded system resources.
<command>systemd-sysupdate</command> will clean up all instances of the feature's transfers whenever it
is disabled, effectively uninstalling it.</para>
<para>Optional Features are described by <filename>sysupdate.d/*.feature</filename> files, which are
defined below.
Transfers can declare that they belong to a feature via the <varname>Features=</varname> setting.
Feature definitions support drop-in files, which are most commonly used to override the
<varname>Enabled=</varname> setting.
They can also be masked to hide the availability of the feature entirely.</para>
<para>Each <filename>*.feature</filename> file contains one section: [Feature].</para>
</refsect1>
<refsect1>
<title>[Feature] Section Options</title>
<para>This section defines general properties of this feature.</para>
<variablelist>
<varlistentry>
<term><varname>Description=</varname></term>
<listitem><para>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 <filename>sysupdate.d/</filename>.</para>
<xi:include href="version-info.xml" xpointer="v257"/></listitem>
</varlistentry>
<varlistentry>
<term><varname>Documentation=</varname></term>
<listitem><para>A user-presentable URL to documentation about this feature.
This setting supports specifier expansion; see below for details on supported specifiers.</para>
<xi:include href="version-info.xml" xpointer="v257"/></listitem>
</varlistentry>
<varlistentry>
<term><varname>AppStream=</varname></term>
<listitem><para>A URL to an
<ulink url="https://www.freedesktop.org/software/appstream/docs/chap-CatalogData.html">AppStream catalog</ulink>
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, changelogs, icons, and more.
This setting supports specifier expansion; see below for details on supported specifiers.</para>
<xi:include href="version-info.xml" xpointer="v257"/></listitem>
</varlistentry>
<varlistentry>
<term><varname>Enabled=</varname></term>
<listitem><para>Whether or not this feature is enabled. If unspecified, the feature is disabled
by default.</para>
<xi:include href="version-info.xml" xpointer="v257"/></listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1>
<title>Specifiers</title>
<para>Specifiers may be used in the <varname>Documentation=</varname> and <varname>AppStream=</varname>
settings. The following expansions are understood:</para>
<table class='specifiers'>
<title>Specifiers available</title>
<tgroup cols='3' align='left' colsep='1' rowsep='1'>
<colspec colname="spec" />
<colspec colname="mean" />
<colspec colname="detail" />
<thead>
<row>
<entry>Specifier</entry>
<entry>Meaning</entry>
<entry>Details</entry>
</row>
</thead>
<tbody>
<xi:include href="standard-specifiers.xml" xpointer="a"/>
<xi:include href="standard-specifiers.xml" xpointer="A"/>
<xi:include href="standard-specifiers.xml" xpointer="b"/>
<xi:include href="standard-specifiers.xml" xpointer="B"/>
<xi:include href="standard-specifiers.xml" xpointer="H"/>
<xi:include href="standard-specifiers.xml" xpointer="l"/>
<xi:include href="standard-specifiers.xml" xpointer="m"/>
<xi:include href="standard-specifiers.xml" xpointer="M"/>
<xi:include href="standard-specifiers.xml" xpointer="o"/>
<xi:include href="standard-specifiers.xml" xpointer="v"/>
<xi:include href="standard-specifiers.xml" xpointer="w"/>
<xi:include href="standard-specifiers.xml" xpointer="W"/>
<xi:include href="standard-specifiers.xml" xpointer="T"/>
<xi:include href="standard-specifiers.xml" xpointer="V"/>
<xi:include href="standard-specifiers.xml" xpointer="percent"/>
</tbody>
</tgroup>
</table>
</refsect1>
<refsect1>
<title>Examples</title>
<example>
<title>Development Tools for Image-Based OS</title>
<para>We'll use the hypothetical "foobarOS" described in
<citerefentry><refentrytitle>sysupdate.d</refentrytitle><manvolnum>5</manvolnum></citerefentry> 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
<citerefentry><refentrytitle>systemd-sysext</refentrytitle><manvolnum>8</manvolnum></citerefentry>)
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:
</para>
<para><programlisting># /usr/lib/sysupdate.d/devel.feature
[Feature]
Description=Development Tools
Documentation=https://developer.example.com/foobarOS/getting-started
Enabled=false
</programlisting></para>
<para>The above defines the <literal>devel</literal> feature, and disables it by default.
Now let's define a transfer that's associated with this feature:</para>
<para><programlisting># /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
</programlisting></para>
<para>With these two files, we have created a feature called <literal>devel</literal> that, when
enabled, will download and decompress the appropriate version of
<literal>https://download.example.com/foobarOS_@v_devel.raw.xz</literal> into
<literal>/var/lib/extensions/foobarOS_@v_devel.raw</literal> during each OS update.</para>
<para>The developers of foobarOS can enable the <literal>devel</literal> feature on their workstations
by creating the following drop-in:</para>
<para><programlisting># /etc/sysupdate.d/devel.feature.d/enable.conf
[Feature]
Enabled=true
</programlisting></para>
</example>
<example>
<title>Proprietary Drivers</title>
<para>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.</para>
<para>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.</para>
<para>Let's start by defining an optional feature named <literal>mvisual-driver</literal>:</para>
<para><programlisting># /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
</programlisting></para>
<para>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:</para>
<para><programlisting># /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
</programlisting></para>
<para><programlisting># /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
</programlisting></para>
<para><programlisting># /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
</programlisting></para>
</example>
<example>
<title>Intersecting Features</title>
<para>Suppose that MVISUAL releases special tooling to help a distribution developer troubleshoot
crashes in their proprietary driver.
Let's define a transfer:</para>
<para><programlisting># /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
</programlisting></para>
<para>This transfer will be used only if both the <literal>devel</literal> and
<literal>mvisual-driver</literal> features are enabled.</para>
</example>
</refsect1>
<refsect1>
<title>See Also</title>
<para><simplelist type="inline">
<member><citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry></member>
<member><citerefentry><refentrytitle>systemd-sysupdate</refentrytitle><manvolnum>8</manvolnum></citerefentry></member>
<member><citerefentry><refentrytitle>sysupdate.d</refentrytitle><manvolnum>5</manvolnum></citerefentry></member>
</simplelist></para>
</refsect1>
</refentry>
|
