man/portablectl.xml

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   2 <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
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   5 <!-- SPDX-License-Identifier: LGPL-2.1+ -->
   6
   7 <refentry id="portablectl" conditional='ENABLE_PORTABLED'
   8     xmlns:xi="http://www.w3.org/2001/XInclude">
   9
  10   <refentryinfo>
  11     <title>portablectl</title>
  12     <productname>systemd</productname>
  13   </refentryinfo>
  14
  15   <refmeta>
  16     <refentrytitle>portablectl</refentrytitle>
  17     <manvolnum>1</manvolnum>
  18   </refmeta>
  19
  20   <refnamediv>
  21     <refname>portablectl</refname>
  22     <refpurpose>Attach, detach or inspect portable service images</refpurpose>
  23   </refnamediv>
  24
  25   <refsynopsisdiv>
  26     <cmdsynopsis>
  27       <command>portablectl</command>
  28       <arg choice="opt" rep="repeat">OPTIONS</arg>
  29       <arg choice="req">COMMAND</arg>
  30       <arg choice="opt" rep="repeat">NAME</arg>
  31     </cmdsynopsis>
  32   </refsynopsisdiv>
  33
  34   <refsect1>
  35     <title>Description</title>
  36
  37     <para><command>portablectl</command> may be used to attach, detach or inspect portable service images. It's
  38     primarily a command interfacing with
  39     <citerefentry><refentrytitle>systemd-portabled.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
  40
  41     <para>Portable service images contain an OS file system tree along with
  42     <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry> unit file
  43     information. A service image may be "attached" to the local system. If attached, a set of unit files are copied
  44     from the image to the host, and extended with <varname>RootDirectory=</varname> or <varname>RootImage=</varname>
  45     assignments (in case of service units) pointing to the image file or directory, ensuring the services will run
  46     within the file system context of the image.</para>
  47
  48     <para>Portable service images are an efficient way to bundle multiple related services and other units together,
  49     and transfer them as a whole between systems. When these images are attached the local system the contained units
  50     may run in most ways like regular system-provided units, either with full privileges or inside strict sandboxing,
  51     depending on the selected configuration.</para>
  52
  53     <para>Specifically portable service images may be of the following kind:</para>
  54
  55     <itemizedlist>
  56       <listitem><para>Directory trees containing an OS, including the top-level directories <filename>/usr/</filename>,
  57       <filename>/etc/</filename>, and so on.</para></listitem>
  58
  59       <listitem><para>btrfs subvolumes containing OS trees, similar to normal directory trees.</para></listitem>
  60
  61       <listitem><para>Binary "raw" disk images containing MBR or GPT partition tables and Linux file system
  62       partitions. (These must be regular files, with the <filename>.raw</filename> suffix.)</para></listitem>
  63     </itemizedlist>
  64
  65   </refsect1>
  66
  67   <refsect1>
  68     <title>Options</title>
  69
  70     <para>The following options are understood:</para>
  71
  72     <variablelist>
  73       <varlistentry>
  74         <term><option>-q</option></term>
  75         <term><option>--quiet</option></term>
  76
  77         <listitem><para>Suppresses additional informational output while running.</para></listitem>
  78       </varlistentry>
  79
  80       <varlistentry>
  81         <term><option>-p</option> <replaceable>PROFILE</replaceable></term>
  82         <term><option>--profile=</option><replaceable>PROFILE</replaceable></term>
  83
  84         <listitem><para>When attaching an image, select the profile to use. By default the <literal>default</literal>
  85         profile is used. For details about profiles, see below.</para></listitem>
  86       </varlistentry>
  87
  88       <varlistentry>
  89         <term><option>--copy=</option></term>
  90
  91         <listitem><para>When attaching an image, select whether to prefer copying or symlinking of files installed into
  92         the host system. Takes one of <literal>copy</literal> (to prefer copying of files), <literal>symlink</literal>
  93         (to prefer creation of symbolic links) or <literal>auto</literal> for an intermediary mode where security
  94         profile drop-ins are symlinked while unit files are copied. Note that this option expresses a preference only,
  95         in cases where symbolic links cannot be created — for example when the image operated on is a raw disk image,
  96         and hence not directly referentiable from the host file system — copying of files is used
  97         unconditionally.</para></listitem>
  98       </varlistentry>
  99
 100       <varlistentry>
 101         <term><option>--runtime</option></term>
 102
 103         <listitem><para>When specified the unit and drop-in files are placed in
 104         <filename>/run/systemd/system.attached/</filename> instead of
 105         <filename>/etc/systemd/system.attached/</filename>. Images attached with this option set hence remain attached
 106         only until the next reboot, while they are normally attached persistently.</para></listitem>
 107       </varlistentry>
 108
 109       <varlistentry>
 110         <term><option>--no-reload</option></term>
 111
 112         <listitem><para>Don't reload the service manager after attaching or detaching a portable service
 113         image. Normally the service manager is reloaded to ensure it is aware of added or removed unit
 114         files.</para></listitem>
 115       </varlistentry>
 116
 117       <varlistentry>
 118         <term><option>--cat</option></term>
 119
 120         <listitem><para>When inspecting portable service images, show the (unprocessed) contents of the metadata files
 121         pulled from the image, instead of brief summaries. Specifically, this will show the
 122         <citerefentry><refentrytitle>os-release</refentrytitle><manvolnum>5</manvolnum></citerefentry> and unit file
 123         contents of the image.</para></listitem>
 124       </varlistentry>
 125
 126       <xi:include href="user-system-options.xml" xpointer="host" />
 127       <xi:include href="user-system-options.xml" xpointer="machine" />
 128
 129       <xi:include href="standard-options.xml" xpointer="no-pager" />
 130       <xi:include href="standard-options.xml" xpointer="no-legend" />
 131       <xi:include href="standard-options.xml" xpointer="no-ask-password" />
 132       <xi:include href="standard-options.xml" xpointer="help" />
 133       <xi:include href="standard-options.xml" xpointer="version" />
 134     </variablelist>
 135   </refsect1>
 136
 137   <refsect1>
 138     <title>Commands</title>
 139
 140     <para>The following commands are understood:</para>
 141
 142     <variablelist>
 143
 144       <varlistentry>
 145         <term><command>list</command></term>
 146
 147         <listitem><para>List available portable service images. This will list all portable service images discovered
 148         in the portable image search paths (see below), along with brief metadata and state information. Note that many
 149         of the commands below may both operate on images inside and outside of the search paths. This command is hence
 150         mostly a convenience option, the commands are generally not restricted to what this list
 151         shows.</para></listitem>
 152       </varlistentry>
 153
 154       <varlistentry>
 155         <term><command>attach</command> <replaceable>IMAGE</replaceable> [<replaceable>PREFIX…</replaceable>]</term>
 156
 157         <listitem><para>Attach a portable service image to the host system. Expects a file system path to a portable
 158         service image file or directory as first argument. If the specified path contains no slash character
 159         (<literal>/</literal>) it is understood as image filename that is searched for in the portable service image
 160         search paths (see below). To reference a file in the current working directory prefix the filename with
 161         <literal>./</literal> to avoid this search path logic.</para>
 162
 163         <para>When a portable service is attached four operations are executed:</para>
 164
 165         <orderedlist>
 166
 167           <listitem><para>All unit files of types <filename>.service</filename>, <filename>.socket</filename>,
 168           <filename>.target</filename>, <filename>.timer</filename> and <filename>.path</filename> which match the
 169           indicated unit file name prefix are copied from the image to the host's
 170           <filename>/etc/systemd/system.attached/</filename> directory (or
 171           <filename>/run/systemd/system.attached/</filename> — depending whether <option>--runtime</option> is
 172           specified, see above), which is included in the built-in unit search path of the system service
 173           manager.</para></listitem>
 174
 175           <listitem><para>For unit files of type <filename>.service</filename> a drop-in is added to these copies that
 176           adds <varname>RootDirectory=</varname> or <varname>RootImage=</varname> settings (see
 177           <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry> for
 178           details), that ensures these services are run within the file system of the originating portable service
 179           image.</para></listitem>
 180
 181           <listitem><para>A second drop-in is created: the "profile" drop-in, that may contain additional security
 182           settings (and other settings). A number of profiles are available by default but administrators may define
 183           their own ones. See below.</para></listitem>
 184
 185           <listitem><para>If the portable service image file is not already in the search path (see below), a symbolic
 186           link to it is created in <filename>/etc/portables/</filename> or
 187           <filename>/run/portables/</filename>, to make sure it is included in it.</para></listitem>
 188         </orderedlist>
 189
 190         <para>By default all unit files whose names start with a prefix generated from the image's file name are copied
 191         out. Specifically, the prefix is determined from the image file name with any suffix such as
 192         <filename>.raw</filename> removed, truncated at the first occurrence of and underscore character
 193         (<literal>_</literal>), if there is one. The underscore logic is supposed to be used to versioning so that the
 194         an image file <filename>foobar_47.11.raw</filename> will result in a unit file matching prefix of
 195         <filename>foobar</filename>. This prefix is then compared with all unit files names contained in the image in
 196         the usual directories, but only unit file names where the prefix is followed by <literal>-</literal>,
 197         <literal>.</literal> or <literal>@</literal> are considered. Example: if a portable service image file is named
 198         <filename>foobar_47.11.raw</filename> then by default all its unit files with names such as
 199         <filename>foobar-quux-waldi.service</filename>, <filename>foobar.service</filename> or
 200         <filename>foobar@.service</filename> will be considered. It's possible to override the matching prefix: all
 201         strings listed on the command line after the image file name are considered prefixes, overriding the implicit
 202         logic where the prefix is derived from the image file name.</para>
 203
 204         <para>By default, after the unit files are attached the service manager's configuration is reloaded, except
 205         when <option>--no-reload</option> is specified (see above). This ensures that the new units made available to
 206         the service manager are seen by it.</para>
 207         </listitem>
 208       </varlistentry>
 209
 210       <varlistentry>
 211         <term><command>detach</command> <replaceable>IMAGE</replaceable></term>
 212
 213         <listitem><para>Detaches a portable service image from the host. This undoes the operations executed by the
 214         <command>attach</command> command above, and removes the unit file copies, drop-ins and image symlink
 215         again. This command expects an image name or path as parameter. Note that if a path is specified only the last
 216         component of it (i.e. the file or directory name itself, not the path to it) is used for finding matching unit
 217         files. This is a convencience feature to allow all arguments passed as <command>attach</command> also to
 218         <command>detach</command>.</para></listitem>
 219       </varlistentry>
 220
 221       <varlistentry>
 222         <term><command>inspect</command> <replaceable>IMAGE</replaceable> [<replaceable>PREFIX…</replaceable>]</term>
 223
 224         <listitem><para>Extracts various metadata from a portable service image and presents it to the
 225         caller. Specifically, the
 226         <citerefentry><refentrytitle>os-release</refentrytitle><manvolnum>5</manvolnum></citerefentry> file of the
 227         image is retrieved as well as all matching unit files. By default a short summary showing the most relevant
 228         metadata in combination with a list of matching unit files is shown (that is the unit files
 229         <command>attach</command> would install to the host system). If combined with <option>--cat</option> (see
 230         above), the <filename>os-release</filename> data and the units files' contents is displayed unprocessed. This
 231         command is useful to determine whether an image qualifies as portable service image, and which unit files are
 232         included. This command expects the path to the image as parameter, optionally followed by a list of unit file
 233         prefixes to consider, similar to the <command>attach</command> command described above.</para>
 234         </listitem>
 235       </varlistentry>
 236
 237       <varlistentry>
 238         <term><command>is-attached</command> <replaceable>IMAGE</replaceable></term>
 239
 240         <listitem><para>Determines whether the specified image is currently attached or not. Unless combined with the
 241         <option>--quiet</option> switch this will show a short state identifier for the image. Specifically:</para>
 242
 243         <table>
 244           <title>Image attachment states</title>
 245           <tgroup cols='2'>
 246             <colspec colname='state'/>
 247             <colspec colname='description'/>
 248             <thead>
 249               <row>
 250                 <entry>State</entry>
 251                 <entry>Description</entry>
 252               </row>
 253             </thead>
 254             <tbody>
 255               <row>
 256                 <entry><option>detached</option></entry>
 257                 <entry>The image is currently not attached.</entry>
 258               </row>
 259               <row>
 260                 <entry><option>attached</option></entry>
 261                 <entry>The image is currently attached, i.e. its unit files have been made available to the host system.</entry>
 262               </row>
 263               <row>
 264                 <entry><option>attached-runtime</option></entry>
 265                 <entry>Like <option>attached</option>, but the unit files have been made available transiently only, i.e. the <command>attach</command> command has been invoked with the <option>--runtime</option> option.</entry>
 266               </row>
 267               <row>
 268                 <entry><option>enabled</option></entry>
 269                 <entry>The image is currently attached, and at least one unit file associated with it has been enabled.</entry>
 270               </row>
 271               <row>
 272                 <entry><option>enabled-runtime</option></entry>
 273                 <entry>Like <option>enabled</option>, but the the unit files have been made available transiently only, i.e. the <command>attach</command> command has been invoked with the <option>--runtime</option> option.</entry>
 274               </row>
 275               <row>
 276                 <entry><option>running</option></entry>
 277                 <entry>The image is currently attached, and at least one unit file associated with it is running.</entry>
 278               </row>
 279               <row>
 280                 <entry><option>running-runtime</option></entry>
 281                 <entry>The image is currently attached transiently, and at least one unit file associated with it is running.</entry>
 282               </row>
 283             </tbody>
 284           </tgroup>
 285         </table>
 286
 287         </listitem>
 288       </varlistentry>
 289
 290       <varlistentry>
 291         <term><command>read-only</command> <replaceable>IMAGE</replaceable> [<replaceable>BOOL</replaceable>]</term>
 292
 293         <listitem><para>Marks or (unmarks) a portable service image read-only. Takes an image name, followed by a
 294         boolean as arguments. If the boolean is omitted, positive is implied, i.e. the image is marked
 295         read-only.</para></listitem>
 296       </varlistentry>
 297
 298       <varlistentry>
 299         <term><command>remove</command> <replaceable>IMAGE</replaceable>…</term>
 300
 301         <listitem><para>Removes one or more portable service images. Note that this command will only remove the
 302         specified image path itself — it refers to a symbolic link then the symbolic link is removed and not the
 303         image it points to.</para></listitem>
 304       </varlistentry>
 305
 306       <varlistentry>
 307         <term><command>set-limit</command> [<replaceable>IMAGE</replaceable>] <replaceable>BYTES</replaceable></term>
 308
 309         <listitem><para>Sets the maximum size in bytes that a specific portable service image, or all images, may grow
 310         up to on disk (disk quota). Takes either one or two parameters. The first, optional parameter refers to a
 311         portable service image name. If specified, the size limit of the specified image is changed. If omitted, the
 312         overall size limit of the sum of all images stored locally is changed. The final argument specifies the size
 313         limit in bytes, possibly suffixed by the usual K, M, G, T units. If the size limit shall be disabled, specify
 314         <literal>-</literal> as size.</para>
 315
 316         <para>Note that per-image size limits are only supported on btrfs file systems. Also, depending on
 317         <varname>BindPaths=</varname> settings in the portable service's unit files directories from the host might be
 318         visible in the image environment during runtime which are not affected by this setting, as only the image
 319         itself is counted against this limit.</para></listitem>
 320       </varlistentry>
 321
 322     </variablelist>
 323
 324   </refsect1>
 325
 326   <refsect1>
 327     <title>Files and Directories</title>
 328
 329     <para>Portable service images are preferably stored in <filename>/var/lib/portables/</filename>, but are also
 330     searched for in <filename>/etc/portables/</filename>, <filename>/run/systemd/portables/</filename>,
 331     <filename>/usr/local/lib/portables/</filename> and <filename>/usr/lib/portables/</filename>. It's recommended not
 332     to place image files directly in <filename>/etc/portables/</filename> or
 333     <filename>/run/systemd/portables/</filename> (as these are generally not suitable for storing large or non-textual
 334     data), but use these directories only for linking images located elsewhere into the image search path.</para>
 335
 336     <para>When a portable service image is attached, matching unit files are copied onto the host into the
 337     <filename>/etc/systemd/system.attached/</filename> and <filename>/run/systemd/system.attached/</filename>
 338     directories. When an image is detached, the unit files are removed again from these directories.</para>
 339   </refsect1>
 340
 341   <refsect1>
 342     <title>Profiles</title>
 343
 344     <para>When portable service images are attached a "profile" drop-in is linked in, which may be used to enforce
 345     additional security (and other) restrictions locally. Four profile drop-ins are defined by default, and shipped in
 346     <filename>/usr/lib/systemd/portable/profile/</filename>. Additional, local profiles may be defined by placing them
 347     in <filename>/etc/systemd/portable/profile/</filename>. The default profiles are:</para>
 348
 349     <table>
 350       <title>Profiles</title>
 351       <tgroup cols='2'>
 352         <colspec colname='state'/>
 353         <colspec colname='description'/>
 354         <thead>
 355           <row>
 356             <entry>Name</entry>
 357             <entry>Description</entry>
 358           </row>
 359         </thead>
 360         <tbody>
 361           <row>
 362             <entry><filename>default</filename></entry>
 363             <entry>This is the default profile if no other profile name is set via the <option>--profile=</option> (see above). It's fairly restrictive, but should be useful for common, unprivileged system workloads. This includes write access to the logging framework, as well as IPC access to the D-Bus system.</entry>
 364           </row>
 365           <row>
 366             <entry><filename>nonetwork</filename></entry>
 367             <entry>Very similar to <filename>default</filename>, but networking is turned off for any services of the portable service image.</entry>
 368           </row>
 369           <row>
 370             <entry><filename>strict</filename></entry>
 371             <entry>A profile with very strict settings. This profile excludes IPC (D-Bus) and network access.</entry>
 372           </row>
 373           <row>
 374             <entry><filename>trusted</filename></entry>
 375             <entry>A profile with very relaxed settings. In this profile the services run with full privileges.</entry>
 376           </row>
 377         </tbody>
 378       </tgroup>
 379     </table>
 380
 381     <para>For details on this profiles, and their effects please have a look at their precise definitions,
 382     e.g. <filename>/usr/lib/systemd/portable/profile/default/service.conf</filename> and similar.</para>
 383   </refsect1>
 384
 385   <refsect1>
 386     <title>Exit status</title>
 387
 388     <para>On success, 0 is returned, a non-zero failure code otherwise.</para>
 389   </refsect1>
 390
 391   <xi:include href="less-variables.xml" />
 392
 393   <refsect1>
 394     <title>See Also</title>
 395     <para>
 396       <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 397       <citerefentry><refentrytitle>systemd-portabled.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>
 398     </para>
 399   </refsect1>
 400
 401 </refentry>