man/systemd-tmpfiles.xml

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   2 <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
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   4 <!-- SPDX-License-Identifier: LGPL-2.1-or-later -->
   5
   6 <refentry id="systemd-tmpfiles"
   7     xmlns:xi="http://www.w3.org/2001/XInclude">
   8
   9   <refentryinfo>
  10     <title>systemd-tmpfiles</title>
  11     <productname>systemd</productname>
  12   </refentryinfo>
  13
  14   <refmeta>
  15     <refentrytitle>systemd-tmpfiles</refentrytitle>
  16     <manvolnum>8</manvolnum>
  17   </refmeta>
  18
  19   <refnamediv>
  20     <refname>systemd-tmpfiles</refname>
  21     <refname>systemd-tmpfiles-setup.service</refname>
  22     <refname>systemd-tmpfiles-setup-dev.service</refname>
  23     <refname>systemd-tmpfiles-clean.service</refname>
  24     <refname>systemd-tmpfiles-clean.timer</refname>
  25     <refpurpose>Creates, deletes and cleans up volatile
  26     and temporary files and directories</refpurpose>
  27   </refnamediv>
  28
  29   <refsynopsisdiv>
  30     <cmdsynopsis>
  31       <command>systemd-tmpfiles</command>
  32       <arg choice="opt" rep="repeat">OPTIONS</arg>
  33       <arg choice="opt" rep="repeat"><replaceable>CONFIGFILE</replaceable></arg>
  34     </cmdsynopsis>
  35
  36     <para>System units:
  37 <literallayout><filename>systemd-tmpfiles-setup.service</filename>
  38 <filename>systemd-tmpfiles-setup-dev.service</filename>
  39 <filename>systemd-tmpfiles-clean.service</filename>
  40 <filename>systemd-tmpfiles-clean.timer</filename></literallayout></para>
  41
  42     <para>User units:
  43 <literallayout><filename>systemd-tmpfiles-setup.service</filename>
  44 <filename>systemd-tmpfiles-clean.service</filename>
  45 <filename>systemd-tmpfiles-clean.timer</filename></literallayout></para>
  46   </refsynopsisdiv>
  47
  48   <refsect1>
  49     <title>Description</title>
  50
  51     <para><command>systemd-tmpfiles</command> creates, deletes, and cleans up volatile and temporary files
  52     and directories, using the configuration file format and location specified in
  53     <citerefentry><refentrytitle>tmpfiles.d</refentrytitle><manvolnum>5</manvolnum></citerefentry>. It must
  54     be invoked with one or more options <option>--create</option>, <option>--remove</option>, and
  55     <option>--clean</option>, to select the respective subset of operations.</para>
  56
  57     <para>By default, directives from all configuration files are applied. When invoked with
  58     <option>--replace=<replaceable>PATH</replaceable></option>, arguments specified on the command line are
  59     used instead of the configuration file <replaceable>PATH</replaceable>. Otherwise, if one or more
  60     absolute filenames are passed on the command line, only the directives in these files are applied. If
  61     <literal>-</literal> is specified instead of a filename, directives are read from standard input. If only
  62     the basename of a configuration file is specified, all configuration directories as specified in
  63     <citerefentry><refentrytitle>tmpfiles.d</refentrytitle><manvolnum>5</manvolnum></citerefentry> are
  64     searched for a matching file and the file found that has the highest priority is executed.</para>
  65
  66     <para>System services (<filename>systemd-tmpfiles-setup.service</filename>,
  67     <filename>systemd-tmpfiles-setup-dev.service</filename>,
  68     <filename>systemd-tmpfiles-clean.service</filename>) invoke <command>systemd-tmpfiles</command> to create
  69     system files and to perform system wide cleanup. Those services read administrator-controlled
  70     configuration files in <filename>tmpfiles.d/</filename> directories. User services
  71     (<filename>systemd-tmpfiles-setup.service</filename>,
  72     <filename>systemd-tmpfiles-clean.service</filename>) also invoke <command>systemd-tmpfiles</command>, but
  73     it reads a separate set of files, which includes user-controlled files under
  74     <filename>~/.config/user-tmpfiles.d/</filename> and <filename>~/.local/share/user-tmpfiles.d/</filename>,
  75     and administrator-controlled files under <filename>/usr/share/user-tmpfiles.d/</filename>. Users may use
  76     this to create and clean up files under their control, but the system instance performs global cleanup
  77     and is not influenced by user configuration. Note that this means a time-based cleanup configured in the
  78     system instance, such as the one typically configured for <filename>/tmp/</filename>, will thus also
  79     affect files created by the user instance if they are placed in <filename>/tmp/</filename>, even if the
  80     user instance's time-based cleanup is turned off.</para>
  81
  82     <para>To re-apply settings after configuration has been modified, simply restart
  83     <filename>systemd-tmpfiles-clean.service</filename>, which will apply any settings which can be safely
  84     executed at runtime. To debug <command>systemd-tmpfiles</command>, it may be useful to invoke it
  85     directly from the command line with increased log level (see <varname>$SYSTEMD_LOG_LEVEL</varname>
  86     below).</para>
  87   </refsect1>
  88
  89   <refsect1>
  90     <title>Options</title>
  91
  92     <para>The following options are understood:</para>
  93
  94     <variablelist>
  95       <varlistentry>
  96         <term><option>--create</option></term>
  97         <listitem><para>If this option is passed, all files and
  98         directories marked with
  99         <varname>f</varname>,
 100         <varname>F</varname>,
 101         <varname>w</varname>,
 102         <varname>d</varname>,
 103         <varname>D</varname>,
 104         <varname>v</varname>,
 105         <varname>p</varname>,
 106         <varname>L</varname>,
 107         <varname>c</varname>,
 108         <varname>b</varname>,
 109         <varname>m</varname>
 110         in the configuration files are created or written to. Files
 111         and directories marked with
 112         <varname>z</varname>,
 113         <varname>Z</varname>,
 114         <varname>t</varname>,
 115         <varname>T</varname>,
 116         <varname>a</varname>, and
 117         <varname>A</varname> have their ownership, access mode and
 118         security labels set.</para></listitem>
 119       </varlistentry>
 120
 121       <varlistentry>
 122         <term><option>--clean</option></term>
 123         <listitem><para>If this option is passed, all files and
 124         directories with an age parameter configured will be cleaned
 125         up.</para></listitem>
 126       </varlistentry>
 127
 128       <varlistentry>
 129         <term><option>--remove</option></term>
 130         <listitem><para>If this option is passed, the contents of
 131         directories marked with <varname>D</varname> or
 132         <varname>R</varname>, and files or directories themselves
 133         marked with <varname>r</varname> or <varname>R</varname> are
 134         removed unless an exclusive or shared BSD lock is taken on them (see <citerefentry
 135         project='man-pages'><refentrytitle>flock</refentrytitle><manvolnum>2</manvolnum></citerefentry>).
 136         </para></listitem>
 137       </varlistentry>
 138
 139       <varlistentry>
 140         <term><option>--user</option></term>
 141         <listitem><para>Execute "user" configuration, i.e. <filename>tmpfiles.d</filename>
 142         files in user configuration directories.</para></listitem>
 143       </varlistentry>
 144
 145       <varlistentry>
 146         <term><option>--boot</option></term>
 147         <listitem><para>Also execute lines with an exclamation mark. Lines that are not safe to be executed
 148         on a running system may be marked in this way. <command>systemd-tmpfiles</command> is executed in
 149         early boot with <option>--boot</option> specified and will execute those lines. When invoked again
 150         later, it should be called without <option>--boot</option>.</para></listitem>
 151       </varlistentry>
 152
 153       <varlistentry>
 154         <term><option>--graceful</option></term>
 155         <listitem><para>Ignore configuration lines pertaining to unknown users or groups. This option is
 156         intended to be used in early boot before all users or groups have been created.</para></listitem>
 157       </varlistentry>
 158
 159       <varlistentry>
 160         <term><option>--prefix=<replaceable>path</replaceable></option></term>
 161         <listitem><para>Only apply rules with paths that start with
 162         the specified prefix. This option can be specified multiple
 163         times.</para></listitem>
 164       </varlistentry>
 165
 166       <varlistentry>
 167         <term><option>--exclude-prefix=<replaceable>path</replaceable></option></term>
 168         <listitem><para>Ignore rules with paths that start with the
 169         specified prefix. This option can be specified multiple
 170         times.</para></listitem>
 171       </varlistentry>
 172
 173       <varlistentry>
 174         <term><option>-E</option></term>
 175         <listitem><para>A shortcut for <literal>--exclude-prefix=/dev --exclude-prefix=/proc
 176         --exclude-prefix=/run --exclude-prefix=/sys</literal>, i.e. exclude the hierarchies typically backed
 177         by virtual or memory file systems. This is useful in combination with <option>--root=</option>, if
 178         the specified directory tree contains an OS tree without these virtual/memory file systems mounted
 179         in, as it is typically not desirable to create any files and directories below these subdirectories
 180         if they are supposed to be overmounted during runtime.</para></listitem>
 181       </varlistentry>
 182
 183       <varlistentry>
 184         <term><option>--root=<replaceable>root</replaceable></option></term>
 185         <listitem><para>Takes a directory path as an argument. All paths will be prefixed with the given alternate
 186         <replaceable>root</replaceable> path, including config search paths.</para>
 187
 188         <para>When this option is used, the libc Name Service Switch (NSS) is bypassed for resolving users
 189         and groups. Instead the files <filename>/etc/passwd</filename> and <filename>/etc/group</filename>
 190         inside the alternate root are read directly. This means that users/groups not listed in these files
 191         will not be resolved, i.e. LDAP NIS and other complex databases are not considered.</para>
 192
 193         <para>Consider combining this with <option>-E</option> to ensure the invocation does not create files
 194         or directories below mount points in the OS image operated on that are typically overmounted during
 195         runtime.</para></listitem>
 196       </varlistentry>
 197
 198       <varlistentry>
 199         <term><option>--image=<replaceable>image</replaceable></option></term>
 200
 201         <listitem><para>Takes a path to a disk image file or block device node. If specified all operations
 202         are applied to file system in the indicated disk image. This is similar to <option>--root=</option>
 203         but operates on file systems stored in disk images or block devices. The disk image should either
 204         contain just a file system or a set of file systems within a GPT partition table, following the
 205         <ulink url="https://uapi-group.org/specifications/specs/discoverable_partitions_specification">Discoverable Partitions
 206         Specification</ulink>. For further information on supported disk images, see
 207         <citerefentry><refentrytitle>systemd-nspawn</refentrytitle><manvolnum>1</manvolnum></citerefentry>'s
 208         switch of the same name.</para>
 209
 210         <para>Implies <option>-E</option>.</para></listitem>
 211       </varlistentry>
 212
 213       <xi:include href="standard-options.xml" xpointer="image-policy-open" />
 214
 215       <varlistentry>
 216         <term><option>--replace=<replaceable>PATH</replaceable></option></term>
 217         <listitem><para>When this option is given, one or more positional arguments
 218         must be specified. All configuration files found in the directories listed in
 219         <citerefentry><refentrytitle>tmpfiles.d</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 220         will be read, and the configuration given on the command line will be
 221         handled instead of and with the same priority as the configuration file
 222         <replaceable>PATH</replaceable>.</para>
 223
 224         <para>This option is intended to be used when package installation scripts
 225         are running and files belonging to that package are not yet available on
 226         disk, so their contents must be given on the command line, but the admin
 227         configuration might already exist and should be given higher priority.
 228         </para></listitem>
 229       </varlistentry>
 230
 231       <xi:include href="standard-options.xml" xpointer="cat-config" />
 232       <xi:include href="standard-options.xml" xpointer="no-pager" />
 233       <xi:include href="standard-options.xml" xpointer="help" />
 234       <xi:include href="standard-options.xml" xpointer="version" />
 235     </variablelist>
 236
 237     <para>It is possible to combine <option>--create</option>, <option>--clean</option>, and <option>--remove</option>
 238     in one invocation (in which case removal and cleanup are executed before creation of new files). For example,
 239     during boot the following command line is executed to ensure that all temporary and volatile directories are
 240     removed and created according to the configuration file:</para>
 241
 242     <programlisting>systemd-tmpfiles --remove --create</programlisting>
 243   </refsect1>
 244
 245   <refsect1>
 246     <title>Credentials</title>
 247
 248     <para><command>systemd-tmpfiles</command> supports the service credentials logic as implemented by
 249     <varname>LoadCredential=</varname>/<varname>SetCredential=</varname> (see
 250     <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>1</manvolnum></citerefentry> for
 251     details). The following credentials are used when passed in:</para>
 252
 253     <variablelist>
 254       <varlistentry>
 255         <term><literal>tmpfiles.extra</literal></term>
 256
 257         <listitem><para> The contents of this credential may contain additional lines to operate on. The
 258         credential contents should follow the same format as any other <filename>tmpfiles.d/</filename>
 259         drop-in configuration file. If this credential is passed it is processed after all of the drop-in
 260         files read from the file system. The lines in the credential can hence augment existing lines of the
 261         OS, but not override them.</para></listitem>
 262       </varlistentry>
 263     </variablelist>
 264
 265     <para>Note that by default the <filename>systemd-tmpfiles-setup.service</filename> unit file (and related
 266     unit files) is set up to inherit the <literal>tmpfiles.extra</literal> credential from the service
 267     manager.</para>
 268   </refsect1>
 269
 270   <refsect1>
 271     <title>Environment</title>
 272
 273     <variablelist class='environment-variables'>
 274       <xi:include href="common-variables.xml" xpointer="log-level" />
 275       <xi:include href="common-variables.xml" xpointer="log-color" />
 276       <xi:include href="common-variables.xml" xpointer="log-time" />
 277       <xi:include href="common-variables.xml" xpointer="log-location" />
 278       <xi:include href="common-variables.xml" xpointer="log-target" />
 279       <xi:include href="common-variables.xml" xpointer="pager" />
 280       <xi:include href="common-variables.xml" xpointer="less" />
 281       <xi:include href="common-variables.xml" xpointer="lesscharset" />
 282       <xi:include href="common-variables.xml" xpointer="lesssecure" />
 283       <xi:include href="common-variables.xml" xpointer="colors" />
 284       <xi:include href="common-variables.xml" xpointer="urlify" />
 285     </variablelist>
 286   </refsect1>
 287
 288   <refsect1>
 289     <title>Unprivileged --cleanup operation</title>
 290
 291     <para><command>systemd-tmpfiles</command> tries to avoid changing
 292     the access and modification times on the directories it accesses,
 293     which requires <constant>CAP_FOWNER</constant> privileges. When
 294     running as non-root, directories which are checked for files to
 295     clean up will have their access time bumped, which might prevent
 296     their cleanup.
 297     </para>
 298   </refsect1>
 299
 300   <refsect1>
 301     <title>Exit status</title>
 302
 303     <para>On success, 0 is returned. If the configuration was syntactically invalid (syntax errors, missing
 304     arguments, …), so some lines had to be ignored, but no other errors occurred, <constant>65</constant> is
 305     returned (<constant>EX_DATAERR</constant> from <filename>/usr/include/sysexits.h</filename>). If the
 306     configuration was syntactically valid, but could not be executed (lack of permissions, creation of files
 307     in missing directories, invalid contents when writing to <filename>/sys/</filename> values, …),
 308     <constant>73</constant> is returned (<constant>EX_CANTCREAT</constant> from
 309     <filename>/usr/include/sysexits.h</filename>). Otherwise, <constant>1</constant> is returned
 310     (<constant>EXIT_FAILURE</constant> from <filename>/usr/include/stdlib.h</filename>).</para>
 311
 312     <para>Note: when creating items, if the target already exists, but is of the wrong type or otherwise does
 313     not match the requested state, and forced operation has not been requested with <literal>+</literal>,
 314     a message is emitted, but the failure is otherwise ignored.</para>
 315   </refsect1>
 316
 317   <refsect1>
 318     <title>See Also</title>
 319     <para>
 320       <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 321       <citerefentry><refentrytitle>tmpfiles.d</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 322     </para>
 323   </refsect1>
 324
 325 </refentry>