man/systemd-tmpfiles.xml

   1 <?xml version='1.0'?> <!--*-nxml-*-->
   2 <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
   3   "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
   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.
 148         </para></listitem>
 149       </varlistentry>
 150
 151       <varlistentry>
 152         <term><option>--prefix=<replaceable>path</replaceable></option></term>
 153         <listitem><para>Only apply rules with paths that start with
 154         the specified prefix. This option can be specified multiple
 155         times.</para></listitem>
 156       </varlistentry>
 157
 158       <varlistentry>
 159         <term><option>--exclude-prefix=<replaceable>path</replaceable></option></term>
 160         <listitem><para>Ignore rules with paths that start with the
 161         specified prefix. This option can be specified multiple
 162         times.</para></listitem>
 163       </varlistentry>
 164
 165       <varlistentry>
 166         <term><option>-E</option></term>
 167         <listitem><para>A shortcut for <literal>--exclude-prefix=/dev --exclude-prefix=/proc
 168         --exclude-prefix=/run --exclude-prefix=/sys</literal>, i.e. exclude the hierarchies typically backed
 169         by virtual or memory file systems. This is useful in combination with <option>--root=</option>, if
 170         the specified directory tree contains an OS tree without these virtual/memory file systems mounted
 171         in, as it is typically not desirable to create any files and directories below these subdirectories
 172         if they are supposed to be overmounted during runtime.</para></listitem>
 173       </varlistentry>
 174
 175       <varlistentry>
 176         <term><option>--root=<replaceable>root</replaceable></option></term>
 177         <listitem><para>Takes a directory path as an argument. All paths will be prefixed with the given alternate
 178         <replaceable>root</replaceable> path, including config search paths.</para>
 179
 180         <para>When this option is used, the libc Name Service Switch (NSS) is bypassed for resolving users
 181         and groups. Instead the files <filename>/etc/passwd</filename> and <filename>/etc/group</filename>
 182         inside the alternate root are read directly. This means that users/groups not listed in these files
 183         will not be resolved, i.e. LDAP NIS and other complex databases are not considered.</para>
 184
 185         <para>Consider combining this with <option>-E</option> to ensure the invocation does not create files
 186         or directories below mount points in the OS image operated on that are typically overmounted during
 187         runtime.</para></listitem>
 188       </varlistentry>
 189
 190       <varlistentry>
 191         <term><option>--image=<replaceable>image</replaceable></option></term>
 192
 193         <listitem><para>Takes a path to a disk image file or block device node. If specified all operations
 194         are applied to file system in the indicated disk image. This is similar to <option>--root=</option>
 195         but operates on file systems stored in disk images or block devices. The disk image should either
 196         contain just a file system or a set of file systems within a GPT partition table, following the
 197         <ulink url="https://uapi-group.org/specifications/specs/discoverable_partitions_specification">Discoverable Partitions
 198         Specification</ulink>. For further information on supported disk images, see
 199         <citerefentry><refentrytitle>systemd-nspawn</refentrytitle><manvolnum>1</manvolnum></citerefentry>'s
 200         switch of the same name.</para>
 201
 202         <para>Implies <option>-E</option>.</para></listitem>
 203       </varlistentry>
 204
 205       <xi:include href="standard-options.xml" xpointer="image-policy-open" />
 206
 207       <varlistentry>
 208         <term><option>--replace=<replaceable>PATH</replaceable></option></term>
 209         <listitem><para>When this option is given, one or more positional arguments
 210         must be specified. All configuration files found in the directories listed in
 211         <citerefentry><refentrytitle>tmpfiles.d</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 212         will be read, and the configuration given on the command line will be
 213         handled instead of and with the same priority as the configuration file
 214         <replaceable>PATH</replaceable>.</para>
 215
 216         <para>This option is intended to be used when package installation scripts
 217         are running and files belonging to that package are not yet available on
 218         disk, so their contents must be given on the command line, but the admin
 219         configuration might already exist and should be given higher priority.
 220         </para></listitem>
 221       </varlistentry>
 222
 223       <xi:include href="standard-options.xml" xpointer="cat-config" />
 224       <xi:include href="standard-options.xml" xpointer="no-pager" />
 225       <xi:include href="standard-options.xml" xpointer="help" />
 226       <xi:include href="standard-options.xml" xpointer="version" />
 227     </variablelist>
 228
 229     <para>It is possible to combine <option>--create</option>, <option>--clean</option>, and <option>--remove</option>
 230     in one invocation (in which case removal and cleanup are executed before creation of new files). For example,
 231     during boot the following command line is executed to ensure that all temporary and volatile directories are
 232     removed and created according to the configuration file:</para>
 233
 234     <programlisting>systemd-tmpfiles --remove --create</programlisting>
 235   </refsect1>
 236
 237   <refsect1>
 238     <title>Credentials</title>
 239
 240     <para><command>systemd-tmpfiles</command> supports the service credentials logic as implemented by
 241     <varname>LoadCredential=</varname>/<varname>SetCredential=</varname> (see
 242     <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>1</manvolnum></citerefentry> for
 243     details). The following credentials are used when passed in:</para>
 244
 245     <variablelist>
 246       <varlistentry>
 247         <term><literal>tmpfiles.extra</literal></term>
 248
 249         <listitem><para> The contents of this credential may contain additional lines to operate on. The
 250         credential contents should follow the same format as any other <filename>tmpfiles.d/</filename>
 251         drop-in configuration file. If this credential is passed it is processed after all of the drop-in
 252         files read from the file system. The lines in the credential can hence augment existing lines of the
 253         OS, but not override them.</para></listitem>
 254       </varlistentry>
 255     </variablelist>
 256
 257     <para>Note that by default the <filename>systemd-tmpfiles-setup.service</filename> unit file (and related
 258     unit files) is set up to inherit the <literal>tmpfiles.extra</literal> credential from the service
 259     manager.</para>
 260   </refsect1>
 261
 262   <refsect1>
 263     <title>Environment</title>
 264
 265     <variablelist class='environment-variables'>
 266       <xi:include href="common-variables.xml" xpointer="log-level" />
 267       <xi:include href="common-variables.xml" xpointer="log-color" />
 268       <xi:include href="common-variables.xml" xpointer="log-time" />
 269       <xi:include href="common-variables.xml" xpointer="log-location" />
 270       <xi:include href="common-variables.xml" xpointer="log-target" />
 271       <xi:include href="common-variables.xml" xpointer="pager" />
 272       <xi:include href="common-variables.xml" xpointer="less" />
 273       <xi:include href="common-variables.xml" xpointer="lesscharset" />
 274       <xi:include href="common-variables.xml" xpointer="lesssecure" />
 275       <xi:include href="common-variables.xml" xpointer="colors" />
 276       <xi:include href="common-variables.xml" xpointer="urlify" />
 277     </variablelist>
 278   </refsect1>
 279
 280   <refsect1>
 281     <title>Unprivileged --cleanup operation</title>
 282
 283     <para><command>systemd-tmpfiles</command> tries to avoid changing
 284     the access and modification times on the directories it accesses,
 285     which requires <constant>CAP_FOWNER</constant> privileges. When
 286     running as non-root, directories which are checked for files to
 287     clean up will have their access time bumped, which might prevent
 288     their cleanup.
 289     </para>
 290   </refsect1>
 291
 292   <refsect1>
 293     <title>Exit status</title>
 294
 295     <para>On success, 0 is returned. If the configuration was syntactically invalid (syntax errors, missing
 296     arguments, …), so some lines had to be ignored, but no other errors occurred, <constant>65</constant> is
 297     returned (<constant>EX_DATAERR</constant> from <filename>/usr/include/sysexits.h</filename>). If the
 298     configuration was syntactically valid, but could not be executed (lack of permissions, creation of files
 299     in missing directories, invalid contents when writing to <filename>/sys/</filename> values, …),
 300     <constant>73</constant> is returned (<constant>EX_CANTCREAT</constant> from
 301     <filename>/usr/include/sysexits.h</filename>). Otherwise, <constant>1</constant> is returned
 302     (<constant>EXIT_FAILURE</constant> from <filename>/usr/include/stdlib.h</filename>).</para>
 303
 304     <para>Note: when creating items, if the target already exists, but is of the wrong type or otherwise does
 305     not match the requested state, and forced operation has not been requested with <literal>+</literal>,
 306     a message is emitted, but the failure is otherwise ignored.</para>
 307   </refsect1>
 308
 309   <refsect1>
 310     <title>See Also</title>
 311     <para>
 312       <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 313       <citerefentry><refentrytitle>tmpfiles.d</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 314     </para>
 315   </refsect1>
 316
 317 </refentry>