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diff --git a/man/tmpfiles.d.xml b/man/tmpfiles.d.xml new file mode 100644 index 0000000..971b7e6 --- /dev/null +++ b/man/tmpfiles.d.xml @@ -0,0 +1,910 @@ +<?xml version='1.0'?> +<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN" + "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd"> +<!-- + SPDX-License-Identifier: LGPL-2.1-or-later + + Copyright © 2010 Brandon Philips +--> +<refentry id="tmpfiles.d" + xmlns:xi="http://www.w3.org/2001/XInclude"> + + <refentryinfo> + <title>tmpfiles.d</title> + <productname>systemd</productname> + </refentryinfo> + + <refmeta> + <refentrytitle>tmpfiles.d</refentrytitle> + <manvolnum>5</manvolnum> + </refmeta> + + <refnamediv> + <refname>tmpfiles.d</refname> + <refpurpose>Configuration for creation, deletion and cleaning of + volatile and temporary files</refpurpose> + </refnamediv> + + <refsynopsisdiv> + <para><literallayout><filename>/etc/tmpfiles.d/*.conf</filename> +<filename>/run/tmpfiles.d/*.conf</filename> +<filename>/usr/lib/tmpfiles.d/*.conf</filename> + </literallayout></para> + + <para><literallayout><filename>~/.config/user-tmpfiles.d/*.conf</filename> +<filename>$XDG_RUNTIME_DIR/user-tmpfiles.d/*.conf</filename> +<filename>~/.local/share/user-tmpfiles.d/*.conf</filename> +<filename index='false'>…</filename> +<filename>/usr/share/user-tmpfiles.d/*.conf</filename> + </literallayout></para> + + <programlisting>#Type Path Mode User Group Age Argument +f /file/to/create mode user group - content +f+ /file/to/create-or-truncate mode user group - content +w /file/to/write-to - - - - content +w+ /file/to/append-to - - - - content +d /directory/to/create-and-clean-up mode user group cleanup-age - +D /directory/to/create-and-remove mode user group cleanup-age - +e /directory/to/clean-up mode user group cleanup-age - +v /subvolume-or-directory/to/create mode user group cleanup-age - +q /subvolume-or-directory/to/create mode user group cleanup-age - +Q /subvolume-or-directory/to/create mode user group cleanup-age - +p /fifo/to/create mode user group - - +p+ /fifo/to/[re]create mode user group - - +L /symlink/to/create - - - - symlink/target/path +L+ /symlink/to/[re]create - - - - symlink/target/path +c /dev/char-device-to-create mode user group - major:minor +c+ /dev/char-device-to-[re]create mode user group - major:minor +b /dev/block-device-to-create mode user group - major:minor +b+ /dev/block-device-to-[re]create mode user group - major:minor +C /target/to/create - - - cleanup-age /source/to/copy +C+ /target/to/create - - - cleanup-age /source/to/copy +x /path-or-glob/to/ignore/recursively - - - cleanup-age - +X /path-or-glob/to/ignore - - - cleanup-age - +r /path-or-glob/to/remove - - - - - +R /path-or-glob/to/remove/recursively - - - - - +z /path-or-glob/to/adjust/mode mode user group - - +Z /path-or-glob/to/adjust/mode/recursively mode user group - - +t /path-or-glob/to/set/xattrs - - - - xattrs +T /path-or-glob/to/set/xattrs/recursively - - - - xattrs +h /path-or-glob/to/set/attrs - - - - file attrs +H /path-or-glob/to/set/attrs/recursively - - - - file attrs +a /path-or-glob/to/set/acls - - - - POSIX ACLs +a+ /path-or-glob/to/append/acls - - - - POSIX ACLs +A /path-or-glob/to/set/acls/recursively - - - - POSIX ACLs +A+ /path-or-glob/to/append/acls/recursively - - - - POSIX ACLs + +</programlisting> + </refsynopsisdiv> + + <refsect1> + <title>Description</title> + + <para><filename>tmpfiles.d</filename> configuration files provide a generic mechanism to define the + <emphasis>creation</emphasis> of regular files, directories, pipes, and device nodes, adjustments to + their <emphasis>access mode, ownership, attributes, quota assignments, and contents</emphasis>, and + finally their time-based <emphasis>removal</emphasis>. It is mostly commonly used for volatile and + temporary files and directories (such as those located under <filename>/run/</filename>, + <filename>/tmp/</filename>, <filename>/var/tmp/</filename>, the API file systems such as + <filename>/sys/</filename> or <filename>/proc/</filename>, as well as some other directories below + <filename>/var/</filename>).</para> + + <para><citerefentry><refentrytitle>systemd-tmpfiles</refentrytitle><manvolnum>8</manvolnum></citerefentry> + uses this configuration to create volatile files and directories during boot and to do periodic cleanup + afterwards. See + <citerefentry><refentrytitle>systemd-tmpfiles</refentrytitle><manvolnum>8</manvolnum></citerefentry> for + the description of <filename>systemd-tmpfiles-setup.service</filename>, + <filename>systemd-tmpfiles-clean.service</filename>, and associated units.</para> + + <para>System daemons frequently require private runtime directories below <filename>/run/</filename> to + store communication sockets and similar. For these, it is better to use + <varname>RuntimeDirectory=</varname> in their unit files (see + <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry> for + details), if the flexibility provided by <filename>tmpfiles.d</filename> is not required. The advantages + are that the configuration required by the unit is centralized in one place, and that the lifetime of the + directory is tied to the lifetime of the service itself. Similarly, <varname>StateDirectory=</varname>, + <varname>CacheDirectory=</varname>, <varname>LogsDirectory=</varname>, and + <varname>ConfigurationDirectory=</varname> should be used to create directories under + <filename>/var/lib/</filename>, <filename>/var/cache/</filename>, <filename>/var/log/</filename>, and + <filename>/etc/</filename>. <filename>tmpfiles.d</filename> should be used for files whose lifetime is + independent of any service or requires more complicated configuration.</para> + </refsect1> + + <refsect1> + <title>Configuration Directories and Precedence</title> + + <para>Each configuration file shall be named in the style of + <filename><replaceable>package</replaceable>.conf</filename> or + <filename><replaceable>package</replaceable>-<replaceable>part</replaceable>.conf</filename>. + The second variant should be used when it is desirable to make it + easy to override just this part of configuration.</para> + + <para>Files in <filename>/etc/tmpfiles.d</filename> override files with the same name in + <filename>/usr/lib/tmpfiles.d</filename> and <filename>/run/tmpfiles.d</filename>. Files in + <filename>/run/tmpfiles.d</filename> override files with the same name in + <filename>/usr/lib/tmpfiles.d</filename>. Packages should install their configuration files in + <filename>/usr/lib/tmpfiles.d</filename>. Files in <filename>/etc/tmpfiles.d</filename> are reserved for + the local administrator, who may use this logic to override the configuration files installed by vendor + packages. All configuration files are sorted by their filename in lexicographic order, regardless of + which of the directories they reside in. If multiple files specify the same path, the entry in the file + with the lexicographically earliest name will be applied (note that lines suppressed due to the + <literal>!</literal> are filtered before application, meaning that if an early line carries the + exclamation mark and is suppressed because of that, a later line matching in path will be applied). All + other conflicting entries will be logged as errors. When two lines are prefix path and suffix path of + each other, then the prefix line is always created first, the suffix later (and if removal applies to the + line, the order is reversed: the suffix is removed first, the prefix later). Lines that take globs are + applied after those accepting no globs. If multiple operations shall be applied on the same file (such as + ACL, xattr, file attribute adjustments), these are always done in the same fixed order. Except for those + cases, the files/directories are processed in the order they are listed.</para> + + <para>If the administrator wants to disable a configuration file + supplied by the vendor, the recommended way is to place a symlink + to <filename>/dev/null</filename> in + <filename>/etc/tmpfiles.d/</filename> bearing the same filename. + </para> + </refsect1> + + <refsect1> + <title>Configuration File Format</title> + + <para>The configuration format is one line per path, containing type, path, mode, ownership, age, and + argument fields. The lines are separated by newlines, the fields by whitespace:</para> + + <programlisting>#Type Path Mode User Group Age Argument… +d /run/user 0755 root root 10d - +L /tmp/foobar - - - - /dev/null</programlisting> + + <para>Fields may contain C-style escapes. With the exception of the seventh field (the "argument") all + fields may be enclosed in quotes. Note that any whitespace found in the line after the beginning of the + argument field will be considered part of the argument field. To begin the argument field with a + whitespace character, use C-style escapes (e.g. <literal>\x20</literal>).</para> + + <refsect2> + <title>Type</title> + + <para>The type consists of a single letter and optionally one or more modifier characters: a plus sign + (<literal>+</literal>), exclamation mark (<literal>!</literal>), minus sign (<literal>-</literal>), + equals sign (<literal>=</literal>), tilde character (<literal>~</literal>) and/or caret + (<literal>^</literal>).</para> + + <para>The following line types are understood:</para> + + <variablelist> + <varlistentry> + <term><varname>f</varname></term> + <term><varname>f+</varname></term> + <listitem><para><varname>f</varname> will create a file if it does not exist yet. If the argument + parameter is given and the file did not exist yet, it will be written to the file. + <varname>f+</varname> will create or truncate the file. If the argument parameter is given, it will + be written to the file. Does not follow symlinks.</para></listitem> + </varlistentry> + + <varlistentry> + <term><varname>w</varname></term> + <term><varname>w+</varname></term> + <listitem><para>Write the argument parameter to a file, if the file exists. + If suffixed with <varname>+</varname>, the line will be appended to the file. + If your configuration writes multiple lines to the same file, use <varname>w+</varname>. + Lines of this type accept shell-style globs in place of normal path names. + The argument parameter will be written without a trailing newline. + C-style backslash escapes are interpreted. Follows symlinks.</para></listitem> + </varlistentry> + + <varlistentry> + <term><varname>d</varname></term> + <listitem><para>Create a directory. The mode and ownership will be adjusted if specified. Contents + of this directory are subject to time-based cleanup if the age argument is specified. + </para></listitem> + </varlistentry> + + <varlistentry> + <term><varname>D</varname></term> + <listitem><para>Similar to <varname>d</varname>, but in addition the contents of the directory will + be removed when <option>--remove</option> is used.</para></listitem> + </varlistentry> + + <varlistentry> + <term><varname>e</varname></term> + <listitem><para>Adjust the mode and ownership of existing directories and remove their contents + based on age. Lines of this type accept shell-style globs in place of normal path names. Contents + of the directories are subject to time-based cleanup if the age argument is specified. If the age + argument is <literal>0</literal>, contents will be unconditionally deleted every time + <citerefentry><refentrytitle>systemd-tmpfiles</refentrytitle><manvolnum>8</manvolnum></citerefentry> + <option>--clean</option> is run.</para> + + <para>For this entry to be useful, at least one of the mode, user, group, or age arguments must be + specified, since otherwise this entry has no effect. As an exception, an entry with no effect may + be useful when combined with <varname>!</varname>, see the examples.</para> + + <xi:include href="version-info.xml" xpointer="v230"/></listitem> + </varlistentry> + + <varlistentry> + <term><varname>v</varname></term> + <listitem><para>Create a subvolume if the path does not exist yet, the file system supports + subvolumes (btrfs), and the system itself is installed into a subvolume (specifically: the root + directory <filename>/</filename> is itself a subvolume). Otherwise, create a normal directory, in + the same way as <varname>d</varname>.</para> + + <para>A subvolume created with this line type is not assigned to any higher-level quota group. For + that, use <varname>q</varname> or <varname>Q</varname>, which allow creating simple quota group + hierarchies, see below.</para> + + <xi:include href="version-info.xml" xpointer="v219"/></listitem> + </varlistentry> + + <varlistentry> + <term><varname>q</varname></term> + <listitem><para>Create a subvolume or directory the same as <varname>v</varname>, but assign the + subvolume to the same higher-level quota groups as the parent. This ensures that higher-level + limits and accounting applied to the parent subvolume also include the specified subvolume. On + non-btrfs file systems, this line type is identical to <varname>d</varname>.</para> + + <para>If the subvolume already exists, no change to the quota hierarchy is made, regardless of whether the + subvolume is already attached to a quota group or not. Also see <varname>Q</varname> below. See + <citerefentry project='url'><refentrytitle url='https://btrfs.readthedocs.io/en/latest/btrfs-qgroup.html'>btrfs-qgroup</refentrytitle><manvolnum>8</manvolnum></citerefentry> + for details about the btrfs quota group concept.</para> + + <xi:include href="version-info.xml" xpointer="v228"/></listitem> + </varlistentry> + + <varlistentry> + <term><varname>Q</varname></term> + <listitem><para>Create the subvolume or directory the same as <varname>v</varname>, but assign the + new subvolume to a new leaf quota group. Instead of copying the higher-level quota group + assignments from the parent as is done with <varname>q</varname>, the lowest quota group of the + parent subvolume is determined that is not the leaf quota group. Then, an "intermediary" quota + group is inserted that is one level below this level, and shares the same ID part as the specified + subvolume. If no higher-level quota group exists for the parent subvolume, a new quota group at + level 255 sharing the same ID as the specified subvolume is inserted instead. This new intermediary + quota group is then assigned to the parent subvolume's higher-level quota groups, and the specified + subvolume's leaf quota group is assigned to it.</para> + + <para>Effectively, this has a similar effect as <varname>q</varname>, however introduces a new higher-level + quota group for the specified subvolume that may be used to enforce limits and accounting to the specified + subvolume and children subvolume created within it. Thus, by creating subvolumes only via + <varname>q</varname> and <varname>Q</varname>, a concept of "subtree quotas" is implemented. Each subvolume + for which <varname>Q</varname> is set will get a "subtree" quota group created, and all child subvolumes + created within it will be assigned to it. Each subvolume for which <varname>q</varname> is set will not get + such a "subtree" quota group, but it is ensured that they are added to the same "subtree" quota group as + their immediate parents.</para> + + <para>It is recommended to use <varname>Q</varname> for subvolumes that typically contain further subvolumes, + and where it is desirable to have accounting and quota limits on all child subvolumes together. Examples for + <varname>Q</varname> are typically <filename>/home/</filename> or <filename>/var/lib/machines/</filename>. In + contrast, <varname>q</varname> should be used for subvolumes that either usually do not include further + subvolumes or where no accounting and quota limits are needed that apply to all child subvolumes + together. Examples for <varname>q</varname> are typically <filename>/var/</filename> or + <filename>/var/tmp/</filename>. </para> + + <para>As with <varname>q</varname>, <varname>Q</varname> has no effect on the quota group hierarchy if the + subvolume already exists, regardless of whether the subvolume already belong to a quota group or not. + </para> + + <xi:include href="version-info.xml" xpointer="v228"/></listitem> + </varlistentry> + + <varlistentry> + <term><varname>p</varname></term> + <term><varname>p+</varname></term> + <listitem><para>Create a named pipe (FIFO) if it does not + exist yet. If suffixed with <varname>+</varname> and a file + already exists where the pipe is to be created, it will be + removed and be replaced by the pipe.</para></listitem> + </varlistentry> + + <varlistentry> + <term><varname>L</varname></term> + <term><varname>L+</varname></term> + <listitem><para>Create a symlink if it does not exist + yet. If suffixed with <varname>+</varname> and a file or + directory already exists where the symlink is to be created, + it will be removed and be replaced by the symlink. If the + argument is omitted, symlinks to files with the same name + residing in the directory + <filename>/usr/share/factory/</filename> are created. Note + that permissions and ownership on symlinks are ignored. + </para></listitem> + </varlistentry> + + <varlistentry> + <term><varname>c</varname></term> + <term><varname>c+</varname></term> + <listitem><para>Create a character device node if it does + not exist yet. If suffixed with <varname>+</varname> and a + file already exists where the device node is to be created, + it will be removed and be replaced by the device node. It is + recommended to suffix this entry with an exclamation mark to + only create static device nodes at boot, as udev will not + manage static device nodes that are created at runtime. + </para></listitem> + </varlistentry> + + <varlistentry> + <term><varname>b</varname></term> + <term><varname>b+</varname></term> + <listitem><para>Create a block device node if it does not + exist yet. If suffixed with <varname>+</varname> and a file + already exists where the device node is to be created, it + will be removed and be replaced by the device node. It is + recommended to suffix this entry with an exclamation mark to + only create static device nodes at boot, as udev will not + manage static device nodes that are created at runtime. + </para></listitem> + </varlistentry> + + <varlistentry> + <term><varname>C</varname></term> + <term><varname>C+</varname></term> + <listitem><para>Recursively copy a file or directory, if the destination files or directories do + not exist yet or the destination directory is empty. Note that this command will not descend into + subdirectories if the destination directory already exists and is not empty, unless the action is + suffixed with <varname>+</varname>. Instead, the entire copy operation is skipped. If the argument + is omitted, files from the source directory <filename>/usr/share/factory/</filename> with the same + name are copied. Does not follow symlinks. Contents of the directories are subject to time-based + cleanup if the age argument is specified. + </para> + + <xi:include href="version-info.xml" xpointer="v214"/></listitem> + </varlistentry> + + <varlistentry> + <term><varname>x</varname></term> + <listitem><para>Ignore a path during cleaning. Use this type + to exclude paths from clean-up as controlled with the Age + parameter. Note that lines of this type do not influence the + effect of <varname>r</varname> or <varname>R</varname> + lines. Lines of this type accept shell-style globs in place + of normal path names. </para></listitem> + </varlistentry> + + <varlistentry> + <term><varname>X</varname></term> + <listitem><para>Ignore a path during cleaning. Use this type + to exclude paths from clean-up as controlled with the Age + parameter. Unlike <varname>x</varname>, this parameter will + not exclude the content if path is a directory, but only + directory itself. Note that lines of this type do not + influence the effect of <varname>r</varname> or + <varname>R</varname> lines. Lines of this type accept + shell-style globs in place of normal path names. + </para> + + <xi:include href="version-info.xml" xpointer="v198"/></listitem> + </varlistentry> + + <varlistentry> + <term><varname>r</varname></term> + <listitem><para>Remove a file or directory if it exists. + This may not be used to remove non-empty directories, use + <varname>R</varname> for that. Lines of this type accept + shell-style globs in place of normal path + names. Does not follow symlinks.</para></listitem> + </varlistentry> + + <varlistentry> + <term><varname>R</varname></term> + <listitem><para>Recursively remove a path and all its + subdirectories (if it is a directory). Lines of this type + accept shell-style globs in place of normal path + names. Does not follow symlinks.</para></listitem> + </varlistentry> + + <varlistentry> + <term><varname>z</varname></term> + <listitem><para>Adjust the access mode, user and group ownership, and restore the SELinux security + context of a file or directory, if it exists. Lines of this type accept shell-style globs in place + of normal path names. Does not follow symlinks.</para></listitem> + </varlistentry> + + <varlistentry> + <term><varname>Z</varname></term> + <listitem><para>Recursively set the access mode, user and group ownership, and restore the SELinux + security context of a file or directory if it exists, as well as of its subdirectories and the + files contained therein (if applicable). Lines of this type accept shell-style globs in place of + normal path names. Does not follow symlinks.</para></listitem> + </varlistentry> + + <varlistentry> + <term><varname>t</varname></term> + <listitem><para>Set extended attributes, see <citerefentry + project='man-pages'><refentrytitle>attr</refentrytitle> + <manvolnum>5</manvolnum></citerefentry> for details. The argument field should take one or more + assignment expressions in the form + <replaceable>namespace</replaceable>.<replaceable>attribute</replaceable>=<replaceable>value</replaceable>, + for examples see below. Lines of this type accept shell-style globs in place of normal path + names. This can be useful for setting SMACK labels. Does not follow symlinks.</para> + + <para>Please note that extended attributes settable with this line type are a different concept + from the Linux file attributes settable with <varname>h</varname>/<varname>H</varname>, see + below.</para> + + <xi:include href="version-info.xml" xpointer="v218"/></listitem> + </varlistentry> + + <varlistentry> + <term><varname>T</varname></term> + <listitem><para>Same as <varname>t</varname>, but operates recursively.</para> + + <xi:include href="version-info.xml" xpointer="v219"/></listitem> + </varlistentry> + + <varlistentry> + <term><varname>h</varname></term> + <listitem><para>Set Linux file/directory attributes. Lines of this type accept shell-style globs in + place of normal path names.</para> + + <para>The format of the argument field is <varname>[+-=][aAcCdDeijPsStTu]</varname>. The prefix + <varname>+</varname> (the default one) causes the attributes to be added; <varname>-</varname> + causes the attributes to be removed; <varname>=</varname> causes the attributes to be set exactly + as the following letters. The letters <literal>aAcCdDeijPsStTu</literal> select the new attributes + for the files, see <citerefentry project='man-pages'><refentrytitle>chattr</refentrytitle> + <manvolnum>1</manvolnum></citerefentry> for further information. + </para> + + <para>Passing only <varname>=</varname> as argument resets all the file attributes listed above. It + has to be pointed out that the <varname>=</varname> prefix limits itself to the attributes + corresponding to the letters listed here. All other attributes will be left untouched. Does not + follow symlinks.</para> + + <para>Please note that the Linux file attributes settable with this line type are a different + concept from the extended attributes settable with <varname>t</varname>/<varname>T</varname>, + see above.</para></listitem> + </varlistentry> + + <varlistentry> + <term><varname>H</varname></term> + <listitem><para>Sames as <varname>h</varname>, but operates recursively.</para> + + <xi:include href="version-info.xml" xpointer="v220"/></listitem> + </varlistentry> + + <varlistentry> + <term><varname>a</varname></term> + <term><varname>a+</varname></term> + <listitem><para>Set POSIX ACLs (access control lists), see + <citerefentry project='man-pages'><refentrytitle>acl</refentrytitle><manvolnum>5</manvolnum></citerefentry>. + Additionally, if 'X' is used, the execute bit is set only if the file is a directory or already has + execute permission for some user, as mentioned in + <citerefentry project='man-pages'><refentrytitle>setfacl</refentrytitle><manvolnum>1</manvolnum></citerefentry>. + If suffixed with <varname>+</varname>, the specified entries will be added to the existing set. + <citerefentry><refentrytitle>systemd-tmpfiles</refentrytitle><manvolnum>8</manvolnum></citerefentry> + will automatically add the required base entries for user and group based on the access mode of the + file, unless base entries already exist or are explicitly specified. The mask will be added if not + specified explicitly or already present. Lines of this type accept shell-style globs in place of + normal path names. This can be useful for allowing additional access to certain files. Does not + follow symlinks.</para> + + <xi:include href="version-info.xml" xpointer="v219"/></listitem> + </varlistentry> + + <varlistentry> + <term><varname>A</varname></term> + <term><varname>A+</varname></term> + <listitem><para>Same as <varname>a</varname> and + <varname>a+</varname>, but recursive. Does not follow + symlinks.</para> + + <xi:include href="version-info.xml" xpointer="v219"/></listitem> + </varlistentry> + </variablelist> + </refsect2> + + <refsect2> + <title>Type Modifiers</title> + + <para>If the exclamation mark (<literal>!</literal>) is used, this line is only safe to execute during + boot, and can break a running system. Lines without the exclamation mark are presumed to be safe to + execute at any time, e.g. on package upgrades. + <citerefentry><refentrytitle>systemd-tmpfiles</refentrytitle><manvolnum>8</manvolnum></citerefentry> + will take lines with an exclamation mark only into consideration, if the <option>--boot</option> option + is given.</para> + + <para>For example: + <programlisting># Make sure these are created by default so that nobody else can +d /tmp/.X11-unix 1777 root root 10d + +# Unlink the X11 lock files +r! /tmp/.X[0-9]*-lock</programlisting> + The second line in contrast to the first one would break a + running system, and will only be executed with + <option>--boot</option>.</para> + + <para>If the minus sign (<literal>-</literal>) is used, this line failing to run successfully during + create (and only create) will not cause the execution of <command>systemd-tmpfiles</command> to return + an error.</para> + + <para>For example: + <programlisting># Modify sysfs but don't fail if we are in a container with a read-only /proc +w- /proc/sys/vm/swappiness - - - - 10</programlisting></para> + + <para>If the equals sign (<literal>=</literal>) is used, the file types of existing objects in the specified path + are checked, and removed if they do not match. This includes any implicitly created parent directories (which can + be either directories or directory symlinks). For example, if there is a FIFO in place of one of the parent path + components it will be replaced with a directory.</para> + + <para>If the tilde character (<literal>~</literal>) is used, the argument (i.e. 6th) column is <ulink + url="https://www.rfc-editor.org/rfc/rfc4648.html">Base64 decoded</ulink> before use. This modifier is + only supported on line types that can write file contents, i.e. <varname>f</varname>, + <varname>f+</varname>, <varname>w</varname>, <varname>+</varname>. This is useful for writing arbitrary + binary data (including newlines and NUL bytes) to files. Note that if this switch is used, the argument + is not subject to specifier expansion, neither before nor after Base64 decoding.</para> + + <para>If the caret character (<literal>^</literal>) is used, the argument (i.e. 6th) column takes a + service credential name to read the argument data from. See <ulink + url="https://systemd.io/CREDENTIALS">System and Service Credentials</ulink> for details about the + credentials concept. This modifier is only supported on line types that can write file contents, + i.e. <varname>f</varname>, <varname>f+</varname>, <varname>w</varname>, <varname>w+</varname>. This is + useful for writing arbitrary files with contents sourced from elsewhere, including from VM or container + managers further up. If the specified credential is not set for the <command>systemd-tmpfiles</command> + service, the line is silently skipped. If <literal>^</literal> and <literal>~</literal> are combined + Base64 decoding is applied to the credential contents.</para> + + <para>Note that for all line types that result in creation of any kind of file node + (i.e. <varname>f</varname>/<varname>F</varname>, + <varname>d</varname>/<varname>D</varname>/<varname>v</varname>/<varname>q</varname>/<varname>Q</varname>, + <varname>p</varname>, <varname>L</varname>, <varname>c</varname>/<varname>b</varname> and <varname>C</varname>) + leading directories are implicitly created if needed, owned by root with an access mode of 0755. In order to + create them with different modes or ownership make sure to add appropriate <varname>d</varname> lines.</para> + </refsect2> + + <refsect2> + <title>Path</title> + + <para>The file system path specification supports simple + specifier expansion, see below. The path (after expansion) must be + absolute.</para> + </refsect2> + + <refsect2> + <title>Mode</title> + + <para>The file access mode to use when creating this file or directory. If omitted or when set to + <literal>-</literal>, the default is used: 0755 for directories, 0644 for all other file objects. For + <varname>z</varname>, <varname>Z</varname> lines, if omitted or when set to <literal>-</literal>, the + file access mode will not be modified. This parameter is ignored for <varname>x</varname>, + <varname>r</varname>, <varname>R</varname>, <varname>L</varname>, <varname>t</varname>, and + <varname>a</varname> lines.</para> + + <para>Optionally, if prefixed with <literal>~</literal>, the access mode is masked based on the already + set access bits for existing file or directories: if the existing file has all executable bits unset, + all executable bits are removed from the new access mode, too. Similarly, if all read bits are removed + from the old access mode, they will be removed from the new access mode too, and if all write bits are + removed, they will be removed from the new access mode too. In addition, the sticky/SUID/SGID bit is + removed unless applied to a directory. This functionality is particularly useful in conjunction with + <varname>Z</varname>.</para> + + <para>By default the access mode of listed inodes is set to the specified mode regardless if it is + created anew, or already existed. Optionally, if prefixed with <literal>:</literal>, the configured + access mode is only applied when creating new inodes, and if the inode the line refers to + already exists, its access mode is left in place unmodified.</para> + </refsect2> + + <refsect2> + <title>User, Group</title> + + <para>The user and group to use for this file or directory. This may either be a numeric ID or a + user/group name. If omitted or when set to <literal>-</literal>, the user and group of the user who + invokes + <citerefentry><refentrytitle>systemd-tmpfiles</refentrytitle><manvolnum>8</manvolnum></citerefentry> is + used. For <varname>z</varname> and <varname>Z</varname> lines, when omitted or when set to + <literal>-</literal>, the file ownership will not be modified. These parameters are ignored for + <varname>x</varname>, <varname>r</varname>, <varname>R</varname>, <varname>L</varname>, + <varname>t</varname>, and <varname>a</varname> lines.</para> + + <para>This field should generally only reference system users/groups, i.e. users/groups that are + guaranteed to be resolvable during early boot. If this field references users/groups that only become + resolveable during later boot (i.e. after NIS, LDAP or a similar networked directory service become + available), execution of the operations declared by the line will likely fail. Also see <ulink + url="https://systemd.io/UIDS-GIDS/#notes-on-resolvability-of-user-and-group-names">Notes on + Resolvability of User and Group Names</ulink> for more information on requirements on system user/group + definitions.</para> + + <para>By default the ownership of listed inodes is set to the specified user/group regardless if it is + created anew, or already existed. Optionally, if prefixed with <literal>:</literal>, the configured + user/group information is only applied when creating new inodes, and if the inode the line refers to + already exists, its user/group is left in place unmodified.</para> + </refsect2> + + <refsect2> + <title>Age</title> + + <para>The date field, when set, is used to decide what files to + delete when cleaning. If a file or directory is older than the + current time minus the age field, it is deleted. The field + format is a series of integers each followed by one of the + following suffixes for the respective time units: + <constant>s</constant>, + <constant>m</constant> or <constant>min</constant>, + <constant>h</constant>, + <constant>d</constant>, + <constant>w</constant>, + <constant>ms</constant>, and + <constant>us</constant>, + meaning seconds, minutes, hours, days, weeks, + milliseconds, and microseconds, respectively. Full names of the time units can + be used too. + </para> + + <para>If multiple integers and units are specified, the time + values are summed. If an integer is given without a unit, + <constant>s</constant> is assumed. + </para> + + <para>When the age is set to zero, the files are cleaned + unconditionally.</para> + + <para>The age field only applies to lines starting with + <varname>d</varname>, <varname>D</varname>, <varname>e</varname>, + <varname>v</varname>, <varname>q</varname>, + <varname>Q</varname>, <varname>C</varname>, <varname>x</varname> + and <varname>X</varname>. If omitted or set to + <literal>-</literal>, no automatic clean-up is done.</para> + + <para>If the age field starts with a tilde character <literal>~</literal>, clean-up is only applied to + files and directories one level inside the directory specified, but not the files and directories + immediately inside it.</para> + + <para>The age of a file system entry is determined from its last + modification timestamp (mtime), its last access timestamp (atime), + and (except for directories) its last status change timestamp + (ctime). By default, any of these three (or two) values will + prevent cleanup if it is more recent than the current time minus + the age field. To restrict the deletion based on particular type + of file timestamps, the age-by argument can be used.</para> + + <para>The age-by argument overrides the timestamp types to be used for the age check. It can be + specified by prefixing the age argument with a sequence of characters to specify the timestamp types + and a colon (<literal>:</literal>): + <literal><replaceable>age-by</replaceable>...:<replaceable>cleanup-age</replaceable></literal>. The + argument can consist of <constant>a</constant> (<constant>A</constant> for directories), + <constant>b</constant> (<constant>B</constant> for directories), <constant>c</constant> + (<constant>C</constant> for directories), or <constant>m</constant> (<constant>M</constant> for + directories). Those respectively indicate access, creation, last status change, and last modification + time of a file system entry. The lower-case letter signifies that the given timestamp type should be + considered for files, while the upper-case letter signifies that the given timestamp type should be + considered for directories. See <citerefentry + project='man-pages'><refentrytitle>statx</refentrytitle><manvolnum>2</manvolnum></citerefentry> file + timestamp fields for more details about timestamp types.</para> + + <para>If not specified, the age-by field defaults to <constant>abcmABM</constant>, i.e. by default all + file timestamps are taken into consideration, with the exception of the last status change timestamp + (ctime) for directories. This is because the aging logic itself will alter the ctime whenever it + deletes a file inside it. To ensure that running the aging logic does not feed back into the next + iteration of itself, ctime for directories is ignored by default.</para> + + <para>For example:<programlisting> +# Files created and modified, and directories accessed more than +# an hour ago in "/tmp/foo/bar", are subject to time-based cleanup. +d /tmp/foo/bar - - - bmA:1h -</programlisting></para> + + <para>Note that while the aging algorithm is run an exclusive BSD file lock (see <citerefentry + project='man-pages'><refentrytitle>flock</refentrytitle><manvolnum>2</manvolnum></citerefentry>) is + taken on each directory/file the algorithm decides to remove. If the aging algorithm finds a lock + (shared or exclusive) is already taken on some directory/file, it (and everything below it) is skipped. + Applications may use this to temporarily exclude certain directory subtrees from the aging algorithm: + the applications can take a BSD file lock themselves, and as long as they keep it aging of the + directory/file and everything below it is disabled.</para> + + <para>This behavior can be used to ensure guaranteed cleanup of files or directories whose lifetime + should be aligned with the process that created them by having that process create them in a location + monitored by <command>systemd-tmpfiles</command> with an age of <literal>0</literal>, and having the + process immediately lock the directory or file before using it. Because the BSD lock is process + specific, the file is guaranteed to be unlocked as soon as the process exits, meaning that even if the + process crashes, those files and directories will be unlocked and cleaned up by + <command>systemd-tmpfiles</command>.</para> + </refsect2> + + <refsect2> + <title>Argument</title> + + <para>For <varname>L</varname> lines determines the destination path of the symlink. For <varname>c</varname> and + <varname>b</varname>, determines the major/minor of the device node, with major and minor formatted as integers, + separated by <literal>:</literal>, e.g. <literal>1:3</literal>. For <varname>f</varname>, <varname>F</varname>, + and <varname>w</varname>, the argument may be used to specify a short string that is written to the file, + suffixed by a newline. For <varname>C</varname>, specifies the source file or directory. For <varname>t</varname> + and <varname>T</varname>, determines extended attributes to be set. For <varname>a</varname> and + <varname>A</varname>, determines ACL attributes to be set. For <varname>h</varname> and <varname>H</varname>, + determines the file attributes to set. Ignored for all other lines.</para> + + <para>This field can contain specifiers, see below.</para> + </refsect2> + </refsect1> + + <refsect1> + <title>Specifiers</title> + + <para>Specifiers can be used in the "path" and "argument" fields. + An unknown or unresolvable specifier is treated as invalid configuration. + 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"/> + <row> + <entry><literal>%C</literal></entry> + <entry>System or user cache directory</entry> + <entry>In <option>--user</option> mode, this is the same as <varname>$XDG_CACHE_HOME</varname>, and <filename>/var/cache</filename> otherwise.</entry> + </row> + <row> + <entry><literal>%g</literal></entry> + <entry>User group</entry> + <entry>This is the name of the group running the command. In case of the system instance this resolves to <literal>root</literal>.</entry> + </row> + <row> + <entry><literal>%G</literal></entry> + <entry>User GID</entry> + <entry>This is the numeric GID of the group running the command. In case of the system instance this resolves to <constant>0</constant>.</entry> + </row> + <row> + <entry><literal>%h</literal></entry> + <entry>User home directory</entry> + <entry>This is the home directory of the user running the command. In case of the system instance this resolves to <literal>/root</literal>.</entry> + </row> + <xi:include href="standard-specifiers.xml" xpointer="H"/> + <xi:include href="standard-specifiers.xml" xpointer="l"/> + <row> + <entry><literal>%L</literal></entry> + <entry>System or user log directory</entry> + <entry>In <option>--user</option> mode, this is the same as <varname>$XDG_STATE_HOME</varname> with <filename index="false">/log</filename> appended, and <filename>/var/log</filename> otherwise.</entry> + </row> + <xi:include href="standard-specifiers.xml" xpointer="m"/> + <xi:include href="standard-specifiers.xml" xpointer="M"/> + <xi:include href="standard-specifiers.xml" xpointer="o"/> + <row> + <entry><literal>%S</literal></entry> + <entry>System or user state directory</entry> + <entry>In <option>--user</option> mode, this is the same as <varname>$XDG_STATE_HOME</varname>, and <filename>/var/lib</filename> otherwise.</entry> + </row> + <row> + <entry><literal>%t</literal></entry> + <entry>System or user runtime directory</entry> + <entry>In <option>--user</option> mode, this is the same <varname>$XDG_RUNTIME_DIR</varname>, and <filename>/run/</filename> otherwise.</entry> + </row> + <xi:include href="standard-specifiers.xml" xpointer="T"/> + <row> + <entry><literal>%u</literal></entry> + <entry>User name</entry> + <entry>This is the name of the user running the command. In case of the system instance this resolves to <literal>root</literal>.</entry> + </row> + <row> + <entry><literal>%U</literal></entry> + <entry>User UID</entry> + <entry>This is the numeric UID of the user running the command. In case of the system instance this resolves to <constant>0</constant>.</entry> + </row> + <xi:include href="standard-specifiers.xml" xpointer="v"/> + <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="percent"/> + </tbody> + </tgroup> + </table> + </refsect1> + + <refsect1> + <title>Examples</title> + <example> + <title>Create directories with specific mode and ownership</title> + <para> + <citerefentry project='die-net'><refentrytitle>screen</refentrytitle><manvolnum>1</manvolnum></citerefentry>, + needs two directories created at boot with specific modes and ownership:</para> + + <programlisting># /usr/lib/tmpfiles.d/screen.conf +d /run/screens 1777 root screen 10d +d /run/uscreens 0755 root screen 10d12h +</programlisting> + + <para>Contents of <filename>/run/screens</filename> and /run/uscreens will + be cleaned up after 10 and 10½ days, respectively.</para> + </example> + + <example> + <title>Create a directory with a SMACK attribute</title> + <programlisting>D /run/cups - - - - +t /run/cups - - - - security.SMACK64=printing user.attr-with-spaces="foo bar" + </programlisting> + + <para>The directory will be owned by root and have default mode. Its contents are + not subject to time-based cleanup, but will be obliterated when + <command>systemd-tmpfiles --remove</command> runs.</para> + </example> + + <example> + <title>Create a directory and prevent its contents from cleanup</title> + <para> + <citerefentry project='die-net'><refentrytitle>abrt</refentrytitle><manvolnum>1</manvolnum></citerefentry>, + needs a directory created at boot with specific mode and ownership and its content + should be preserved from the automatic cleanup applied to the contents of + <filename>/var/tmp</filename>:</para> + + <programlisting># /usr/lib/tmpfiles.d/tmp.conf +d /var/tmp 1777 root root 30d +</programlisting> + + <programlisting># /usr/lib/tmpfiles.d/abrt.conf +d /var/tmp/abrt 0755 abrt abrt - +</programlisting> + </example> + + <example> + <title>Apply clean up during boot and based on time</title> + + <programlisting># /usr/lib/tmpfiles.d/dnf.conf +r! /var/cache/dnf/*/*/download_lock.pid +r! /var/cache/dnf/*/*/metadata_lock.pid +r! /var/lib/dnf/rpmdb_lock.pid +e /var/cache/dnf/ - - - 30d +</programlisting> + + <para>The lock files will be removed during boot. Any files and directories in + <filename>/var/cache/dnf/</filename> will be removed after they have not been + accessed in 30 days.</para> + </example> + + <example> + <title>Empty the contents of a cache directory on boot</title> + + <programlisting># /usr/lib/tmpfiles.d/krb5rcache.conf +e! /var/cache/krb5rcache - - - 0 +</programlisting> + + <para>Any files and subdirectories in <filename>/var/cache/krb5rcache/</filename> + will be removed on boot. The directory will not be created. + </para> + </example> + + <example> + <title>Provision SSH public key access for root user via Credentials in QEMU</title> + + <programlisting>-smbios type=11,value=io.systemd.credential.binary:tmpfiles.extra=$(echo "f~ /root/.ssh/authorized_keys 700 root root - $(ssh-add -L | base64 -w 0)" | base64 -w 0) +</programlisting> + + <para>By passing this line to QEMU, the public key of the current user will be encoded in base64, added + to a tmpfiles.d line that tells <command>systemd-tmpfiles</command> to decode it into + <filename>/root/.ssh/authorized_keys</filename>, encode that line itself in base64 and pass it as a + Credential that will be picked up by systemd from SMBIOS on boot. + </para> + </example> + </refsect1> + + <refsect1> + <title><filename>/run/</filename> and <filename>/var/run/</filename></title> + <para><filename>/var/run/</filename> is a deprecated symlink to <filename>/run/</filename>, and + applications should use the latter. <command>systemd-tmpfiles</command> will warn if + <filename>/var/run/</filename> is used.</para> + </refsect1> + + <refsect1> + <title>See Also</title> + <para> + <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>, + <citerefentry><refentrytitle>systemd-tmpfiles</refentrytitle><manvolnum>8</manvolnum></citerefentry>, + <citerefentry><refentrytitle>systemd-delta</refentrytitle><manvolnum>1</manvolnum></citerefentry>, + <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>, + <citerefentry project='man-pages'><refentrytitle>attr</refentrytitle><manvolnum>5</manvolnum></citerefentry>, + <citerefentry project='man-pages'><refentrytitle>getfattr</refentrytitle><manvolnum>1</manvolnum></citerefentry>, + <citerefentry project='man-pages'><refentrytitle>setfattr</refentrytitle><manvolnum>1</manvolnum></citerefentry>, + <citerefentry project='man-pages'><refentrytitle>setfacl</refentrytitle><manvolnum>1</manvolnum></citerefentry>, + <citerefentry project='man-pages'><refentrytitle>getfacl</refentrytitle><manvolnum>1</manvolnum></citerefentry>, + <citerefentry project='man-pages'><refentrytitle>chattr</refentrytitle><manvolnum>1</manvolnum></citerefentry>, + <citerefentry project='url'><refentrytitle url='https://btrfs.readthedocs.io/en/latest/btrfs-subvolume.html'>btrfs-subvolume</refentrytitle><manvolnum>8</manvolnum></citerefentry>, + <citerefentry project='url'><refentrytitle url='https://btrfs.readthedocs.io/en/latest/btrfs-qgroup.html'>btrfs-qgroup</refentrytitle><manvolnum>8</manvolnum></citerefentry> + </para> + </refsect1> + +</refentry> |