| <?xml version='1.0'?> <!--*-nxml-*--> |
| <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN" |
| "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd"> |
| |
| <!-- |
| This file is part of systemd. |
| |
| Copyright 2010 Lennart Poettering |
| |
| systemd is free software; you can redistribute it and/or modify it |
| under the terms of the GNU Lesser General Public License as published by |
| the Free Software Foundation; either version 2.1 of the License, or |
| (at your option) any later version. |
| |
| systemd is distributed in the hope that it will be useful, but |
| WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| Lesser General Public License for more details. |
| |
| You should have received a copy of the GNU Lesser General Public License |
| along with systemd; If not, see <http://www.gnu.org/licenses/>. |
| --> |
| |
| <refentry id="systemd.journal-fields"> |
| |
| <refentryinfo> |
| <title>systemd.journal-fields</title> |
| <productname>systemd</productname> |
| |
| <authorgroup> |
| <author> |
| <contrib>Developer</contrib> |
| <firstname>Lennart</firstname> |
| <surname>Poettering</surname> |
| <email>lennart@poettering.net</email> |
| </author> |
| </authorgroup> |
| </refentryinfo> |
| |
| <refmeta> |
| <refentrytitle>systemd.journal-fields</refentrytitle> |
| <manvolnum>7</manvolnum> |
| </refmeta> |
| |
| <refnamediv> |
| <refname>systemd.journal-fields</refname> |
| <refpurpose>Special journal fields</refpurpose> |
| </refnamediv> |
| |
| <refsect1> |
| <title>Description</title> |
| |
| <para>Entries in the journal resemble an environment |
| block in their syntax, however with fields that can |
| include binary data. Primarily, fields are formatted |
| UTF-8 text strings, and binary formatting is used only |
| where formatting as UTF-8 text strings makes little |
| sense. New fields may freely be defined by |
| applications, but a few fields have special |
| meaning. All fields with special meanings are |
| optional. In some cases fields may appear more than |
| once per entry.</para> |
| </refsect1> |
| |
| <refsect1> |
| <title>User Journal Fields</title> |
| |
| <para>User fields are fields that are directly passed |
| from clients and stored in the journal.</para> |
| |
| <variablelist class='journal-directives'> |
| <varlistentry> |
| <term><varname>MESSAGE=</varname></term> |
| <listitem> |
| <para>The human readable |
| message string for this |
| entry. This is supposed to be |
| the primary text shown to the |
| user. It is usually not |
| translated (but might be in |
| some cases), and is not |
| supposed to be parsed for meta |
| data.</para> |
| </listitem> |
| </varlistentry> |
| |
| <varlistentry> |
| <term><varname>MESSAGE_ID=</varname></term> |
| <listitem> |
| <para>A 128bit message |
| identifier ID for recognizing |
| certain message types, if this |
| is desirable. This should |
| contain a 128bit id formatted |
| as lower-case hexadecimal |
| string, without any separating |
| dashes or suchlike. This is |
| recommended to be a UUID |
| compatible ID, but this is not |
| enforced, and formatted |
| differently. Developers can |
| generate a new ID for this |
| purpose with |
| <command>journalctl |
| --new-id</command>.</para> |
| </listitem> |
| </varlistentry> |
| |
| <varlistentry> |
| <term><varname>PRIORITY=</varname></term> |
| <listitem> |
| <para>A priority value between |
| 0 (<literal>emerg</literal>) |
| and 7 |
| (<literal>debug</literal>) |
| formatted as decimal |
| string. This field is |
| compatible with syslog's |
| priority concept.</para> |
| </listitem> |
| </varlistentry> |
| |
| <varlistentry> |
| <term><varname>CODE_FILE=</varname></term> |
| <term><varname>CODE_LINE=</varname></term> |
| <term><varname>CODE_FUNC=</varname></term> |
| <listitem> |
| <para>The code location |
| generating this message, if |
| known. Contains the source |
| file name, the line number and |
| the function name.</para> |
| </listitem> |
| </varlistentry> |
| |
| <varlistentry> |
| <term><varname>ERRNO=</varname></term> |
| <listitem> |
| <para>The low-level Unix error |
| number causing this entry, if |
| any. Contains the numeric |
| value of |
| <citerefentry><refentrytitle>errno</refentrytitle><manvolnum>3</manvolnum></citerefentry> |
| formatted as decimal |
| string.</para> |
| </listitem> |
| </varlistentry> |
| |
| <varlistentry> |
| <term><varname>SYSLOG_FACILITY=</varname></term> |
| <term><varname>SYSLOG_IDENTIFIER=</varname></term> |
| <term><varname>SYSLOG_PID=</varname></term> |
| <listitem> |
| <para>Syslog compatibility |
| fields containing the facility |
| (formatted as decimal string), |
| the identifier string |
| (i.e. "tag"), and the client |
| PID.</para> |
| </listitem> |
| |
| </varlistentry> |
| </variablelist> |
| </refsect1> |
| |
| <refsect1> |
| <title>Trusted Journal Fields</title> |
| |
| <para>Fields prefixed with an underscore are trusted |
| fields, i.e. fields that are implicitly added by the |
| journal and cannot be altered by client code.</para> |
| |
| <variablelist class='journal-directives'> |
| <varlistentry> |
| <term><varname>_PID=</varname></term> |
| <term><varname>_UID=</varname></term> |
| <term><varname>_GID=</varname></term> |
| <listitem> |
| <para>The process, user and |
| group ID of the process the |
| journal entry originates from |
| formatted as decimal |
| string.</para> |
| </listitem> |
| </varlistentry> |
| |
| <varlistentry> |
| <term><varname>_COMM=</varname></term> |
| <term><varname>_EXE=</varname></term> |
| <term><varname>_CMDLINE=</varname></term> |
| <listitem> |
| <para>The name, the executable |
| path and the command line of |
| the process the journal entry |
| originates from.</para> |
| </listitem> |
| </varlistentry> |
| |
| <varlistentry> |
| <term><varname>_AUDIT_SESSION=</varname></term> |
| <term><varname>_AUDIT_LOGINUID=</varname></term> |
| <listitem> |
| <para>The session and login |
| UID of the process the journal |
| entry originates from, as |
| maintained by the kernel audit |
| subsystem.</para> |
| </listitem> |
| </varlistentry> |
| |
| <varlistentry> |
| <term><varname>_SYSTEMD_CGROUP=</varname></term> |
| <term><varname>_SYSTEMD_SESSION=</varname></term> |
| <term><varname>_SYSTEMD_UNIT=</varname></term> |
| <term><varname>_SYSTEMD_OWNER_UID=</varname></term> |
| |
| <listitem> |
| <para>The contol group path in |
| the systemd hierarchy, the |
| systemd session ID (if any), |
| the systemd unit name (if any) |
| and the owner UID of the |
| systemd session (if any) of |
| the process the journal entry |
| originates from.</para> |
| </listitem> |
| </varlistentry> |
| |
| <varlistentry> |
| <term><varname>_SELINUX_CONTEXT=</varname></term> |
| <listitem> |
| <para>The SELinux security |
| context of the process the |
| journal entry originates |
| from.</para> |
| </listitem> |
| </varlistentry> |
| |
| <varlistentry> |
| <term><varname>_SOURCE_REALTIME_TIMESTAMP=</varname></term> |
| <listitem> |
| <para>The earliest trusted |
| timestamp of the message, if |
| any is known that is different |
| from the reception time of the |
| journal. This is the time in |
| usec since the epoch UTC |
| formatted as decimal |
| string.</para> |
| </listitem> |
| </varlistentry> |
| |
| <varlistentry> |
| <term><varname>_BOOT_ID=</varname></term> |
| <listitem> |
| <para>The kernel boot ID for |
| the boot the message was |
| generated in, formatted as |
| 128bit hexadecimal |
| string.</para> |
| </listitem> |
| </varlistentry> |
| |
| <varlistentry> |
| <term><varname>_MACHINE_ID=</varname></term> |
| <listitem> |
| <para>The machine ID of the |
| originating host, as available |
| in |
| <citerefentry><refentrytitle>machine-id</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para> |
| </listitem> |
| </varlistentry> |
| |
| <varlistentry> |
| <term><varname>_HOSTNAME=</varname></term> |
| <listitem> |
| <para>The name of the |
| originating host.</para> |
| </listitem> |
| </varlistentry> |
| |
| <varlistentry> |
| <term><varname>_TRANSPORT=</varname></term> |
| <listitem> |
| <para>How the entry was |
| received by the journal |
| service. One of |
| <literal>driver</literal>, |
| <literal>syslog</literal>, |
| <literal>journal</literal>, |
| <literal>stdout</literal>, |
| <literal>kernel</literal> for |
| internally generated messages, |
| for those received via the |
| local syslog socket with the |
| syslog protocol, for those |
| received via the native |
| journal protocol, for the |
| those read from a services' |
| standard output or error |
| output, or for those read |
| from the kernel, respectively. |
| </para> |
| </listitem> |
| </varlistentry> |
| </variablelist> |
| </refsect1> |
| |
| <refsect1> |
| <title>Kernel Journal Fields</title> |
| |
| <para>Kernel fields are fields that are used by |
| messages originating in the kernel and stored in the |
| journal.</para> |
| |
| <variablelist> |
| <varlistentry> |
| <term>_KERNEL_DEVICE=</term> |
| <listitem> |
| <para>The kernel device |
| name. If the entry is |
| associated to a block device, |
| the major and minor of the |
| device node, separated by ':' |
| and prefixed by 'b'. Similar |
| for character devices, but |
| prefixed by 'c'. For network |
| devices the interface index, |
| prefixed by 'n'. For all other |
| devices '+' followed by the |
| subsystem name, followed by |
| ':', followed by the kernel |
| device name.</para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term>_KERNEL_SUBSYSTEM=</term> |
| <listitem> |
| <para>The kernel subsystem name.</para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term>_UDEV_SYSNAME=</term> |
| <listitem> |
| <para>The kernel device name |
| as it shows up in the device |
| tree below |
| <filename>/sys</filename>.</para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term>_UDEV_DEVNODE=</term> |
| <listitem> |
| <para>The device node path of |
| this device in |
| <filename>/dev</filename>.</para> |
| </listitem> |
| </varlistentry> |
| <varlistentry> |
| <term>_UDEV_DEVLINK=</term> |
| <listitem> |
| <para>Additional symlink names |
| pointing to the device node in |
| <filename>/dev</filename>. This |
| field is frequently set more |
| than once per entry.</para> |
| </listitem> |
| </varlistentry> |
| </variablelist> |
| </refsect1> |
| |
| <refsect1> |
| <title>Address Fields</title> |
| |
| <para>During serialization into external formats the |
| addresses of journal entries are serialized into |
| fields prefixed with double underscores. Note that |
| these aren't proper fields when stored in the journal, |
| but addressing meta data of entries. They cannot be |
| written as part of structured log entries via calls |
| such as |
| <citerefentry><refentrytitle>sd_journal_send</refentrytitle><manvolnum>3</manvolnum></citerefentry>. They |
| may also not be used as matches for |
| <citerefentry><refentrytitle>sd_journal_add_match</refentrytitle><manvolnum>3</manvolnum></citerefentry></para> |
| |
| <variablelist class='journal-directives'> |
| <varlistentry> |
| <term><varname>__CURSOR=</varname></term> |
| <listitem> |
| <para>The cursor for the |
| entry. A cursor is an opaque |
| text string that uniquely |
| describes the position of an |
| entry in the journal and is |
| portable across machines, |
| platforms and journal |
| files.</para> |
| </listitem> |
| </varlistentry> |
| |
| <varlistentry> |
| <term><varname>__REALTIME_TIMESTAMP=</varname></term> |
| <listitem> |
| <para>The wallclock time |
| (CLOCK_REALTIME) at the point |
| in time the entry was received |
| by the journal, in usec since |
| the epoch UTC formatted as |
| decimal string. This has |
| different properties from |
| <literal>_SOURCE_REALTIME_TIMESTAMP=</literal> |
| as it is usually a bit later |
| but more likely to be |
| monotonic.</para> |
| </listitem> |
| </varlistentry> |
| |
| <varlistentry> |
| <term><varname>__MONOTONIC_TIMESTAMP=</varname></term> |
| <listitem> |
| <para>The monotonic time |
| (CLOCK_MONOTONIC) at the point |
| in time the entry was received |
| by the journal in usec |
| formatted as decimal |
| string. To be useful as an |
| address for the entry this |
| should be combined with with |
| boot ID in |
| <literal>_BOOT_ID=</literal>.</para> |
| </listitem> |
| </varlistentry> |
| </variablelist> |
| </refsect1> |
| |
| <refsect1> |
| <title>See Also</title> |
| <para> |
| <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>, |
| <citerefentry><refentrytitle>journalctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>, |
| <citerefentry><refentrytitle>journald.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>, |
| <citerefentry><refentrytitle>sd-journal</refentrytitle><manvolnum>3</manvolnum></citerefentry> |
| </para> |
| </refsect1> |
| |
| </refentry> |