man: systemd.journal-fields: document _SYSTEMD_INVOCATION_ID (#5316)

#4067 added documentation to systemd.exec(5), but not systemd.journal-fields(7).

diff --git a/man/systemd.journal-fields.xml b/man/systemd.journal-fields.xml
index 494f97a..2b0acee 100644 (file)
--- a/man/systemd.journal-fields.xml
+++ b/man/systemd.journal-fields.xml
@@ -243,6 +243,16 @@
       </varlistentry>
 
       <varlistentry>
+        <term><varname>_SYSTEMD_INVOCATION_ID=</varname></term>
+        <listitem>
+          <para>The invocation ID for the runtime cycle of the unit
+          the message was generated in, as available to processes
+          of the unit in <varname>$INVOCATION_ID</varname> (see
+          <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>).</para>
+        </listitem>
+      </varlistentry>
+
+      <varlistentry>
         <term><varname>_HOSTNAME=</varname></term>
         <listitem>
           <para>The name of the originating host.</para>