man: document NetworkNamespacePath=

2 files changed, 34 insertions, 17 deletions

diff --git a/man/systemd.exec.xml b/man/systemd.exec.xml
index b8843f1ea0..2ed8c38f37 100644
--- a/man/systemd.exec.xml
+++ b/man/systemd.exec.xml
@@ -1100,7 +1100,29 @@ BindReadOnlyPaths=/var/lib/systemd</programlisting>
 
         <para>Note that the implementation of this setting might be impossible (for example if network namespaces are
         not available), and the unit should be written in a way that does not solely rely on this setting for
-        security.</para></listitem>
+        security.</para>
+
+        <para>When this option is used on a socket unit any sockets bound on behalf of this unit will be
+        bound within a private network namespace. This may be combined with
+        <varname>JoinsNamespaceOf=</varname> to listen on sockets inside of network namespaces of other
+        services.</para></listitem>
+      </varlistentry>
+
+      <varlistentry>
+        <term><varname>NetworkNamespacePath=</varname></term>
+
+        <listitem><para>Takes an absolute file system path refererring to a Linux network namespace
+        pseudo-file (i.e. a file like <filename>/proc/$PID/ns/net</filename> or a bind mount or symlink to
+        one). When set the invoked processes are added to the network namespace referenced by that path. The
+        path has to point to a valid namespace file at the moment the processes are forked off. If this
+        option is used <varname>PrivateNetwork=</varname> has no effect. If this option is used together with
+        <varname>JoinsNamespaceOf=</varname> then it only has an effect if this unit is started before any of
+        the listed units that have <varname>PrivateNetwork=</varname> or
+        <varname>NetworkNamespacePath=</varname> configured, as otherwise the network namespace of those
+        units is reused.</para>
+
+        <para>When this option is used on a socket unit any sockets bound on behalf of this unit will be
+        bound within the specified network namespace.</para></listitem>
       </varlistentry>
 
       <varlistentry>
diff --git a/man/systemd.unit.xml b/man/systemd.unit.xml
index 82c63e1609..14418c359f 100644
--- a/man/systemd.unit.xml
+++ b/man/systemd.unit.xml
@@ -728,23 +728,18 @@
       <varlistentry>
         <term><varname>JoinsNamespaceOf=</varname></term>
 
-        <listitem><para>For units that start processes (such as
-        service units), lists one or more other units whose network
-        and/or temporary file namespace to join. This only applies to
-        unit types which support the
-        <varname>PrivateNetwork=</varname> and
+        <listitem><para>For units that start processes (such as service units), lists one or more other units
+        whose network and/or temporary file namespace to join. This only applies to unit types which support
+        the <varname>PrivateNetwork=</varname>, <varname>NetworkNamespacePath=</varname> and
         <varname>PrivateTmp=</varname> directives (see
-        <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>
-        for details). If a unit that has this setting set is started,
-        its processes will see the same <filename>/tmp</filename>,
-        <filename>/var/tmp</filename> and network namespace as one
-        listed unit that is started. If multiple listed units are
-        already started, it is not defined which namespace is joined.
-        Note that this setting only has an effect if
-        <varname>PrivateNetwork=</varname> and/or
-        <varname>PrivateTmp=</varname> is enabled for both the unit
-        that joins the namespace and the unit whose namespace is
-        joined.</para></listitem>
+        <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry> for
+        details). If a unit that has this setting set is started, its processes will see the same
+        <filename>/tmp</filename>, <filename>/var/tmp</filename> and network namespace as one listed unit
+        that is started. If multiple listed units are already started, it is not defined which namespace is
+        joined.  Note that this setting only has an effect if
+        <varname>PrivateNetwork=</varname>/<varname>NetworkNamespacePath=</varname> and/or
+        <varname>PrivateTmp=</varname> is enabled for both the unit that joins the namespace and the unit
+        whose namespace is joined.</para></listitem>
       </varlistentry>
 
       <varlistentry>