On Thu, 2025-03-06 at 19:10 -0500, Benjamin Marzinski wrote: > Add a section with information about how to communicate with the > multipathd daemon to the man page. Also mention that multipathd > CLI commands can be run without the -k option. > > Signed-off-by: Benjamin Marzinski <bmarzins@xxxxxxxxxx> Reviewed-by: Martin Wilck <mwilck@xxxxxxxx> > --- > multipathd/multipathd.8.in | 31 +++++++++++++++++++++++++++++++ > 1 file changed, 31 insertions(+) > > diff --git a/multipathd/multipathd.8.in b/multipathd/multipathd.8.in > index 315884eb..5b1aeb42 100644 > --- a/multipathd/multipathd.8.in > +++ b/multipathd/multipathd.8.in > @@ -83,6 +83,11 @@ multipathd executes the given command (see > \fBCOMMANDS\fR below). If the > command contains whitespace or shell special characters, it needs to > be quoted > like in \fImultipathd -k'show topology'\fR. No whitespace is allowed > between > the \fB-k\fR and the command string. > + > +Commands can also be issued without using \fB-k\fR. In this case, > the command > +string should not be quoted. Command arguments that contain > whitespace or > +special characters still need to be quoted, like in \fImultipathd > show paths > +format "%n %w"\fR > . > .TP > .B \-k > @@ -103,6 +108,32 @@ multipath devices on dmevents. Use this flag to > force it to use the old event > waiting method, based on creating a separate thread for each device. > . > . > +.\" ---------------------------------------------------------------- > ------------ > +.SH COMMUNICATING WITH MULTIPATHD > +.\" ---------------------------------------------------------------- > ------------ > + > +In addition to the multipathd CLI, the \fBlibmpathcmd\fR library can > be used to > +send commands (see \fBCOMMANDS\fR below) to the multipathd daemon > from other > +programs. By default, multipathd listens on both the > \fI@ABSTRACT_SOCKET@\fR > +abstract namespace socket and the \fI@PATHNAME_SOCKET@\fR socket > file. > +libmpathcmd will use either of these sockets to connect to > multipathd. The > +socket file can be useful to communicate with multipathd from > different > +namespaces since it can be bind mounted in them, unlike the abstract > namespace > +socket. Multipathd will accept \fBlist|show\fR commands from any > user. All > +other commands must be issued by root. > + > +It is possible to change the sockets that multipathd listens on. If > +\fImultipathd.socket\fR is running, multipathd will use the sockets > it listens > +on. A maximum of two sockets can be defined by > \fImultipathd.socket\fR, and by > +default it listens on \fI@ABSTRACT_SOCKET@\fR and > \fI@PATHNAME_SOCKET@\fR. If > +\fImultipathd.socket\fR is not running, a single socket can be > configured for > +listening on by setting the \fIMULTIPATH_SOCKET_NAME\fR environment > variable > +when starting multipathd. This environment variable must also be set > to make > +multipathd CLI commands (or any other program using libmpathcmd) > connect to the > +multipathd daemon using a non-default socket, regardless of whether > that socket > +was set for the daemon using \fImultipathd.socket\fR or the > +\fIMULTIPATH_SOCKET_NAME\fR environment variable. > +. > . > .\" ---------------------------------------------------------------- > ------------ > .SH COMMANDS
