Add in external_command_pipe

Allow for specific commands to be passed into cssh via a command pipe.
This will allow for adding in new sessions and retiling existing
sessions.

More commands may be added over time.

Changes

@@ -1,6 +1,7 @@
 4.10_03 0000-00-00 Duncan Ferguson <duncan_ferguson@user.sf.net>
 - Fix for multiple range expansion, as in 'h{a,b}{1,2}' (Github issue #97) (Thanks to lazyfrosch)
 - Upgrade Perl::Tidy requirement to version 20171214 (Github issue #99) (Thanks to eserte)
+- Add in 'external command pipe' to allow for some commands being passed in from the command line
 
 4.10_02 2017-08-08 Duncan Ferguson <duncan_ferguson@user.sf.net>
 - Include coverage tests in the resources

lib/App/ClusterSSH.pm

@@ -171,6 +171,22 @@ sub exit_prog() {
     my ($self) = @_;
     $self->debug( 3, "Exiting via normal routine" );
 
+    if ( $self->config->{external_command_pipe}
+        && -e $self->config->{external_command_pipe} )
+    {
+        close( $self->{external_command_pipe_fh} )
+            or warn(
+            "Could not close pipe "
+                . $self->config->{external_command_pipe} . ": ",
+            $!
+            );
+        $self->debug( 2, "Removing external command pipe" );
+        unlink( $self->config->{external_command_pipe} )
+            || warn "Could not unlink "
+            . $self->config->{external_command_pipe}
+            . ": ", $!;
+    }
+
     # for each of the client windows, send a kill.
     # to make sure we catch all children, even when they haven't
     # finished starting or received the kill signal, do it like this
@@ -1435,6 +1451,35 @@ sub setup_repeat() {
                 $self->config->{internal_count}
             );
 
+            # See if there are any commands in the external command pipe
+            {
+                my $ext_cmd;
+                sysread( $self->{external_command_pipe_fh}, $ext_cmd, 400 );
+                if ($ext_cmd) {
+                    my @external_commands = split( /\n/, $ext_cmd );
+                    for my $cmd_line (@external_commands) {
+                        chomp($cmd_line);
+                        my ( $cmd, @tags ) = split /\s+/, $cmd_line;
+                        $self->debug( 2,
+                            "Got external command: $cmd -> @tags" );
+
+                        for ($cmd) {
+                            if (m/^open$/) {
+                                my @new_hosts = $self->resolve_names(@tags);
+                                $self->open_client_windows(@new_hosts);
+                                $self->build_hosts_menu();
+                                last;
+                            }
+                            if (m/^retile$/) {
+                                $self->retile_hosts();
+                                last;
+                            }
+                            warn "Unknown external command: $cmd_line", $/;
+                        }
+                    }
+                }
+            }
+
 #$self->debug( 3, "Number of servers in hash is: ", scalar( keys(%servers) ) );
 
             foreach my $svr ( keys(%servers) ) {
@@ -2233,6 +2278,44 @@ sub run {
     $windows{main_window}->positionfrom('user')
         ;    # user puts it somewhere, leave it there
 
+    # set up external command pipe
+    if ( $self->config->{external_command_pipe} ) {
+
+        if ( -e $self->config->{external_command_pipe} ) {
+            $self->debug( 1, "Removing pre-existing external command pipe" );
+            unlink( $self->config->{external_command_pipe} )
+                or die(
+                "Could not remove "
+                    . $self->config->{external_command_pipe}
+                    . " prior to creation: "
+                    . $!,
+                $/
+                );
+        }
+
+        $self->debug( 2, "Creating external command pipe" );
+
+        mkfifo(
+            $self->config->{external_command_pipe},
+            oct( $self->config->{external_command_mode} )
+            )
+            or die(
+            "Could not create "
+                . $self->config->{external_command_pipe} . ": ",
+            $!
+            );
+
+        sysopen(
+            $self->{external_command_pipe_fh},
+            $self->config->{external_command_pipe},
+            O_NONBLOCK | O_RDONLY
+            )
+            or die(
+            "Could not open " . $self->config->{external_command_pipe} . ": ",
+            $!
+            );
+    }
+
     $self->debug( 2, "Setting up repeat" );
     $self->setup_repeat();
 

lib/App/ClusterSSH/Config.pm

@@ -77,6 +77,8 @@ my %default_config = (
     extra_tag_file           => '',
     extra_cluster_file       => '',
     external_cluster_command => '',
+    external_command_mode    => '0600',
+    external_command_pipe    => '',
 
     unmap_on_redraw => "no",    # Debian #329440
 

lib/App/ClusterSSH/Getopt.pm

@@ -675,6 +675,22 @@ would replace the <Alt-n> with the client's name in each window.}
         q{Set the initial position of the console - if empty then let the window manager decide.  Format is '+<x>+<y>', i.e. '+0+0' is top left hand corner of the screen, '+0-70' is bottom left hand side of screen (more or less).}
     );
 
+    output '=item external_command_mode = 0600';
+    output $self->loc(q{File mode bits for the external_command_pipe.});
+
+    output '=item external_command_pipe = <null>';
+    output $self->loc(
+        q{Define the full path to an external command pipe that can be written to for controlling some aspects of ClusterSSH, such as opening sessions to more clusters.
+
+Commands:
+
+C<< open <tag|hostname> >> - open new sessions to provided tag or hostname
+
+C<< retile >> - force window retiling
+    
+e.g.: C<< echo 'open localhost' >> /path/to/external_command_pipe >>}
+    );
+
     output '=item external_cluster_command = <null>';
     output $self->loc(
         q{Define the full path to an external command that can be used to resolve tags to host names.  This command can be written in any language.  The script must accept a list of tags to resolve and output a list of hosts (space separated on a single line).  Any tags that cannot be resolved should be returned unchanged.

t/15config.t

@@ -88,6 +88,8 @@ Readonly::Hash my %default_config => {
     extra_tag_file           => "",
     extra_cluster_file       => "",
     external_cluster_command => '',
+    external_command_mode    => '0600',
+    external_command_pipe    => '',
 
     unmap_on_redraw => "no",
 
@@ -547,6 +549,8 @@ console=console
 console_args=
 console_position=
 external_cluster_command=
+external_command_mode=0600
+external_command_pipe=
 extra_cluster_file=
 extra_tag_file=
 fillscreen=no