Fix behaviour when no cluster command defined

Also tidyup output to 'cssh -L' when no external clusters defined

Changes

@@ -1,3 +1,6 @@
+4.03_02 2014-08-10 Duncan Ferguson <duncan_ferguson@user.sf.net>
+- Fix behaviour when external cluster command is not defined or doesn't exist
+
 4.03_01 2014-07-09 Duncan Ferguson <duncan_ferguson@user.sf.net>
 - Amended host parsing to include alternative IPv6 address port definitions, e.g. 1::2::3::4/5567
 - List available external tags with -L option and also add into 'Add Host' in UI

META.json

@@ -47,7 +47,7 @@
    "provides" : {
       "App::ClusterSSH" : {
          "file" : "lib/App/ClusterSSH.pm",
-         "version" : "4.03_01"
+         "version" : "4.03_02"
       },
       "App::ClusterSSH::Base" : {
          "file" : "lib/App/ClusterSSH/Base.pm",
@@ -94,5 +94,5 @@
          "http://github.com/duncs/clusterssh"
       ]
    },
-   "version" : "4.03_01"
+   "version" : "4.03_02"
 }

META.yml

@@ -25,7 +25,7 @@ name: App-ClusterSSH
 provides:
   App::ClusterSSH:
     file: lib/App/ClusterSSH.pm
-    version: 4.03_01
+    version: 4.03_02
   App::ClusterSSH::Base:
     file: lib/App/ClusterSSH/Base.pm
     version: 0.02
@@ -62,4 +62,4 @@ resources:
   bugtracker: http://sourceforge.net/tracker/?group_id=89139
   homepage: http://clusterssh.sourceforge.net/
   license: http://dev.perl.org/licenses/
-version: 4.03_01
+version: 4.03_02

lib/App/ClusterSSH.pm

@@ -3,7 +3,7 @@ package App::ClusterSSH;
 use 5.008.004;
 use warnings;
 use strict;
-use version; our $VERSION = version->new('4.03_01');
+use version; our $VERSION = version->new('4.03_02');
 
 use Carp;
 
@@ -1945,8 +1945,11 @@ sub run {
         print( 'Available cluster tags:', $/ );
         print "\t", $_, $/ foreach ( sort( $self->cluster->list_tags ) );
 
+        my @external_clusters = $self->cluster->list_external_clusters;
+        if(@external_clusters) {
             print( 'Available external command tags:', $/ );
-        print "\t", $_, $/ foreach ( sort( $self->cluster->list_external_clusters ) );
+            print "\t", $_, $/ foreach ( sort( @external_clusters ) );
+        }
 
         $self->debug(
             4,

lib/App/ClusterSSH/Cluster.pm

@@ -69,6 +69,11 @@ sub _run_external_clusters {
 
     my $external_command = $self->parent->config->{external_cluster_command};
 
+    if(!$external_command || ! -x $external_command) {
+        $self->debug( 1, 'Cannot run external cluster command: ', $external_command || '');
+        return;
+    }
+
     $self->debug( 3, 'Running tags through external command' );
     $self->debug( 4, 'External command: ', $external_command );
     $self->debug( 3, 'Args ', join( ',', @args ) );

t/30cluster.t

@@ -109,8 +109,7 @@ $expected{tag20} = [ 'host10', ];
 $expected{tag30} = [ 'host10', ];
 $expected{tag40} = [ 'host20', 'host30', ];
 $expected{tag50} = [ 'host30', ];
-$cluster1->read_tag_file( $Bin . '/30cluster.tag1' );
+$cluster1->read_tag_file( $Bin . '/30cluster.tag1' ); test_expected( 'tag 1', %expected );
-test_expected( 'tag 1', %expected );
 
 $cluster1->read_cluster_file( $Bin . '/30cluster.file3' );
 my @default_expected = (qw/ host7 host8 host9 /);
@@ -155,6 +154,22 @@ is_deeply( $count, 10, 'tag list count correct' );
 # now checks against running an external command
 
 my @external_expected;
+
+# text fetching external clusters when no command set or runnable
+#$mock_object->{external_cluster_command} = '/tmp/doesnt_exist';
+trap {
+@external_expected = $cluster1->_run_external_clusters();
+};
+is( $trap->leaveby, 'return', 'non-existant tag returns correctly' );
+is( $trap->stdout,  '',       'no stdout for non-existant get_tag' );
+is( $trap->stderr,  '',       'no stderr for non-existant get_tag' );
+is( $tags,          undef,    'non-existant tag returns undef' );
+@external_expected = $cluster1->list_external_clusters();
+is_deeply( \@external_expected, [],
+    'External command doesnt exist'
+);
+is( scalar $cluster1->list_external_clusters, 0, 'External command failed tag count');
+
 $mock_object->{external_cluster_command} = "$Bin/external_cluster_command";
 
 @external_expected = $cluster1->list_external_clusters();