* Add Informix plugin for concurrent session counting contributed by …

…Ralph Grothe

node/node.d/ifx_concurrent_sessions_.in

@@ -0,0 +1,175 @@
+#!@@PERL@@ -Tw
+#
+#%# family=contrib
+#%# capabilities=autoconf suggest
+
+=head1 NAME
+
+ifx_concurrent_sessions_ - Munin wildcard plug-in that connects to
+Informix instance and counts number of concurrent sessions from
+syssqlstat view of sysmaster of instance.
+
+=head1 APPLICABLE SYSTEMS
+
+Connects over the network to Informix databases.  Uses informix
+commands to connect to the databases so these must be present on the
+munin-node it runs on.
+
+=head1 CONFIGURATION
+
+As Informix installations can vary wildly the autoconf may fail.
+However, it is recommended to let munin-node-configure set the plugin
+links by e.g.
+
+   # @@SBINDIR@@/munin-node-configure --families contrib --shell |
+     grep concurrent | sh -
+
+Yet, for this plugin to work it is most likely required to grant
+select to the user the munin-node runs this plugin as.  This usually
+requires to login as user "informix" and execute the following
+command:
+
+   $ echo "grant select on syssqlstat to munin as informix" |
+     INFORMIXDIR=/path/to/ifx_base INFORMIXSERVER=inst_name dbaccess sysmaster
+
+The value of INFORMIXSERVER usually equals to that of DBSERVERNAME in
+the $INFORMIXDIR/etc/onconfig file.
+
+=head1 VERSION
+
+ $Id: $
+
+=head1 BUGS
+
+May not autoconfigure correctly as noted above.
+
+=head1 AUTHOR
+
+Contributed by <ralph dot grothe at itdz minus berlin dot de>
+
+=head1 LICENSE
+
+GPLv2
+
+=cut
+
+use strict;
+use File::Find;  # In perl 5 since the start
+
+my @infdir;
+if (@ARGV && $ARGV[0] =~ /autoconf|suggest/) {
+    # Taint mode requires this
+    local $ENV{PATH} = '/usr/bin';
+    # First, try lookup in proc table
+    # Note, this will only work if oninit was started with full path
+    # On Linux we could easily retreive INFORMIXDIR from /proc by
+    # tr \\00 \\012 < /proc/$PID/environ | grep INFORMIXDIR
+    # Following ps command should work on Linux and Solaris
+    my $pscmd = '/usr/bin/ps -p `/usr/bin/pgrep -P1 oninit -d,` -o ppid= -o args=';
+    # while HP-UX discerns itself once more
+    $pscmd = 'UNIX95= /usr/bin/ps -C oninit -o ppid= -o args='
+    	if ($^O =~ /hp-?ux/i);
+    @infdir = map $_->[1],
+	grep $_->[0]==1,
+	map [m|(\d+)\s+(\S+)/bin|],
+	qx($pscmd);
+
+    # Second, try lookup in filesystem Might also fail if we cannot
+    # run find as root However, an oninit binary must exist somewhere
+    # but for sanity reasons we restrict find to /opt and /usr. Note,
+    # if this aborts with Perl Taint mode errors try removing -T in
+    # shebang
+
+    unless (@infdir) {
+	no warnings; # to hush single usage of File::Find::name warning
+	File::Find::find(sub { -f $_ && -r _ && /^oninit\z/s
+				 && push @infdir,
+				   $File::Find::name =~ m[(\S+)/bin]},
+			 qw(/opt /usr));
+    }
+
+    if ($ARGV[0] eq 'autoconf') {
+	if (@infdir) {
+	    print "yes\n";
+	    exit;
+	}
+	else {
+	    print "no (Could not find oninit on this host)\n";
+	    exit 1;
+	}
+    }
+
+    if ($ARGV[0] eq 'suggest') {
+	# Here we need to retreive INFORMIXSERVER
+	# Common Informix installations stick to $INFORMIXDIR/etc/onconfig
+	foreach my $dir (@infdir) {
+	    local *ONCONFIG;
+	    my $onconfig = "$dir/etc/onconfig";
+	    next unless -f $onconfig && -r _;
+	    open ONCONFIG, $onconfig or die "Couldn't open $onconfig\n";
+	    my ($infsrv) = grep /^\s*DBSERVERNAME/sm, <ONCONFIG>;
+	    close ONCONFIG;
+
+	    # The directory separator must be replaced by some shell
+	    # immune unusual character Note, munin-run (as probably
+	    # munin-node) only permit "." as remaining valid character
+	    $dir =~ tr,/,.,;
+
+	    # Store INFORMIXDIR and INFORMIXSERVER in the symlink's
+	    # basename This releives the user from having to export
+	    # these via plugins.conf entries in matching instance
+	    # sections but leads to ugly link names
+	    print "$dir.$1\n" if $infsrv =~ /DBSERVERNAME\s+(\S+)/;
+	}
+    }
+    exit;
+}
+
+# Retreive vital Informix environment from plugin's name
+@ENV{qw(INFORMIXDIR INFORMIXSERVER)} = $0 =~ /[^.]+(.+)\.(.+)/;
+$ENV{INFORMIXDIR} =~ tr,.,/,;
+$ENV{PATH} = "$ENV{INFORMIXDIR}/bin";
+
+# Plugin's config section
+if (@ARGV && $ARGV[0] =~ /config/i) {
+	my $config = qq{
+	    graph_title Number of Concurrent Sessions of $ENV{INFORMIXSERVER}
+	    graph_category Informix
+	    graph_vlabel Number
+            graph_info Number of concurrent sessions to $ENV{INFORMIXSERVER}. Note that a constant value of -1 indicates missing grantsfor the plugin user (often "munin") on syssqlstat view.
+	    sessions.label Sessions
+	    sessions.type GAUGE
+	};
+	$config =~ s/^\s+//gm;
+	print $config;
+	exit;
+}
+
+#printf "%s\n%s\n", @ENV{qw(INFORMIXDIR INFORMIXSERVER)};exit;
+
+# Usually redundant double check
+#local *SQLHOSTS;
+#my $SQLHOSTS = "$ENV{INFORMIXDIR}/etc/sqlhosts";
+#open SQLHOSTS, $SQLHOSTS or die "Cannot open $SQLHOSTS\n";
+#my ($infpar) = map [(split /\s+/, $_)[0,2]],
+#	       grep /$IFX_INSTT/, <SQLHOSTS>;
+#close SQLHOSTS;
+
+#$ENV{INFORMIXSERVER} = $infpar->[0];
+
+# Actual SQL statement to count sessions
+# Could be easily replaced by any other valid Sysmaster query to extend plugin
+
+my $query = q{select count(*) from syssqlstat where sqs_dbname != '-';};
+
+local *DBACCESS;
+open DBACCESS, "echo \"$query\"|dbaccess sysmaster 2>/dev/null|"
+    or die "Cannot open reading pipe from dbaccess\n";
+my ($sessions) = grep /^\s*\d+\s*$/sm, <DBACCESS>;
+close DBACCESS;
+
+# Of course, we need to subtract our own session. Note, that constant
+# output of -1 often indicates lack of select grant on syssqlstat view
+# to the user the munin-node runs this plugin as (usually munin)
+
+print 'sessions.value ', $sessions ? --$sessions : 'U', "\n";