Add Munin graphing script

svn path=/trunk/scripts/munin/; revision=1788

diff --git a/web/usage.cgi b/web/usage.cgi
new file mode 100755 (executable)
index 0000000..073b34c
--- /dev/null
+++ b/web/usage.cgi
@@ -0,0 +1,75 @@
+#!/usr/bin/perl -wT
+
+use diagnostics;
+use constant GRAPH_DIR => "/var/lib/munin/xvm-prod-hosts.mit.edu";
+use CGI;
+use CGI::Carp qw(fatalsToBrowser);
+use RRDs;
+use File::Spec::Functions;
+
+our %graph_types = (cpu => "xen_cpu");
+our %formats = qw(svg image/svg+xml png image/png eps application/postscript pdf application/pdf);
+
+my @args = (qw(
+--font LEGEND:7:/usr/share/munin/VeraMono.ttf
+--font UNIT:7:/usr/share/munin/VeraMono.ttf
+--font AXIS:7:/usr/share/munin/VeraMono.ttf
+-
+--title), "Domain CPU usage", qw(
+--base 1000
+-r
+--lower-limit 0
+--vertical-label %
+--height 175
+--width 400
+--units-exponent 0));
+
+my $q = new CGI;
+
+my $format = $q->param("format") || "png";
+my $mime_type;
+if (exists($formats{$format})) {
+    $format =~ m|^(\w+)$| or die "Invalid format";
+    $format = $1;
+    $mime_type = $formats{$format};
+} else {
+    die "Invalid format";
+}
+
+push @args, "--imgformat", uc($format);
+
+my $days = $q->param("days") || "8";
+$days =~ m|^(\d+)$| or die "Invalid number of days specified";
+$days = int($1);
+
+my $uuid = $q->param("uuid");
+$uuid =~ m|^([0-9a-f]{8})-([0-9a-f]{4})-([0-9a-f]{4})-([0-9a-f]{4})-([0-9a-f]{12})$| or die "Invalid UUID specified";
+$uuid = "$1_$2_$3_$4_$5";
+
+my $type = $q->param("type") || "cpu";
+$type =~ m|^(\w+)$| or die "Invalid graph type";
+$type = $graph_types{$1} or die "Invalid graph type";
+
+my $path = catfile(GRAPH_DIR, "*-$type-$uuid-?.rrd");
+my @files = glob $path or die "No data found";
+
+push @args, "--start", "-".$days."d";
+
+foreach my $i (0..$#files) {
+  $files[$i] =~ m|^([^:]+)$|;
+  push @args, "DEF:odata$i=$1:42:AVERAGE";
+  push @args, "CDEF:data$i=odata$i,UN,0,odata$i,IF,10000,/";
+}
+push @args, "CDEF:total=0,".join(",+,", map {"data$_"} 0..$#files).",+";
+push @args, "AREA:total#0000FF";
+
+$ENV{"PATH"} = "/usr/local/bin:/usr/bin:/bin";
+
+print $q->header(-type=>$mime_type);
+$|=1;
+
+{
+    use Data::Dumper;
+    print STDERR "XVM usage: ", Dumper(\@args);
+}
+RRDs::graph (@args);