Add support for remapping hostnames for individual client entries,

to make it possible to gather Munin and Nagios status for hosts
behind VPN connections and with non-unique host names.

3 files changed, 59 insertions, 7 deletions

diff --git a/README b/README
index dfafdb4..e0be004 100644
--- a/README
+++ b/README
@@ -28,12 +28,12 @@ to enable Munin autoconfig on the sitesummary collector
 Sitesummary generated Nagios configuration
 ------------------------------------------
 
-Since version 0.0.51, there is experimental code in sitesummary to
-generate Nagios configuration based on the collected information.  To
-enable this, install nagios3 and nagios-plugins-standard, edit
-/etc/default/nagios3 to include
-'NAGIOSCFG=/etc/nagios3/sitesummary.cfg' and run the sitesummary cron
-job.  Running these commands as root normally does the trick.
+Since version 0.0.51, there is code in sitesummary to generate Nagios
+configuration based on the collected information.  To enable this,
+install nagios3 and nagios-plugins-standard, edit /etc/default/nagios3
+to include 'NAGIOSCFG=/etc/nagios3/sitesummary.cfg' and run the
+sitesummary cron job.  Running these commands as root normally does
+the trick.
 
   aptitude install nagios3 nagios-plugins-standard
   echo 'NAGIOSCFG="/etc/nagios3/sitesummary.cfg"' >> /etc/default/nagios3
@@ -70,6 +70,24 @@ to query Nagios NRPE on the clients.
   sitesummary-client sitesummary-client/nagios-server string sitesummary
   sitesummary-client sitesummary-client/enable-nagios-nrpe-config boolean true
 
+Handling hosts behind VPN connections
+-------------------------------------
+
+To handle hosts with hostnames missing in DNS or IP adresses not
+available directly from the Nagios and Munin server, a mechanism to
+map entries to new hostnames is provided.
+
+To enable it, create a file /etc/sitesummary/hostmap with content like this
+
+  ether-AA:BB:CC:DD:EE:FF new-name
+
+The ether-* name is the host entry name from
+/var/lib/sitesummary/entries/, and the new-name entry is the hostname
+to use instead of the value in system/hostname.
+
+For this to work, the new-name entry must map to a IP address, either
+in DNS via an entry in /etc/hosts.
+
 Design draft
 ------------
 system to collect key info about all the machines on a site, to help
diff --git a/SiteSummary.pm b/SiteSummary.pm
index f2c856f..bc8271f 100644
--- a/SiteSummary.pm
+++ b/SiteSummary.pm
@@ -35,6 +35,26 @@ my $pwd = "/var/lib/sitesummary/entries";  # Path to the entries
 # File for debian-edu configuration
 my $debian_edu_config = "/debian-edu/config";
 
+# Provide mechanism to remap host names for hosts private networks
+# available via tunnels.
+
+my $hostmapfile = "/etc/sitesummary/hostmap";
+my %hostmap;
+
+sub load_hostmap {
+    if (open(my $fh, '<', $hostmapfile)) {
+        %hostmap = (); # Clear hostmap
+        while (<$fh>) {
+            chomp;
+            my ($hostid, $newhostname) = split(/;/);
+            $hostmap{$hostid} = $newhostname;
+        }
+        close $fh;
+    } else {
+        return;
+    }
+}
+
 sub get_filepath_current {
     my ($hostid, $file) = @_;
     return "$pwd/$hostid$file";
@@ -172,7 +192,11 @@ sub get_primary_macaddress {
 #
 sub get_hostname {
     my $hostid = shift;
-    return get_file_string($hostid, "/system/hostname");
+    if (exists $hostmap{$hostid}) {
+        return $hostmap{$hostid};
+    } else {
+        return get_file_string($hostid, "/system/hostname");
+    }
 }
 
 #
@@ -389,6 +413,7 @@ sub get_age_group {
     return $thisgroup;
 }
 
+load_hostmap();
 1;
 
 ########################################################################
diff --git a/debian/changelog b/debian/changelog
index 5aecc56..d09168b 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -1,3 +1,12 @@
+sitesummary (0.0.72~test0) UNRELEASED; urgency=low
+
+  [ Petter Reinholdtsen ]
+  * Add support for remapping hostnames for individual client entries,
+    to make it possible to gather Munin and Nagios status for hosts
+    behind VPN connections and with non-unique host names.
+
+ -- Petter Reinholdtsen <pere@debian.org>  Sat, 17 Dec 2011 12:06:31 +0100
+
 sitesummary (0.0.71) unstable; urgency=low
 
   * Make sure 'site-summary -l' report handle hosts without a site set.