Add support for hostmap.d/ and comments.

2 files changed, 26 insertions, 10 deletions

diff --git a/README b/README
index e0be004..4d89049 100644
--- a/README
+++ b/README
@@ -77,10 +77,16 @@ 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
+To enable it, create a file /etc/sitesummary/hostmap or a file in
+/etc/sitesummary/hostmap.d/ with content like this
 
   ether-AA:BB:CC:DD:EE:FF new-name
 
+Empty lines are ignored.  The # character indicate the start of a
+comment.  Entries in /etc/sitesummary/hostmap.d/ override entries in
+/etc/sitesummary/hostmap, and the entries in hostmap.d/ are read in
+alphabetic order, where the last entry take effect.
+
 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.
diff --git a/SiteSummary.pm b/SiteSummary.pm
index 43d459d..53b3c50 100644
--- a/SiteSummary.pm
+++ b/SiteSummary.pm
@@ -39,20 +39,30 @@ my $debian_edu_config = "/debian-edu/config";
 # available via tunnels.
 
 my $hostmapfile = "/etc/sitesummary/hostmap";
+my $hostmapdir = "/etc/sitesummary/hostmap.d";
 my %hostmap;
 
 sub load_hostmap {
-    if (open(my $fh, '<', $hostmapfile)) {
-        %hostmap = (); # Clear hostmap
-        while (<$fh>) {
-            chomp;
-            my ($hostid, $newhostname) = split(/\s+/);
-            $hostmap{$hostid} = $newhostname;
+    my @files = ($hostmapfile);
+    %hostmap = (); # Clear hostmap
+
+    if (opendir(my $dh, $hostmapdir)) {
+        push(@files, grep { /^\./ && -f "$some_dir/$_" } sort readdir($dh));
+        closedir $dh;
+    }
+    for my $file (@files) {
+        if (open(my $fh, '<', $file)) {
+            while (<$fh>) {
+                chomp;
+                s/\#.*$//;
+                next if m/^\s*$/;
+                my ($hostid, $newhostname) = split(/\s+/);
+                $hostmap{$hostid} = $newhostname;
+            }
+            close $fh;
         }
-        close $fh;
-    } else {
-        return;
     }
+    return;
 }
 
 sub get_filepath_current {