X-Git-Url: https://git.openstreetmap.org./dns.git/blobdiff_plain/305a05819502360eb874be0b0d4010ae11239497..8871e8ca47f806db05cf82b77f85429689359f04:/bin/mkgeo?ds=sidebyside

diff --git a/bin/mkgeo b/bin/mkgeo
index 9ec063e..2b7d3af 100755
--- a/bin/mkgeo
+++ b/bin/mkgeo
@@ -1,5 +1,7 @@
 #!/usr/bin/perl
 
+use v5.12;
+
 use strict;
 use warnings;
 
@@ -7,12 +9,15 @@ use IO::File;
 use Math::Trig qw(deg2rad pip2 great_circle_distance);
 use JSON::XS;
 use LWP::UserAgent;
-use XML::TreeBuilder;
-use YAML;
+use YAML::XS qw(LoadFile DumpFile);
 
-my $source = shift @ARGV;
+my $originfile = shift @ARGV;
+my $clusterfile = shift @ARGV;
 my $zone = shift @ARGV;
-my $clusters = YAML::LoadFile("src/${source}");
+my $targetoriginfile = shift @ARGV;
+my $origins = LoadFile($originfile);
+my $clusters = LoadFile($clusterfile);
+my $gdnsname = shift @ARGV;
 my @servers;
 
 # Initialise cluster details
@@ -20,12 +25,12 @@ while (my($name,$cluster) = each %$clusters)
 {
     if ($cluster->{servers})
     {
-        $cluster->{bandwidth} = 0;
+        $cluster->{requests} = 0;
 
         foreach my $server (@{$cluster->{servers}})
         {
             $server->{cluster} = $cluster;
-            $cluster->{bandwidth} = $cluster->{bandwidth} + $server->{bandwidth};
+            $cluster->{requests} = $cluster->{requests} + $server->{requests};
 
             push @servers, $server;
         }
@@ -34,8 +39,9 @@ while (my($name,$cluster) = each %$clusters)
     {
         my $server = {
             cluster => $cluster,
-            pingdom => $cluster->{pingdom},
-            bandwidth => $cluster->{bandwidth},
+            statuscake => $cluster->{statuscake},
+            requests => $cluster->{requests},
+            cname => $cluster->{cname},
             ipv4 => $cluster->{ipv4},
             ipv6 => $cluster->{ipv6}
         };
@@ -46,301 +52,442 @@ while (my($name,$cluster) = each %$clusters)
     }
 
     $cluster->{name} = $name;
-
-    if ($ENV{PINGDOM_USERNAME} && $ENV{PINGDOM_PASSWORD})
-    {
-        $cluster->{status} = "down";
-    }
-    else
-    {
-        $cluster->{status} = "up";
-    }
+    $cluster->{status} = "down";
 }
 
 # Initialise server details
 foreach my $server (@servers)
 {
-    if ($ENV{PINGDOM_USERNAME} && $ENV{PINGDOM_PASSWORD})
+    $server->{status} = "up";
+}
+
+# If statuscake support is enabled then check which servers are up
+if ($ENV{STATUSCAKE_APIKEY})
+{
+    my $ua = LWP::UserAgent->new;
+    my $cache;
+
+    $ua->agent("mkgeo/1.0");
+    $ua->default_header("Authorization", "Bearer $ENV{STATUSCAKE_APIKEY}");
+
+    if (-f "statuscake.yml")
     {
-        $server->{status} = "down";
+        $cache = LoadFile("statuscake.yml");
     }
     else
     {
-        $server->{status} = "up";
+        $cache = {};
     }
-}
-
-# If pingdom support is enabled then check which servers are up
-if ($ENV{PINGDOM_USERNAME} && $ENV{PINGDOM_PASSWORD})
-{
-    my $ua = LWP::UserAgent->new;
 
-    $ua->default_header("App-Key", "2cohi62u5haxvqmypk3ljqqrze1jufrh");
-    $ua->credentials("api.pingdom.com:443", "Pingdom API", $ENV{PINGDOM_USERNAME}, $ENV{PINGDOM_PASSWORD});
+    my $page = 1;
+    my $pages = 1;
 
-    foreach my $server (@servers)
+    while ($page <= $pages)
     {
-        if (my $checkid = $server->{pingdom})
+        my $response = $ua->get("https://api.statuscake.com/v1/uptime?nouptime=true&limit=100&page=${page}");
+
+        if ($response->is_success)
         {
-            my $response = $ua->get("https://api.pingdom.com/api/2.0/checks/${checkid}");
+            my $uptime = decode_json($response->content);
 
-            if ($response->is_success)
+            foreach my $test (@{$uptime->{data}})
             {
-                my $check = decode_json($response->content);
+                my $testid = $test->{id};
 
-                $server->{status} = $check->{check}->{status};
-
-                if ($server->{status} eq "up")
+                if ($test->{status} eq "up" && !$test->{paused})
                 {
-                    $server->{cluster}->{status} = "up";
+                    $cache->{$testid} = "up";
                 }
                 else
                 {
-                    $server->{cluster}->{bandwidth} = $server->{cluster}->{bandwidth} - $server->{bandwidth};
+                    $cache->{$testid} = "down";
                 }
             }
+
+            $page = $page + 1;
+            $pages = $uptime->{metadata}->{page_count};
+        }
+    }
+
+    foreach my $server (@servers)
+    {
+        if (my $testids = $server->{statuscake})
+        {
+            $server->{status} = "up";
+
+            for my $testid (@$testids)
+            {
+                my $testresult = $cache->{$testid} || "down";
+
+                $server->{status} = "down" if $testresult eq "down";
+            }
+        }
+        else
+        {
+            $server->{status} = "down";
         }
     }
+
+    DumpFile("statuscake-$$.yml", $cache);
+    rename("statuscake-$$.yml", "statuscake.yml");
 }
 
-# Initialise cluster details
-while (my($name,$cluster) = each %$clusters)
+# Mark a cluster as up if any servers are up
+foreach my $server (@servers)
 {
-    $cluster->{bandwidth_limit} = $cluster->{bandwidth} * 1024 * 1024;
-    $cluster->{bandwidth_used} = 0;
+    if ($server->{status} eq "up")
+    {
+        $server->{cluster}->{status} = "up";
+    }
+    else
+    {
+        $server->{cluster}->{requests} = $server->{cluster}->{requests} - $server->{requests};
+    }
 }
 
-my %countries = ();
-my @mappings = ();
-
-# Create a parser for the country database
-my $countries = XML::TreeBuilder->new;
+# Create target origins object
+my $targetorigins = {};
 
-# Parse the country database
-$countries->parsefile("lib/countries.xml");
+# Initialise cluster details
+while (my($name,$cluster) = each %$clusters)
+{
+    $cluster->{requests_limit} = $cluster->{requests};
+    $cluster->{requests_used} = 0;
 
-# Load the per-country bandwidth details
-my $bandwidth = YAML::LoadFile("bandwidth/${source}.yml");
+    next if $cluster->{global};
 
-# Fill in country table and work out which clusters each can use
-foreach my $country ($countries->look_down("_tag" => "country"))
-{
-    my $code = $country->look_down("_tag" => "countryCode")->as_text;
-    my $name = $country->look_down("_tag" => "countryName")->as_text;
-    my $population = $country->look_down("_tag" => "population")->as_text;
-    my $bandwidth = $bandwidth->{$code} || 0;
-    my $continent = $country->look_down("_tag" => "continent")->as_text;
-    my $west = $country->look_down("_tag" => "west")->as_text;
-    my $north = $country->look_down("_tag" => "north")->as_text;
-    my $east = $country->look_down("_tag" => "east")->as_text;
-    my $south = $country->look_down("_tag" => "south")->as_text;
-    my $lat = centre_lat( $south, $north );
-    my $lon = centre_lon( $west, $east );
-
-    $countries{$code} = {
-        code => $code, name => $name, continent => $continent,
-        bandwidth => $bandwidth, lat => $lat, lon => $lon
+    $targetorigins->{$cluster->{name}} = {
+        code => $cluster->{name},
+        name => $cluster->{name},
+        lat => $cluster->{lat},
+        lon => $cluster->{lon},
+        requests => 0
     };
+}
 
+my @mappings = ();
+
+# Scan origins and work out which clusters each can use
+foreach my $origin (values %$origins)
+{
     foreach my $cluster (values %$clusters)
     {
-        my $match = match_country($cluster, $code, $continent);
+        my $match = match_origin($cluster, $origin);
 
         if ($cluster->{status} eq "up" && $match ne "denied")
         {
             my $priority = $match eq "preferred" ? 20 : 10;
-            my $distance = distance($lat, $lon, $cluster->{lat}, $cluster->{lon});
+            my $distance;
+
+            if ($cluster->{global})
+            {
+                $distance = 0;
+            }
+            else
+            {
+                $distance = distance($origin->{lat}, $origin->{lon}, $cluster->{lat}, $cluster->{lon});
+            }
 
             push @mappings, {
-                country => $countries{$code}, cluster => $cluster,
+                origin => $origin, cluster => $cluster,
                 priority => $priority, distance => $distance
             };
         }
     }
 }
 
-# Discard the parsed country database
-$countries->delete;
-
 # Allocate each country to a cluster
-allocate_clusters(\@mappings);
+allocate_clusters(@mappings);
 
-# If we failed to allocate every country then loop, increasing
-# the bandwidth for each cluster by a little and retrying until
+# If we failed to allocate every origin then loop, increasing
+# the requests for each cluster by a little and retrying until
 # we manage to allocate everything
-while (grep { !exists($_->{cluster}) } values %countries)
+while (grep { !exists($_->{cluster}) } values %$origins)
 {
     # Clear any existing mappings of countries to clusters
-    foreach my $country (values %countries)
+    foreach my $origin (values %$origins)
     {
-        delete $country->{cluster};
+        delete $origin->{cluster};
     }
 
-    # Reset bandwidth usage for clusters and increase limits by 10%
+    # Reset requests usage for clusters and increase limits by 10%
     foreach my $cluster (values %$clusters)
     {
-        $cluster->{bandwidth_used} = 0;
-        $cluster->{bandwidth_limit} = $cluster->{bandwidth_limit} * 1.1;
+        $cluster->{requests_used} = 0;
+        $cluster->{requests_limit} = $cluster->{requests_limit} * 1.1;
     }
 
     # Try the allocate again
-    allocate_clusters(\@mappings);
+    allocate_clusters(@mappings);
+}
+
+# Report on allocation results
+foreach my $name (sort keys %$clusters)
+{
+    my $cluster = $clusters->{$name};
+    my $used = int($cluster->{requests_used} + 0.5);
+    my $limit = $cluster->{requests_limit};
+
+    if ($limit > 0)
+    {
+        my $proportion = int($used / $limit * 100 + 0.5);
+    
+        print "${name}: used ${used} of ${limit} (${proportion}%)\n";
+    }
+    else
+    {
+        print "${name}: used ${used} of ${limit}\n";
+    }
 }
 
 # Create JSON collection object
 my @json;
 
 # Open output files
-my $zonefile = IO::File->new("> data/${zone}") || die "$!";
-my $jsonfile = IO::File->new("> json/${zone}.json") || die "$!";
+my $zonefile = IO::File->new("> include/${zone}.js") || die "$!";
+my $jsonfile = IO::File->new("> json/${zone}.openstreetmap.org.json") || die "$!";
+
+# Output headers
+$zonefile->print("var \U${zone}\E_RECORDS = [\n");
 
 # Output details for each country
-foreach my $country (values %countries)
+foreach my $origin (sort { $a->{name} cmp $b->{name} } values %$origins)
 {
-    my $cluster = $country->{cluster};
-    my $clon = $country->{lon};
-    my $clat = $country->{lat};
-    my $slon = $cluster->{lon};
-    my $slat = $cluster->{lat};
+    my $cluster = $origin->{cluster};
 
-    if ($clon > 0 && $slon < 0 && 360 + $slon - $clon < $clon - $slon)
+    if (!defined($gdnsname))
     {
-        $slon = $slon + 360;
+        $zonefile->print("  CNAME(\"\L$origin->{code}\E.${zone}\", \"$cluster->{name}.${zone}.openstreetmap.org.\", TTL(\"10m\")),\n");
     }
-    elsif ($slon > 0 && $clon < 0 && 360 + $clon - $slon < $slon - $clon)
+
+    if ($cluster->{lon} && $cluster->{lat})
     {
-        $clon = $clon + 360;
+        my $clon = $origin->{lon};
+        my $clat = $origin->{lat};
+        my $slon = $cluster->{lon};
+        my $slat = $cluster->{lat};
+
+        if ($clon > 0 && $slon < 0 && 360 + $slon - $clon < $clon - $slon)
+        {
+            $slon = $slon + 360;
+        }
+        elsif ($slon > 0 && $clon < 0 && 360 + $clon - $slon < $slon - $clon)
+        {
+            $clon = $clon + 360;
+        }
+
+        push @json, {
+            type => "Feature",
+            geometry => {
+                type => "LineString",
+                coordinates => [ [ $clon, $clat ], [ $slon, $slat ] ]
+            },
+            properties => {
+                origin => $origin->{name},
+                server => $cluster->{name},
+                colour => $cluster->{colour}
+            }
+        };
     }
 
-    $zonefile->print("# $country->{name}\n");
-    $zonefile->print("C\L$country->{code}\E.${zone}:$cluster->{name}.${zone}:600\n");
+    next if $cluster->{global};
 
-    push @json, {
-        type => "Feature",
-        geometry => {
-            type => "LineString",
-            coordinates => [ [ $clon, $clat ], [ $slon, $slat ] ]
-        },
-        properties => {
-            country => $country->{name},
-            server => $cluster->{name},
-            colour => $cluster->{colour}
-        }
-    };
+    $targetorigins->{$cluster->{name}}->{requests} += $origin->{requests};
 }
 
-# Output default records for IPs that can't be mapped to a country
-foreach my $cluster (grep { $clusters->{$_}->{default} } keys %$clusters)
+# Skip default records if we don't need them
+if (!defined($gdnsname))
 {
-    $zonefile->print("# Unknown countries\n");
-    $zonefile->print("Cxx.${zone}:${cluster}.${zone}:600\n");
-}
+    # Output default records for IPs that can't be mapped to a country
+    foreach my $cluster (sort { $a->{name} cmp $b->{name} } values %$clusters)
+    {
+        my $name = $cluster->{name};
 
-$zonefile->print("# Servers\n");
+        if (my $default = $cluster->{default})
+        {
+            output_server($zonefile, "${default}.${zone}", $cluster, 0);
+        }
+        elsif (exists($cluster->{default}))
+        {
+            output_server($zonefile, "${zone}", $cluster, 0);
+        }
+    }
+}
 
 # Output A records for each cluster
-while (my($name,$cluster) = each %$clusters)
+foreach my $cluster (sort { $a->{name} cmp $b->{name} } values %$clusters)
 {
-    foreach my $server (@{$cluster->{servers}})
-    {
-        if ($server->{status} eq "up")
-        {
-            $zonefile->print("+${name}.${zone}:$server->{ipv4}:600\n");
+    my $name = $cluster->{name};
 
-            if ($server->{ipv6})
-            {
-#                $zonefile->print("3${name}.${zone}:$server->{ipv6}:600\n");
-            }
-        }
+    if (@{$cluster->{servers}} > 1)
+    {
+        output_server($zonefile, "${name}-%02d.${zone}", $cluster, 1);
+    }
+    else
+    {
+        output_server($zonefile, "${name}.${zone}", $cluster, 1);
     }
 }
 
 # Output the GeoJSON text
 $jsonfile->print(encode_json(\@json));
 
+# Output footers
+$zonefile->print("];\n");
+
 # Close the output files
-$jsonfile->close();
+$zonefile->close();
 $zonefile->close();
 
-exit 0;
-
-#
-# Find the centre value between two latitudes
-#
-sub centre_lat
+# Output gdnsd configuration
+if (defined($gdnsname))
 {
-    my $south = shift;
-    my $north = shift;
+    my $gdnsmapfile = IO::File->new("> gdns/${gdnsname}.map") || die "$!";
+    my $gdnsresourcefile = IO::File->new("> gdns/${gdnsname}.resource") || die "$!";
+    my $gdnsweightedfile = IO::File->new("> gdns/${gdnsname}.weighted") || die "$!";
+    my $continent = "";
+
+    $gdnsmapfile->print("${gdnsname} => {\n");
+    $gdnsmapfile->print("  geoip2_db => /usr/share/GeoIP/GeoLite2-Country.mmdb\n");
+    $gdnsmapfile->print("  datacenters => [" . join(",", sort(keys(%$clusters))) . "]\n");
+    $gdnsmapfile->print("  map => {\n");
+    $gdnsmapfile->print("    default => [" . join(",", sort(map { $_->{name} } grep { $_->{default} } values(%$clusters))) . "]\n");
+
+    foreach my $origin (sort { $a->{continent} cmp $b->{continent} || $a->{code} cmp $b->{code} } values %$origins)
+    {
+        my $code = $origin->{code};
+        my $cluster = $origin->{cluster}->{name};
 
-    return ( $south + $north ) / 2;
-}
+        next if $code eq "XK";
 
-#
-# Find the centre value between two longitudes
-#
-sub centre_lon
-{
-    my $west = shift;
-    my $east = shift;
-    my $lon;
+        if ($continent ne $origin->{continent})
+        {
+            $gdnsmapfile->print("    }\n") if $continent;
 
-    if ($west < $east)
-    {
-        $lon = ( $west + $east ) / 2;
+            $continent = $origin->{continent};
+
+            $gdnsmapfile->print("    ${continent} => {\n");
+        }
+
+        $gdnsmapfile->print("      ${code} => [${cluster}]\n");
     }
-    else
+
+    $gdnsmapfile->print("    }\n") if $continent;
+
+    $gdnsmapfile->print("  }\n");
+    $gdnsmapfile->print("}\n");
+
+    $gdnsresourcefile->print("${gdnsname} => {\n");
+    $gdnsresourcefile->print("  map => ${gdnsname}\n");
+    $gdnsresourcefile->print("  dcmap => {\n");
+
+    foreach my $cluster (sort { $a->{name} cmp $b->{name} } values %$clusters)
     {
-        $lon = ( $west + $east + 360 ) / 2;
+        my $name = $cluster->{name};
+
+        if (@{$cluster->{servers}} > 1 && grep { $_->{status} eq "up" } @{$cluster->{servers}})
+        {
+            $gdnsweightedfile->print("${name} => {\n");
+
+            while (my($index,$server) = each @{$cluster->{servers}})
+            {
+                if ($server->{status} eq "up")
+                {
+                    my $number = sprintf("%02d", $index + 1);
+                    my $requests = $server->{requests};
+
+                    if (my $cname = $server->{cname})
+                    {
+                        $gdnsweightedfile->print("  ${name}-${number} = [ ${cname}., ${requests} ]\n");
+                    }
+                    else
+                    {
+                        $gdnsweightedfile->print("  ${name}-${number} = [ ${name}-${number}.${zone}.openstreetmap.org., ${requests} ]\n");
+                    }
+                }
+            }
+
+            $gdnsweightedfile->print("}\n");
+
+            $gdnsresourcefile->print("    ${name} => %weighted!${name}\n");
+        }
+        elsif (my $cname = $cluster->{cname})
+        {
+            $gdnsresourcefile->print("    ${name} => ${cname}.\n");
+        }
+        else
+        {
+            $gdnsresourcefile->print("    ${name} => ${name}.${zone}.openstreetmap.org.\n");
+        }
     }
 
-    $lon = $lon - 360 if $lon > 180;
+    $gdnsresourcefile->print("  }\n");
+    $gdnsresourcefile->print("}\n");
 
-    return $lon
+    $gdnsweightedfile->close();
+    $gdnsresourcefile->close();
+    $gdnsmapfile->close();
 }
 
+# Output the target details in origin format if required
+DumpFile($targetoriginfile, $targetorigins) if $targetoriginfile;
+
+exit 0;
+
 #
-# Match a country against a cluster
+# Match an origin against a cluster
 #
-sub match_country
+sub match_origin
 {
     my $cluster = shift;
-    my $country = shift;
-    my $continent = shift;
+    my $origin = shift;
     my $match;
 
     if ($cluster->{preferred} &&
-        $cluster->{preferred}->{countries} &&
-        grep { $_ eq $country } @{$cluster->{preferred}->{countries}})
+        $cluster->{preferred}->{origins} &&
+        grep { $_ eq $origin->{name} } @{$cluster->{preferred}->{origins}})
     {
         $match = "preferred";
     }
+    elsif ($cluster->{allowed} &&
+           $cluster->{allowed}->{origins} &&
+           grep { $_ eq $origin->{name} } @{$cluster->{allowed}->{origins}})
+    {
+        $match = "allowed";
+    }
     elsif ($cluster->{preferred} &&
-           $cluster->{preferred}->{continents} &&
-           grep { $_ eq $continent } @{$cluster->{preferred}->{continents}})
+           $cluster->{preferred}->{countries} &&
+           grep { $_ eq $origin->{country} } @{$cluster->{preferred}->{countries}})
     {
         $match = "preferred";
     }
     elsif ($cluster->{allowed} &&
            $cluster->{allowed}->{countries} &&
-           grep { $_ eq $country } @{$cluster->{allowed}->{countries}})
-    {
-        $match = "allowed";
-    }
-    elsif ($cluster->{allowed} &&
-           $cluster->{allowed}->{continents} &&
-           grep { $_ eq $continent } @{$cluster->{allowed}->{continents}})
+           grep { $_ eq $origin->{country} } @{$cluster->{allowed}->{countries}})
     {
         $match = "allowed";
     }
     elsif ($cluster->{denied} &&
            $cluster->{denied}->{countries} &&
-           grep { $_ eq $country } @{$cluster->{preferred}->{countries}})
+           grep { $_ eq $origin->{country} } @{$cluster->{denied}->{countries}})
     {
         $match = "denied";
     }
+    elsif ($cluster->{preferred} &&
+           $cluster->{preferred}->{continents} &&
+           grep { $_ eq $origin->{continent} } @{$cluster->{preferred}->{continents}})
+    {
+        $match = "preferred";
+    }
+    elsif ($cluster->{allowed} &&
+           $cluster->{allowed}->{continents} &&
+           grep { $_ eq $origin->{continent} } @{$cluster->{allowed}->{continents}})
+    {
+        $match = "allowed";
+    }
     elsif ($cluster->{denied} &&
            $cluster->{denied}->{continents} &&
-           grep { $_ eq $continent } @{$cluster->{preferred}->{continents}})
+           grep { $_ eq $origin->{continent} } @{$cluster->{denied}->{continents}})
     {
         $match = "denied";
     }
@@ -370,24 +517,88 @@ sub distance
 }
 
 #
-# Allocate each country to a cluster
+# Allocate each origin to a cluster
 #
 sub allocate_clusters
 {
-    my $mappings = shift;
+    my @mappings = sort { compare_mappings($a, $b) } @_;
 
-    # Loop over the mappings, trying to assign each country to the
-    # nearest cluster, but subject to the bandwidth limits
-    foreach my $mapping (sort {  $b->{priority} <=> $a->{priority} || $a->{distance} <=> $b->{distance} } @$mappings)
+    # Loop over the mappings, trying to assign each origin to the
+    # nearest cluster, but subject to the request limits
+    while (my $mapping = shift @mappings)
     {
-        my $country = $mapping->{country};
-        my $cluster = $mapping->{cluster};
+        my @group;
+
+        push @group, $mapping;
 
-        if (!exists($country->{cluster}) &&
-            $cluster->{bandwidth_used} + $country->{bandwidth} <= $cluster->{bandwidth_limit})
+        while (@mappings && compare_mappings($mapping, $mappings[0]) == 0)
         {
-            $country->{cluster} = $cluster;
-            $cluster->{bandwidth_used} = $cluster->{bandwidth_used} + $country->{bandwidth};
+            push @group, shift @mappings;
+        }
+
+        for my $mapping (sort compare_requests @group)
+        {
+            my $origin = $mapping->{origin};
+            my $cluster = $mapping->{cluster};
+
+            if (!exists($origin->{cluster}) &&
+                $cluster->{requests_used} + $origin->{requests} <= $cluster->{requests_limit})
+            {
+                $origin->{cluster} = $cluster;
+                $cluster->{requests_used} = $cluster->{requests_used} + $origin->{requests};
+            }
+        }
+    }
+
+    return;
+}
+
+#
+# Compare two mappings to decide which to use
+#
+sub compare_mappings
+{
+    my $a = shift;
+    my $b = shift;
+
+    return $b->{priority} <=> $a->{priority} ||
+           $a->{distance} <=> $b->{distance};
+}
+
+#
+# Compare two mappings to decide which to try first
+#
+sub compare_requests
+{
+    my $a_used = ( $a->{cluster}->{requests_used} * 100.0 ) / ( $a->{cluster}->{requests_limit} * 1.0 );
+    my $b_used = ( $b->{cluster}->{requests_used} * 100.0 ) / ( $b->{cluster}->{requests_limit} * 1.0 );
+
+    return $a_used <=> $b_used;
+}
+
+#
+# Output DNS records for a server
+#
+sub output_server
+{
+    my $zonefile = shift;
+    my $name = shift;
+    my $cluster = shift;
+    my $all = shift;
+
+    while (my($index,$server) = each @{$cluster->{servers}})
+    {
+        if ($all || $server->{status} eq "up")
+        {
+            if ($server->{ipv4})
+            {
+                $zonefile->printf("  A(\"${name}\", \"$server->{ipv4}\", TTL(\"10m\")),\n", $index + 1);
+            }
+
+            if ($server->{ipv6})
+            {
+                $zonefile->printf("  AAAA(\"${name}\", \"$server->{ipv6}\", TTL(\"10m\")),\n", $index + 1);
+            }
         }
     }