diff --git a/Dockerfile.planetgen b/Dockerfile.planetgen
new file mode 100644
index 0000000..e5c6f0d
--- /dev/null
+++ b/Dockerfile.planetgen
@@ -0,0 +1,17 @@
+FROM debian:12-slim
+ADD ./planetgen /opt/planetgen
+RUN <<EOF
+	set -e
+	export DEBIAN_FRONTEND=noninteractive
+	export DEBCONF_NONINTERACTIVE_SEEN=true
+	apt-get update && apt-get dist-upgrade -uy
+
+	apt-get install -y perl povray
+
+	mkdir -p /var/spool/pgen/{input,output}
+	chown -R www-data:www-data /var/spool/pgen
+EOF
+
+VOLUME /var/spool/pgen/input /var/spool/pgen/output
+
+ENTRYPOINT ["/opt/planetgen/planetmaker.pl"]
diff --git a/planetgen/planetmaker.pl b/planetgen/planetmaker.pl
index 80433e6..0d659e1 100755
--- a/planetgen/planetmaker.pl
+++ b/planetgen/planetmaker.pl
@@ -1,45 +1,58 @@
 #!/usr/bin/perl
 
 #
-# Checks the /tmp/pgen/req-<version>-<start>-<count> files at regular
+# Checks the input dir for req-<version>-<start>-<count> files at regular
 # intervals and generate planets accordingly.
 #
 # Syntax : ./planetmaker.pl
 #
 
-$outDir = "/mnt/planets";
+use strict; use warnings;
 
-close(STDIN);
-close(STDERR);
-close(STDOUT);
-if	(fork())
-{
-	exit(0);
-}
+use FindBin qw($Bin);
+require File::Temp;
+use File::Temp ();
+use File::Temp qw/ :seekable /;
 
-chdir("/opt/planetgen");
-mkdir("/tmp/pgen", 01777) if (! -d "/tmp/pgen");
-while	(1)
-{
-	chop($find = `find /tmp/pgen/ -name 'req-*-*-*'`);
-	if	($find ne "")
-	{
-		@list = split /\n/, $find;
+my $outDir = $ENV{PGEN_OUTPUT} || "/tmp/pgen-out";
+my $inDir = $ENV{PGEN_INPUT} || "/tmp/pgen-input";
 
-		foreach my $name (@list)
-		{
-			unlink($name);
-			my ($junk,$version,$first,$count) = split /-/, $name;
+chdir $Bin;
+print "Entering main loop\n";
+print "   Input directory:  $inDir\n";
+print "   Output directory: $outDir\n";
+mkdir($inDir, 01777) unless -d $inDir;
+mkdir($outDir, 00755) unless -d $outDir;
 
-			for	($i=$first;$i<$first+$count;$i++)
-			{
-				my	$fn = "/tmp/pgen/out.pov";
-				`./generate.pl $fn`;
-				`povray +W80 +H80 +O$outDir/$version/l/$i.png -D -V $fn >/dev/null 2>&1`;
-				`povray +W30 +H30 +O$outDir/$version/s/$i.png -D -V $fn >/dev/null 2>&1`;
-				unlink($fn);
-			}
+while (1) {
+	opendir(my $dir, $inDir) or die "Could not open $inDir: $! $_";
+	my @list = grep {
+		-f "$inDir/$_" && /^req-[a-z0-9]+-\d+-\d+$/
+	} readdir $dir;
+	close $dir;
+
+	foreach my $name (@list) {
+		unlink("$inDir/$name");
+		my ($junk,$version,$first,$count) = split /-/, $name;
+		print "Generating planets for $version.\n";
+		print "  First planet $first.\n";
+		print "  $count planets\n";
+
+		my $verDir = "$outDir/$version";
+		foreach my $suffix ("", "/l", "/s") {
+			my $dir = $verDir . $suffix;
+			mkdir($dir) unless -d $dir
+		}
+
+		for (my $i=$first;$i<$first+$count;$i++) {
+			my $fn = File::Temp->new(SUFFIX => '.pov');
+			`./generate.pl $fn`;
+			`povray +W80 +H80 +O$verDir/l/$i.png -D -V $fn >/dev/null 2>&1`;
+			`povray +W30 +H30 +O$verDir/s/$i.png -D -V $fn >/dev/null 2>&1`;
+			unlink($fn);
 		}
 	}
+
 	sleep(60);
+	print "Sleeping...\n";
 }