1 files changed, 119 insertions, 0 deletions
diff --git a/distributed/build-remote.pl b/distributed/build-remote.pl
new file mode 100755
index 000000000..f1a9b10f4
--- /dev/null
+++ b/distributed/build-remote.pl
@@ -0,0 +1,119 @@
+#! /usr/bin/perl -w
+
+use strict;
+
+my $amWilling = shift @ARGV;
+my $localSystem = shift @ARGV;
+my $neededSystem = shift @ARGV;
+my $storeExpr = shift @ARGV;
+
+# Decline if the local system can do the build.
+if ($amWilling && ($localSystem eq $neededSystem)) {
+    print "decline\n";
+    exit 0;
+}
+
+# Otherwise find a willing remote machine.
+my %machines;
+my %systemTypes;
+my %sshKeys;
+my %maxJobs;
+my %curJobs;
+
+# Read the list of machines.
+open CONF, "< /home/eelco/nix/distributed/remote-systems.conf" or die;
+
+while (<CONF>) {
+    chomp;
+    next if /^\s*$/;
+    /^\s*(\S+)\s+(\S+)\s+(\S+)\s+(\d+)\s*$/ or die;
+    $machines{$1} = "";
+    $systemTypes{$1} = $2;
+    $sshKeys{$1} = $3;
+    $maxJobs{$1} = $4;
+}
+
+close CONF;
+
+# Read the current load status.
+open LOAD, "< /home/eelco/nix/distributed/current-load" or die;
+while (<LOAD>) {
+    chomp;
+    next if /^\s*$/;
+    /^\s*(\S+)\s+(\d+)\s*$/ or die;
+    $curJobs{$1} = $2;
+}
+close LOAD;
+
+sub sendReply {
+    my $reply = shift;
+    open OUT, ">&3" or die;
+    print OUT "$reply\n";
+    close OUT;
+}
+
+# Find a suitable system.
+my $rightType = 0;
+my $machine;
+foreach my $cur (keys %machines) {
+    if ($neededSystem eq $systemTypes{$cur}) {
+        $rightType = 1;
+        if (!defined $curJobs{$cur} or
+            ($curJobs{$cur} < $maxJobs{$cur}))
+        {
+            $machine = $cur;
+            last;
+        }
+    }
+}
+
+if (!defined $machine) {
+    if ($rightType) {
+        sendReply "postpone";
+        exit 0;
+    } else {
+        sendReply "decline";
+        exit 0;
+    }
+}
+
+sendReply "accept";
+open IN, "<&4" or die;
+my $x = <IN>;
+chomp $x;
+print "got $x\n";  
+close IN;
+
+print "BUILDING REMOTE: $storeExpr on $machine\n";
+
+my $ssh = "ssh -i $sshKeys{$machine} -x";
+
+my $inputs = `cat inputs`;
+$inputs =~ s/\n/ /g;
+
+my $outputs = `cat outputs`;
+$outputs =~ s/\n/ /g;
+
+my $successors = `cat successors`;
+$successors =~ s/\n/ /g;
+
+system "rsync -a -e '$ssh' $storeExpr $inputs $machine:/nix/store";
+die "cannot rsync inputs to $machine" if ($? != 0);
+
+system "$ssh $machine /nix/bin/nix-store --validpath $storeExpr $inputs";
+die "cannot set valid paths on $machine" if ($? != 0);
+
+system "$ssh $machine /nix/bin/nix-store --successor $successors";
+die "cannot set successors on $machine" if ($? != 0);
+
+print "BUILDING...\n";
+
+system "$ssh $machine /nix/bin/nix-store -qnfvvvv $storeExpr";
+die "remote build on $machine failed" if ($? != 0);
+
+print "REMOTE BUILD DONE\n";
+
+foreach my $output (split '\n', $outputs) {
+    system "rsync -a -e '$ssh' $machine:$output /nix/store";
+    die "cannot rsync outputs from $machine" if ($? != 0);
+}