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Diffstat (limited to 'scripts/build-remote.pl.in')
| -rwxr-xr-x | scripts/build-remote.pl.in | 208 |
1 files changed, 208 insertions, 0 deletions
diff --git a/scripts/build-remote.pl.in b/scripts/build-remote.pl.in new file mode 100755 index 000000000000..9d582c566adb --- /dev/null +++ b/scripts/build-remote.pl.in @@ -0,0 +1,208 @@ +#! @perl@ -w + +use strict; +use Fcntl ':flock'; +use English '-no_match_vars'; + +# General operation: +# +# Try to find a free machine of type $neededSystem. We do this as +# follows: +# - We acquire an exclusive lock on $currentLoad/main-lock. +# - For each machine $machine of type $neededSystem and for each $slot +# less than the maximum load for that machine, we try to get an +# exclusive lock on $currentLoad/$machine-$slot (without blocking). +# If we get such a lock, we send "accept" to the caller. Otherwise, +# we send "postpone" and exit. +# - We release the exclusive lock on $currentLoad/main-lock. +# - We perform the build on $neededSystem. +# - We release the exclusive lock on $currentLoad/$machine-$slot. +# +# The nice thing about this scheme is that if we die prematurely, the +# locks are released automatically. + +my $loadIncreased = 0; + +my $amWilling = shift @ARGV; +my $localSystem = shift @ARGV; +my $neededSystem = shift @ARGV; +my $drvPath = shift @ARGV; + +sub sendReply { + my $reply = shift; + open OUT, ">&3" or die; + print OUT "$reply\n"; + close OUT; +} + +sub decline { + sendReply "decline"; + exit 0; +} + +my $currentLoad = $ENV{"NIX_CURRENT_LOAD"}; +decline unless defined $currentLoad; +mkdir $currentLoad, 0777 or die unless -d $currentLoad; + +my $conf = $ENV{"NIX_REMOTE_SYSTEMS"}; +decline if !defined $conf || ! -e $conf; + +# Decline if the local system can do the build. +decline if $amWilling && ($localSystem eq $neededSystem); + + +# Otherwise find a willing remote machine. +my %machines; +my %systemTypes; +my %sshKeys; +my %maxJobs; +my %curJobs; + + +# Read the list of machines. +open CONF, "< $conf" or die; + +while (<CONF>) { + chomp; + s/\#.*$//g; + 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; + + +# Acquire the exclusive lock on $currentLoad/main-lock. +my $mainLock = "$currentLoad/main-lock"; +open MAINLOCK, ">>$mainLock" or die; +flock(MAINLOCK, LOCK_EX) or die; + + +# Find a suitable system. +my $rightType = 0; +my $machine; +LOOP: foreach my $cur (keys %machines) { + if ($neededSystem eq $systemTypes{$cur}) { + $rightType = 1; + + # We have a machine of the right type. Try to get a lock on + # one of the machine's lock files. + my $slot = 0; + while ($slot < $maxJobs{$cur}) { + my $slotLock = "$currentLoad/$cur-$slot"; + open SLOTLOCK, ">>$slotLock" or die; + if (flock(SLOTLOCK, LOCK_EX | LOCK_NB)) { + $machine = $cur; + last LOOP; + } + close SLOTLOCK; + $slot++; + } + } +} + +close MAINLOCK; + + +# Didn't find one? +if (!defined $machine) { + if ($rightType) { + sendReply "postpone"; + exit 0; + } else { + decline; + } +} + +# Yes we did, accept. +sendReply "accept"; +open IN, "<&4" or die; +my $x = <IN>; +chomp $x; +#print "got $x\n"; +close IN; + +if ($x ne "okay") { + exit 0; +} + + +# Do the actual job. +print "BUILDING REMOTE: $drvPath on $machine\n"; + +# Make sure that we don't get any SSH passphrase or host key popups - +# if there is any problem it should fail, not do something +# interactive. +$ENV{"DISPLAY"} = ""; +$ENV{"SSH_PASSWORD_FILE="} = ""; +$ENV{"SSH_ASKPASS="} = ""; + +my $sshOpts = "-i $sshKeys{$machine} -x"; + +# Hack to support Cygwin: if we login without a password, we don't +# have exactly the same right as when we do. This causes the +# Microsoft C compiler to fail with certain flags: +# +# http://connect.microsoft.com/VisualStudio/feedback/ViewFeedback.aspx?FeedbackID=99676 +# +# So as a workaround, we pass a verbatim password. ssh tries to makes +# this very hard; the trick is to make it call SSH_ASKPASS to get the +# password. (It only calls this command when there is no controlling +# terminal, but Nix ensures that is is the case. When doing this +# manually, use setsid(1).) +if ($sshKeys{$machine} =~ /^password:/) { + my $passwordFile = $sshKeys{$machine}; + $passwordFile =~ s/^password://; + $sshOpts = "ssh -x"; + $ENV{"SSH_PASSWORD_FILE"} = $passwordFile; + $ENV{"SSH_ASKPASS"} = "/tmp/writepass"; + + open WRITEPASS, ">/tmp/writepass" or die; + print WRITEPASS "#! /bin/sh\ncat \"\$SSH_PASSWORD_FILE\""; + close WRITEPASS; + chmod 0755, "/tmp/writepass" or die; +} + +my $inputs = `cat inputs`; die if ($? != 0); +$inputs =~ s/\n/ /g; + +my $outputs = `cat outputs`; die if ($? != 0); +$outputs =~ s/\n/ /g; + +print "COPYING INPUTS...\n"; + +my $maybeSign = ""; +$maybeSign = "--sign" if -e "/nix/etc/nix/signing-key.sec"; + +system("NIX_SSHOPTS=\"$sshOpts\" nix-copy-closure $machine $maybeSign $drvPath $inputs") == 0 + or die "cannot copy inputs to $machine: $?"; + +print "BUILDING...\n"; + +system("ssh $sshOpts $machine 'nix-store -rvvK $drvPath'") == 0 + or die "remote build on $machine failed: $?"; + +print "REMOTE BUILD DONE: $drvPath on $machine\n"; + +foreach my $output (split '\n', $outputs) { + my $maybeSignRemote = ""; + $maybeSignRemote = "--sign" if $UID != 0; + + system("ssh $sshOpts $machine 'nix-store --export $maybeSignRemote $output' > dump") == 0 + or die "cannot copy $output from $machine: $?"; + + # This doesn't work yet, since the caller has a lock on the output + # path. We should move towards lock-free invocation of build + # hooks and substitutes. + #system("nix-store --import < dump") == 0 + # or die "cannot import $output: $?"; + + # Hack: skip the first 8 bytes (the nix-store --export next + # archive marker). The archive follows. + system("(dd bs=1 count=8 of=/dev/null && cat) < dump | nix-store --restore $output") == 0 + or die "cannot restore $output: $?"; +} |