nix/scripts/nix-unpack-closure.in
Eelco Dolstra e4d4969ae9 * New tools nix-pack-closure and nix-unpack-closure. These provide a
useful way to transfer the closure of a store path to another
  machine.

  These commands provide functionality previously possible through
  `nix-push --copy'.  However, they are much more convenient in many
  situations (though possibly less efficient).
  
  Example:
  $ nix-pack-closure /nix/store/hj232g1r...-subversion-1.3.0 > svn.closure
  (on another machine:)
  $ nix-unpack-closure < svn.closure

  Note that Subversion is added to the store, but not installed into a
  user environment.  One should do `nix-env -i
  /nix/store/hj232g1r...-subversion-1.3.0' for that.

  Another example: copy the application Azureus to the machine
  `scratchy' through ssh:
  
  $ nix-pack-closure $(which azureus) | ssh scratchy nix-unpack-closure
2006-01-12 15:17:51 +00:00

82 lines
2.1 KiB
Plaintext

#! @perl@ -w
# This tool unpacks the closures created by "nix-pack-closure" and
# adds them to the Nix store.
# TODO: make this program "streamy", i.e., don't use a temporary
# directory.
use strict;
use POSIX qw(tmpnam);
my $binDir = $ENV{"NIX_BIN_DIR"};
$binDir = "@bindir@" unless defined $binDir;
my $tmpDir;
do { $tmpDir = tmpnam(); }
until mkdir $tmpDir, 0777;
END { system "rm -rf '$tmpDir'"; }
# Unpack the NAR archive on standard input.
system("nix-store --restore '$tmpDir/unpacked'") == 0
or die "nix-store --restore failed";
open VALID, ">$tmpDir/validity" or die;
# For each path in the closure that is not yet valid, add it to the
# store. TODO: use proper locking. Or even better, let nix-store do
# this.
opendir(DIR, "$tmpDir/unpacked/contents") or die "cannot open directory: $!";
foreach my $name (sort(readdir DIR)) {
next if $name eq "." or $name eq "..";
my $storePath = "/nix/store/$name"; # !!!
# !!! this really isn't a good validity check!
system "/nix/bin/nix-store --check-validity '$storePath' 2> /dev/null";
if ($? != 0) {
print STDERR "unpacking `$storePath'...\n";
# !!! race
system("rm -rf '$storePath'") == 0
or die "cannot remove `$storePath': $?";
system("$binDir/nix-store --restore '$storePath' < '$tmpDir/unpacked/contents/$name'") == 0
or die "nix-store --dump failed on `$storePath': $?";
print VALID "$storePath\n";
open DRV, "<$tmpDir/unpacked/derivers/$name" or die;
my $deriver = <DRV>;
chomp $deriver;
$deriver = "" if $deriver eq "unknown-deriver";
close DRV;
my @refs;
open REFS, "<$tmpDir/unpacked/references/$name" or die;
while (<REFS>) {
chomp;
push @refs, $_;
}
close REFS;
print VALID "$deriver\n";
print VALID (scalar @refs), "\n";
foreach my $ref (@refs) {
print VALID "$ref\n";
}
}
}
closedir(DIR) or die;
# Register the invalid paths as valid.
system("nix-store --register-validity <'$tmpDir/validity'") == 0
or die "nix-store --register-validity failed";