channel-scripts/mirror-channel.pl

91 lines
2.9 KiB
Perl
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use strict;
use readmanifest;
use File::Basename;
use File::stat;
use File::Temp qw/tempfile/;
use Fcntl ':flock';
if (scalar @ARGV != 3 && scalar @ARGV != 4) {
print STDERR "Syntax: perl mirror-channel.pl <src-channel-url> <dst-channel-url> <dst-channel-dir> [<nix-exprs-url>]\n";
exit 1;
}
my $curl = "curl --location --silent --show-error --fail";
my $srcChannelURL = $ARGV[0];
my $dstChannelURL = $ARGV[1];
my $dstChannelPath = $ARGV[2];
my $nixexprsURL = $ARGV[3] || "$srcChannelURL/nixexprs.tar.bz2";
die "$dstChannelPath doesn't exist\n" unless -d $dstChannelPath;
open LOCK, ">$dstChannelPath/.lock" or die;
flock LOCK, LOCK_EX;
my ($fh, $tmpManifest) = tempfile(UNLINK => 1);
system("$curl '$srcChannelURL/MANIFEST' > $tmpManifest") == 0 or die;
# Read the manifest.
my %narFiles;
my %localPaths;
my %patches;
my $version = readManifest($tmpManifest, \%narFiles, \%localPaths, \%patches);
%localPaths = ();
%patches = (); # not supported yet
my $size = scalar (keys %narFiles);
print "$size store paths in manifest\n";
# Protect against Hydra problems that leave the channel empty.
die "cowardly refusing to mirror an empty channel" if $size == 0;
# Download every file that we don't already have, and update every URL
# to point to the mirror. Also fill in the size and hash fields in
# the manifest in order to be compatible with Nix < 0.13.
while (my ($storePath, $files) = each %narFiles) {
foreach my $file (@{$files}) {
my $narHash = $file->{narHash};
my $srcURL = $file->{url};
my $dstName = $narHash;
$dstName =~ s/:/_/; # `:' in filenames might cause problems
my $dstFile = "$dstChannelPath/$dstName";
my $dstURL = "$dstChannelURL/$dstName";
$file->{url} = $dstURL;
if (! -e $dstFile) {
print "downloading $srcURL\n";
my $dstFileTmp = "$dstChannelPath/.tmp.$$.nar.$dstName";
system("$curl '$srcURL' > $dstFileTmp") == 0 or die;
rename($dstFileTmp, $dstFile) or die "cannot rename $dstFileTmp";
}
$file->{size} = stat($dstFile)->size or die;
my $hashFile = "$dstChannelPath/.hash.$dstName";
my $hash;
if (-e $hashFile) {
open HASH, "<$hashFile" or die;
$hash = <HASH>;
close HASH;
} else {
$hash = `nix-hash --flat --type sha256 --base32 '$dstFile'` or die;
chomp $hash;
open HASH, ">$hashFile" or die;
print HASH $hash;
close HASH;
}
$file->{hash} = "sha256:$hash";
}
}
# Write the new manifest.
writeManifest("$dstChannelPath/MANIFEST", \%narFiles, \%patches);
# Mirror nixexprs.tar.bz2.
my $tmpFile = "$dstChannelPath/.tmp.$$.nixexprs.tar.bz2";
system("$curl '$nixexprsURL' > $tmpFile") == 0 or die;
rename($tmpFile, "$dstChannelPath/nixexprs.tar.bz2") or die "cannot rename $tmpFile";