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#! @perl@ -w @perlFlags@
use utf8;
use strict;
use File::Basename;
use File::Path qw(mkpath);
use Nix::Config;
use Nix::Manifest;
use File::Temp qw(tempdir);
binmode STDERR, ":encoding(utf8)";
Nix::Config::readConfig;
my $manifestDir = $Nix::Config::manifestDir;
# Turn on caching in nix-prefetch-url.
my $channelCache = "$Nix::Config::stateDir/channel-cache";
mkdir $channelCache, 0755 unless -e $channelCache;
$ENV{'NIX_DOWNLOAD_CACHE'} = $channelCache if -W $channelCache;
# Figure out the name of the `.nix-channels' file to use.
my $home = $ENV{"HOME"} or die '$HOME not set\n';
my $channelsList = "$home/.nix-channels";
my $nixDefExpr = "$home/.nix-defexpr";
# Figure out the name of the channels profile.
my $userName = getpwuid($<) || $ENV{"USER"} or die "cannot figure out user name";
my $profile = "$Nix::Config::stateDir/profiles/per-user/$userName/channels";
mkpath(dirname $profile, 0, 0755);
my %channels;
# Reads the list of channels.
sub readChannels {
return if (!-f $channelsList);
open CHANNELS, "<$channelsList" or die "cannot open ‘$channelsList’: $!";
while (<CHANNELS>) {
chomp;
next if /^\s*\#/;
my ($url, $name) = split ' ', $_;
$url =~ s/\/*$//; # remove trailing slashes
$name = basename $url unless defined $name;
$channels{$name} = $url;
}
close CHANNELS;
}
# Writes the list of channels.
sub writeChannels {
open CHANNELS, ">$channelsList" or die "cannot open ‘$channelsList’: $!";
foreach my $name (keys %channels) {
print CHANNELS "$channels{$name} $name\n";
}
close CHANNELS;
}
# Adds a channel.
sub addChannel {
my ($url, $name) = @_;
die "invalid channel URL ‘$url’" unless $url =~ /^(file|http|https):\/\//;
die "invalid channel identifier ‘$name’" unless $name =~ /^[a-zA-Z0-9_][a-zA-Z0-9_\-\.]*$/;
readChannels;
$channels{$name} = $url;
writeChannels;
}
# Remove a channel.
sub removeChannel {
my ($name) = @_;
readChannels;
my $url = $channels{$name};
deleteOldManifests($url . "/MANIFEST", undef) if defined $url;
delete $channels{$name};
writeChannels;
system("$Nix::Config::binDir/nix-env --profile '$profile' -e '$name'") == 0
or die "cannot remove channel ‘$name’\n";
}
# Fetch Nix expressions and pull manifests from the subscribed
# channels.
sub update {
my @channelNames = @_;
readChannels;
# Download each channel.
my $exprs = "";
foreach my $name (keys %channels) {
next if scalar @channelNames > 0 && ! grep { $_ eq $name } @{channelNames};
my $url = $channels{$name};
my $origUrl = "$url/MANIFEST";
# We want to download the url to a file to see if it's a tarball while also checking if we
# got redirected in the process, so that we can grab the various parts of a nix channel
# definition from a consistent location if the redirect changes mid-download.
my $tmpdir = tempdir( CLEANUP => 1 );
my $filename;
($url, $filename) = `cd $tmpdir && $Nix::Config::curl --silent --write-out '%{url_effective}\n%{filename_effective}' -L '$url' -O`;
die "$0: unable to check ‘$url’\n" if $? != 0;
chomp $url;
# If the URL contains a version number, append it to the name
# attribute (so that "nix-env -q" on the channels profile
# shows something useful).
my $cname = $name;
$cname .= $1 if basename($url) =~ /(-\d.*)$/;
my $path;
my $ret = -1;
if (-e "$tmpdir/$filename" && $filename =~ /\.tar\.(gz|bz2|xz)$/) {
# Get our temporary download into the store.
(my $hash, $path) = `PRINT_PATH=1 QUIET=1 $Nix::Config::binDir/nix-prefetch-url 'file://$tmpdir/$filename'`;
chomp $path;
# Try unpacking the expressions to see if they'll be valid for us to process later.
# Like anything in nix, this will cache the result so we don't do it again outside of the loop below.
$ret = system("$Nix::Config::binDir/nix-build --no-out-link -E 'import <nix/unpack-channel.nix> " .
"{ name = \"$cname\"; channelName = \"$name\"; src = builtins.storePath \"$path\"; }'");
}
# The URL doesn't unpack directly, so let's try treating it like a full channel folder with files in it
my $extraAttrs = "";
if ($ret != 0) {
# Check if the channel advertises a binary cache.
my $binaryCacheURL = `$Nix::Config::curl --silent '$url'/binary-cache-url`;
my $getManifest = ($Nix::Config::config{"force-manifest"} // "false") eq "true";
if ($? == 0 && $binaryCacheURL ne "") {
$extraAttrs .= "binaryCacheURL = \"$binaryCacheURL\"; ";
deleteOldManifests($origUrl, undef);
} else {
$getManifest = 1;
}
if ($getManifest) {
# No binary cache, so pull the channel manifest.
mkdir $manifestDir, 0755 unless -e $manifestDir;
die "$0: you do not have write permission to ‘$manifestDir’!\n" unless -W $manifestDir;
$ENV{'NIX_ORIG_URL'} = $origUrl;
system("$Nix::Config::binDir/nix-pull", "--skip-wrong-store", "$url/MANIFEST") == 0
or die "cannot pull manifest from ‘$url’\n";
}
# Download the channel tarball.
my $fullURL = "$url/nixexprs.tar.xz";
system("$Nix::Config::curl --fail --silent --head '$fullURL' > /dev/null") == 0 or
$fullURL = "$url/nixexprs.tar.bz2";
print STDERR "downloading Nix expressions from ‘$fullURL’...\n";
(my $hash, $path) = `PRINT_PATH=1 QUIET=1 $Nix::Config::binDir/nix-prefetch-url '$fullURL'`;
die "cannot fetch ‘$fullURL’\n" if $? != 0;
chomp $path;
}
# Regardless of where it came from, add the expression representing this channel to accumulated expression
$exprs .= "'f: f { name = \"$cname\"; channelName = \"$name\"; src = builtins.storePath \"$path\"; $extraAttrs }' ";
}
# Unpack the channel tarballs into the Nix store and install them
# into the channels profile.
print STDERR "unpacking channels...\n";
system("$Nix::Config::binDir/nix-env --profile '$profile' " .
"-f '<nix/unpack-channel.nix>' -i -E $exprs --quiet") == 0
or die "cannot unpack the channels";
# Make the channels appear in nix-env.
unlink $nixDefExpr if -l $nixDefExpr; # old-skool ~/.nix-defexpr
mkdir $nixDefExpr or die "cannot create directory ‘$nixDefExpr’" if !-e $nixDefExpr;
my $channelLink = "$nixDefExpr/channels";
unlink $channelLink; # !!! not atomic
symlink($profile, $channelLink) or die "cannot symlink ‘$channelLink’ to ‘$profile’";
}
die "$0: argument expected\n" if scalar @ARGV == 0;
while (scalar @ARGV) {
my $arg = shift @ARGV;
if ($arg eq "--add") {
die "$0: ‘--add’ requires one or two arguments\n" if scalar @ARGV < 1 || scalar @ARGV > 2;
my $url = shift @ARGV;
my $name = shift @ARGV;
unless (defined $name) {
$name = basename $url;
$name =~ s/-unstable//;
$name =~ s/-stable//;
}
addChannel($url, $name);
last;
}
if ($arg eq "--remove") {
die "$0: ‘--remove’ requires one argument\n" if scalar @ARGV != 1;
removeChannel(shift @ARGV);
last;
}
if ($arg eq "--list") {
die "$0: ‘--list’ requires one argument\n" if scalar @ARGV != 0;
readChannels;
foreach my $name (keys %channels) {
print "$name $channels{$name}\n";
}
last;
}
elsif ($arg eq "--update") {
update(@ARGV);
last;
}
elsif ($arg eq "--rollback") {
die "$0: ‘--rollback’ has at most one argument\n" if scalar @ARGV > 1;
my $generation = shift @ARGV;
my @args = ("$Nix::Config::binDir/nix-env", "--profile", $profile);
if (defined $generation) {
die "invalid channel generation number ‘$generation’" unless $generation =~ /^[0-9]+$/;
push @args, "--switch-generation", $generation;
} else {
push @args, "--rollback";
}
system(@args) == 0 or exit 1;
last;
}
elsif ($arg eq "--help") {
exec "man nix-channel" or die;
}
elsif ($arg eq "--version") {
print "nix-channel (Nix) $Nix::Config::version\n";
exit 0;
}
else {
die "unknown argument ‘$arg’; try ‘--help’\n";
}
}
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