* Quick prototype of a substituter that copies paths from other Nix

stores (typically remote Nix stores mounted via e.g. NFS, or the Nix
  store on the NixOS installation CD).  Example use:

  $ sshfs foo@example.org:/ /mnt
  $ NIX_OTHER_STORES=/mnt/nix \
    NIX_SUBSTITUTERS=.../copy-from-other-stores.pl \
    nix-env -i foo

  This will be especially useful for the installation CD since it
  doesn't require a manifest for the CD contents.
This commit is contained in:
Eelco Dolstra 2008-07-12 18:58:24 +00:00
parent 7cd88b1dec
commit 15f39aba8c
2 changed files with 84 additions and 1 deletions

View file

@ -9,7 +9,7 @@ noinst_SCRIPTS = nix-profile.sh generate-patches.pl \
nix-pull nix-push: readmanifest.pm readconfig.pm download-using-manifests.pl nix-pull nix-push: readmanifest.pm readconfig.pm download-using-manifests.pl
install-exec-local: readmanifest.pm download-using-manifests.pl find-runtime-roots.pl install-exec-local: readmanifest.pm download-using-manifests.pl copy-from-other-stores.pl find-runtime-roots.pl
$(INSTALL) -d $(DESTDIR)$(sysconfdir)/profile.d $(INSTALL) -d $(DESTDIR)$(sysconfdir)/profile.d
$(INSTALL_PROGRAM) nix-profile.sh $(DESTDIR)$(sysconfdir)/profile.d/nix.sh $(INSTALL_PROGRAM) nix-profile.sh $(DESTDIR)$(sysconfdir)/profile.d/nix.sh
$(INSTALL) -d $(DESTDIR)$(libexecdir)/nix $(INSTALL) -d $(DESTDIR)$(libexecdir)/nix
@ -31,6 +31,7 @@ EXTRA_DIST = nix-collect-garbage.in \
readconfig.pm.in \ readconfig.pm.in \
nix-build.in \ nix-build.in \
download-using-manifests.pl.in \ download-using-manifests.pl.in \
copy-from-other-stores.pl.in \
generate-patches.pl.in \ generate-patches.pl.in \
nix-pack-closure.in nix-unpack-closure.in \ nix-pack-closure.in nix-unpack-closure.in \
nix-copy-closure.in \ nix-copy-closure.in \

View file

@ -0,0 +1,82 @@
#! @perl@ -w
use strict;
use File::Basename;
#print STDERR "FOO: @ARGV\n";
die unless defined $ENV{"NIX_OTHER_STORES"};
my @remoteStores = split ':', $ENV{"NIX_OTHER_STORES"};
sub findStorePath {
my $storePath = shift;
my $storePathName = basename $storePath;
#print STDERR "GET $storePath\n";
foreach my $store (@remoteStores) {
# Determine whether $storePath exists by looking for the
# existence of the info file, and if so, get store path info
# from that file. This rather breaks abstraction: we should
# be using `nix-store' for that. But right now there is no
# good way to tell nix-store to access a store mounted under a
# different location (there's $NIX_STORE, but that only works
# if the remote store is mounted under its "real" location).
my $infoFile = "$store/var/nix/db/info/$storePathName";
my $storePath2 = "$store/store/$storePathName";
if (-f $infoFile && -e $storePath2) {
#print STDERR "FOUND IN $infoFile\n";
return ($infoFile, $storePath2);
}
}
}
if ($ARGV[0] eq "--query-paths") {
# !!! not implemented yet; needed for `nix-env -qas'
}
elsif ($ARGV[0] eq "--query-info") {
shift @ARGV;
foreach my $storePath (@ARGV) {
(my $infoFile) = findStorePath $storePath;
#print STDERR "XXX $infoFile\n";
my $deriver = "";
my @references = ();
open INFO, "<$infoFile" or die "cannot read info file $infoFile\n";
while (<INFO>) {
chomp;
#print STDERR "GOT $_\n";
/^([\w-]+): (.*)$/ or die "bad info file";
my $key = $1;
my $value = $2;
if ($key eq "Deriver") { $deriver = $value; }
elsif ($key eq "References") { @references = split ' ', $value; }
}
close INFO;
print "$storePath\n";
print "$deriver\n";
print scalar @references, "\n";
print "$_\n" foreach @references;
}
}
elsif ($ARGV[0] eq "--substitute") {
die unless scalar @ARGV == 2;
my $storePath = $ARGV[1];
(my $infoFile, my $sourcePath) = findStorePath $storePath;
print "\n*** Copying `$storePath' from `$sourcePath'\n\n";
system("nix-store --dump $sourcePath | nix-store --restore $storePath") == 0
or die "cannot copy `$sourcePath' to `$storePath'";
}
else { die; }