grub modernize (#374844)

use Class::Struct;

use XML::LibXML;

use File::Basename;

use File::Path;

use File::Path qw(make_path);

use File::stat;

use File::Copy;

use File::Copy::Recursive qw(rcopy pathrm);

    my ($fn) = @_;

    # enable slurp mode: read entire file in one go

    local $/ = undef;

    open my $fh, "<$fn" or return undef;

    open my $fh, "<", $fn

        or return;

    my $s = <$fh>;

    close $fh;

    # disable slurp mode

sub writeFile {

    my ($fn, $s) = @_;

    open my $fh, ">$fn" or die "cannot create $fn: $!\n";

    open my $fh, ">", $fn or die "cannot create $fn: $!\n";

    print $fh $s or die "cannot write to $fn: $!\n";

    close $fh or die "cannot close $fn: $!\n";

}

print STDERR "updating GRUB 2 menu...\n";

mkpath("$bootPath/grub", 0, 0700);

make_path("$bootPath/grub", {  mode => 0700 });

# Discover whether the bootPath is on the same filesystem as / and

# /nix/store.  If not, then all kernels and initrds must be copied to

$conf .= "\n";

my %copied;

mkpath("$bootPath/kernels", 0, 0755) if $copyKernels;

make_path("$bootPath/kernels", { mode => 0755 }) if $copyKernels;

sub copyToKernelsDir {

    my ($path) = @_;

        my $systemName = basename(Cwd::abs_path("$path"));

        my $initrdSecretsPath = "$bootPath/kernels/$systemName-secrets";

        mkpath(dirname($initrdSecretsPath), 0, 0755);

        make_path(dirname($initrdSecretsPath), { mode => 0755 });

        my $oldUmask = umask;

        # Make sure initrd is not world readable (won't work if /boot is FAT)

        umask 0137;

# because it is read line-by-line.

sub readGrubState {

    my $defaultGrubState = GrubState->new(name => "", version => "", efi => "", devices => "", efiMountPoint => "", extraGrubInstallArgs => () );

    open FILE, "<$bootPath/grub/state" or return $defaultGrubState;

    open my $fh, "<", "$bootPath/grub/state" or return $defaultGrubState;

    local $/ = "\n";

    my $name = <FILE>;

    my $name = <$fh>;

    chomp($name);

    my $version = <FILE>;

    my $version = <$fh>;

    chomp($version);

    my $efi = <FILE>;

    my $efi = <$fh>;

    chomp($efi);

    my $devices = <FILE>;

    my $devices = <$fh>;

    chomp($devices);

    my $efiMountPoint = <FILE>;

    my $efiMountPoint = <$fh>;

    chomp($efiMountPoint);

    # Historically, arguments in the state file were one per each line, but that

    # gets really messy when newlines are involved, structured arguments

    # when we need to remove a setting in the future. Thus, the 6th line is a JSON

    # object that can store structured data, with named keys, and all new state

    # should go in there.

    my $jsonStateLine = <FILE>;

    my $jsonStateLine = <$fh>;

    # For historical reasons we do not check the values above for un-definedness

    # (that is, when the state file has too few lines and EOF is reached),

    # because the above come from the first version of this logic and are thus

    }

    my %jsonState = %{decode_json($jsonStateLine)};

    my @extraGrubInstallArgs = exists($jsonState{'extraGrubInstallArgs'}) ? @{$jsonState{'extraGrubInstallArgs'}} : ();

    close FILE;

    close $fh;

    my $grubState = GrubState->new(name => $name, version => $version, efi => $efi, devices => $devices, efiMountPoint => $efiMountPoint, extraGrubInstallArgs => \@extraGrubInstallArgs );

    return $grubState

}

    my $stateFile = "$bootPath/grub/state";

    my $stateFileTmp = $stateFile . ".tmp";

    open FILE, ">$stateFileTmp" or die "cannot create $stateFileTmp: $!\n";

    print FILE get("fullName"), "\n" or die;

    print FILE get("fullVersion"), "\n" or die;

    print FILE $efiTarget, "\n" or die;

    print FILE join( ",", @deviceTargets ), "\n" or die;

    print FILE $efiSysMountPoint, "\n" or die;

    open my $fh, ">", "$stateFileTmp" or die "cannot create $stateFileTmp: $!\n";

    print $fh get("fullName"), "\n" or die;

    print $fh get("fullVersion"), "\n" or die;

    print $fh $efiTarget, "\n" or die;

    print $fh join( ",", @deviceTargets ), "\n" or die;

    print $fh $efiSysMountPoint, "\n" or die;

    my %jsonState = (

        extraGrubInstallArgs => \@extraGrubInstallArgs

    );

    my $jsonStateLine = encode_json(\%jsonState);

    print FILE $jsonStateLine, "\n" or die;

    close FILE or die;

    print $fh $jsonStateLine, "\n" or die;

    close $fh or die;

    # Atomically switch to the new state file

    rename $stateFileTmp, $stateFile or die "cannot rename $stateFileTmp to $stateFile: $!\n";