[pve-devel] [PATCH container] Fix #2124: restore: support external de-compressor

[Alwin Antreich]

This patch adds support to restore archives that have been compressed
with a compressor not natively supported by tar. This had to be added
for zstd support.

Signed-off-by: Alwin Antreich <a.antreich at proxmox.com>
---
 src/PVE/LXC/Create.pm | 31 +++++++++++++++++++++----------
 1 file changed, 21 insertions(+), 10 deletions(-)

diff --git a/src/PVE/LXC/Create.pm b/src/PVE/LXC/Create.pm
index 029c940..a7aec9a 100644
--- a/src/PVE/LXC/Create.pm
+++ b/src/PVE/LXC/Create.pm
@@ -71,21 +71,28 @@ sub restore_archive {
     my $archive_fh;
     my $tar_input = '<&STDIN';
     my @compression_opt;
+    my $decomp;
     if ($archive ne '-') {
 	# GNU tar refuses to autodetect this... *sigh*
 	my %compression_map = (
-	    '.gz'  => '-z',
-	    '.bz2' => '-j',
-	    '.xz'  => '-J',
-	    '.lzo'  => '--lzop',
+	    'gz'  => '-z',
+	    'bz2' => '-j',
+	    'xz'  => '-J',
+	    'lzo'  => '--lzop',
 	);
-	if ($archive =~ /\.tar(\.[^.]+)?$/) {
-	    if (defined($1)) {
-		die "unrecognized compression format: $1\n" if !defined($compression_map{$1});
-		@compression_opt = $compression_map{$1};
+
+	$archive =~ /\.(tar)\.?([^.]+)?$/;
+	    my $format = $1;
+	    my $comp = $2;
+
+	if (defined($comp)) {
+	    if (defined($compression_map{$comp})) {
+		@compression_opt = $compression_map{$comp};
+	    } else {
+		$decomp = PVE::Storage::decompressor_info(undef, $comp);
 	    }
 	} else {
-	    die "file does not look like a template archive: $archive\n";
+	    die "file does not look like a template archive: $archive\n" if ($format ne 'tar');
 	}
 	sysopen($archive_fh, $archive, O_RDONLY)
 	    or die "failed to open '$archive': $!\n";
@@ -106,8 +113,12 @@ sub restore_archive {
     push @$cmd, '--anchored';
     push @$cmd, '--exclude' , './dev/*';
 
+    $cmd = [$decomp, $cmd] if defined($decomp);
+
     if (defined($bwlimit)) {
-	$cmd = [ ['cstream', '-t', $bwlimit*1024], $cmd ];
+	    my $cstream = ['cstream', '-t', $bwlimit*1024];
+	    # unpack if $decomp, otherwise to many array levels
+	    $cmd = defined($decomp) ? [ $cstream, @$cmd ] : [ $cstream, $cmd ];
     }
 
     if ($archive eq '-') {
-- 
2.11.0