[pve-devel] [PATCH storage v2 10/11] allow .tar container templates

[Wolfgang Bumiller]

*Mostly* LGTM and can be applied independently from the rest of the
series.

But I have 1 concern with a not so pretty suggestion... (see below)

On Wed, Jun 11, 2025 at 04:49:02PM +0200, Filip Schauer wrote:
> This is needed for OCI container images bundled as tar files, as
> generated by `docker save`. OCI images do not need additional
> compression, since the content is usually compressed already.
> 
> Signed-off-by: Filip Schauer <f.schauer at proxmox.com>
> ---
>  src/PVE/Storage.pm        | 2 +-
>  src/PVE/Storage/Plugin.pm | 2 +-
>  2 files changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/src/PVE/Storage.pm b/src/PVE/Storage.pm
> index 3962077..0d43df1 100755
> --- a/src/PVE/Storage.pm
> +++ b/src/PVE/Storage.pm
> @@ -117,7 +117,7 @@ PVE::Storage::Plugin->init();
>  
>  our $ISO_EXT_RE_0 = qr/\.(?:iso|img)/i;
>  
> -our $VZTMPL_EXT_RE_1 = qr/\.tar\.(gz|xz|zst|bz2)/i;
> +our $VZTMPL_EXT_RE_1 = qr/\.tar(?:\.(gz|xz|zst|bz2))?/i;

This is a publicly exported regex. Potentially also used by external
plugins...

I am almost tempted to turn this into:

    qr/\.(?|(tar)(?!\.)|tar(?:\.(gz|xz|zst|bz2))?)/i

`(?|...)` is the "branch reset" pattern, which means the first `(tar)`
and the second `(gz|xz...)` get the same capture group numbering.

The `(?!\.)` is a negative lookahead - since this RE is not anchored,
the `.tar` should only match if it is not followed by a dot.

This way, the hunk below would be unnecessary, since a simple `.tar`
file would end up putting "tar" into $2. Iow. the regex would be "API
compatible🤞"

Not sure if it is worth the complexity of the regex, though...

>  
>  our $BACKUP_EXT_RE_2 = qr/\.(tgz|(?:tar|vma)(?:\.(${\PVE::Storage::Plugin::COMPRESSOR_RE}))?)/;
>  
> diff --git a/src/PVE/Storage/Plugin.pm b/src/PVE/Storage/Plugin.pm
> index 1d8a8f9..76ffdb6 100644
> --- a/src/PVE/Storage/Plugin.pm
> +++ b/src/PVE/Storage/Plugin.pm
> @@ -1429,7 +1429,7 @@ my $get_subdir_files = sub {
>          } elsif ($tt eq 'vztmpl') {
>              next if $fn !~ m!/([^/]+$PVE::Storage::VZTMPL_EXT_RE_1)$!;
>  
> -            $info = { volid => "$sid:vztmpl/$1", format => "t$2" };
> +            $info = { volid => "$sid:vztmpl/$1", format => $2 ? "t$2" : "tar" };
>  
>          } elsif ($tt eq 'backup') {
>              next if $fn !~ m!/([^/]+$PVE::Storage::BACKUP_EXT_RE_2)$!;
> -- 
> 2.39.5