Re: [PATCH container v6 25/26] migration: intra-cluster: check config can be parsed on target node

["Michael Köppl" <m.koeppl@proxmox.com>]

On Tue Nov 3, 2026 at 1:48 PM CET, Fiona Ebner wrote:

[snip]

> index d243d90..4793c5e 100644
> --- a/src/PVE/LXC/Migrate.pm
> +++ b/src/PVE/LXC/Migrate.pm
> @@ -159,6 +159,39 @@ sub prepare {
>          my $cmd = [@{ $self->{rem_ssh} }, '/bin/true'];
>          eval { $self->cmd_quiet($cmd); };
>          die "Can't connect to destination address using public key\n" if $@;
> +
> +        if (!$self->{opts}->{'skip-config-check'}) {
> +            if (PVE::Cluster::node_pvecfg_version_at_least($self->{node}, 9, 2, 26)) {
> +                # Fork a short-lived tunnel for checking the config. Later, the proper tunnel with
> +                # SSH forwarding info is forked.
> +                my $tunnel = PVE::Tunnel::fork_ssh_tunnel(
> +                    $self->{rem_ssh},
> +                    ['pct', 'mtunnel'],
> +                    undef,
> +                    sub {
> +                        my ($level, $msg) = @_;
> +                        $self->log($level, $msg);
> +                    },
> +                );
> +                eval {
> +                    my $nodename = PVE::INotify::nodename();
> +                    PVE::Tunnel::write_tunnel($tunnel, 30, "config $vmid $nodename");
> +                };
> +                my $err = $@;
> +
> +                eval { PVE::Tunnel::finish_tunnel($tunnel); };
> +                $self->log('warn', "failed to finish tunnel in prepare() - $@") if $@;
> +
> +                if ($err) {
> +                    chomp($err);
> +                    die "$err - use 'skip-config-check' flag to migrate regardless\n";
> +                }
> +            } else {
> +                $self->log('info', "skipping config check - target pve-manager version < 9.2.26");
> +            }
> +        } else {
> +            $self->log('info', "skipping config check - override option is set");
> +        }

suggestion: since this block only differs from the qemu-server one by
how the tunnel is forked, could this perhaps be moved to
pve-guest-common? Could be done in PVE::AbstractMigrate and
fork_tunnel() could there exist as an abstract that only has to be
implemented in pve-container as well, since qemu-server already has it.

>      }
>
>      # in restart mode, we shutdown the container before migrating