[pve-devel] [PATCH container] CentOS 6: add '--nohangup' as mingetty arg

[Stoiko Ivanov]

When creating an unprivileged container with CentOS 6 (which will be EOL in
Nov 2020 [0]) the console does not work.

The problem is mitigated by adding the --nohangup argument to the mingetty
invocations during bootup (in /etc/init/tty.conf).

The idea for the fix is based on the legacy template builder-scripts from
lxc:
https://github.com/lxc/lxc-templates/blob/master/templates/lxc-centos.in#L308

Since '/etc/init/tty.conf' is only written during container creation/restore
and since it is guarded to CentOS versions < 7, the potential for regression
should be rather small.

Tested by creating an unprivileged and a privileged CentOS6 container and
with nesting enabled and disabled for both - the console showed up in
all cases with this fix.

[0] https://wiki.centos.org/About/Product
Signed-off-by: Stoiko Ivanov <s.ivanov at proxmox.com>
---
I shortly considered setting the contents of '/etc/init/tty.conf' irrespective
of the existence of the file, but went with the safer route (should people
have customized templates). Additionally this part of the code will probably
be removed with EOL of CentOS 6 anyways.

Thanks to Martin for reporting this!

 src/PVE/LXC/Setup/CentOS.pm                     | 11 ++++++++---
 src/test/test-centos6-001/etc/init/tty.conf.exp |  2 +-
 2 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/src/PVE/LXC/Setup/CentOS.pm b/src/PVE/LXC/Setup/CentOS.pm
index d73c0cf..1e6894b 100644
--- a/src/PVE/LXC/Setup/CentOS.pm
+++ b/src/PVE/LXC/Setup/CentOS.pm
@@ -46,7 +46,7 @@ stop on runlevel [S016]
 
 respawn
 instance \$TTY
-exec /sbin/mingetty \$TTY
+exec /sbin/mingetty --nohangup \$TTY
 usage 'tty TTY=/dev/ttyX  - where X is console id'
 __EOD__
     
@@ -88,8 +88,13 @@ sub template_fixup {
 	$self->ct_make_path('/etc/init');
 
 	my $filename = "/etc/init/tty.conf";
-	$self->ct_file_set_contents($filename, $tty_conf)
-	    if ! $self->ct_file_exists($filename);
+	if ($self->ct_file_exists($filename)) {
+	    my $data = $self->ct_file_get_contents($filename);
+	    $data =~ s|^(exec /sbin/mingetty)(?!.*--nohangup) (.*)$|$1 --nohangup $2|gm;
+	    $self->ct_file_set_contents($filename, $data);
+	} else {
+	    $self->ct_file_set_contents($filename, $tty_conf);
+	}
 
 	$filename = "/etc/init/start-ttys.conf";
 	$self->ct_file_set_contents($filename, $start_ttys_conf)
diff --git a/src/test/test-centos6-001/etc/init/tty.conf.exp b/src/test/test-centos6-001/etc/init/tty.conf.exp
index 5dcd7ad..efad240 100644
--- a/src/test/test-centos6-001/etc/init/tty.conf.exp
+++ b/src/test/test-centos6-001/etc/init/tty.conf.exp
@@ -9,5 +9,5 @@ stop on runlevel [S016]
 
 respawn
 instance $TTY
-exec /sbin/mingetty $TTY
+exec /sbin/mingetty --nohangup $TTY
 usage 'tty TTY=/dev/ttyX  - where X is console id'
-- 
2.20.1