Fix sporadic failures on nmcli invocation

The serial console somehow looks like it messes up with the interpolation
of `mn_id`. Using serial terminal produces more stable results and problem
seems to go away.
In additional there are changes to prevent the uninitialized value
warnings in autoinst-log on this jobs.

https://progress.opensuse.org/issues/155170

lib/mm_network.pm

@@ -58,11 +58,11 @@ sub configure_static_ip {
     my $ip = $args{ip};
     my $mtu = $args{mtu} // get_var('MM_MTU', 1380);
     my $is_nm = $args{is_nm} // is_networkmanager();
-    my $device = $args{device};
+    my $device = $args{device} // '\S';
 
     if ($is_nm) {
         my $nm_id;
-        my $nm_list = script_output("nmcli -t -f DEVICE,NAME c | grep -v ^lo: | grep '$device' | head -n1");
+        my $nm_list = script_output("nmcli -t -f DEVICE,NAME c | grep -v '^lo:' | grep -e '$device' | head -n1");
         ($device, $nm_id) = split(':', $nm_list);
 
         record_info('set_ip', "Device: $device\n NM ID: $nm_id\nIP: $ip\nMTU: $mtu");
@@ -105,11 +105,11 @@ sub configure_dhcp {
 sub configure_default_gateway {
     my (%args) = @_;
     my $is_nm = $args{is_nm} // is_networkmanager();
-    my $device = $args{device};
+    my $device = $args{device} // '\S';
     if ($is_nm) {
         my $nm_id;
         # When $device is not specified grep just does nothing and first connection is selected
-        my $nm_list = script_output("nmcli -t -f DEVICE,NAME c | grep -v ^lo: | grep '$device' | head -n1");
+        my $nm_list = script_output("nmcli -t -f DEVICE,NAME c | grep -v '^lo:' | grep -e '$device' | head -n1");
         ($device, $nm_id) = split(':', $nm_list);
 
         assert_script_run "nmcli connection modify '$nm_id' ipv4.gateway 10.0.2.2";
@@ -127,8 +127,7 @@ sub configure_static_dns {
     my $servers = join(" ", @{$conf->{nameserver}});
 
     if ($is_nm) {
-        $nm_id = script_output('nmcli -t -f NAME c | grep -v ^lo: | head -n 1') unless ($nm_id);
-
+        $nm_id = script_output("nmcli -t -f NAME c | grep -v '^lo' | head -n 1") unless ($nm_id);
         assert_script_run "nmcli connection modify '$nm_id' ipv4.dns '$servers'";
     } else {
         assert_script_run("sed -i -e 's|^NETCONFIG_DNS_STATIC_SERVERS=.*|NETCONFIG_DNS_STATIC_SERVERS=\"$servers\"|' /etc/sysconfig/network/config");

tests/network/setup_multimachine.pm

@@ -15,6 +15,7 @@ use mm_network 'setup_static_mm_network';
 use utils qw(zypper_call permit_root_ssh set_hostname ping_size_check);
 use Utils::Systemd qw(disable_and_stop_service systemctl check_unit_file);
 use version_utils qw(is_sle is_opensuse);
+use serial_terminal 'select_serial_terminal';
 
 sub run {
     my ($self) = @_;
@@ -28,8 +29,7 @@ sub run {
     }
     mutex_wait 'barrier_setup_mm_done';
 
-    select_console 'root-console';
-
+    select_serial_terminal;
     # Do not use external DNS for our internal hostnames
     assert_script_run('echo "10.0.2.101 server master" >> /etc/hosts');
     assert_script_run('echo "10.0.2.102 client minion" >> /etc/hosts');