[PATCH qemu-server 1/1] qemu: add offline migration from dead node

[Alexandre Derumier]

verify that node is dead from corosync && ssh
and move config file from /etc/pve directly

Signed-off-by: Alexandre Derumier <alexandre.derumier at groupe-cyllene.com>
---
 PVE/API2/Qemu.pm | 56 ++++++++++++++++++++++++++++++++++++++++++++----
 1 file changed, 52 insertions(+), 4 deletions(-)

diff --git a/PVE/API2/Qemu.pm b/PVE/API2/Qemu.pm
index 156b1c7b..58c454a6 100644
--- a/PVE/API2/Qemu.pm
+++ b/PVE/API2/Qemu.pm
@@ -4764,6 +4764,9 @@ __PACKAGE__->register_method({
 		description => "Target node.",
 		completion =>  \&PVE::Cluster::complete_migration_target,
             }),
+            deadnode => get_standard_option('pve-node', {
+                description => "Dead source node.",
+            }),
 	    online => {
 		type => 'boolean',
 		description => "Use online/live migration if VM is running. Ignored if VM is stopped.",
@@ -4813,8 +4816,9 @@ __PACKAGE__->register_method({
 	my $authuser = $rpcenv->get_user();
 
 	my $target = extract_param($param, 'target');
+	my $deadnode = extract_param($param, 'deadnode');
 
-	my $localnode = PVE::INotify::nodename();
+	my $localnode = $deadnode ? $deadnode : PVE::INotify::nodename();
 	raise_param_exc({ target => "target is local node."}) if $target eq $localnode;
 
 	PVE::Cluster::check_cfs_quorum();
@@ -4835,14 +4839,43 @@ __PACKAGE__->register_method({
 	raise_param_exc({ migration_network => "Only root may use this option." })
 	    if $param->{migration_network} && $authuser ne 'root at pam';
 
+	raise_param_exc({ deadnode => "Only root may use this option." })
+	    if $param->{deadnode} && $authuser ne 'root at pam';
+
 	# test if VM exists
-	my $conf = PVE::QemuConfig->load_config($vmid);
+	my $conf = $deadnode ? PVE::QemuConfig->load_config($vmid, $deadnode) : PVE::QemuConfig->load_config($vmid);
 
 	# try to detect errors early
 
 	PVE::QemuConfig->check_lock($conf);
 
-	if (PVE::QemuServer::check_running($vmid)) {
+        if ($deadnode) {
+	    die "Can't do online migration of a dead node.\n" if $param->{online};
+	    my $members = PVE::Cluster::get_members();
+	    die "The deadnode $deadnode seem to be alive" if $members->{$deadnode} && $members->{$deadnode}->{online};
+
+	    print "test if deadnode $deadnode respond to ping\n";
+	    eval {
+		PVE::Tools::run_command("/usr/bin/ping -c 1 $members->{$deadnode}->{ip}");
+	    };
+	    if(!$@){
+		die "error: ping to target $deadnode is still working. Node seem to be alive.";
+	    }
+
+	    #make an extra ssh connection to double check that it's not just a corosync crash
+	    my $sshinfo = PVE::SSHInfo::get_ssh_info($deadnode);
+	    my $sshcmd = PVE::SSHInfo::ssh_info_to_command($sshinfo);
+	    push @$sshcmd, 'hostname';
+	    print "test if deadnode $deadnode respond to ssh\n";
+	    eval {
+		PVE::Tools::run_command($sshcmd, timeout => 1);
+	    };
+	    if(!$@){
+		die "error: ssh connection to target $deadnode is still working. Node seem to be alive.";
+	    }
+
+
+	} elsif (PVE::QemuServer::check_running($vmid)) {
 	    die "can't migrate running VM without --online\n" if !$param->{online};
 
 	    my $repl_conf = PVE::ReplicationConfig->new();
@@ -4881,7 +4914,22 @@ __PACKAGE__->register_method({
 	    PVE::QemuServer::check_storage_availability($storecfg, $conf, $target);
 	}
 
-	if (PVE::HA::Config::vm_is_ha_managed($vmid) && $rpcenv->{type} ne 'ha') {
+	if ($deadnode) {
+	    my $realcmd = sub {
+		my $config_fn = PVE::QemuConfig->config_file($vmid, $deadnode);
+		my $new_config_fn = PVE::QemuConfig->config_file($vmid, $target);
+
+		rename($config_fn, $new_config_fn)
+		    or die "failed to move config file to node '$target': $!\n";
+	    };
+
+	    my $worker = sub {
+		return PVE::GuestHelpers::guest_migration_lock($vmid, 10, $realcmd);
+	    };
+
+	    return $rpcenv->fork_worker('qmigrate', $vmid, $authuser, $worker);
+
+        } elsif (PVE::HA::Config::vm_is_ha_managed($vmid) && $rpcenv->{type} ne 'ha') {
 
 	    my $hacmd = sub {
 		my $upid = shift;
-- 
2.39.5