#!/usr/bin/perl -w

use strict;
use Getopt::Long;
use PVE::SafeSyslog;
use IO::Select;
use IPC::Open3;
use IPC::Open2;
use PVE::Cluster;
use PVE::QemuServer;
use PVE::Storage;
use POSIX qw(strftime);

# fimxe: adopt for new cluster filestem

die "not implemented - fixme!";

# fixme: kvm > 88 has more migration options and verbose status

initlog('qmigrate');
PVE::Cluster::cfs_update();

sub print_usage {
    my $msg = shift;

    print STDERR "ERROR: $msg\n" if $msg;
    print STDERR "USAGE: qmigrate [--online] [--verbose]\n";
    print STDERR "                destination_address VMID\n";
    exit (-1);
}


# fixme: bwlimit ?

my $opt_online;
my $opt_verbose;

sub logmsg {
    my ($level, $msg) = @_;

    chomp $msg;

    return if !$msg;

    my $tstr = strftime ("%b %d %H:%M:%S", localtime);

    syslog ($level, $msg);

    foreach my $line (split (/\n/, $msg)) {
	print STDOUT "$tstr $line\n";
    }
    \*STDOUT->flush();
}

if (!GetOptions ('online' => \$opt_online, 
		 'verbose' => \$opt_verbose)) {
    print_usage ();
} 

if (scalar (@ARGV) != 2) {
    print_usage ();
}

my $host = shift;
my $vmid = shift;

# blowfish is a fast block cipher, much faster then 3des
my @ssh_opts = ('-c', 'blowfish', '-o', 'BatchMode=yes');
my @ssh_cmd = ('/usr/bin/ssh', @ssh_opts);
my @rem_ssh = (@ssh_cmd, "root\@$host");
my @scp_cmd = ('/usr/bin/scp', @ssh_opts);
my $qm_cmd = '/usr/sbin/qm';

$ENV{RSYNC_RSH} = join (' ', @ssh_cmd);

logmsg ('err', "illegal VMID") if $vmid !~ m/^\d+$/;
$vmid = int ($vmid); # remove leading zeros

my $storecfg = PVE::Storage::config(); 

my $conffile = PVE::QemuServer::config_file ($vmid);

my $delayed_interrupt = 0;

$SIG{INT} = $SIG{TERM} = $SIG{QUIT} = $SIG{HUP} = $SIG{PIPE} = sub {
    logmsg ('err', "received interrupt - delayed");
    $delayed_interrupt = 1;
};

sub eval_int {
    my ($func) = @_;

    eval {
	local $SIG{INT} = $SIG{TERM} = $SIG{QUIT} = $SIG{HUP} = sub {
	    $delayed_interrupt = 0;
	    logmsg ('err', "received interrupt");
	    die "interrupted by signal\n";
	};
	local $SIG{PIPE} = sub {
	    $delayed_interrupt = 0;
	    logmsg ('err', "received broken pipe interrupt");
	    die "interrupted by signal\n";
	};

	my $di = $delayed_interrupt;
	$delayed_interrupt = 0;

	die "interrupted by signal\n" if $di;

	&$func();
    };
}

sub prepare {

    die "VM $vmid does not exist\n" if ! -f $conffile;

    # test ssh connection
    my $cmd = [ @rem_ssh, '/bin/true' ];
    eval { PVE::Storage::run_command ($cmd); };
    die "Can't connect to destination address using public key\n" if $@;
  
    # test if VM already exists
    $cmd = [ @rem_ssh, $qm_cmd, 'status', $vmid ];
    my $stat = '';
    eval { 
	PVE::Storage::run_command ($cmd, outfunc => sub { $stat .= shift; });
    };
    die "can't query VM status on host '$host'\n" if $@;

    die "VM $vmid already exists on destination host\n" if $stat !~ m/^unknown$/;
}

sub sync_disks {
    my ($conf, $rhash, $running) = @_;

    logmsg ('info', "copying disk images");

    my $res = [];

    eval {

	my $volhash = {};

	# get list from PVE::Storage (for unused volumes)
	my $dl = PVE::Storage::vdisk_list ($storecfg, undef, $vmid);
	PVE::Storage::foreach_volid ($dl, sub {
	    my ($volid, $sid, $volname) = @_;

	    my $scfg =  PVE::Storage::storage_config ($storecfg, $sid);

	    return if $scfg->{shared};

	    $volhash->{$volid} = 1;
	});

	# and add used,owned/non-shared disks (just to be sure we have all)  

	my $sharedvm = 1;
	PVE::QemuServer::foreach_drive($conf, sub {
	    my ($ds, $drive) = @_;

	    return if PVE::QemuServer::drive_is_cdrom ($drive);

	    my $volid = $drive->{file};

	    return if !$volid;
	    die "cant migrate local file/device '$volid'\n" if $volid =~ m|^/|;

	    my ($sid, $volname) = PVE::Storage::parse_volume_id ($volid);
	    
	    my $scfg =  PVE::Storage::storage_config ($storecfg, $sid);

	    return if $scfg->{shared};

	    $sharedvm = 0;

	    my ($path, $owner) = PVE::Storage::path ($storecfg, $volid);

	    die "can't migrate volume '$volid' - owned by other VM (owner = VM $owner)\n" 
		if !$owner || ($owner != $vmid);

	    $volhash->{$volid} = 1;
	});

	if ($running && !$sharedvm) {
	    die "can't do online migration - VM uses local disks\n";
	}

	# do some checks first
	foreach my $volid (keys %$volhash) {
	    my ($sid, $volname) = PVE::Storage::parse_volume_id ($volid);
	    my $scfg =  PVE::Storage::storage_config ($storecfg, $sid);

	    die "can't migrate '$volid' - storagy type '$scfg->{type}' not supported\n"
		if $scfg->{type} ne 'dir';
	}

	foreach my $volid (keys %$volhash) {
	    my ($sid, $volname) = PVE::Storage::parse_volume_id ($volid);
	    push @{$rhash->{volumes}}, $volid;
	    PVE::Storage::storage_migrate ($storecfg, $volid, $host, $sid);
	}

    };
    die "Failed to sync data - $@" if $@;
}

sub fork_tunnel {
    my ($remhost, $lport, $rport) = @_;

    my $cmd = [@ssh_cmd, '-o', 'BatchMode=yes',
	       '-L', "$lport:localhost:$rport", $remhost,
	       'qm', 'mtunnel' ];
    
    my $tunnel = PVE::Storage::fork_command_pipe ($cmd);

    my $reader = $tunnel->{reader};

    my $helo;
    eval { 
	PVE::Storage::run_with_timeout (60, sub { $helo = <$reader>; }); 
	die "no reply\n" if !$helo;
	die "got strange reply from mtunnel ('$helo')\n" 
	    if $helo !~ m/^tunnel online$/;
    };
    my $err = $@;

    if ($err) {
	PVE::Storage::finish_command_pipe ($tunnel);
	die "can't open migration tunnel - $err";
    }
    return $tunnel;
}

sub finish_tunnel { 
    my $tunnel = shift;

    my $writer = $tunnel->{writer};

    eval { 
	PVE::Storage::run_with_timeout (30, sub {
	    print $writer "quit\n";
	    $writer->flush();
	}); 
    };
    my $err = $@;
	
    PVE::Storage::finish_command_pipe ($tunnel);
    
    die $err if $err;
}

sub phase1 {
    my ($conf, $rhash, $running) = @_;

    logmsg ('info', "starting migration of VM $vmid to host '$host'");

    my $loc_res = 0;
    $loc_res = 1 if $conf->{hostusb};
    $loc_res = 1 if $conf->{hostpci};
    $loc_res = 1 if $conf->{serial};
    $loc_res = 1 if $conf->{parallel};

    if ($loc_res) {
	if ($running) {
	    die "can't migrate VM which uses local devices\n";
	} else {
	    logmsg ('info', "migrating VM which uses local devices");
	}
    }

    # set migrate lock in config file
    $rhash->{clearlock} = 1;

    my $settings = { lock => 'migrate' };
    PVE::QemuServer::change_config_nolock  ($vmid, $settings, {}, 1);

    # copy config to remote host
    eval {
	my $cmd = [ @scp_cmd, $conffile, "root\@$host:$conffile"];
	PVE::Storage::run_command ($cmd);
	$rhash->{conffile} = 1;
    };
    die "Failed to copy config file - $@" if $@;

    sync_disks ($conf, $rhash, $running);
};

sub phase2 {
    my ($conf, $rhash) = shift;

    logmsg ('info', "starting VM on remote host '$host'");

    my $rport;

    ## start on remote host 
    my $cmd = [@rem_ssh, $qm_cmd, '--skiplock', 'start', $vmid, '--incoming', 'tcp'];

    PVE::Storage::run_command ($cmd, outfunc => sub {
	my $line = shift;

	if ($line =~ m/^migration listens on port (\d+)$/) {
	    $rport = $1;
	}
    });

    die "unable to detect remote migration port\n" if !$rport;

    logmsg ('info', "starting migration tunnel");
    ## create tunnel to remote port
    my $lport = PVE::QemuServer::next_migrate_port ();
    $rhash->{tunnel} = fork_tunnel ($host, $lport, $rport);

    logmsg ('info', "starting online/live migration");
    # start migration

    my $start = time();

    PVE::QemuServer::vm_monitor_command ($vmid, "migrate -d \"tcp:localhost:$lport\"");

    my $lstat = '';
    while (1) {
	sleep (2);
	my $stat = PVE::QemuServer::vm_monitor_command ($vmid, "info migrate", 1);
	if ($stat =~ m/^Migration status: (active|completed|failed|cancelled)$/im) {
	    my $ms = $1;

	    if ($stat ne $lstat) {
		if ($ms eq 'active') {
		    my ($trans, $rem, $total) = (0, 0, 0);
		    $trans = $1 if $stat =~ m/^transferred ram: (\d+) kbytes$/im;
		    $rem = $1 if $stat =~ m/^remaining ram: (\d+) kbytes$/im;
		    $total = $1 if $stat =~ m/^total ram: (\d+) kbytes$/im;

		    logmsg ('info', "migration status: $ms (transferred ${trans}KB, " .
			    "remaining ${rem}KB), total ${total}KB)");
		} else {
		    logmsg ('info', "migration status: $ms");
		}
	    }

	    if ($ms eq 'completed') {
		my $delay = time() - $start;
		if ($delay > 0) {
		    my $mbps = sprintf "%.2f", $conf->{memory}/$delay;
		    logmsg ('info', "migration speed: $mbps MB/s");
		}
	    }

	    if ($ms eq 'failed' || $ms eq 'cancelled') {
		die "aborting\n"
	    }

	    last if $ms ne 'active';
	} else {
	    die "unable to parse migration status '$stat' - aborting\n";
	}
	$lstat = $stat;
    };
}

my $errors;

my $starttime = time();

# lock config during migration 
PVE::QemuServer::lock_config ($vmid, sub {

    eval_int (\&prepare);
    die $@ if $@;

    my $conf = PVE::QemuServer::load_config($vmid);

    PVE::QemuServer::check_lock ($conf);
	
    my $running = 0;
    if (PVE::QemuServer::check_running ($vmid)) {
	die "cant migrate running VM without --online\n" if !$opt_online;
	$running = 1;
    }

    my $rhash = {};
    eval_int (sub { phase1 ($conf, $rhash, $running); });
    my $err = $@;

    if ($err) {
	if ($rhash->{clearlock}) {
	    my $unset = { lock => 1 };
	    eval { PVE::QemuServer::change_config_nolock ($vmid, {}, $unset, 1) };
	    logmsg ('err', $@) if $@;
	}
	if ($rhash->{conffile}) {
	    my $cmd = [ @rem_ssh, '/bin/rm', '-f', $conffile ];
	    eval { PVE::Storage::run_command ($cmd); };
	    logmsg ('err', $@) if $@;
	}
	if ($rhash->{volumes}) {
	    foreach my $volid (@{$rhash->{volumes}}) {
		logmsg ('err', "found stale volume copy '$volid' on host '$host'");
	    }
	}

	die $err;
    }

    # vm is now owned by other host
    my $volids = $rhash->{volumes};

    if ($running) {
    
	$rhash = {};
	eval_int (sub { phase2 ($conf, $rhash); });
	my $err = $@;

	# always kill tunnel
	if ($rhash->{tunnel}) {
	    eval_int (sub { finish_tunnel ($rhash->{tunnel}) });
	    if ($@) {
		logmsg ('err', "stopping tunnel failed - $@");
		$errors = 1;
	    }
	}

	# always stop local VM - no interrupts possible
	eval { PVE::QemuServer::vm_stop ($vmid, 1); };
	if ($@) {
	    logmsg ('err', "stopping vm failed - $@");
	    $errors = 1;
	}

	if ($err) {
	    $errors = 1;
	    logmsg ('err', "online migrate failure - $err");
	}
    }

    # finalize -- clear migrate lock
    eval_int (sub {
	my $cmd = [@rem_ssh, $qm_cmd, 'unlock', $vmid ]; 
	PVE::Storage::run_command ($cmd);
    });
    if ($@) {
	logmsg ('err', "failed to clear migrate lock - $@");
	$errors = 1;
    }
    
    unlink $conffile;

    # destroy local copies
    foreach my $volid (@$volids) {
	eval_int (sub { PVE::Storage::vdisk_free ($storecfg, $volid); });
	my $err = $@;

	if ($err) {
	    logmsg ('err', "removing local copy of '$volid' failed - $err");
	    $errors = 1;
	    
	    last if $err =~ /^interrupted by signal$/;
	}
    }
});

my $err = $@;

my $delay = time () - $starttime;
my $mins = int ($delay/60);
my $secs = $delay - $mins*60;
my $hours =  int ($mins/60);
$mins = $mins - $hours*60;

my $duration = sprintf "%02d:%02d:%02d", $hours, $mins, $secs;

if ($err) {
    logmsg ('err', $err) if $err;
    logmsg ('info', "migration aborted");
    exit (-1);
}

if ($errors) {
    logmsg ('info', "migration finished with problems (duration $duration)");
    exit (-1);
}

logmsg ('info', "migration finished successfuly (duration $duration)");

exit (0);

__END__

=head1 NAME

qmigrate - utility for VM migration between hardware nodes (kvm/qemu)

=head1 SYNOPSIS

qmigrate [--online] [--verbose] destination_address VMID

=head1 DESCRIPTION

no info available.