FenceConfig: early return if file is empty

[pve-ha-manager.git] / src / PVE / HA / FenceConfig.pm

package PVE::HA::FenceConfig;

use strict;
use warnings;

use PVE::Tools;

sub parse_config {
    my ($fn, $raw) = @_;

    return {} if !$raw;

    my $config = {};

    my $lineno = 0;
    my $priority = 0;

    eval  {
	while ($raw =~ /^\h*(.*?)\h*$/gm) {
	    my $line = $1;
	    $lineno++;

	    next if !$line || $line =~ /^#/;

	    if ($line =~ m/^(device|connect)\s+(\S+)\s+(\S+)\s+(.+)$/) {
		my ($command, $dev_name, $target) = ($1, $2, $3);

		my $arg_array = PVE::Tools::split_args($4);

		my $dev_number = 1; # default

		# check for parallel devices
		if ($dev_name =~ m/^(\w+)(:(\d+))?/) {
		    $dev_name = $1;
		    $dev_number = $3 if $3;
		}

		if ($command eq "device") {

		    my $dev = $config->{$dev_name} || {};

		    die "device '$dev_name:$dev_number' already declared\n"
			if $dev && $dev->{sub_devs}->{$dev_number};

		    $dev->{sub_devs}->{$dev_number} = {
			agent => $target,
			args =>  $arg_array,
		    };
		    $dev->{priority} = $priority++ if !$dev->{priority};

		    $config->{$dev_name} = $dev;

		} else { # connect nodes to devices

		    die "device '$dev_name' must be declared before you can connect to it\n"
			if !$config->{$dev_name};

		    die "No parallel device '$dev_name:$dev_number' found\n"
			if !$config->{$dev_name}->{sub_devs}->{$dev_number};

		    my $sdev = $config->{$dev_name}->{sub_devs}->{$dev_number};

		    my ($node) = $target =~ /node=(\w+)/;
		    die "node=nodename needed to connect device '$dev_name' to node\n" 
			if !$node;

		    die "node '$node' already connected to device '$dev_name:$dev_number'\n" 
			if $sdev->{node_args}->{$node};

		    $sdev->{node_args}->{$node} = $arg_array;

		    $config->{$dev_name}->{sub_devs}->{$dev_number} = $sdev;
		}

	    } else {
		warn "$fn ignore line $lineno: $line\n"
	    }
	}
    };
    if (my $err = $@) {
	die "error in '$fn' at $lineno: $err";
    }

    return $config;
}

sub write_config {
    my ($fn, $data) = @_;

    my $raw = '';

    my $prev_priority = -1;

    foreach my $dev_name (sort {$data->{$a}->{priority} <=> $data->{$b}->{priority}} keys %$data) {
	my $d = $data->{$dev_name};

	die "Device '$dev_name' reuses priority! Priorities must be unique\n"
	  if $prev_priority == $d->{priority};

	$prev_priority = $d->{priority};

	foreach my $sub_dev_nr (sort keys %{$d->{sub_devs}}) {
	    my $sub_dev = $d->{sub_devs}->{$sub_dev_nr};
	    my $dev_arg_str = PVE::Tools::cmd2string($sub_dev->{args});

	    $raw .= "\ndevice $dev_name:$sub_dev_nr $sub_dev->{agent} $dev_arg_str\n";

	    foreach my $node (sort keys %{$sub_dev->{node_args}}) {
		my $node_arg_str = join (' ', @{$sub_dev->{node_args}->{$node}});

		$raw .= "connect $dev_name:$sub_dev_nr node=$node $node_arg_str\n";
	    }
	}
    }

    return $raw;
}



sub gen_arg_str {
    my (@arguments) = @_;

    my @shell_args = ();
    foreach my $arg (@arguments) {
	my ($key, $val) = split /=/, $arg;
	# we need to differ long and short opts!
	if (length($key) == 1) {
	    push @shell_args, "-${key}";
	    push @shell_args, PVE::Tools::shellquote($val) if defined($val);
	} else {
	    $key  .= '='. PVE::Tools::shellquote($val) if defined($val);
	    push @shell_args, "--$key";
	}
    }

    return join (' ', @shell_args);
}


# returns command list to execute,
# can be more than one command if parallel devices are configured
# 'try' denotes the number of devices we should skip and normaly equals to
# failed fencing tries
sub get_commands {
    my ($node, $try, $config) = @_;

    return undef if !$node || !$config;

    $try = 0 if !$try || $try<0;

    foreach my $device (sort {$a->{priority} <=> $b->{priority}} values %$config) {
	my @commands;

	#foreach my $sub_dev (values %{$device->{sub_devs}}) {
	foreach my $sub_dev_nr (sort keys %{$device->{sub_devs}}) {
	    my $sub_dev = $device->{sub_devs}->{$sub_dev_nr};

	    if (my $node_args = $sub_dev->{node_args}->{$node}) {
		push @commands, { agent=>$sub_dev->{agent},
				  sub_dev => $sub_dev_nr,
				  param => [@{$sub_dev->{args}}, @{$node_args}]};
	    }

	}

	if (@commands>0) {
	    $try--;
	    return [ @commands ] if $try<0;
	}
    }

    # out of tries or no device for this node
    return undef;
}


sub count_devices {
    my ($node, $config) = @_;

    my $count = 0;

    return 0 if !$config;

    foreach my $device (values %$config) {
	foreach my $sub_dev (values %{$device->{sub_devs}}) {
	    if ($sub_dev->{node_args}->{$node}) {
		$count++;
		last; # no need to count parallel devices
	    }
	}
    }

    return $count;
}

1;