Files
netdisco/Netdisco/bin/netdisco-daemon
2012-12-17 18:31:16 +00:00

140 lines
3.2 KiB
Perl
Executable File

#!/usr/bin/env perl
use FindBin;
use lib "$FindBin::Bin/../lib";
use App::Netdisco;
use Dancer qw/:moose :script/;
use Dancer::Plugin::DBIC 'schema';
use Daemon::Generic::While1;
use Parallel::Prefork;
use Net::Domain 'hostfqdn';
use Role::Tiny;
use Try::Tiny;
# Parallel::Prefork instance
my $pp = undef;
# track worker pids and their roles
my %workers = ();
my $next_role = undef;
# must come after globals initialization
newdaemon(
progname => 'netdisco-daemon',
($> != 0 ? (pidbase => './') : ()),
logpriority => 'daemon.info',
);
sub gd_preconfig {
my $gd = shift;
# used for locking jobs in central Pg queue
$gd->{nd_host} = hostfqdn;
set(daemon_pollers => 2)
if !defined setting('daemon_pollers');
set(daemon_interactives => 2)
if !defined setting('daemon_interactives');
# need to do this after setting defaults
$pp = Parallel::Prefork->new(
max_workers => (1 + setting('daemon_pollers')
+ setting('daemon_interactives')),
spawn_interval => 2,
before_fork => \&set_next_worker_role,
after_fork => \&register_worker,
on_child_reap => \&unregister_worker,
trap_signals => {
TERM => 'TERM',
INT => 'TERM',
},
);
# do not remove this line - required by Daemon::Generic
return ();
}
# main loop
sub gd_run_body {
my $gd = shift;
$gd->handle_term
if $pp->signal_received =~ m/^(?:TERM|INT)$/;
$pp->start(sub {
print STDERR ">>> new $next_role worker starting...\n";
with "App::Netdisco::Daemon::Worker::$next_role";
$gd->worker_begin if $gd->can('worker_begin');
$gd->worker_body;
$gd->worker_end if $gd->can('worker_end');
});
# I don't think Parallel::Prefork ever returns from start()
# until a child exits. Not sure this is ever reached.
$gd->gd_sleep( setting('daemon_sleep_time') || 5 )
if not $pp->signal_received;
}
sub register_worker {
my (undef, $pid) = @_;
$workers{$pid} = $next_role;
}
sub unregister_worker {
my (undef, $pid, $status) = @_;
delete $workers{$pid};
# also check for bad exit status?
# revert any running jobs (will be such if child died)
try {
schema('daemon')->resultset('Admin')
->search({status => "running-$pid"})
->update({status => 'queued', started => undef});
}
catch { warn "error reverting jobs for pid $pid: $_\n" };
}
sub set_next_worker_role {
my $pp = shift;
$next_role = _find_next_worker_role();
}
sub _find_next_worker_role {
my @cur = values %workers;
my $manager = scalar grep {$_ eq 'Manager'} @cur;
my $poller = scalar grep {$_ eq 'Poller'} @cur;
my $inter = scalar grep {$_ eq 'Interactive'} @cur;
return 'Manager' if $manager < 1;
my $need_poller = $poller < setting('daemon_pollers');
my $need_inter = $inter < setting('daemon_interactives');
if ($need_poller and $need_inter) {
return (int(rand(2)) ? 'Interactive' : 'Poller');
}
return 'Interactive' if $need_inter;
return 'Poller' if $need_poller;
}
sub handle_term {
my $gd = shift;
$pp->wait_all_children;
$gd->gd_quit_event
}
# in case we screw up and die ourselves
END {
if (defined $pp) {
$pp->signal_all_children('TERM');
$pp->wait_all_children;
}
}
# nullify this to permit Parallel::Prefork to register handlers instead
sub gd_setup_signals {}