--- /dev/null
+package PVE::Daemon;
+
+# Abstract class to implement Daemons
+#
+# Features:
+# * lock and write PID file /var/run/$name.pid to make sure onyl
+# one instance is running.
+# * correctly daemonize (redirect STDIN/STDOUT)
+# * daemon restart (option 'restart_on_error')
+
+use strict;
+use warnings;
+use PVE::SafeSyslog;
+use PVE::INotify;
+
+use POSIX ":sys_wait_h";
+use Fcntl ':flock';
+use Getopt::Long;
+use Time::HiRes qw (gettimeofday);
+
+use base qw(PVE::CLIHandler);
+
+$SIG{'__WARN__'} = sub {
+ my $err = $@;
+ my $t = $_[0];
+ chomp $t;
+ print "$t\n";
+ syslog('warning', "WARNING: %s", $t);
+ $@ = $err;
+};
+
+$ENV{'PATH'} = '/sbin:/bin:/usr/sbin:/usr/bin';
+
+my $daemon_initialized = 0; # we only allow one instance
+
+my $lockpidfile = sub {
+ my ($self) = @_;
+
+ my $lkfn = $self->{pidfile} . ".lock";
+
+ if (!open (FLCK, ">>$lkfn")) {
+ my $msg = "can't aquire lock on file '$lkfn' - $!";
+ syslog ('err', $msg);
+ die "ERROR: $msg\n";
+ }
+
+ if (!flock (FLCK, LOCK_EX|LOCK_NB)) {
+ close (FLCK);
+ my $msg = "can't aquire lock '$lkfn' - $!";
+ syslog ('err', $msg);
+ die "ERROR: $msg\n";
+ }
+};
+
+my $writepidfile = sub {
+ my ($self) = @_;
+
+ my $pidfile = $self->{pidfile};
+
+ if (!open (PIDFH, ">$pidfile")) {
+ my $msg = "can't open pid file '$pidfile' - $!";
+ syslog ('err', $msg);
+ die "ERROR: $msg\n";
+ }
+ print PIDFH "$$\n";
+ close (PIDFH);
+};
+
+my $server_cleanup = sub {
+ my ($self) = @_;
+
+ unlink $self->{pidfile} . ".lock";
+ unlink $self->{pidfile};
+};
+
+my $server_run = sub {
+ my ($self, $debug) = @_;
+
+ &$lockpidfile($self);
+
+ # run in background
+ my $spid;
+
+ my $restart = $ENV{RESTART_PVE_DAEMON};
+
+ delete $ENV{RESTART_PVE_DAEMON};
+
+ $self->{debug} = 1 if $debug;
+
+ $self->init();
+
+ if (!$debug) {
+ open STDIN, '</dev/null' || die "can't read /dev/null";
+ open STDOUT, '>/dev/null' || die "can't write /dev/null";
+ }
+
+ if (!$restart && !$debug) {
+ PVE::INotify::inotify_close();
+ $spid = fork();
+ if (!defined ($spid)) {
+ my $msg = "can't put server into background - fork failed";
+ syslog('err', $msg);
+ die "ERROR: $msg\n";
+ } elsif ($spid) { # parent
+ exit (0);
+ }
+ PVE::INotify::inotify_init();
+ }
+
+ &$writepidfile($self);
+
+ if ($restart) {
+ syslog('info' , "restarting server");
+ } else {
+ syslog('info' , "starting server");
+ }
+
+ open STDERR, '>&STDOUT' || die "can't close STDERR\n";
+
+ $SIG{INT} = $SIG{TERM} = $SIG{QUIT} = sub {
+ $SIG{INT} = 'DEFAULT';
+
+ eval { $self->shutdown(); };
+ warn $@ if $@;
+
+ &$server_cleanup($self);
+ };
+
+ $SIG{HUP} = sub {
+ eval { $self->hup(); };
+ warn $@ if $@;
+ };
+
+ eval { $self->run() };
+ my $err = $@;
+
+ if ($err) {
+ syslog ('err', "ERROR: $err");
+ if (my $wait_time = $self->{restart_on_error}) {
+ $self->restart_daemon($wait_time);
+ } else {
+ $self->exit_daemon(-1);
+ }
+ }
+
+ $self->exit_daemon(0);
+};
+
+sub new {
+ my ($this, $name, $cmdline, %params) = @_;
+
+ die "please run as root\n" if $> != 0;
+
+ die "missing name" if !$name;
+
+ die "can't create more that one PVE::Daemon" if $daemon_initialized;
+ $daemon_initialized = 1;
+
+ PVE::INotify::inotify_init();
+
+ initlog($name);
+
+ my $class = ref($this) || $this;
+
+ my $self = bless { name => $name }, $class;
+
+ $self->{pidfile} = "/var/run/${name}.pid";
+
+ $self->{nodename} = PVE::INotify::nodename();
+
+ $self->{cmdline} = $cmdline;
+
+ $0 = $name;
+
+ foreach my $opt (keys %params) {
+ my $value = $params{$opt};
+ if ($opt eq 'restart_on_error') {
+ $self->{$opt} = $value;
+ } elsif ($opt eq 'stop_wait_time') {
+ $self->{$opt} = $value;
+ } else {
+ die "unknown option '$opt'";
+ }
+ }
+
+ return $self;
+}
+
+sub exit_daemon {
+ my ($self, $status) = @_;
+
+ syslog("info", "server stopped");
+
+ &$server_cleanup($self);
+
+ exit($status);
+}
+
+sub restart_daemon {
+ my ($self, $waittime) = @_;
+
+ syslog('info', "server shutdown (restart)");
+
+ $ENV{RESTART_PVE_DAEMON} = 1;
+
+ sleep($waittime) if $waittime; # avoid high server load due to restarts
+
+ PVE::INotify::inotify_close();
+
+ exec (@{$self->{cmdline}});
+
+ exit (-1); # never reached?
+}
+
+# please overwrite in subclass
+# this is called at startup - before forking
+sub init {
+ my ($self) = @_;
+
+}
+
+# please overwrite in subclass
+sub shutdown {
+ my ($self) = @_;
+
+ syslog('info' , "server closing");
+
+ # wait for children
+ 1 while (waitpid(-1, POSIX::WNOHANG()) > 0);
+}
+
+# please overwrite in subclass
+sub hup {
+ my ($self) = @_;
+
+ syslog('info' , "received signal HUP (restart)");
+}
+
+# please overwrite in subclass
+sub run {
+ my ($self) = @_;
+
+ for (;;) { # forever
+ syslog('info' , "server is running");
+ sleep(5);
+ }
+}
+
+sub start {
+ my ($self, $debug) = @_;
+
+ &$server_run($self, $debug);
+}
+
+sub running {
+ my ($self) = @_;
+
+ my $pid = int(PVE::Tools::file_read_firstline($self->{pidfile}) || 0);
+
+ if ($pid) {
+ my $res = PVE::ProcFSTools::check_process_running($pid) ? 1 : 0;
+ return wantarray ? ($res, $pid) : $res;
+ }
+
+ return wantarray ? (0, 0) : 0;
+}
+
+sub stop {
+ my ($self) = @_;
+
+ my $pid = int(PVE::Tools::file_read_firstline($self->{pidfile}) || 0);
+ return if !$pid;
+
+ if (PVE::ProcFSTools::check_process_running($pid)) {
+ kill(15, $pid); # send TERM signal
+ # give some time
+ my $wait_time = $self->{stop_wait_time} || 5;
+ my $running = 1;
+ for (my $i = 0; $i < $wait_time; $i++) {
+ $running = PVE::ProcFSTools::check_process_running($pid);
+ last if !$running;
+ sleep (1);
+ }
+
+ syslog('err', "server still running - send KILL") if $running;
+
+ # to be sure
+ kill(9, $pid);
+ waitpid($pid, 0);
+ }
+
+ if (-f $self->{pidfile}) {
+ # try to get the lock
+ &$lockpidfile($self);
+ &$server_cleanup($self);
+ }
+}
+
+sub register_start_command {
+ my ($self, $class, $description) = @_;
+
+ $class->register_method({
+ name => 'start',
+ path => 'start',
+ method => 'POST',
+ description => $description || "Start the daemon.",
+ parameters => {
+ additionalProperties => 0,
+ properties => {
+ debug => {
+ description => "Debug mode - stay in foreground",
+ type => "boolean",
+ optional => 1,
+ default => 0,
+ },
+ },
+ },
+ returns => { type => 'null' },
+
+ code => sub {
+ my ($param) = @_;
+
+ $self->start($param->{debug});
+
+ return undef;
+ }});
+}
+
+sub register_restart_command {
+ my ($self, $class, $description) = @_;
+
+ $class->register_method({
+ name => 'restart',
+ path => 'restart',
+ method => 'POST',
+ description => $description || "Restart the daemon (or start if not running).",
+ parameters => {
+ additionalProperties => 0,
+ properties => {},
+ },
+ returns => { type => 'null' },
+
+ code => sub {
+ my ($param) = @_;
+
+ if (my $restart = $ENV{RESTART_PVE_DAEMON}) {
+ $self->start();
+ } else {
+ my ($running, $pid) = $self->running();
+ if (!$running) {
+ $self->start();
+ } else {
+ kill(1, $pid);
+ }
+ }
+
+ return undef;
+ }});
+}
+
+sub register_stop_command {
+ my ($self, $class, $description) = @_;
+
+ $class->register_method({
+ name => 'stop',
+ path => 'stop',
+ method => 'POST',
+ description => $description || "Stop the daemon.",
+ parameters => {
+ additionalProperties => 0,
+ properties => {},
+ },
+ returns => { type => 'null' },
+
+ code => sub {
+ my ($param) = @_;
+
+ $self->stop();
+
+ return undef;
+ }});
+}
+
+sub register_status_command {
+ my ($self, $class, $description) = @_;
+
+ $class->register_method({
+ name => 'status',
+ path => 'status',
+ method => 'GET',
+ description => "Get daemon status.",
+ parameters => {
+ additionalProperties => 0,
+ properties => {},
+ },
+ returns => {
+ type => 'string',
+ enum => ['stopped', 'running'],
+ },
+ code => sub {
+ my ($param) = @_;
+
+ return $self->running() ? 'running' : 'stopped';
+ }});
+}
+
+1;
+
projects / pve-common.git / commitdiff