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390802ab DM |
1 | package PVE::Daemon; |
2 | ||
3 | # Abstract class to implement Daemons | |
4 | # | |
5 | # Features: | |
6 | # * lock and write PID file /var/run/$name.pid to make sure onyl | |
7 | # one instance is running. | |
8 | # * correctly daemonize (redirect STDIN/STDOUT) | |
9 | # * daemon restart (option 'restart_on_error') | |
10 | ||
11 | use strict; | |
12 | use warnings; | |
13 | use PVE::SafeSyslog; | |
14 | use PVE::INotify; | |
15 | ||
16 | use POSIX ":sys_wait_h"; | |
17 | use Fcntl ':flock'; | |
18 | use Getopt::Long; | |
19 | use Time::HiRes qw (gettimeofday); | |
20 | ||
21 | use base qw(PVE::CLIHandler); | |
22 | ||
23 | $SIG{'__WARN__'} = sub { | |
24 | my $err = $@; | |
25 | my $t = $_[0]; | |
26 | chomp $t; | |
27 | print "$t\n"; | |
28 | syslog('warning', "WARNING: %s", $t); | |
29 | $@ = $err; | |
30 | }; | |
31 | ||
32 | $ENV{'PATH'} = '/sbin:/bin:/usr/sbin:/usr/bin'; | |
33 | ||
34 | my $daemon_initialized = 0; # we only allow one instance | |
35 | ||
36 | my $lockpidfile = sub { | |
37 | my ($self) = @_; | |
38 | ||
39 | my $lkfn = $self->{pidfile} . ".lock"; | |
40 | ||
41 | if (!open (FLCK, ">>$lkfn")) { | |
42 | my $msg = "can't aquire lock on file '$lkfn' - $!"; | |
43 | syslog ('err', $msg); | |
44 | die "ERROR: $msg\n"; | |
45 | } | |
46 | ||
47 | if (!flock (FLCK, LOCK_EX|LOCK_NB)) { | |
48 | close (FLCK); | |
49 | my $msg = "can't aquire lock '$lkfn' - $!"; | |
50 | syslog ('err', $msg); | |
51 | die "ERROR: $msg\n"; | |
52 | } | |
53 | }; | |
54 | ||
55 | my $writepidfile = sub { | |
56 | my ($self) = @_; | |
57 | ||
58 | my $pidfile = $self->{pidfile}; | |
59 | ||
60 | if (!open (PIDFH, ">$pidfile")) { | |
61 | my $msg = "can't open pid file '$pidfile' - $!"; | |
62 | syslog ('err', $msg); | |
63 | die "ERROR: $msg\n"; | |
64 | } | |
65 | print PIDFH "$$\n"; | |
66 | close (PIDFH); | |
67 | }; | |
68 | ||
69 | my $server_cleanup = sub { | |
70 | my ($self) = @_; | |
71 | ||
72 | unlink $self->{pidfile} . ".lock"; | |
73 | unlink $self->{pidfile}; | |
74 | }; | |
75 | ||
76 | my $server_run = sub { | |
77 | my ($self, $debug) = @_; | |
78 | ||
79 | &$lockpidfile($self); | |
80 | ||
81 | # run in background | |
82 | my $spid; | |
83 | ||
84 | my $restart = $ENV{RESTART_PVE_DAEMON}; | |
85 | ||
86 | delete $ENV{RESTART_PVE_DAEMON}; | |
87 | ||
88 | $self->{debug} = 1 if $debug; | |
89 | ||
90 | $self->init(); | |
91 | ||
92 | if (!$debug) { | |
93 | open STDIN, '</dev/null' || die "can't read /dev/null"; | |
94 | open STDOUT, '>/dev/null' || die "can't write /dev/null"; | |
95 | } | |
96 | ||
97 | if (!$restart && !$debug) { | |
98 | PVE::INotify::inotify_close(); | |
99 | $spid = fork(); | |
100 | if (!defined ($spid)) { | |
101 | my $msg = "can't put server into background - fork failed"; | |
102 | syslog('err', $msg); | |
103 | die "ERROR: $msg\n"; | |
104 | } elsif ($spid) { # parent | |
105 | exit (0); | |
106 | } | |
107 | PVE::INotify::inotify_init(); | |
108 | } | |
109 | ||
110 | &$writepidfile($self); | |
111 | ||
112 | if ($restart) { | |
113 | syslog('info' , "restarting server"); | |
114 | } else { | |
115 | syslog('info' , "starting server"); | |
116 | } | |
117 | ||
118 | open STDERR, '>&STDOUT' || die "can't close STDERR\n"; | |
119 | ||
120 | $SIG{INT} = $SIG{TERM} = $SIG{QUIT} = sub { | |
121 | $SIG{INT} = 'DEFAULT'; | |
122 | ||
123 | eval { $self->shutdown(); }; | |
124 | warn $@ if $@; | |
125 | ||
126 | &$server_cleanup($self); | |
127 | }; | |
128 | ||
129 | $SIG{HUP} = sub { | |
130 | eval { $self->hup(); }; | |
131 | warn $@ if $@; | |
132 | }; | |
133 | ||
134 | eval { $self->run() }; | |
135 | my $err = $@; | |
136 | ||
137 | if ($err) { | |
138 | syslog ('err', "ERROR: $err"); | |
139 | if (my $wait_time = $self->{restart_on_error}) { | |
140 | $self->restart_daemon($wait_time); | |
141 | } else { | |
142 | $self->exit_daemon(-1); | |
143 | } | |
144 | } | |
145 | ||
146 | $self->exit_daemon(0); | |
147 | }; | |
148 | ||
149 | sub new { | |
150 | my ($this, $name, $cmdline, %params) = @_; | |
151 | ||
152 | die "please run as root\n" if $> != 0; | |
153 | ||
154 | die "missing name" if !$name; | |
155 | ||
156 | die "can't create more that one PVE::Daemon" if $daemon_initialized; | |
157 | $daemon_initialized = 1; | |
158 | ||
159 | PVE::INotify::inotify_init(); | |
160 | ||
161 | initlog($name); | |
162 | ||
163 | my $class = ref($this) || $this; | |
164 | ||
165 | my $self = bless { name => $name }, $class; | |
166 | ||
167 | $self->{pidfile} = "/var/run/${name}.pid"; | |
168 | ||
169 | $self->{nodename} = PVE::INotify::nodename(); | |
170 | ||
171 | $self->{cmdline} = $cmdline; | |
172 | ||
173 | $0 = $name; | |
174 | ||
175 | foreach my $opt (keys %params) { | |
176 | my $value = $params{$opt}; | |
177 | if ($opt eq 'restart_on_error') { | |
178 | $self->{$opt} = $value; | |
179 | } elsif ($opt eq 'stop_wait_time') { | |
180 | $self->{$opt} = $value; | |
181 | } else { | |
182 | die "unknown option '$opt'"; | |
183 | } | |
184 | } | |
185 | ||
186 | return $self; | |
187 | } | |
188 | ||
189 | sub exit_daemon { | |
190 | my ($self, $status) = @_; | |
191 | ||
192 | syslog("info", "server stopped"); | |
193 | ||
194 | &$server_cleanup($self); | |
195 | ||
196 | exit($status); | |
197 | } | |
198 | ||
199 | sub restart_daemon { | |
200 | my ($self, $waittime) = @_; | |
201 | ||
202 | syslog('info', "server shutdown (restart)"); | |
203 | ||
204 | $ENV{RESTART_PVE_DAEMON} = 1; | |
205 | ||
206 | sleep($waittime) if $waittime; # avoid high server load due to restarts | |
207 | ||
208 | PVE::INotify::inotify_close(); | |
209 | ||
210 | exec (@{$self->{cmdline}}); | |
211 | ||
212 | exit (-1); # never reached? | |
213 | } | |
214 | ||
215 | # please overwrite in subclass | |
216 | # this is called at startup - before forking | |
217 | sub init { | |
218 | my ($self) = @_; | |
219 | ||
220 | } | |
221 | ||
222 | # please overwrite in subclass | |
223 | sub shutdown { | |
224 | my ($self) = @_; | |
225 | ||
226 | syslog('info' , "server closing"); | |
227 | ||
228 | # wait for children | |
229 | 1 while (waitpid(-1, POSIX::WNOHANG()) > 0); | |
230 | } | |
231 | ||
232 | # please overwrite in subclass | |
233 | sub hup { | |
234 | my ($self) = @_; | |
235 | ||
236 | syslog('info' , "received signal HUP (restart)"); | |
237 | } | |
238 | ||
239 | # please overwrite in subclass | |
240 | sub run { | |
241 | my ($self) = @_; | |
242 | ||
243 | for (;;) { # forever | |
244 | syslog('info' , "server is running"); | |
245 | sleep(5); | |
246 | } | |
247 | } | |
248 | ||
249 | sub start { | |
250 | my ($self, $debug) = @_; | |
251 | ||
252 | &$server_run($self, $debug); | |
253 | } | |
254 | ||
255 | sub running { | |
256 | my ($self) = @_; | |
257 | ||
258 | my $pid = int(PVE::Tools::file_read_firstline($self->{pidfile}) || 0); | |
259 | ||
260 | if ($pid) { | |
261 | my $res = PVE::ProcFSTools::check_process_running($pid) ? 1 : 0; | |
262 | return wantarray ? ($res, $pid) : $res; | |
263 | } | |
264 | ||
265 | return wantarray ? (0, 0) : 0; | |
266 | } | |
267 | ||
268 | sub stop { | |
269 | my ($self) = @_; | |
270 | ||
271 | my $pid = int(PVE::Tools::file_read_firstline($self->{pidfile}) || 0); | |
272 | return if !$pid; | |
273 | ||
274 | if (PVE::ProcFSTools::check_process_running($pid)) { | |
275 | kill(15, $pid); # send TERM signal | |
276 | # give some time | |
277 | my $wait_time = $self->{stop_wait_time} || 5; | |
278 | my $running = 1; | |
279 | for (my $i = 0; $i < $wait_time; $i++) { | |
280 | $running = PVE::ProcFSTools::check_process_running($pid); | |
281 | last if !$running; | |
282 | sleep (1); | |
283 | } | |
284 | ||
285 | syslog('err', "server still running - send KILL") if $running; | |
286 | ||
287 | # to be sure | |
288 | kill(9, $pid); | |
289 | waitpid($pid, 0); | |
290 | } | |
291 | ||
292 | if (-f $self->{pidfile}) { | |
293 | # try to get the lock | |
294 | &$lockpidfile($self); | |
295 | &$server_cleanup($self); | |
296 | } | |
297 | } | |
298 | ||
299 | sub register_start_command { | |
300 | my ($self, $class, $description) = @_; | |
301 | ||
302 | $class->register_method({ | |
303 | name => 'start', | |
304 | path => 'start', | |
305 | method => 'POST', | |
306 | description => $description || "Start the daemon.", | |
307 | parameters => { | |
308 | additionalProperties => 0, | |
309 | properties => { | |
310 | debug => { | |
311 | description => "Debug mode - stay in foreground", | |
312 | type => "boolean", | |
313 | optional => 1, | |
314 | default => 0, | |
315 | }, | |
316 | }, | |
317 | }, | |
318 | returns => { type => 'null' }, | |
319 | ||
320 | code => sub { | |
321 | my ($param) = @_; | |
322 | ||
323 | $self->start($param->{debug}); | |
324 | ||
325 | return undef; | |
326 | }}); | |
327 | } | |
328 | ||
329 | sub register_restart_command { | |
330 | my ($self, $class, $description) = @_; | |
331 | ||
332 | $class->register_method({ | |
333 | name => 'restart', | |
334 | path => 'restart', | |
335 | method => 'POST', | |
336 | description => $description || "Restart the daemon (or start if not running).", | |
337 | parameters => { | |
338 | additionalProperties => 0, | |
339 | properties => {}, | |
340 | }, | |
341 | returns => { type => 'null' }, | |
342 | ||
343 | code => sub { | |
344 | my ($param) = @_; | |
345 | ||
346 | if (my $restart = $ENV{RESTART_PVE_DAEMON}) { | |
347 | $self->start(); | |
348 | } else { | |
349 | my ($running, $pid) = $self->running(); | |
350 | if (!$running) { | |
351 | $self->start(); | |
352 | } else { | |
353 | kill(1, $pid); | |
354 | } | |
355 | } | |
356 | ||
357 | return undef; | |
358 | }}); | |
359 | } | |
360 | ||
361 | sub register_stop_command { | |
362 | my ($self, $class, $description) = @_; | |
363 | ||
364 | $class->register_method({ | |
365 | name => 'stop', | |
366 | path => 'stop', | |
367 | method => 'POST', | |
368 | description => $description || "Stop the daemon.", | |
369 | parameters => { | |
370 | additionalProperties => 0, | |
371 | properties => {}, | |
372 | }, | |
373 | returns => { type => 'null' }, | |
374 | ||
375 | code => sub { | |
376 | my ($param) = @_; | |
377 | ||
378 | $self->stop(); | |
379 | ||
380 | return undef; | |
381 | }}); | |
382 | } | |
383 | ||
384 | sub register_status_command { | |
385 | my ($self, $class, $description) = @_; | |
386 | ||
387 | $class->register_method({ | |
388 | name => 'status', | |
389 | path => 'status', | |
390 | method => 'GET', | |
391 | description => "Get daemon status.", | |
392 | parameters => { | |
393 | additionalProperties => 0, | |
394 | properties => {}, | |
395 | }, | |
396 | returns => { | |
397 | type => 'string', | |
398 | enum => ['stopped', 'running'], | |
399 | }, | |
400 | code => sub { | |
401 | my ($param) = @_; | |
402 | ||
403 | return $self->running() ? 'running' : 'stopped'; | |
404 | }}); | |
405 | } | |
406 | ||
407 | 1; | |
408 |