1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
|
.\" Copyright (c) 2007-2015 The OpenRC Authors.
.\" See the Authors file at the top-level directory of this distribution and
.\" https://github.com/OpenRC/openrc/blob/master/AUTHORS
.\"
.\" This file is part of OpenRC. It is subject to the license terms in
.\" the LICENSE file found in the top-level directory of this
.\" distribution and at https://github.com/OpenRC/openrc/blob/master/LICENSE
.\" This file may not be copied, modified, propagated, or distributed
.\" except according to the terms contained in the LICENSE file.
.\"
.Dd April 27, 2016
.Dt supervise-DAEMON 8 SMM
.Os OpenRC
.Sh NAME
.Nm supervise-daemon
.Nd starts a daemon and restarts it if it crashes
.Sh SYNOPSIS
.Nm
.Fl d , -chdir
.Ar path
.Fl e , -env
.Ar var=value
.Fl g , -group
.Ar group
.Fl I , -ionice
.Ar arg
.Fl k , -umask
.Ar value
.Fl N , -nicelevel
.Ar level
.Fl p , -pidfile
.Ar pidfile
.Fl u , -user
.Ar user
.Fl r , -chroot
.Ar chrootpath
.Fl R , -respawn-limit
.Ar limit
.Fl 1 , -stdout
.Ar logfile
.Fl 2 , -stderr
.Ar logfile
.Fl S , -start
.Ar daemon
.Op Fl -
.Op Ar arguments
.Nm
.Fl K , -stop
.Ar daemon
.Fl p , -pidfile
.Ar pidfile
.Fl r , -chroot
.Ar chrootpath
.Sh DESCRIPTION
.Nm
provides a consistent method of starting, stopping and restarting
daemons. If
.Fl K , -stop
is not provided, then we assume we are starting the daemon.
.Nm
only works with daemons which do not fork. Also, it uses its own pid
file, so the daemon should not write a pid file, or the pid file passed
to
.Nm
should not be the one the daemon writes.
.Pp
Here are the options to specify the daemon and how it should start or stop:
.Bl -tag -width indent
.It Fl p , -pidfile Ar pidfile
When starting, we write a
.Ar pidfile
so we know which supervisor to stop. When stopping we only stop the pid(s)
listed in the
.Ar pidfile .
.It Fl u , -user Ar user Ns Op : Ns Ar group
Start the daemon as the
.Ar user
and update $HOME accordingly or stop daemons
owned by the user. You can optionally append a
.Ar group
name here also.
.It Fl v , -verbose
Print the action(s) that are taken just before doing them.
.Pp
The options are as follows:
.Bl -tag -width indent
.It Fl d , -chdir Ar path
chdir to this directory before starting the daemon.
.It Fl e , -env Ar VAR=VALUE
Set the environment variable VAR to VALUE.
.It Fl g , -group Ar group
Start the daemon as in the group.
.It Fl I , -ionice Ar class Ns Op : Ns Ar data
Modifies the IO scheduling priority of the daemon.
Class can be 0 for none, 1 for real time, 2 for best effort and 3 for idle.
Data can be from 0 to 7 inclusive.
.It Fl k , -umask Ar mode
Set the umask of the daemon.
.It Fl N , -nicelevel Ar level
Modifies the scheduling priority of the daemon.
.It Fl r , -chroot Ar path
chroot to this directory before starting the daemon. All other paths, such
as the path to the daemon, chdir and pidfile, should be relative to the chroot.
.It Fl R , -respawn-limit Ar limit
Control how agressively
.Nm
will try to respawn a daemon when it fails to start. The limit argument
can be a pair of integers separated bya colon or the string unlimited.
.Pp
If a pair of integers is given, the first is a maximum number of respawn
attempts and the second is a time period. It should be interpreted as:
If the daemon dies and has to be respawned more than <first number>
times in any time period of <second number> seconds, exit and give up.
.Pp
For example, the default is 10:5.
This means if the supervisor respawns a daemon more than ten times
in any 5 second period, it gives up and exits.
.Pp
if unlimited is given as the limit, it means that the supervisor will
not exit or give up, no matter how many times the daemon it is
supervising needs to be respawned.
.It Fl u , -user Ar user
Start the daemon as the specified user.
.It Fl 1 , -stdout Ar logfile
Redirect the standard output of the process to logfile.
Must be an absolute pathname, but relative to the path optionally given with
.Fl r , -chroot .
The logfile can also be a named pipe.
.It Fl 2 , -stderr Ar logfile
The same thing as
.Fl 1 , -stdout
but with the standard error output.
.El
.Sh ENVIRONMENT
.Va SSD_NICELEVEL
can also set the scheduling priority of the daemon, but the command line
option takes precedence.
.Sh NOTE
.Nm
uses
.Xr getopt 3
to parse its options, which allows it to accept the `--' option which will
cause it to stop processing options at that point. Any subsequent arguments
are passed as arguments to the daemon to start and used when finding a daemon
to stop or signal.
.Sh SEE ALSO
.Xr chdir 2 ,
.Xr chroot 2 ,
.Xr getopt 3 ,
.Xr nice 2 ,
.Xr rc_find_pids 3
.Sh BUGS
.Nm
cannot stop an interpreted daemon that no longer exists without a pidfile.
.Sh HISTORY
.Nm
first appeared in Debian.
.Pp
This is a complete re-implementation with the process finding code in the
OpenRC library (librc, -lrc) so other programs can make use of it.
.Sh AUTHORS
.An William Hubbs <w.d.hubbs@gmail.com>
|
