1.\" $OpenBSD: rc.subr.8,v 1.45 2022/05/27 12:27:39 ajacoutot Exp $ 2.\" 3.\" Copyright (c) 2021 Antoine Jacoutot 4.\" Copyright (c) 2011 Robert Nagy, Antoine Jacoutot, Ingo Schwarze 5.\" All rights reserved. 6.\" 7.\" Redistribution and use in source and binary forms, with or without 8.\" modification, are permitted provided that the following conditions 9.\" are met: 10.\" 11.\" 1. Redistributions of source code must retain the above copyright 12.\" notice, this list of conditions and the following disclaimer. 13.\" 2. Redistributions in binary form must reproduce the above copyright 14.\" notice, this list of conditions and the following disclaimer in the 15.\" documentation and/or other materials provided with the distribution. 16.\" 17.\" THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR 18.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 19.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 20.\" IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT, 21.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 22.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 26.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27.\" 28.Dd $Mdocdate: May 27 2022 $ 29.Dt RC.SUBR 8 30.Os 31.Sh NAME 32.Nm rc.subr 33.Nd daemon control scripts routines 34.Sh SYNOPSIS 35.Nm daemon Ns = Ns Ar path_to_executable 36.Nm .\& 37.Pa /etc/rc.d/rc.subr 38.Nm rc_cmd 39.Ar action 40.Sh DESCRIPTION 41Apart from a few notable exceptions, rc scripts must follow this 42naming policy: 43.Pp 44.Bl -enum -compact 45.It 46When possible, use the same name as the 47.Nm daemon 48it is referring to. 49.It 50It must follow 51.Xr ksh 1 52variable naming: begin with an alphabetic or underscore character, followed by 53one or more alphanumeric or underscore characters. 54Dashes 55.Pq Sq - 56have to be converted to 57underscores 58.Pq Sq _ . 59.El 60.Pp 61Every script under 62.Pa /etc/rc.d 63follows this pattern: 64.Pp 65.Bl -enum -compact 66.It 67Define the 68.Va daemon 69variable. 70.It 71Define service-specific defaults for one or more 72.Va daemon_* 73variables (optional). 74.It 75Source 76.Nm , 77which defines default shell functions and variable values. 78.It 79Override the 80.Va pexp 81variable or any of the 82.Ic rc_* 83functions and set the 84.Va rc_bg 85or 86.Va rc_reload 87variables, if needed. 88.It 89Define an 90.Ic rc_pre 91and/or 92.Ic rc_post 93function, if needed. 94.It 95Call the 96.Ic rc_cmd 97function as 98.Dq "rc_cmd $1" . 99.El 100.Pp 101The following shell functions are defined by 102.Nm : 103.Bl -tag -width rc_reload 104.It Ic rc_check 105Search for processes of the service with 106.Xr pgrep 1 107using the regular expression given in the 108.Va pexp 109variable. 110.It Ic rc_cmd Ar action 111Run the 112.Ar action 113for the current 114.Nm rc.d 115script, based on the settings of various shell variables. 116.Ic rc_cmd 117is extremely flexible, and allows fully functional 118.Nm rc.d 119scripts to be implemented in a small amount of shell code. 120For a given 121.Ar action , 122if the 123.Ic rc_${action} 124function is not defined, then a default function is provided by 125.Nm rc.subr . 126In addition actions can be disabled by setting the 127.Va rc_${action} 128variable to 129.Dq NO . 130For example, if 131.Dq rc_reload=NO 132is set in the 133.Nm rc.d 134script, and 135.Ic rc_cmd 136is called for the reload action, an error will be raised. 137Similarly, the special variable 138.Va rc_usercheck 139must be set to 140.Dq NO 141if the 142.Cm check 143.Ar action 144requires root privileges. 145.Pp 146The 147.Ar action 148argument can be 149.Cm start , 150.Cm stop , 151.Cm reload , 152.Cm restart , 153or 154.Cm check : 155.Bl -tag -width restart 156.It Ic check 157Call 158.Ic rc_check . 159Return 0 if the daemon is running or 1 if it is not. 160.It Ic start 161Check that the service is running by calling 162.Ic rc_check . 163If it's not running, call 164.Ic rc_pre 165if it exists, then 166.Ic rc_start . 167.It Ic stop 168Check that the service is running by calling 169.Ic rc_check . 170If it is running, 171call 172.Ic rc_stop 173and wait up to 30 seconds for the daemon to properly shutdown. 174If successful, run 175.Ic rc_post 176if it exists. 177.It Ic restart 178Run the 179.Ar action 180argument 181.Cm stop , 182then if successful run 183.Cm start . 184.It Ic reload 185Check that the service is running by calling 186.Ic rc_check . 187If it is running, 188call 189.Ic rc_reload . 190.El 191.It Ic rc_exec 192Execute argument using 193.Xr su 1 194according to 195.Va daemon_class , 196.Va daemon_execdir , 197.Va daemon_user , 198.Va daemon_rtable 199and 200.Va daemon_logger 201values. 202.It Ic rc_reload 203Send the 204.Va rc_reload_signal 205using 206.Xr pkill 1 207on the regular expression given in the 208.Va pexp 209variable. 210One has to make sure that sending 211.Dv SIGHUP 212to a daemon will have the desired effect, 213i.e. that it will reload its configuration. 214.It Ic rc_start 215Start the daemon. 216Defaults to: 217.Bd -literal -offset indent 218rc_exec "${daemon} ${daemon_flags}" 219.Ed 220.It Ic rc_stop 221Stop the daemon. 222Send the 223.Va rc_stop_signal 224using 225.Xr pkill 1 226on the regular expression given in the 227.Va pexp 228variable. 229.El 230.Sh ENVIRONMENT 231.Ic rc_cmd 232uses the following shell variables to control its behaviour. 233.Bl -tag -width "daemon_timeout" 234.It Va daemon 235The path to the daemon, optionally followed by one or more 236whitespace separated arguments. 237Arguments included here are always used, even if 238.Va daemon_flags 239is empty. 240This variable is required. 241It is an error to source 242.Nm 243without defining 244.Va daemon 245first. 246.It Va daemon_class 247Login class to run the daemon with, using 248.Xr su 1 . 249This is a read only variable that gets set by 250.Nm rc.subr 251itself. 252It searches 253.Xr login.conf 5 254for a login class that has the same name as the 255.Nm rc.d 256script itself and uses that. 257If no such login class exists then 258.Dq daemon 259will be used. 260.It Va daemon_execdir 261Change to this directory before running 262.Ic rc_exec . 263.It Va daemon_flags 264Arguments to call the daemon with. 265.It Ar daemon_logger 266Redirect standard output and error to 267.Xr logger 1 268using the configured priority (e.g. "daemon.info"). 269.It Va daemon_rtable 270Routing table to run the daemon under, using 271.Xr route 8 . 272.It Va daemon_timeout 273Maximum time in seconds to wait for the 274.Cm start , 275.Cm stop 276and 277.Cm reload 278actions to return. 279This is only guaranteed with the default 280.Ic rc_start , 281.Ic rc_stop 282and 283.Ic rc_reload 284functions. 285.It Va daemon_user 286User to run the daemon as, using 287.Xr su 1 . 288.It Va pexp 289A regular expression to be passed to 290.Xr pgrep 1 291in order to find the desired process or to be passed to 292.Xr pkill 1 293to stop it. 294By default this variable contains the 295.Va daemon 296and 297.Va daemon_flags 298variables. 299To override the default value, an 300.Nm rc.d 301script has to redefine this variable 302.Em after 303sourcing 304.Nm . 305.It Va rc_bg 306Can be set to 307.Cm YES 308in an 309.Nm rc.d 310script to force starting the daemon in background when using the default 311.Ic rc_start . 312.It Va rc_reload 313Can be set to 314.Dq NO 315in an 316.Nm rc.d 317script to disable the reload action if the respective daemon 318does not support reloading its configuration. 319.Em The same is possible, but almost never useful, for other actions. 320.It Va rc_reload_signal 321Signal sent to the daemon process 322.Pq Va pexp 323by the default 324.Fn rc_reload 325function. 326Default to 327.Em HUP . 328.It Va rc_stop_signal 329Signal sent to the daemon process 330.Pq Va pexp 331by the default 332.Fn rc_stop 333function. 334Default to 335.Em TERM . 336.It Va rc_usercheck 337Can be set to 338.Dq NO 339in an 340.Nm rc.d 341script, if the 342.Cm check 343action needs root privileges. 344.El 345.Pp 346All 347.Va daemon_* 348variables are set in the following ways: 349.Bl -enum 350.It 351Global defaults are provided by 352.Nm : 353.Bd -literal -offset indent 354daemon_class=daemon 355daemon_execdir= 356daemon_flags= 357daemon_logger= 358daemon_rtable=0 359daemon_timeout=30 360daemon_user=root 361.Ed 362.It 363Service-specific defaults may be provided in the respective 364.Nm rc.d 365script 366.Em before 367sourcing 368.Nm , 369thus overriding the global defaults. 370.It 371As noted in 372.Xr rc.d 8 , 373site-specific values provided in 374.Xr rc.conf.local 8 375for 376.Va daemon_execdir , 377.Va daemon_flags , 378.Va daemon_logger , 379.Va daemon_rtable , 380.Va daemon_timeout , 381and 382.Va daemon_user 383will override those defaults. 384.El 385.Sh FILES 386.Bl -tag -width Ds 387.It Pa /etc/rc.d/ 388Directory containing daemon control scripts. 389.It Pa /etc/rc.d/rc.subr 390Functions and variables used by 391.Nm rc.d 392scripts. 393.It Pa /usr/ports/infrastructure/templates/rc.template 394A sample 395.Nm rc.d 396script. 397.El 398.Sh SEE ALSO 399.Xr rc 8 , 400.Xr rc.conf 8 , 401.Xr rc.d 8 402.Sh HISTORY 403The 404.Nm 405framework 406first appeared in 407.Ox 4.9 . 408.Sh AUTHORS 409.An -nosplit 410The 411.Nm 412framework was written by 413.An Robert Nagy Aq Mt robert@openbsd.org , 414.An Antoine Jacoutot Aq Mt ajacoutot@openbsd.org , 415and 416.An Ingo Schwarze Aq Mt schwarze@openbsd.org . 417