Date: Tue, 07 Jul 2009 07:05:45 +0900 (JST) From: Hiroki Sato <hrs@FreeBSD.org> To: freebsd-rc@FreeBSD.org Cc: freebsd-current@FreeBSD.org Subject: RFC: set_rcvar in rc.subr Message-ID: <20090707.070545.02771440.hrs@allbsd.org>
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Hi,
I would like to propose an expansion of set_rcvar() in rc.subr. The
motivation and the change are the following.
The current rc.d scripts depend on variables defined in
/etc/defaults/rc.conf. However, it is unclear that which variables
are used in a script and assigning a default value to a variable is
scattered and inconsistent. Also, it is difficult to detect
definition of obsolete variables in /etc/rc.conf and
/etc/defaults/rc.conf.
The proposed changes are:
1. Add a functionality to declare a rc.conf variable and its default
value to set_rcvar(). The syntax is:
set_rcvar <varname> <defvalue> <desc>
The declared variables are set by load_rc_config(). Note that
this behavior of set_rcvar() is backward compatible.
For example, a script for routed(8) will be something like this:
----
name="routed"
rcvar=`set_rcvar`
set_rcvar ${name}_enable NO
set_rcvar ${name}_flags "-q" \
"Flags for ${name}(8)."
set_rcvar ${name}_program "/usr/sbin/routed" \
"Program name for ${name}(8)."
load_rc_config $name
run_rc_command "$1"
----
2. Display the declared variables by "rc.d/foo rcvar" with
the default value and description like this:
% /etc/rc.d/routed rcvar
# routed : network RIP and router discovery routing daemon
#
routed_enable="NO"
# (default: "NO")
routed_flags="-q"
# - Flags for routed(8).
# (default: "-q")
routed_program="/sbin/routed"
# - Program name for routed(8).
# (default: "/usr/sbin/routed")
It should be easier to understand the variables than the current
/etc/defaults/rc.conf and always consistent.
To do this, all of rc.d scripts have to have run_rc_command()
while currently some scripts which always run have no $rcvar and
run_rc_command(). Adding run_rc_command() becomes no problem and
rather good for consistency, IMHO. Also, $desc is added for
description of the script displayed in above example.
Entries for each rc.d script in /etc/defaults/rc.conf can be
removed, and the equivalent contents can be generated by the
following command:
# for F in `rcorder /etc/rc.d/*`; do $F rcvar; done
3. Add a way to obsolete a variable. This is done by adding
set_rcvar_obsolete() function.
set_rcvar_obsolete <oldvar> <newvar>
If <oldvar> is defined, do newvar=$oldvar and display a warning in
load_rc_config(). This makes easier to detect an obsolete
variable in an old rc.conf file.
The attached patch is a working example. If there is no strong
objection I want to convert all of the current rc.d scripts in this
way. Note that this patch include a change not directly related to
the above; handling $_override_command in run_rc_command() looks
wrong to me. When ${name}_program is defined and $command is not the
former is used as the command, and if $command is defined directly it
is used by priority.
Comments or objections?
-- Hiroki
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Index: rc.subr
===================================================================
--- rc.subr (revision 195284)
+++ rc.subr (working copy)
@@ -72,38 +72,64 @@
# functions
# ---------
+# set_rcvar [var] [defval] [desc]
#
-# set_rcvar base_var
-# Set the variable name enabling a specific service.
-# FreeBSD uses ${service}_enable, while NetBSD uses
-# just the name of the service. For example:
-# FreeBSD: sendmail_enable="YES"
-# NetBSD : sendmail="YES"
-# $1 - if $name is not the base to work of off, specify
-# a different one
+# Echo or define a rc.conf(5) variable name. Global variable
+# $rcvars is used.
#
+# If no argument is specified, echo "${name}_enable".
+#
+# If only a var is specified, echo "${var}_enable".
+#
+# If var and defval are specified, the ${var} is defined as
+# rc.conf(5) variable and the default value is ${defvar}. An
+# optional argument $desc can also be specified to add a
+# description for that.
+#
set_rcvar()
{
- if [ -z "$1" ]; then
- base_var=${name}
- else
- base_var="$1"
- fi
-
- case ${OSTYPE} in
- FreeBSD)
- echo ${base_var}_enable
+ case $# in
+ 0)
+ echo ${name}_enable
;;
- NetBSD)
- echo ${base_var}
+ 1)
+ echo ${1}_enable
;;
*)
- echo 'XXX'
+ debug "rcvar_define: \$$1=$2 is added" \
+ " as a rc.conf(5) variable."
+
+ local _var
+ _var=$1
+ rcvars="${rcvars# } $_var"
+ eval ${_var}_defval=\"$2\"
+ shift 2
+ # encode multiple lines of _desc
+ for l in "$@"; do
+ eval ${_var}_desc=\"\${${_var}_desc#^^}^^$l\"
+ done
+ eval ${_var}_desc=\"\${${_var}_desc#^^}\"
;;
esac
}
+# set_rcvar_obsolete oldvar [newvar] [msg]
+# Define obsolete variable.
+# Global variable $rcvars_obsolete is used.
#
+set_rcvar_obsolete()
+{
+ local _var
+ _var=$1
+ debug "rcvar_obsolete: \$$1(old) -> \$$2(new) is defined"
+
+ rcvars_obsolete="${rcvars_obsolete# } $1"
+ eval ${1}_newvar=\"$2\"
+ shift 2
+ eval ${_var}_obsolete_msg=\"$*\"
+}
+
+#
# force_depend script
# Force a service to start. Intended for use by services
# to resolve dependency issues. It is assumed the caller
@@ -401,6 +427,8 @@
# command_interpreter n If not empty, command is interpreted, so
# call check_{pidfile,process}() appropriately.
#
+# desc n Description of script.
+#
# extra_commands n List of extra commands supported.
#
# pidfile n If set, use check_pidfile $pidfile $command,
@@ -574,7 +602,7 @@
esac
eval _override_command=\$${name}_program
- command=${command:+${_override_command:-$command}}
+ command=${command:-${_override_command}}
_keywords="start stop restart rcvar $extra_commands"
rc_pid=
@@ -778,14 +806,49 @@
;;
rcvar)
- echo "# $name"
- if [ -n "$rcvar" ]; then
- if checkyesno ${rcvar}; then
- echo "${rcvar}=YES"
- else
- echo "${rcvar}=NO"
+ echo -n "# $name"
+ if [ -n "$desc" ]; then
+ echo " : $desc"
+ else
+ echo ""
+ fi
+ echo "#"
+ # Get unique vars in $rcvar $rcvars
+ for _v in $rcvar $rcvars; do
+ case $v in
+ $_v\ *|\ *$_v|*\ $_v\ *) ;;
+ *) v="${v# } $_v" ;;
+ esac
+ done
+
+ # Display variables.
+ for _v in $v; do
+ if [ -z "$_v" ]; then
+ continue
fi
- fi
+
+ eval _desc=\$${_v}_desc
+ eval _defval=\$${_v}_defval
+ _h="-"
+
+ eval echo \"$_v=\\\"\$$_v\\\"\"
+ # decode multiple lines of _desc
+ while [ -n "$_desc" ]; do
+ case $_desc in
+ *^^*)
+ echo "# $_h ${_desc%%^^*}"
+ _desc=${_desc#*^^}
+ _h=" "
+ ;;
+ *)
+ echo "# $_h ${_desc}"
+ break
+ ;;
+ esac
+ done
+ echo "# (default: \"$_defval\")"
+ done
+ echo ""
;;
*)
@@ -896,7 +959,8 @@
unset name command command_args command_interpreter \
extra_commands pidfile procname \
- rcvar required_dirs required_files required_vars
+ rcvar rcvars rcvars_obsolete required_dirs required_files \
+ required_vars
eval unset ${_arg}_cmd ${_arg}_precmd ${_arg}_postcmd
case "$_file" in
@@ -927,6 +991,7 @@
#
load_rc_config()
{
+ local _name _var _defval _v _msg _new
_name=$1
if [ -z "$_name" ]; then
err 3 'USAGE: load_rc_config name'
@@ -953,6 +1018,36 @@
# Old variable names support
#
[ -n "$enable_quotas" ] && quota_enable="$enable_quotas"
+
+ # Set defaults if defined.
+ for _var in $rcvar $rcvars; do
+ _defval=`eval echo "\\\$${_var}_defval"`
+ if [ -n "$_defval" ]; then
+ eval : \${$_var:=\$${_var}_defval}
+ fi
+ done
+
+ # check obsolete rc.conf variables
+ for _var in $rcvars_obsolete; do
+ _v=`eval echo \\$$_var`
+ _msg=`eval echo \\$${_var}_obsolete_msg`
+ _new=`eval echo \\$${_var}_newvar`
+ case $_v in
+ "")
+ ;;
+ *)
+ if [ -z "$_new" ]; then
+ _msg="Ignored."
+ else
+ eval $_new=\"\$$_var\"
+ if [ -z "$_msg" ]; then
+ _msg="Use \$$_new instead."
+ fi
+ fi
+ warn "\$$_var is obsolete. $_msg"
+ ;;
+ esac
+ done
}
#
Index: rc.d/routed
===================================================================
--- rc.d/routed (revision 195284)
+++ rc.d/routed (working copy)
@@ -10,13 +10,17 @@
. /etc/rc.subr
name="routed"
+desc="network RIP and router discovery routing daemon"
+rcvar=`set_rcvar`
-# XXX - Executable may be in a different location. The $name variable
-# is different from the variable in rc.conf(5) so the
-# subroutines in rc.subr won't catch it.
-#
+set_rcvar ${name}_enable NO
+set_rcvar ${name}_flags "-q" \
+ "Flags for ${name}(8)."
+set_rcvar ${name}_program "/sbin/routed" \
+ "Program name for ${name}(8)."
+set_rcvar_obsolete router_enable routed_enable
+set_rcvar_obsolete router routed_program
+set_rcvar_obsolete router_flags routed_flags
+
load_rc_config $name
-rcvar="router_enable"
-command="${router:-/sbin/${name}}"
-eval ${name}_flags=\"${router_flags}\"
run_rc_command "$1"
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