From owner-freebsd-hackers@freebsd.org Thu Aug 27 21:21:44 2015 Return-Path: Delivered-To: freebsd-hackers@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 5A17C9C4A6B for ; Thu, 27 Aug 2015 21:21:44 +0000 (UTC) (envelope-from devin@shxd.cx) Received: from shxd.cx (mail.shxd.cx [64.201.244.140]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 4592E19F7; Thu, 27 Aug 2015 21:21:44 +0000 (UTC) (envelope-from devin@shxd.cx) Received: from 50-196-156-133-static.hfc.comcastbusiness.net ([50.196.156.133]:64770 helo=tinkerbell.pixel8networks.com) by shxd.cx with esmtpsa (TLSv1:AES256-SHA:256) (Exim 4.77 (FreeBSD)) (envelope-from ) id 1ZUxZG-000LcP-9z; Thu, 27 Aug 2015 06:50:14 -0700 Mime-Version: 1.0 (Mac OS X Mail 8.2 \(2102\)) Subject: Re: How to control and setup service? From: Devin Teske In-Reply-To: <55DF261C.80009@freebsd.org> Date: Thu, 27 Aug 2015 14:21:39 -0700 Cc: freebsd-hackers@freebsd.org, Devin Teske Message-Id: <988F49BB-5F42-4563-98AF-B8947FAC1EDC@FreeBSD.org> References: <55DF261C.80009@freebsd.org> To: Allan Jude X-Mailer: Apple Mail (2.2102) Sender: devin@shxd.cx Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: quoted-printable X-Content-Filtered-By: Mailman/MimeDel 2.1.20 X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 27 Aug 2015 21:21:44 -0000 > On Aug 27, 2015, at 8:00 AM, Allan Jude wrote: >=20 > sysrc automatically detects values from rc.conf.d directories, and can > edit them if you ask it to. It just defaults to writing your changes = to > /etc/rc.conf >=20 Only if you use the =93-f file=94 argument to point sysrc at said = file(s). Worth mentioning is this is in the sysrc(8) manual: LIMITATIONS The sysrc utility presently does not support the `rc.conf.d' = collection of system configuration files (which requires a service name to be = known during execution). This will be corrected by a future enhancement. So while below Allan shows us how to use `-f file=92 to support = rc.conf.d file(s): > My puppet scripts use: > sysrc -f /etc/rc.conf.d/varnish varnishd_identity=3D"PDX1-01" >=20 >=20 The OP was interested in an enhancement: sysrc -s varnish varnishd_identity=3D=93PDX1-01=94 When given `-s service_name=92, sysrc would do the following: 1. For information purposes, first make sure service_name exists in any = of: a. /etc/rc.d b. $local_startup directories =97 default: /usr/local/etc/rc.d 2. If the service does not exist, issue a warning to stderr but proceed = anyway NB: If we prevent moving ahead, it would be impossible to configure a = setting when service is not installed 3. If service does exist, add the following paths to list of files = checked (in addition to $rc_conf_files) i. /etc/rc.conf.d/$_name ii. ${local_startup%/rc.d}/rc.conf.d/$_name =97 default = /usr/local/etc/rc.conf.d/$_name You can better simulate this effect without the `-s service_name=92 = enhancement, using the currently available `-f file=92 argument (more pedantic than = Allan Jude=92s approach from above): sysrc -f "/etc/rc.conf.d/$_name $( sysrc -n local_startup%/rc.d = )/rc.conf.d/$_name" vimage_enable Where $_name is the service_name. A `-s service_name=92 argument to sysrc would make this easier. ASIDE: While I was diving into this, I discovered a code typo in = /etc/rc.subr NB: The typo has gone unnoticed because it has no effect on outcome =3D=3D=3D BEGIN DIFF =3D=3D=3D --- rc.subr.orig 2015-08-27 12:56:24.445475772 -0700 +++ rc.subr 2015-08-27 12:56:33.980474637 -0700 @@ -1333,7 +1333,7 @@ load_rc_config() _rc_conf_loaded=3Dtrue fi =20 - for _d in /etc ${local_startup%*/rc.d}; do + for _d in /etc ${local_startup%/rc.d}; do if [ -f ${_d}/rc.conf.d/"$_name" ]; then debug "Sourcing ${_d}/rc.conf.d/$_name" . ${_d}/rc.conf.d/"$_name=94 =3D=3D=3D END DIFF =3D=3D=3D FURTHER ASIDE: Why is the code in /etc/rc.subr treating $local_startup as though it=92s a single item? There are many locations in code that consider $local_startup to be a white- space separated list of directories where rc.d scripts can live? I think the above code should perhaps be changed to: =3D=3D=3D BEGIN DIFF =3D=3D=3D --- rc.subr.orig 2015-08-27 12:56:24.445475772 -0700 +++ rc.subr 2015-08-27 13:53:30.976240109 -0700 @@ -1333,7 +1333,8 @@ load_rc_config() _rc_conf_loaded=3Dtrue fi =20 - for _d in /etc ${local_startup%*/rc.d}; do + for _d in /etc/rc.d $local_startup; do + _d=3D"${_d%/rc.d}" if [ -f ${_d}/rc.conf.d/"$_name" ]; then debug "Sourcing ${_d}/rc.conf.d/$_name" . ${_d}/rc.conf.d/"$_name" =3D=3D=3D END DIFF =3D=3D=3D >>=20 >> As a user I would love to have a cool tool to control and configure >> services in way like OpenBSD's rcctl(8) does >> = http://www.openbsd.org/cgi-bin/man.cgi/OpenBSD-current/man8/rcctl.8?query=3D= rcctl. >> # cooltool set mysql-server status on >> That's all. It would take care of those things like getting right >> $rcvar name, choose right rc config file to edit (remember, we have a >> lot of places to check, see above) and enable service, etc. >> This $cooltool can be an extended version of service(8) tool. >> More difficult example: >> # cooltool set flow_capture status on flags "-e 2200 -n 23 -N 0 -V = 5" >> port "8787" datadir "/storage/flows/all_routers" >> would enable flow_capture service and set other stuff using right = $rcvar. >> # cooltool get flow_capture >> would print all of the configured stuff for $service >> # cooltool get flow_capture status >> would print only a status YES/NO (don't forget about exit code ;) ) >> and etc. >=20 > sysrc can do that, it will search all of the directories and find the > final answer. >=20 > The only thing it doesn't do is the translation between the 'service > name' (mysql-server) and the 'rcvar prefix' (mysql_), The rcvar =93prefix" is not actually what you=92re after. In load_rc_config() of /etc/rc.subr we can see that it uses $_name to append to /etc/rc.conf.d/ and /usr/local/etc/rc.conf.d/ What exactly is =93$_name=94 you ask? Good question=85 Almost 100% of the time, it=92s whatever =93name=3D=93 in the rc.d = script. This is not guaranteed to be ${0##*/} (the rc.d script name). However, this just happens to be because almost 100% of the time, rc.d scripts do the following: load_rc_config "$name" So for sysrc to know the proper name of the thing that /etc/rc.subr will source from rc.conf.d collection of directories, we need to know what name=3D in the rc.d script. This seems to be the simplest approach: =3D=3D=3D BEGIN SCRIPT: sconfigs.sh =3D=3D=3D #!/bin/sh sname=3D"$1" sconfigs=3D _name=3D$( service "$sname" rcvar 2> /dev/null | awk 'NR=3D=3D1&&sub(/^# /,""){print;exit}?' 2> /dev/null ) if [ "$_name" ]; then sconfigs=3D"/etc/rc.conf.d/$_name" local_etc=3D$( sysrc -qn local_startup%/rc.d 2> /dev/null ) [ "$local_etc" ] && sconfigs=3D"$sconfigs $local_etc/rc.d/rc.conf.d/$_name" sconfigs=3D"${sconfigs# }" fi echo "sconfigs=3D[$sconfigs]" =3D=3D=3D END SCRIPT: sconfigs.sh =3D=3D=3D Examples: $ ./sconfigs.sh sconfigs=3D[] $ ./sconfigs.sh zfs sconfigs=3D[/etc/rc.conf.d/zfs /usr/local/etc/rc.d/rc.conf.d/zfs] $ ./sconfigs.sh jail sconfigs=3D[/etc/rc.conf.d/jail /usr/local/etc/rc.d/rc.conf.d/jail] $ ./sconfigs.sh nosuchservice sconfigs=3D[] So naturally, if the logic in sconfigs.sh yields a non-NULL value for $sconfigs, this would become the value of `-f files=92 via service name. > which might be a > useful addition, but might make more sense in the service command, > because when I pass something to sysrc, I expect it to be interpreted > literally. I guess it could be a flag for sysrc to specify the service > instead of the rcvar. >=20 > sysrc -s mysql datadir=3D/var/db/mysql Given above talking-points, that would cause: a. sysrc makes sure that =93mysql=94 is an actual service b. sysrc uses =93service mysql rcvar" (piped into awk) to get `name=3D=91 = value NB: This could potentially result in a disconnect IFF the rc.d script = passes something other than =93$name=94 to load_rc_config() (if we=92re = worried about this, I have another recipe =97 further below). c. Sets `-f files=92 value to "/etc/rc.conf.d/mysql = /usr/local/etc/rc.conf.d/mysql=94 ASIDE: The only edge-case would be, for example... =3D=3D=3D BEGIN FILE: /etc/rc.d/fooserv =3D=3D=3D #!/bin/sh . /etc/rc.subr name=3DfoooooooooooooOOOooo load_rc_config foooooooooo run_rc_command "$@=93 =3D=3D=3D END FILE: /etc/rc.d/fooserv =3D=3D=3D Wherein we get the following from =93service =85 rcvar=94: $ service fooserv rcvar | awk NR=3D=3D1 # foooooooooooooOOOooo The above command returns the =93name=3D=93 value but the script doesn=92t= actually pass $name to load_rc_config() and thus what /etc/rc.subr would check for in this case is /etc/rc.conf.d/foooooooooo and /usr/local/etc/rc.conf.d/foooooooooo (versus the camel-case $name). This edge-case exists for a number of services in the base: $ awk '$1 ~ /^name=3D/ { name =3D $0; fn =3D FILENAME } $1 =3D=3D = "load_rc_config" && $2 !~ /\$(name|{name})/{ print "--"; if (fn =3D=3D = FILENAME) print fn ":" name; print FILENAME ":" $0 }' /etc/rc.d/* -- /etc/rc.d/dhclient:name=3D"dhclient" /etc/rc.d/dhclient:load_rc_config network -- /etc/rc.d/fooserv:name=3DfoooooooooooooOOOooo /etc/rc.d/fooserv:load_rc_config foooooooooo -- /etc/rc.d/initrandom:name=3D"initrandom" /etc/rc.d/initrandom:load_rc_config random -- /etc/rc.d/othermta:load_rc_config 'XXX' -- /etc/rc.d/postrandom:name=3D"postrandom" /etc/rc.d/postrandom:load_rc_config random -- /etc/rc.d/swaplate:name=3D"swaplate" /etc/rc.d/swaplate:load_rc_config swap NB: Ignore the /etc/rc.d/fooserv script which I created specifically to = illustrate the disconnect. For the above edge-case services in base, load_rc_config() of = /etc/rc.subr will check the following: dhclient: /etc/rc.conf.d/network /usr/local/etc/rc.conf.d/network initrandom: /etc/rc.conf.d/random /usr/local/etc/rc.conf.d/random othermta: /etc/rc.conf.d/XXX /usr/local/etc/rc.conf.d/XXX postrandom: /etc/rc.conf.d/random /usr/local/etc/rc.conf.d/random swaplate: /etc/rc.conf.d/swap /usr/local/etc/rc.conf.d/swap Let=92s ignore for a second that it seems like an obvious error to be = sourcing /usr/local/etc/rc.conf.d/ANYTHING for a base service in /etc/rc.d/ NB: I can see someone utilizing that as a form of value-add anyways What stands out at first glance is: + If /etc/rc.conf.d/XXX or /usr/local/etc/rc.conf.d/XXX exists, it will be sourced when working on the =93othermta=94 service NB: My testing indicates that othermta can obtain the desired results (of not sourcing any additional rc.conf.d files) by instead passing a single =93.=94 to load_c_config() =97 which does not allow a NULL arg1. + The =93service rcvar | awk =85=94 approach to get =93name=3D=93 value fails for dhclient, initrandom, postrandom, and swaplate. Oh, but it gets worse when you look deeper at the above-mentioned = scripts: $ grep -c load_rc_config /etc/rc.d/* | grep -v ':[01]$' | sed -e = 's/:[[:digit:]]\{1,\}$//' | xargs grep -n load_rc_config=20 /etc/rc.d/dhclient:54:load_rc_config $name /etc/rc.d/dhclient:55:load_rc_config network /etc/rc.d/local_unbound:32:load_rc_config $name /etc/rc.d/local_unbound:90:load_rc_config $name It turns out that the dhclient script will actually source all of (if = any exist; in order): 1. /etc/rc.conf.d/dhclient 2. /usr/local/etc/rc.conf.d/dhclient 3. /etc/rc.conf.d/network 4. /usr/local/etc/rc.conf.d/network I have a recipe that overcomes this edge-case that I=92d like to offer as a potential solution: =3D=3D=3D BEGIN FILE: sconfigs2.sh =3D=3D=3D #!/bin/sh sname=3D"$1" sconfigs=3D local_startup=3D$( sysrc -qn local_startup ) for dir in /etc/rc.d $local_startup; do spath=3D"$dir/$sname" [ -f "$spath" -a -x "$spath" ] || spath=3D continue break done if [ ! "$spath" ]; then echo "$sname does not exist in /etc/rc.d or the local startup" echo "directories ($local_startup)" exit 1 fi _names=3D case "$( file -b "$spath" 2> /dev/null )" in *"shell script"*) _names=3D$( exec 9<&1 1>&- 2>&- last_name=3D print_name() { local name=3D"$1" [ "$name" =3D "$last_name" ] && return echo "$name" >&9 last_name=3D"$name" } eval "$( awk '{ gsub(/load_rc_config /, "print_name ") gsub(/run_rc_command /, ": ") print }' "$spath" )" ) ;; esac for _name in $_names; do for dir in /etc/rc.d $local_startup; do sconfigs=3D"$sconfigs ${dir%/rc.d}/rc.conf.d/$_name" done done sconfigs=3D"${sconfigs# }" echo "sconfigs=3D[$sconfigs]=94 =3D=3D=3D END FILE: sconfigs2.sh =3D=3D=3D Given the above code, we can handle the afore-mentioned edge-casen: $ ./sconfigs2.sh dhclient sconfigs=3D[/etc/rc.conf.d/dhclient /usr/local/etc/rc.conf.d/dhclient = /etc/rc.conf.d/network /usr/local/etc/rc.conf.d/network] $ ./sconfigs2.sh initrandom sconfigs=3D[/etc/rc.conf.d/random /usr/local/etc/rc.conf.d/random] $ ./sconfigs2.sh postrandom sconfigs=3D[/etc/rc.conf.d/random /usr/local/etc/rc.conf.d/random] $ ./sconfigs2.sh swaplate sconfigs=3D[/etc/rc.conf.d/swap /usr/local/etc/rc.conf.d/swap] $ ./sconfigs2.sh local_unbound sconfigs=3D[/etc/rc.conf.d/local_unbound = /usr/local/etc/rc.conf.d/local_unbound] $ ./sconfigs2.sh=20 does not exist in /etc/rc.d or the local startup directories (/usr/local/etc/rc.d) $ ./sconfigs2.sh nosuchservice nosuchservice does not exist in /etc/rc.d or the local startup directories (/usr/local/etc/rc.d) This is looking like a much better approach. >=20 >> IMO such tools would be useful even for ansible/puppet and friends. >> Not just for users ;) >>=20 >=20 > Teaching service to use sysrc might be useful. Making sysrc detect = that > /etc/rc.conf.d/ exists, and use it, else fallback to > /etc/rc.conf might also be nice. >=20 > service mysql-server enable|disable > sets mysql_enable=3D"YES|NO" > service mysql-server set datadir=3D/var/db/mysql > sets mysql_datadir=3D"/var/db/mysql" >=20 > I am currently doing all of this in puppet with sysrc. Adding a =93service =85 enable=94 and =93service =85 disable=94 could be = nice. I=92m sure some of the above logic would be instrumental in that. =97=20 Devin=