net-mgmt/netdata rc script overhaul, fix termination, user config

This script overhaul does the following:
- Read "run as user" from the netdata configuration file,
  and use that to override the default user "netdata", in case
  it is not set in /etc/rc.conf* and friends.
- Kill all children of the PID in the netdata_pid file, too,
  because 1.20.0 would leave some plugin processing lingering.
- Timeout the termination after (configurable) 30 seconds and
  issue SIGKILL
- Cleanup the netdata_pid file after stop, so that a subsequent
  start with a less privileged user (say, start as root, stop,
  start as netdata) will work properly.
- Document all variables, including the all-new netdata_stop_maxwait,
  in the header of the script.
- Quote parameter expansions where appropriate.

PR:		235006
Reported by:	Dries Michiels <driesm.michiels@gmail.com>
Reviewed by:	Dries Michiels <driesm.michiels@gmail.com>
Approved by:	maintainer timeout (mmohki@, ~ 1 year)

2 files changed, 92 insertions, 5 deletions

diff --git a/net-mgmt/netdata/Makefile b/net-mgmt/netdata/Makefile
index 8540b3c64eb6..86b0a77bbab8 100644
--- a/net-mgmt/netdata/Makefile
+++ b/net-mgmt/netdata/Makefile
@@ -3,7 +3,7 @@
 
 PORTNAME=	netdata
 PORTVERSION=	1.20.0
-PORTREVISION=	1
+PORTREVISION=	2
 DISTVERSIONPREFIX=	v
 CATEGORIES=	net-mgmt
 
diff --git a/net-mgmt/netdata/files/netdata.in b/net-mgmt/netdata/files/netdata.in
index bfbdbe04c2a0..d1c93e6609c5 100644
--- a/net-mgmt/netdata/files/netdata.in
+++ b/net-mgmt/netdata/files/netdata.in
@@ -13,24 +13,111 @@
 #				Set it to "YES" to enable netdata.
 # netdata_args (str):		Custom additional arguments to be passed
 #				to netdata (default empty).
+# netdata_conf (str):		Custom configuration file for netdata
+#				(default: %%ETCDIR%%/netdata.conf)
+# netdata_user (str):		Custom user to run netdata as
+#				(default: read from netdata_conf if
+#				 it is set there, or "netdata")
+# netdata_stop_maxwait (int):	Maximum time to wait for termination on stop
+#				before resorting to SIGKILL to stop netdata.
 #
 
+# Written 2017 - 2019 Mahdi Mokhtari (mmokhi@)
+# Written 2020 Matthias Andree (mandree@) with support by Dries Michiels
+
 . /etc/rc.subr
 
 name="netdata"
 rcvar=netdata_enable
+SED=/usr/bin/sed
+TR=/usr/bin/tr
 
 load_rc_config $name
 
 : ${netdata_enable="NO"}
-: ${netdata_user="netdata"}
+: ${netdata_conf="%%ETCDIR%%/${name}.conf"}
 : ${netdata_pid="%%NETDATA_PERST%%/${name}.pid"}
+: # netdata_user set below, it may also be pulled from the netdata_conf file
+: ${netdata_stop_maxwait=30}
+
+# read netdata_conf and print the "run as user =" RHS, or print nothing if unset
+#
+# only permits ASCII letters, digits, dash, underscore - does not permit
+# backtick, curly braces, angle brackets, backslash although passwd(5) would
+# permit these.
+get_user_from_conf() {
+	$SED -n '/^\[global\]/,/^\[/{s/^[[:space:]]*run as user.*=[[:space:]]*\(.*\)[[:space:]]*$/\1/p;}' "${netdata_conf}" \
+	| $TR -c -d 'a-zA-Z0-9_-'
+}
+
+# check if the rc.conf* file set and netdata_conf agree on the name to run the bundle as
+check_user_consistency() {
+	cfusr=$(get_user_from_conf)
+	if [ -z "$cfusr" -o "$cfusr" = "${netdata_user}" ] ; then return 0 ; fi
+	echo >&2 "$0: ERROR: ${netdata_conf} sets 'run as user = $cfusr', but rc.conf* sets '${netdata_user}'. Both must be consistent."
+	return 1
+}
+
+# this is more or less a copy of /etc/rc.subr from 12.1-RELEASE
+# around Early April 2020, but with a timeout, killing children,
+# and SIGKILL added because sometimes netdata hangs.
+stop_cmd() {
+	rc_pid=$(check_pidfile "${netdata_pid}" "${procname}")
+	if [ -z "$rc_pid" ] ; then
+		[ -n "$fc_fast" ] && return 0
+		_run_rc_notrunning
+		return 1
+	fi
+	_prefix=
+	slave_pids=$(pgrep -P $rc_pid)
+	echo "Stopping ${name}."
+	_list="$rc_pid $slave_pids"
+	kill -TERM $_list
+	wtim=0
+	while :; do
+		_nlist=
+		for _j in $_list ; do
+			if kill -0 $_j 2>/dev/null ; then
+				_nlist="$_nlist $_j"
+				[ -n "$_prefix" ] && sleep 1
+			fi
+		done
+		if [ -z "$_nlist" ] ; then
+			break
+		fi
+		_list=$_nlist
+		echo -n ${_prefix:-"Waiting for PIDS: "}$_list
+		_prefix=", "
+		pwait -t 2 $_list 2>/dev/null
+		wtim=$(($wtim + 3))
+		if [ $wtim -gt ${netdata_stop_maxwait} ] ; then
+			echo -n "${_prefix}SIGKILL $_list"
+			kill -KILL $_list
+			break
+		fi
+	done
+	[ -n "$_prefix" ] && echo .
+}
+
+stop_postcmd() {
+	rm -f "${netdata_pid}"
+}
+
+# obtain default user, first from configuration, or default to "netdata"
+    _netdata_user_default=$(get_user_from_conf)
+: ${_netdata_user_default:="netdata"}
+# and then, if rc.conf* don't set it, use the default
+: ${netdata_user="${_netdata_user_default}"}
 
 procname="%%PREFIX%%/sbin/${name}"
 command="/usr/sbin/daemon"
-command_args="-c -f ${procname} -u ${netdata_user} -P ${netdata_pid} ${netdata_args}"
+command_args="-c -f \"${procname}\" -u \"${netdata_user}\" -P \"${netdata_pid}\" ${netdata_args}"
 
-required_files="%%ETCDIR%%/${name}.conf"
+required_files="${netdata_conf}"
 
-run_rc_command "$1"
+start_precmd=check_user_consistency
 
+stop_cmd=stop_cmd
+stop_postcmd=stop_postcmd	# netdata always leaves its pid file behind.
+
+run_rc_command "$1"