Now there are 2 kinds of plugins:

 - plugins.d plugins that are expected to always be in memory and execute
   continiously

 - charts.d scripts that are sourced by the charts.d plugin
   and are all executed together, lowering significantly the resources
   they require (compared to plugins)

2 files changed, 247 insertions, 0 deletions

diff --git a/plugins.d/charts.d.dryrun-helper.sh b/plugins.d/charts.d.dryrun-helper.sh
new file mode 100755
index 0000000000..3d0bcb3732
--- /dev/null
+++ b/plugins.d/charts.d.dryrun-helper.sh
@@ -0,0 +1,73 @@
+#!/bin/sh
+
+# will stop the script for any error
+set -e
+
+me="$0"
+name="$1"
+chart="$2"
+conf="$3"
+
+can_diff=1
+
+tmp1=`mktemp`
+tmp2=`mktemp`
+
+myset() {
+	set | grep -v "^_="	| grep -v "^PIPESTATUS=" | grep -v "^BASH_LINENO="
+}
+
+# save 2 'set'
+myset >"$tmp1"
+myset >"$tmp2"
+
+# make sure they don't differ
+diff "$tmp1" "$tmp2" >/dev/null 2>&1
+if [ $? -ne 0 ]
+then
+	# they differ, we cannot do the check
+	echo >&2 "$me: cannot check with diff."
+	can_diff=0
+fi
+
+# do it again, now including the script
+myset >"$tmp1"
+
+# include the plugin and its config
+if [ -f "$conf" ]
+then
+	. "$conf"
+	if [ $? -ne 0 ]
+	then
+		echo >&2 "$me: cannot load config file $conf"
+		rm "$tmp1" "$tmp2"
+		exit 1
+	fi
+fi
+
+. "$chart"
+if [ $? -ne 0 ]
+then
+	echo >&2 "$me: cannot load chart file $chart"
+	rm "$tmp1" "$tmp2"
+	exit 1
+fi
+
+# remove all variables starting with the plugin name
+myset | grep -v "^$name" >"$tmp2"
+
+if [ $can_diff -eq 1 ]
+then
+	# check if they are different
+	# make sure they don't differ
+	diff "$tmp1" "$tmp2" >&2
+	if [ $? -ne 0 ]
+	then
+		# they differ
+		rm "$tmp1" "$tmp2"
+		exit 1
+	fi
+fi
+
+rm "$tmp1" "$tmp2"
+exit 0
diff --git a/plugins.d/charts.d.plugin b/plugins.d/charts.d.plugin
new file mode 100755
index 0000000000..e10384cb61
--- /dev/null
+++ b/plugins.d/charts.d.plugin
@@ -0,0 +1,174 @@
+#!/bin/sh
+
+check=0
+if [ "$1" = "check" ]
+then
+	check=1
+	shift
+fi
+
+# default sleep function
+loopsleepms() {
+	sleep $1
+}
+# if found and included, this file overwrites loopsleepms()
+# with a high resolution timer function for precise looping.
+. "`dirname $0`/loopsleepms.sh.inc"
+
+# netdata passes the requested update frequency as the first argument
+update_every=$1
+update_every=$(( update_every + 1 - 1))	# makes sure it is a number
+test $update_every -eq 0 && update_every=1 # if it is zero, make it 1
+
+pluginsd="plugins.d"
+confd="conf.d"
+chartsd="charts.d"
+myconfig="$confd/charts.d.conf"
+minimum_update_frequency=1
+
+# load the configuration
+if [ -f "$myconfig" ]
+	then
+	. "$myconfig"
+	if [ $? -ne 0 ]
+	then
+		echo >&2 "charts.d: cannot load $myconfig"
+		echo "DISABLE"
+		exit 1
+	fi
+fi
+
+if [ ! -d "$chartsd" ]
+	then
+	echo >&2 "charts.d: cannot find charts directory '$chartsd'"
+	echo "DISABLE"
+fi
+
+all_charts() {
+	cd "$chartsd"
+	ls *.chart.sh | sed "s/\.chart\.sh$//g"
+}
+
+all_enabled_charts() {
+	local charts=
+
+	# find all enabled charts
+
+	for x in `all_charts`
+	do
+		eval "enabled=\$$x"
+		if [ "$enabled" = "yes" ]
+		then
+			local charts="$charts $x"
+		else
+			echo >&2 "charts.d: chart '$x' is NOT enabled. Add a line with $x=yes in $myconfig to enable it."
+		fi
+	done
+
+	local charts2=
+	for x in $charts
+	do
+		# check the enabled charts
+		local check=`cat "$chartsd/$x.chart.sh" | sed "s/^ \+//g" | grep "^${x}_check()"`
+		if [ -z "$check" ]
+		then
+			echo >&2 "charts.d: chart '$x' does not seem to have a ${x}_check() function. Disabling it."
+			continue
+		fi
+
+		local create=`cat "$chartsd/$x.chart.sh" | sed "s/^ \+//g" | grep "^${x}_create()"`
+		if [ -z "$create" ]
+		then
+			echo >&2 "charts.d: chart '$x' does not seem to have a ${x}_create() function. Disabling it."
+			continue
+		fi
+
+		local update=`cat "$chartsd/$x.chart.sh" | sed "s/^ \+//g" | grep "^${x}_update()"`
+		if [ -z "$update" ]
+		then
+			echo >&2 "charts.d: chart '$x' does not seem to have a ${x}_update() function. Disabling it."
+			continue
+		fi
+
+		# check its config
+		if [ -f "$confd/$x.conf" ]
+		then
+			if [ ! -z "`cat "$confd/$x.conf" | sed "s/^ \+//g" | grep -v "^$" | grep -v "^#" | grep -v "^${x}_"`" ]
+			then
+				echo >&2 "charts.d: chart's $x config $confd/$x.conf should only have lines starting with ${x}_ . Disabling it."
+				continue
+			fi
+		fi
+
+		"$pluginsd/charts.d.dryrun-helper.sh" "$x" "$chartsd/$x.chart.sh" "$confd/$x.conf" >/dev/null
+		if [ $? -ne 0 ]
+		then
+			echo >&2 "charts.d: chart's $x did not pass the dry run check. This means it uses global variables not starting with $x. Disabling it."
+			continue
+		fi
+
+		local charts2="$charts2 $x"
+	done
+
+	echo $charts2
+}
+
+
+active_charts=
+for x in `all_enabled_charts`
+do
+	. "$chartsd/$x.chart.sh"
+
+	if [ -f "$confd/$x.conf" ]
+	then
+		. "$confd/$x.conf"
+	fi
+
+	${x}_check
+	if [ $? -eq 0 ]
+	then
+		active_charts="$active_charts $x"
+	else
+		echo >&2 "charts.d: chart '$x' check() function reports failure."
+	fi
+done
+
+if [ $check -eq 1 ]
+then
+	echo "CHECK RESULT"
+	echo "Will run the charts: $active_charts"
+	exit 0
+fi
+
+run_charts=
+for x in $active_charts
+do
+	${x}_create
+	if [ $? -eq 0 ]
+	then
+		run_charts="$run_charts $x"
+	else
+		echo >&2 "charts.d: chart '$x' create() function reports failure."
+	fi
+done
+
+# work forever
+while [ 1 ]
+do
+	now_charts=$run_charts
+	run_charts=
+
+	for x in $now_charts
+	do
+		${x}_update
+		if [ $? -eq 0 ]
+		then
+			run_charts="$run_charts $x"
+		else
+			echo >&2 "charts.d: chart '$x' update() function reports failure. Disabling it."
+		fi
+	done
+
+	# wait the time you are required to
+	loopsleepms $update_every
+done