prometheus-node-exporter-lua: close io.popen files to reap zombies

Signed-off-by: Leonid Evdokimov <leon@darkk.net.ru>

utils/prometheus-node-exporter-lua/Makefile

@@ -5,7 +5,7 @@ include $(TOPDIR)/rules.mk
 
 PKG_NAME:=prometheus-node-exporter-lua
 PKG_VERSION:=2018.07.23
-PKG_RELEASE:=1
+PKG_RELEASE:=2
 
 PKG_MAINTAINER:=Etienne CHAMPETIER <champetier.etienne@gmail.com>
 PKG_LICENSE:=Apache-2.0

utils/prometheus-node-exporter-lua/files/usr/bin/prometheus-node-exporter-lua

@@ -119,11 +119,13 @@ end
 
 col_mods = {}
 col_names = {}
-for c in io.popen("ls -1 /usr/lib/lua/prometheus-collectors/*.lua"):lines() do
+ls_fd = io.popen("ls -1 /usr/lib/lua/prometheus-collectors/*.lua")
+for c in ls_fd:lines() do
   c = c:match("([^/]+)%.lua$")
   col_mods[c] = require('prometheus-collectors.'..c)
   col_names[#col_names+1] = c
 end
+ls_fd:close()
 
 if port then
   server = assert(socket.bind(bind, port))

utils/prometheus-node-exporter-lua/files/usr/lib/lua/prometheus-collectors/uname.lua

@@ -1,12 +1,16 @@
+local uname_fd = io.popen("uname -m")
+
 local labels = {
   domainname = "",
   nodename = "",
   release = string.sub(get_contents("/proc/sys/kernel/osrelease"), 1, -2),
   sysname = string.sub(get_contents("/proc/sys/kernel/ostype"), 1, -2),
   version = string.sub(get_contents("/proc/sys/kernel/version"), 1, -2),
-  machine = string.sub(io.popen("uname -m"):read("*a"), 1, -2)
+  machine = string.sub(uname_fd:read("*a"), 1, -2)
 }
 
+uname_fd:close()
+
 local function scrape()
   labels["domainname"] = string.sub(get_contents("/proc/sys/kernel/domainname"), 1, -2)
   labels["nodename"] = string.sub(get_contents("/proc/sys/kernel/hostname"), 1, -2)