[fix] Ensure pipes are always closed #15 #32

Fixes #15
Fixes #32

Author: devkapilbansal

openwrt-openwisp-monitoring/files/lib/openwisp/interfaces.lua

@@ -22,7 +22,9 @@ local specialized_interfaces={
   modemmanager=function(_, interface)
     local modem=uci_cursor.get('network', interface['interface'], 'device')
     local info={}
-    local general=io.popen('mmcli --output-json -m '..modem):read("*a")
+    local general_file=io.popen('mmcli --output-json -m '..modem)
+    local general=general_file:read("*a")
+    general_file:close()
     if general and pcall(cjson.decode, general) then
       general=cjson.decode(general)
       general=general.modem
@@ -41,7 +43,9 @@ local specialized_interfaces={
       end
     end
 
-    local signal=io.popen('mmcli --output-json -m '..modem..' --signal-get'):read("*a")
+    local signal_file=io.popen('mmcli --output-json -m '..modem..' --signal-get')
+    local signal = signal_file:read("*a")
+    signal_file:close()
     if signal and pcall(cjson.decode, signal) then
       signal=cjson.decode(signal)
       -- only send data if not empty to avoid generating too much traffic

openwrt-openwisp-monitoring/files/lib/openwisp/neighbors.lua

@@ -1,11 +1,17 @@
 -- retrieve neighbors information
 local cjson=require('cjson')
 local io=require('io')
+local utils=require('openwisp.monitoring_utils')
+
 local neighbors={}
+
 -- parse /proc/net/arp
 function neighbors.parse_arp()
   local arp_info={}
-  for line in io.popen('cat /proc/net/arp 2> /dev/null'):lines() do
+  local arp_data_file=io.popen('cat /proc/net/arp 2> /dev/null')
+  local arp_data=arp_data_file:read("*a")
+  arp_data_file:close()
+  for _,line in ipairs(utils.split(arp_data, "\n")) do
     if line:sub(1, 10) ~='IP address' then
       local ip, _, _, mac, _, dev=line:match("(%S+)%s+(%S+)%s+(%S+)%s+(%S+)%s+(%S+)%s+(%S+)")
       table.insert(arp_info, {
@@ -21,7 +27,9 @@ end
 
 function neighbors.get_ip_neigh_json()
   local arp_info={}
-  local output=io.popen('ip -json neigh 2> /dev/null'):read()
+  local output_file=io.popen('ip -json neigh 2> /dev/null')
+  local output=output_file:read('*a')
+  output_file:close()
   if output ~=nil and pcall(cjson.decode, output) then
     local json_output=cjson.decode(output)
     for _, arp_entry in pairs(json_output) do
@@ -38,8 +46,10 @@ end
 
 function neighbors.get_ip_neigh()
   local arp_info={}
-  local output=io.popen('ip neigh 2> /dev/null')
-  for line in output:lines() do
+  local neigh_data_file=io.popen('ip neigh 2> /dev/null')
+  local neigh_data=neigh_data_file:read("*a")
+  neigh_data_file:close()
+  for _,line in ipairs(utils.split(neigh_data, "\n")) do
     local ip, dev, mac, state=line:match("(%S+)%s+dev%s+(%S+)%s+lladdr%s+(%S+).*%s(%S+)")
     if mac ~=nil then
       table.insert(arp_info, {

openwrt-openwisp-monitoring/files/lib/openwisp/resources.lua

@@ -1,12 +1,15 @@
 -- retrieve resources usage
 local io=require('io')
+local utils=require('openwisp.monitoring_utils')
 
 local resources={}
 
 function resources.parse_disk_usage()
-  local file=io.popen('df')
   local disk_usage_info={}
-  for line in file:lines() do
+  local disk_usage_file=io.popen('df')
+  local disk_usage = disk_usage_file:read("*a")
+  disk_usage_file:close()
+  for _,line in ipairs(utils.split(disk_usage, "\n")) do
     if line:sub(1, 10) ~='Filesystem' then
       local filesystem, size, used, available, percent, location=
         line:match('(%S+)%s+(%S+)%s+(%S+)%s+(%S+)%s+(%S+)%s+(%S+)')
@@ -24,14 +27,14 @@ function resources.parse_disk_usage()
       end
     end
   end
-  file:close()
   return disk_usage_info
 end
 
 function resources.get_cpus()
-  local processors=io.popen('cat /proc/cpuinfo | grep -c processor')
-  local cpus=tonumber(processors:read('*a'))
-  processors:close()
+  local processors_file=io.popen('cat /proc/cpuinfo | grep -c processor')
+  local processors=processors_file:read('*a')
+  processors_file:close()
+  local cpus=tonumber(processors)
   return cpus
 end
 

openwrt-openwisp-monitoring/files/sbin/netjson-monitoring.lua

@@ -17,7 +17,9 @@ local monitoring=require('openwisp.monitoring')
 -- collect system info
 local system_info=ubus:call('system', 'info', {})
 local board=ubus:call('system', 'board', {})
-local loadavg_output=io.popen('cat /proc/loadavg'):read()
+local loadavg_file=io.popen('cat /proc/loadavg')
+local loadavg_output=loadavg_file:read()
+loadavg_file:close()
 loadavg_output=monitoring.utils.split(loadavg_output, ' ')
 local load_average={tonumber(loadavg_output[1]), tonumber(loadavg_output[2]), tonumber(loadavg_output[3])}