Kill hung frame listeners on each verify networks event

Network checker relies on interrupt signal for its own
internal logic, so after interrupt is received - it will
do some parsing work and wont finish immediatly.

But before starting frame listeners in a new run - old frame
listeners may be not interrupted because mcollective failed
due timeout or any other not predicted problem.
So, we need to completely shutdown frame listeners with kill -9

Tested:
  Spawned bunch of - /usr/bin/python /usr/bin/net_probe.py -c listen.conf
  Executed network verification from UI - all old listeners were killed,
  verification succeeded.
  Also, executed same test with removed pid files in /var/run/net_probe folder

Change-Id: I7aa48d00b3f86827ba9860a3e3797ed5bd0eb713
Closes-Bug: 1466020

mcagents/net_probe.rb

@@ -22,6 +22,7 @@ module MCollective
     class Net_probe<RPC::Agent
       def startup_hook
         @pattern = "/var/tmp/net-probe-dump*"
+        @piddir = '/var/run/net_probe'
       end
 
       action "multicast_listen" do
@@ -42,7 +43,7 @@ module MCollective
       end
 
       action "start_frame_listeners" do
-        cleanup_netprobe
+        kill_frame_listeners
         start_frame_listeners
       end
 
@@ -99,11 +100,6 @@ module MCollective
         end
       end
 
-      def cleanup_netprobe
-        status = run("pkill net_probe.py && sleep 2 && pgrep net_probe.py")
-        reply.fail! "Cant stop net_probe.py execution." unless status == 1
-      end
-
       def start_frame_listeners
         validate :interfaces, String
         config = {
@@ -118,9 +114,6 @@ module MCollective
           config.merge!(JSON.parse(request[:config]))
         end
 
-        # we want to be sure that there is no frame listeners running
-        stop_frame_listeners
-
         # wipe out old stuff before start
         Dir.glob(@pattern).each do |file|
           File.delete file
@@ -202,9 +195,23 @@ module MCollective
         f
       end
 
+      def kill_frame_listeners
+        net_probe_pattern = 'net_probe.py'
+
+        Dir.glob('/proc/[0-9]*/cmdline').each do |proc|
+          if File.read(proc).include? net_probe_pattern
+            Process.kill('KILL', proc.split('/')[2].to_i)
+          end
+        end
+
+        # and wipe out all old pidfiles
+        Dir.glob(File.join(@piddir, '*')).each do |pidfile|
+          File.unlink(pidfile)
+        end
+      end
+
       def stop_frame_listeners
-        piddir = "/var/run/net_probe"
-        pidfiles = Dir.glob(File.join(piddir, '*'))
+        pidfiles = Dir.glob(File.join(@piddir, '*'))
         # Send SIGINT to all PIDs in piddir.
         pidfiles.each do |f|
           begin
@@ -226,7 +233,7 @@ module MCollective
               end
             end
           end
-          pidfiles = Dir.glob(File.join(piddir, '*'))
+          pidfiles = Dir.glob(File.join(@piddir, '*'))
         end
       end
     end