Support Go execd plugins with shim (#7283)

plugins/inputs/execd/examples/count.rb

@@ -4,8 +4,16 @@
 
 counter = 0
 
+def time_ns_str(t)
+  ns = t.nsec.to_s
+  (9 - ns.size).times do 
+    ns = "0" + ns # left pad
+  end
+  t.to_i.to_s + ns
+end
+
 loop do
-  puts "counter_ruby count=#{counter}"
+  puts "counter_ruby count=#{counter} #{time_ns_str(Time.now)}"
   STDOUT.flush
   counter += 1
 

plugins/inputs/execd/examples/count.sh

@@ -1,12 +1,12 @@
-#!/bin/bash
+#!/bin/sh
 
 ## Example in bash using STDIN signaling
 
 counter=0
 
-while read; do
+while read LINE; do
     echo "counter_bash count=${counter}"
-    let counter=counter+1
+    counter=$((counter+1))
 done
 
-(>&2 echo "terminate")
+trap "echo terminate 1>&2" EXIT