How not to use AWK at http://blog.ashwanthkumar.in/2016/02/how-not-to-use-awk.html

1.sh

#!/bin/bash

PACKER_LOG_FILE=$1

while read LINE; do
  BUILDER_NAME=$(echo $LINE | awk -F, '{print $2}')
  if [ "X$BUILDER_NAME" != "X" ]; then
    echo "found $BUILDER_NAME on $LINE"
  fi
done < $PACKER_LOG_FILE

1_run_output.log

brindavan:~ ashwanthkumar$ time ./parse-packer packer.log 
found hvm-builder on 1455261963,hvm-builder,artifact-count,1
found hvm-builder on 1455261964,hvm-builder,artifact,0,builder-id,mitchellh.amazonebs
found hvm-builder on 1455261964,hvm-builder,artifact,0,id,us-east-1:ami-abcd
found hvm-builder on 1455261964,hvm-builder,artifact,0,string,AMIs were created:nnus-east-1: ami-abcd
found hvm-builder on 1455261964,hvm-builder,artifact,0,files-count,0
found hvm-builder on 1455261964,hvm-builder,artifact,0,end
found pvm-builder on 1455261964,pvm-builder,artifact-count,1
found pvm-builder on 1455261964,pvm-builder,artifact,0,builder-id,mitchellh.amazonebs
found pvm-builder on 1455261964,pvm-builder,artifact,0,id,us-east-1:ami-efgh
found pvm-builder on 1455261964,pvm-builder,artifact,0,string,AMIs were created:nnus-east-1: ami-efgh
found pvm-builder on 1455261964,pvm-builder,artifact,0,files-count,0
found pvm-builder on 1455261964,pvm-builder,artifact,0,end

real	0m6.265s
user	0m2.829s
sys	0m4.118s