Cyclops

.gitignore

*.log

README.md

Cyclops - a one-dimensional HTTP monitor script

cyclops.sh

#!/bin/bash

##
# Cyclops. A one dimensional monitor script.
#
# Verbose output on stdout. Only changes of state on stderr.
#
# Suggested usage: $ ./cyclops.sh 2> cdn.log
#           ...or: $ nohup ./cyclops.sh > /dev/null 2> cdn.log &
#
# Don't forget to chmod +x me first.
##

nslookup_server() {
(nslookup 2> /dev/null | tail -n2  | cut -d" " -f2) <<EOF
  server $1
  $2
EOF
}

edge_test() {
  curl -w %{http_code} -s -o /dev/null -H Host:$VCDN_HOST http://$1$ASSET_PATH
}

red() {
    echo -ne "\e[00;31m$1\e[00m"
}

green() {
    echo -ne "\e[00;32m$1\e[00m"
}

echo_response() {
  if [ $1 -ne 200 ]
  then
      echo -ne "["
      red $1
      echo -ne "]"
  else
      echo -ne "["
      green $1
      echo -ne "]"
  fi
}

check_results() {
  LAST_CHANGE="${LAST_CHANGES[$1]}"
  LAST_RESULT="${LAST_RESULTS[$1]}"
  CHANGED_AT=$(date --date=@$LAST_CHANGE)

  if [ $2 -eq $LAST_RESULT ]
  then
    echo " since $CHANGED_AT."
  else
    LAST_CHANGES[$1]=$(date -u +%s)
    echo " new result at $CHANGED_AT."
    echo -ne "$3 changed from " 1>&2 && echo_response $LAST_RESULT 1>&2
    echo -ne " to " 1>&2 && echo_response $2 1>&2 && echo -e " at $(date)." 1>&2
    LAST_RESULTS[$1]=$2
  fi
}

run_checks() {
  echo "Starting test run at $(date)"

  echo -ne "Origin\t($ORIGIN_HOST)\t"
  ORIGIN_RESULT=$(curl -w %{http_code} -s -o /dev/null $ORIGIN_URL$ASSET_PATH)
  echo_response $ORIGIN_RESULT
  check_results 0 $ORIGIN_RESULT "Origin ($ORIGIN_HOST)"

  echo -ne "Edge\tLocal DNS\t($DHCP_DNS_IP)\t"
  DHCP_RESULT=$(edge_test $DHCP_DNS_IP)
  echo_response $DHCP_RESULT
  check_results 1 $DHCP_RESULT "Edge Local DNS ($DHCP_DNS_IP)"

  echo -ne "Edge\tOpen DNS\t($OPEN_DNS_IP)\t"
  OPEN_DNS_RESULT=$(edge_test $OPEN_DNS_IP)
  echo_response $OPEN_DNS_RESULT
  check_results 2 $OPEN_DNS_RESULT "Edge Open DNS ($OPEN_DNS_IP)"

  echo -ne "Edge\tGoogle DNS\t($GOOGLE_DNS_IP)\t"
  GOOGLE_DNS_RESULT=$(edge_test $GOOGLE_DNS_IP)
  echo_response $GOOGLE_DNS_RESULT
  check_results 3 $GOOGLE_DNS_RESULT "Edge Google DNS ($GOOGLE_DNS_IP)"

  echo "Finished test run at $(date)"
  echo
}

lookup_dns() {
  DHCP_DNS_IP=$(nslookup_server "" $VCDN_HOST)
  OPEN_DNS_IP=$(nslookup_server $OPEN_DNS_SERVER $VCDN_HOST)
  GOOGLE_DNS_IP=$(nslookup_server $GOOGLE_DNS_SERVER $VCDN_HOST)
}

init() {
  for i in {0..3}
  do
    LAST_RESULTS[$i]=0
    LAST_CHANGES[$i]=$(date -u +%s)
  done
}

# URL config
ORIGIN_HOST="rest-src-sl-01.mh.nokia.com"
ORIGIN_URL="http://$ORIGIN_HOST/p/d/music_asset"
VCDN_HOST="musicassets.vcdn.nokia.com"
VCDN_URL="http://$VCDN_HOST"
ASSET_PATH="/midgard/1.0.209/us/js/lib/modernizr/modernizr.custom.77273.js"

# Some different DNS services
GOOGLE_DNS_SERVER="8.8.4.4"
OPEN_DNS_SERVER="208.67.222.222"

# Run
init
while [ 1 ]
do
  lookup_dns
  run_checks
  sleep 60
done