#!/usr/bin/env bash
#
# swap Pacemaker node IPs
#
# SPDX-License-Identifier: MIT

# Declare an empty array - do not edit
declare -a ip_pairs

## EDIT here ##

## These are basically the /etc/hosts values from old to new IP space
# add as many lines as needed; format: '<from>(comma)<to>' (no spaces!)
ip_pairs+=('172.20.21.89,172.24.16.105')
ip_pairs+=('172.20.21.90,172.24.16.107')
ip_pairs+=('172.20.20.20,172.24.16.108')
ip_pairs+=('172.20.20.21,172.24.16.109')
ip_pairs+=('10.128.132.132,10.132.143.68')
ip_pairs+=('10.128.132.133,10.132.143.69')

## STOP editing here ##

# handy for testing
cibxml=/var/lib/pacemaker/cib/cib.xml

# back everything up
echo "Backing up existing configs..."
DTS=$(date +"%Y%m%d_%H%M")
cp -a /var/lib/pacemaker/cib{,."$DTS"}

# remove the old cluster signature
echo "Removing old XML signature file..."
rm -f /var/lib/pacemaker/cib/cib.xml.sig

# for each element:
#  convert comma to space to make new child array
#  add escapes on . in From to prevent regex interpolation
#  sed the config replace the IP
echo "Replacing IP addresses..."
# shellcheck disable=SC2068
for pair in ${ip_pairs[@]}; do
  # shellcheck disable=SC2206
  _tmparr=(${pair//,/ })
  ipf=${_tmparr[0]//./\\.}
  ipt=${_tmparr[1]}
  sed -i -e "s/\b$ipf\b/$ipt/g" "${cibxml}"
done

# find the epoch (version) and increment it by +1
echo "Updating epoch (version) of config..."
epold=$(sed -n 's/.*\bepoch="\([^"]*\).*/\1/p' "${cibxml}")
epnew=$((epold+1))
sed -i -e "s/\bepoch=\"$epold\"/epoch=\"$epnew\"/g" "${cibxml}"