Synchronise service configurations across servers

sync.sh

#!/bin/bash

# define our parameters
hostArray=("mariadb-90" "mariadb-91" "mariadb-92")
configPath="/etc/maxscale.cnf"
service="maxscale"

# auto variables
currentHost=$(hostname)

# create error logging function
function fatal_error() {
  printf "\033[0;31mFailed to restart $service on $1\033[0m\n"
  printf "Halting syncronistation. Fix errors and try again.\n"
  exit
}

# apply the configuration on our current node
echo "Restarting ${service} on ${currentHost}"
systemctl restart ${service}

# verify we were able to restart on current node.
if [ ! $? -eq 0 ]; then
  fatal_error $currentHost
fi

# apply the configuration to our remaining hosts
for host in ${hostArray[@]}; do

  # dont sync our current host
  if [ "$host" == "$currentHost" ]; then
    continue
  fi

  # perform SCP to sync our config across
  echo "Syncronising to ${host}"
  scp ${configPath} ${host}:${configPath}

  # check we were able to perform our sync
  if [ ! $? -eq 0 ]; then
    echo "Failed to sync config to $host."
    continue
  fi

  # sync performed, do a restart
  ssh $USER@$host systemctl restart $service

  # check our sync has worked
  if [ ! $? -eq 0 ]; then
    fatal_error $host
  fi

  # output success
  echo "Restarted $service on $host"
done

echo "Sync complete."