Deploy a PostgreSQL Database Cluster Using Pacemaker on RHEL 9 | CentOS 9

				
					#!/bin/bash

PGDATA="/var/lib/pgsql/16/data"
PGHBA="${PGDATA}/pg_hba.conf"
NODE_IP="192.168.1.250"
VIRTUAL_IP="192.168.1.12"
REQUIRED_ENTRIES=(
    "host    all             postgres        192.168.1.0/24          trust"
    "host    all             all             192.168.1.247/32        trust"
)

# Get the IP addresses assigned to the current node
CURRENT_IPS=$(hostname -I)

# Check if both the node IP and virtual IP are present on the same node
if echo "${CURRENT_IPS}" | grep -q "${NODE_IP}" && echo "${CURRENT_IPS}" | grep -q "${VIRTUAL_IP}"; then
    echo "Both the node IP (${NODE_IP}) and virtual IP (${VIRTUAL_IP}) are present on this node. Primary is in control. No action required."
    exit 0
fi

# Ensure the required entries are present in pg_hba.conf
for ENTRY in "${REQUIRED_ENTRIES[@]}"; do
    if ! grep -qF "$ENTRY" "${PGHBA}"; then
        echo "$ENTRY" >> "${PGHBA}"
        echo "Added entry to pg_hba.conf: $ENTRY"
    else
	    echo "Entries already updated for PostgreSQL and Zabbix (in pg_hba.conf): [OK]"
    fi
done

# Proceed with promotion if the node is in standby mode
if [ -f "${PGDATA}/standby.signal" ]; then
    pg_ctl -D "${PGDATA}" promote
    if [ $? -eq 0 ]; then
        echo "Promotion successful."
        exit 0
    else
        echo "Promotion failed."
        exit 1
    fi
else
    echo "Standby Node Has Control: [OK]"
    exit 1
fi