pg-backup-configmap.yaml

# pg-configmap.yaml
apiVersion: v1
kind: ConfigMap
metadata:
  name: pg-script-config
data:
  postgresql.sh: |
          # Extract replica name from the pod's hostname (e.g., pg-slave-0)
          REPLICA_NAME=$(hostname | sed 's/-/_/g')
          rm -rf /var/lib/postgresql/data/*  # Ensure the directory is empty
          until pg_isready --host=$PG_MASTER_HOST --port=$PG_PORT; do
            echo "Waiting for master to be ready..."
            sleep 2
          done
          pg_basebackup -h $PG_MASTER_HOST -D /tmp/pgdata -U postgres -v -P --wal-method=stream
          mv /tmp/pgdata/* /var/lib/postgresql/data/
          chown -R postgres:postgres /var/lib/postgresql/data
          psql -h $PG_MASTER_HOST -U postgres -c "SELECT pg_create_physical_replication_slot('${REPLICA_NAME}');"
          echo "primary_slot_name = '${REPLICA_NAME}'" | tee -a /var/lib/postgresql/data/postgresql.conf
          echo "primary_conninfo = 'host=$PG_MASTER_HOST port=$PG_PORT user=postgres password=password application_name=${REPLICA_NAME}'" | tee -a /var/lib/postgresql/data/postgresql.conf
          touch /var/lib/postgresql/data/standby.signal
          chmod 700 /var/lib/postgresql/data/
          rm -rf /tmp/pgdata
          echo "Starting PostgreSQL..."
          exec postgres  # Use exec to replace the shell with the PostgreSQL process