#!/bin/bash
# PGpool stage 1 recovery script
# Reference: http://michael.stapelberg.de/Artikel/replicated_postgresql_with_pgpool
#
TS=$(date +%Y-%m-%d_%H-%M-%S)
MASTER_HOST=$(hostname -f)
# $1 is {{ psql_data_dir }}/main while  $3 is {{ psql_data_dir }}
MASTER_DATA=$1
MASTER_DATA_BASE_DIR={{ psql_data_dir }}
RECOVERY_TARGET=${2}
RECOVERY_DATA=${3}/main
RECOVERY_DATA_BASE_DIR={{ psql_data_dir }}

logger "pgpool_recovery_1: MASTER_DATA=$MASTER_DATA"
logger "pgpool_recovery_1: RECOVERY_DATA=$RECOVERY_DATA"

archive_dir={{ psql_wal_archiving_log_dir }}

# Ensure that postgres is shut down on the target node
ssh -T $RECOVERY_TARGET sudo /etc/init.d/postgresql stop

# Move the PostgreSQL data directory out of our way.
ssh -T $RECOVERY_TARGET \
    "[ -d $RECOVERY_DATA ] && mv $RECOVERY_DATA $RECOVERY_DATA.$TS"

# If the archive dir is not empty the backup fails
ssh -T $RECOVERY_TARGET \
    "[ -d $archive_dir ] && rm $archive_dir/*"

# We only use archived WAL logs during recoveries, so delete all
# logs from the last recovery to limit the growth.
rm $archive_dir/*

# With this file present, our archive_command will actually
# archive WAL files.
touch $archive_dir/backup_in_progress

psql -c "select pg_start_backup('pgpool-recovery')" postgres
echo "restore_command = 'scp $MASTER_HOST:$archive_dir/%f %p'" > $RECOVERY_DATA/recovery.conf
tar -C $MASTER_DATA_BASE_DIR -zcf pgsql.tar.gz main
psql -c 'select pg_stop_backup()' postgres
scp pgsql.tar.gz $RECOVERY_TARGET:$RECOVERY_DATA_BASE_DIR