Bash script for backup Postgresql cluster

db_backup.sh

#!/usr/bin/env bash

# These ENV variables should be specified:
#   * WORKING_DIR
#   * PG_USER
#   * SCP_USER
#   * SCP_HOST
#   * SCP_DIR
#
# Also optional variable MAIL_TO can be specified.
#
# For example:
#   WORKING_DIR=/tmp/db_backup/ PG_USER=postgres SCP_USER=name SCP_HOST=localhost SCP_DIR=uploads ./db_backup.sh
#   MAIL_TO=email@address.com WORKING_DIR=/tmp/db_backup/ PG_USER=postgres SCP_USER=name SCP_HOST=localhost SCP_DIR=uploads ./db_backup.sh

TIMESTAMP=$(date +%Y_%m_%d)
BACKUP_NAME="${TIMESTAMP}_pg_basebackup"
ARCHIVE_NAME="$BACKUP_NAME.tar.gz"
SPLIT_NAME_PREFIX="${ARCHIVE_NAME}_"
SPLIT_SIZE="10G"

log() {
    echo "[$(date)] $1"
}

exit_unless_success() {
    exit_code=$?
    if [ $exit_code -ne 0 ]; then
        send_mail "[$BACKUP_NAME] An unknown error occurred while creating backup. Exit code: $exit_code"
        exit $exit_code
    fi
}

send_mail() {
    if [ -n "$MAIL_TO" ]; then
        log "Sending email to $MAIL_TO..."
        mail -s "$1" $MAIL_TO < /dev/null
    fi
}

if [ ! -d "$WORKING_DIR" ]; then
    mkdir -p "$WORKING_DIR"
    exit_unless_success
fi

cd $WORKING_DIR

log "Creating basebackup..."
pg_basebackup -U $PG_USER --pgdata=$BACKUP_NAME --xlog-method=stream
exit_unless_success

log "Compressing backup..."
tar -czf $ARCHIVE_NAME $BACKUP_NAME
exit_unless_success

log "Splitting archive by parts of $SPLIT_SIZE..."
split -b $SPLIT_SIZE $ARCHIVE_NAME $SPLIT_NAME_PREFIX
exit_unless_success

log "Uploading to remote server..."
scp $SPLIT_NAME_PREFIX* $SCP_USER@$SCP_HOST:$SCP_DIR
exit_unless_success

log "Cleaning..."
rm -rf $BACKUP_NAME*
exit_unless_success

send_mail "[$BACKUP_NAME] Database backup was successfully created."