run.sh

#!/bin/sh
set -e

[ -z "${PG_HOST}" ] && { echo "=> PG_HOST cannot be empty" && exit 1; }
[ -z "${PG_PORT}" ] && { echo "=> PG_PORT cannot be empty" && exit 1; }
[ -z "${PG_USER}" ] && { echo "=> PG_USER cannot be empty" && exit 1; }
[ -z "${PG_DB}" ] && { echo "=> PG_DB cannot be empty" && exit 1; }
[ ! -z "${PG_PASS}" ] && { PG_PASS="PGPASSWORD=\"${PG_PASS}\" "; }

BACKUP_CMD="${PG_PASS} pg_dump -h ${PG_HOST} -p ${PG_PORT} -U ${PG_USER} -d ${PG_DB} ${EXTRA_OPTS} | gzip > /backup/"'${BACKUP_NAME}'

echo "=> Creating backup script"
rm -f /backup.sh
cat <<EOF >> /backup.sh
#!/bin/sh
set -e

MAX_BACKUPS=${MAX_BACKUPS}

BACKUP_NAME=\$(date +\%Y.\%m.\%d.\%H\%M\%S).psql.gz

echo "=> Backup started: \${BACKUP_NAME}"
if ${BACKUP_CMD} ;then
    (cd /backup; rm -f latest.psql.gz; ln -s \${BACKUP_NAME} latest.psql.gz)
    echo "   Backup succeeded"
else
    echo "   Backup failed"
    rm -rf /backup/\${BACKUP_NAME}
fi

if [ -n "\${MAX_BACKUPS}" ]; then
    while [ \$(ls /backup/*.psql.gz -1 | wc -l) -gt \${MAX_BACKUPS} ];
    do
        BACKUP_TO_BE_DELETED=\$(ls /backup/*.psql.gz -1 | sort | head -n 1)
        echo "   Backup \${BACKUP_TO_BE_DELETED} is deleted"
        rm -rf \${BACKUP_TO_BE_DELETED}
    done
fi
echo "=> Backup done"
EOF
chmod +x /backup.sh

echo "=> Creating restore script"
rm -f /restore.sh
cat <<EOF >> /restore.sh
#!/bin/sh
set -e

echo "=> Restore database from \$1"
if cat \$1 | gzip -d | ${PG_PASS} pg_restore -h ${PG_HOST} -p ${PG_PORT} -U ${PG_USER} -d ${PG_DB} ;then
    echo "   Restore succeeded"
else
    echo "   Restore failed"
fi
echo "=> Done"
EOF
chmod +x /restore.sh

touch /pg_backup.log
chown $UID:$GID /pg_backup.log
exec su-exec $UID:$GID tail -F /pg_backup.log &

if [ -n "${INIT_BACKUP}" ]; then
    echo "=> Create a backup on startup"
    /backup.sh
elif [ -n "${INIT_RESTORE_LATEST}" ]; then
    echo "=> Restore latest backup"
    until nc -z $PG_HOST $PG_PORT
    do
        echo "waiting for database container..."
        sleep 1
    done
    ls -d -1 /backup/* | tail -1 | xargs /restore.sh
fi

if [ -n "${NO_CRON}" ]; then
    echo "NO_CRON set, exiting"
else
    echo "${CRON_TIME} /backup.sh >> /pg_backup.log 2>&1" > /crontab.conf
    echo "=> Running cron job"
    exec su-exec $UID:$GID go-crond $UID:/crontab.conf
fi