differential backups using clickhouse-backup

# ubuntu / debian

wget https://github.com/Altinity/clickhouse-backup/releases/download/v2.5.20/clickhouse-backup_2.5.20_amd64.deb 
sudo dpkg -i clickhouse-backup_2.5.20_amd64.deb 

# centos / redhat / fedora 

sudo yum install https://github.com/Altinity/clickhouse-backup/releases/download/v2.5.20/clickhouse-backup-2.5.20-1.x86_64.rpm

# other platforms
wget https://github.com/Altinity/clickhouse-backup/releases/download/v2.5.20/clickhouse-backup.tar.gz
sudo mkdir /etc/clickhouse-backup/
sudo mv clickhouse-backup/config.yml /etc/clickhouse-backup/config.yml.example
sudo mv clickhouse-backup/clickhouse-backup /usr/bin/
rm -rf clickhouse-backup clickhouse-backup.tar.gz

mkdir /opt/clickhouse-backup-diff/

cat << 'END' > /opt/clickhouse-backup-diff/clickhouse-backup-cron.sh

#!/bin/bash
set +x
command_line_argument=$1

backup_name=$(date +%Y-%M-%d-%H-%M-%S)

echo "Creating local backup '${backup_name}' (full, using hardlinks)..."
clickhouse-backup create "${backup_name}"

if [[ "run_diff" == "${command_line_argument}" && "2" -le "$(clickhouse-backup list local | wc -l)" ]]; then
  prev_backup_name="$(clickhouse-backup list local | tail -n 2 | head -n 1 | cut -d " " -f 1)"
  echo "Uploading the backup '${backup_name}' as diff from the previous backup ('${prev_backup_name}')"
  clickhouse-backup upload --diff-from "${prev_backup_name}" "${backup_name}"
elif [[ "" == "${command_line_argument}" ]]; then
  echo "Uploading the backup '${backup_name}, and removing old unneeded backups"
  KEEP_BACKUPS_LOCAL=1 KEEP_BACKUPS_REMOTE=1 clickhouse-backup upload "${backup_name}"
fi
END

chmod +x /opt/clickhouse-backup-diff/clickhouse-backup-cron.sh

last_remote_backup="$(clickhouse-backup list remote | tail -n 1 | cut -d " " -f 1)"
clickhouse-backup download "${last_remote_backup}"
clickhouse-backup restore --rm "${last_remote_backup}"