The script is an adapted version of the script used by the mariadb operator on kubernetes. It runs in a container. The container is created using the podman quadlet container configuration file /etc/containers/systemd/users/1000/mariadb-www-backup.container:

[Unit]
Description=Backup MariaDB on VM www
OnFailure=status_email_simar@%n.service
 
[Container]
Image=docker.io/mariadb:10.11
Environment=MARIADB_OPERATOR_USER=root
Environment=MARIADB_OPERATOR_PASSWORD=[...]
Environment=MARIADB_SERVER=192.168.1.[...]
Volume=$PATH_TO_BACKUP_STORAGE:/backup
Exec=/bin/bash -c "set -euo pipefail; \
echo 💾 Exporting env; \
export BACKUP_FILE=backup.$(date -u +'%%Y-%%m-%%dT%%H:%%M:%%SZ').sql.zstd; \
echo 💾 Writing target file: /backup/0-backup-target.txt; \
printf \"$${BACKUP_FILE}\" > /backup/0-backup-target.txt; \
echo 💾 Setting target file permissions; \
chmod 777 /backup/0-backup-target.txt; \
echo 💾 Taking backup: /backup/$(cat '/backup/0-backup-target.txt'); \
mariadb-dump --user=$${MARIADB_OPERATOR_USER} \
             --password=$${MARIADB_OPERATOR_PASSWORD} \
             --host=$${MARIADB_SERVER} --port=3306 \
             --single-transaction --events --routines --all-databases \
             --skip-add-locks --ignore-table=mysql.global_priv \
| zstd --no-progress -19 -T0 -f -o /backup/$(cat '/backup/0-backup-target.txt')"

/etc/systemd/users/status_email_xyz@.service

[Unit]
Description=status email for %i to xyz
 
[Service]
Type=oneshot
ExecStart=/usr/local/bin/systemd-email xyz@mou.servants.priv %i

/usr/local/bin/systemd-email

#!/bin/sh
 
/usr/sbin/sendmail -t <<ERRMAIL
To: $1
From: systemd <root@$(hostname --fqdn)>
Subject: $2
Content-Transfer-Encoding: 8bit
Content-Type: text/plain; charset=UTF-8
 
$(systemctl --user status --full "$2")
ERRMAIL