add mqtt server on mail server (for the time being)

README.md

@@ -161,3 +161,48 @@ MariaDB [(none)]> insert into aliases (source_username, source_domain, destinati
 # chown -R _rspamd:_rspamd /var/lib/rspamd/dkim
 # chmod 440 /var/lib/rspamd/dkim/*
 ```
+
+
+# MQTT Server
+
+Auf dem Server befindet sich auch ein MQTT Server (Docker Compose)
+
+Einrichten:
+```bash
+# groupadd mqtt
+# usermod -a -G docker mqtt
+# useradd -m -g mqtt -s /bin/bash mqtt
+# ufw allow 1883 # MQTT
+mqtt$ 
+
+
+root@mail:/etc/systemd/system# cat /etc/systemd/system/mqtt.service
+[Unit]
+Description=docker-compose mqtt service
+Requires=docker.service network-online.target
+After=docker.service network-online.target
+
+[Service]
+WorkingDirectory=/home/mqtt
+Type=simple
+TimeoutStartSec=15min
+Restart=always
+User=mqtt
+Group=mqtt
+
+ExecStartPre=/usr/bin/docker-compose pull --quiet --ignore-pull-failures
+ExecStartPre=/usr/bin/docker-compose build --pull
+
+ExecStart=/usr/bin/docker-compose up --remove-orphans --no-color
+
+ExecStop=/usr/bin/docker-compose down --remove-orphans
+
+ExecReload=/usr/bin/docker-compose pull --quiet --ignore-pull-failures
+ExecReload=/usr/bin/docker-compose build --pull
+
+[Install]
+WantedBy=multi-user.target
+
+# systemctl enable mqtt.service
+# systemctl start mqtt.service
+```