debian: add systemd service file (#16802)

debian/fargo.install

@@ -1,3 +1,4 @@
 debian/fargo-manage       /usr/bin
+debian/fargo.service      /lib/systemd/system
 debian/settings.py        /etc/fargo
 debian/debian_config.py   /usr/lib/fargo/

debian/fargo.service

@@ -0,0 +1,26 @@
+[Unit]
+Description=Fargo
+After=network.target postgresql.service
+Wants=postgresql.service
+
+[Service]
+Environment=FARGO_SETTINGS_FILE=/usr/lib/%p/debian_config.py
+User=%p
+Group=%p
+ExecStartPre=/usr/bin/fargo-manage migrate_schemas --noinput
+ExecStartPre=/usr/bin/fargo-manage collectstatic --noinput
+ExecStart=/usr/bin/gunicorn \
+          --bind unix:/run/%p/%p.sock \
+          --worker-class=sync \
+          --workers 5 \
+          --timeout=30 \
+          --name %p \
+          %p.wsgi:application
+ExecReload=/bin/kill -HUP $MAINPID
+TimeoutStartSec=0
+PrivateTmp=true
+Restart=on-failure
+RuntimeDirectory=fargo
+
+[Install]
+WantedBy=multi-user.target