update-rc.d: error: firewall Default-Start contains no runlevels, aborting

Question

I am trying to add a service so that it starts at startup but impossible, I get the following error

$ sudo systemctl enable firewall.service

Synchronizing state of firewall.service with SysV service script with /lib/systemd/systemd-sysv-install.
Executing: /lib/systemd/systemd-sysv-install enable firewall
update-rc.d: error: firewall Default-Start contains no runlevels, aborting

# /etc/systemd/system/firewall.service
[Unit]
ConditionPathExists=/etc/init.d/firewall
after=network.target

[Service]
ExecStart=/etc/init.d/firewall

[Install]
WantedBy=multi-user.target

Answer 1

Edit your firewall file and add this at the beginning

### BEGIN INIT INFO
# Provides:          firewall
# Required-Start:    $all
# Required-Stop:
# Default-Start:     2 3 4 5
# Default-Stop:
# Short-Description: your description here
### END INIT INFO

Move the file to the correct directory

mv /etc/init.d/firewall  /etc/systemd/system/firewall

Create the firewall.service file in /lib/systemd/system/

> /lib/systemd/system/firewall.service

Your firewall.service file should contain this

 [Unit]
 Description=Firewall

 [Service]
 Type=simple
 RemainAfterExit=yes
 ExecStart=/etc/systemd/system/firewall start
 ExecStop=/etc/systemd/system/firewall stop
 ExecReload=/etc/systemd/system/firewall restart

 [Install]
 WantedBy=multi-user.target

Reload systemd manager configuration and enable firewall

systemctl daemon-reload
systemctl enable firewall