start ddclient as daemon with systemd

Question

I'm trying to start ddclient as daemon in my Ubuntu 15.04, which now uses systemd, but was unable to even following the Ubuntu wiki at https://help.ubuntu.com/community/DynamicDNS to words.

I've done,

update-rc.d ddclient defaults

Then tried with,

invoke-rc.d ddclient start

and then,

service ddclient start

but ps listing still have no ddclient in sight.

It is only after I did,

/etc/init.d/ddclient restart

that I start to see ddclient show up in ps listing.

Isn't /etc/init.d/ddclient restart supposed to be deprecated? Shouldn't we use invoke-rc.d ... start or service ... start instead?

What's the proper way to start ddclient as daemon under Ubuntu 15.04 systemd?
What's the proper way to make it always start at machine boot? I suppose the update-rc.d would be no longer working, as invoke-rc.d, right?

Thanks

Answer 1

You can interact with systemd services through the systemctl command. If your package management system has provided a systemd service file with the ddclient package then you can start the service with:

[sudo] systemctl start ddclient.service

And query the status of the service with:

[sudo] systemctl status ddclient.service

Note: systemctl start <service> does not persist across boots. You must systemctl enable <service> to include it in the install target, ie multi-user mode, etc.

Looking at the package source it doesn't seem as though they provide a service file for ddclient. I don't actively use ubuntu so I am not aware of how the migration to systemd as an init service is planned but it may require an issue for the package. They have provided a guide for the concurrent use of both upstart and systemd.