How to use daemonize-liquidsoap.sh script when passing multiple .liq scripts?

[floholl]

Hi Liquidsoapers,

In a current project, I make use of the possibility to pass multiple .liq scripts to the liquidsoap command like so:

liquidsoap radio.liq output.liq

Specifically, I use this to test my radio.liq on my local machine with an output.liq that plays to my laptop's sound card before then deploying the radio.liq script to my public server, where a different output.liq streams the result via Icecast. I love the ability to do this because it prevents me from having to edit my radio.liq script when switching between my test & production environment.

However, I now would like to dameonize my Liquidsoap script on the server, for which I guess the daemonize-liquidsoap.sh script available here is an excellent starting point. Alas, this script only accepts a single .liq script as its argument.

How would I go about using it in my specific situation? Could I simply call daemonize-liquidsoap.sh with two arguments? I.e.

daemonize-liquidsoap.sh radio.liq output.liq

Would I need to work with includes of some sort? Any other ideas?

Many thanks for your help,
Florian

[gAlleb]

You can simply include output.liq into radio.liq in the end of a file:

%include "output.liq"

output.liq should be in the same directory.

---

I guess the daemonize-liquidsoap.sh script available here is an excellent starting point.

daemonize-liquidsoap.sh script seems to be very outdated. Not sure that it's a good idea to use it.

I don't know which distro/os you use but if comes with systemd I would recommend using it to control your liquidsoap instance:

Say you have your script at /home/radio/liquidsoap/myradio1.liq and you user is called radio

You may create systemd file. Please execute following commands:

sudo nano /etc/systemd/system/[email protected]

A new file will open, paste the following into it (remember we are taking into account, that you have created /home/radio/liquidsoap directory and myradio1.liq file within this directory):

[Unit]
Description=Liquidsoap daemon for %I
After=network.target
Documentation=https://www.liquidsoap.info/

[Service]
Type=simple

# edit your user name
User=radio

ExecStart=liquidsoap /home/radio/liquidsoap/%I.liq
Restart=always

[Install]
WantedBy=multi-user.target

Press control + x and enter to save this file. Execute following commands

sudo systemctl daemon-reload
sudo systemctl enable [email protected]

To start/stop the service you can execute usual systemd commands: sudo systemctl start (or stop) liquidsoap@myradio1

This will enable your liquidsoap script (/home/radio/liquidsoap/myradio1.liq) as a service and enable liquidsoap service on system boot. (output.liq is included by you in myradio1.liq).

Same way you can add second instance with different outputs and enable it as easy as sudo systemctl enable liquidsoap@ANOTHER_LS_INSTANCE.service (your ANOTHER_LS_INSTANCE.liq should be inside /home/radio/liquidsoap/ too).

[floholl]

Thanks so much for taking the time to write such a comprehensive reply, which answers another question I had not asked here, but been wondering about (i.e., how upt-to-date daemonize-liquidsoap.sh actually is).

I'm guessing (and will confirm on my own) that in the systemd service you kindly provided, I could probably also run

ExecStart=liquidsoap /home/radio/liquidsoap/%I.liq /home/radio/liquidsoap/output.liq

rather than %include "output.liq" inside myradio1.liq. This would allow modularization along the lines of:

liquidsoap some_source.liq some_output.liq
liquidsoap some_other_source.liq some_output.liq
liquidsoap some_source.liq some_other_output.liq
liquidsoap some_source.liq some_ladspa_effect.liq some_output.liq

So one could, for example, optionally insert a LADSPA effect between source and output (without needing to edit the .liq scripts themselves).

[gAlleb]

I'm guessing (and will confirm on my own) that in the systemd service you kindly provided, I could probably also run

Yes, I think you can do that)

Also, in the systemd service file you can use folder variable the same way if it makes sense to organize your setup in that specific way:

ExecStart=liquidsoap /home/radio/liquidsoap/%I/index.liq

Obviously, main LS script will be then index.liq in a folder of your liking, e.g. /home/radio/liquidsoap/myradio1/index.liq, which can be enabled the same way sudo systemctl enable [email protected] + sudo systemctl start [email protected]

[toots]

Thanks for this answer @gAlleb ! daemonize-liquidsoap.sh is not super up-to date indeed. It seems that these days most linux distrubutions have switched to systemd is that correct? If so we could consider merging something back into the main code.

[vitoyucepi]

Hi @toots,
As far as I know, systemd could be considered the standard init system for most distributions since 2018. But I remember at least two distributions that don't use systemd: Devuan and Alpine.
It might be a good idea to gather all the expectations about the service file and create a dedicated page on the documentation website.
For example, I can add at least two things to the previously discussed code snippet:

1. Start the service with the --user flag or in loginctl enable-linger mode.
2. Harden the service files.

[toots]

@vitoyucepi would you be interested in contributing something back to the main repo?

[vitoyucepi]

I can do that, but I'd prefer to write a short article first.

[gAlleb]

Very nice!

P.S. I run Void Linux BTW with runit as my daily OS and not a fan of systemd 😄
P.P.S. Also would be really great to have a native xbps package for Void sometimes, if it's a possible option cause Void is a stable RR.

[toots]

I can do that, but I'd prefer to write a short article first.

You could also write the article in the doc section of the repo right? Or woul you rather do it in the blog?