call restic backup script with nice (wip)

[felixandersen]

Opening this PR as I did this change locally and thought it would add value to the role. Possibly not as is, with a default 10 priority, but an optional priority parameter? If given could prefix command with /usr/bin/nice -n [priority]. Let me know if this is interesting and I can refine the change.

[DO1JLR]

How did I not heard about nice before... 🤔

Sounds like a good idea. Please continue ❤️

[felixandersen]

@DO1JLR I have now added a conditional part in the service-template as well as some explanation in the README. Let me know if anything needs to be changed.

[kdebisschop]

systemd has an option for Nice in the service

[Service]
    Type=simple
    Restart=always
    RestartSec=60
    #ExecStartPre=/bin/sleep 20 
    User=colibri
    Nice=-10
    StandardOutput=null
    StandardError=null

Seems like maybe it would be better to use that? Or maybe even add a dictionary of service options that could be added as a loop.

[kdebisschop]

The generic version of code is just to add

{% if item.service_options is defined %}
{% for key, value in item.service_options.items() %}
{{key}}={{value}}
{% endfor %}
{% endif %}

after Type=oneshot in restic.service.j2

Then in a job in restic_backups you can add e.g.,

    service_options:
      Nice: "-10"
      CPUQuota: "10%"

[felixandersen]

@kdebisschop that is great input and I agree it would be a better option. One potential drawback of a full dictionary approach would be complexity where a user might break a config by specifying something unexpected. I see it as a net positive tradeoff though.

I vote for full dictionary. At the very least we should use the Nice option in the service instead of wrapping the call like I did.

I have not heard anything from @DO1JLR in a while, but I am happy to rework my PR as @DO1JLR see fit.

[DO1JLR]

sorry