Add alternative utility class for apache subnetutils

[lsiepel]

We try to get rid of dependencies to apache libs per openhab/openhab-addons#7722

we made great progress with #3738
Now there are 5 bindings that make use of subnetutils. I suggest a similar approach here, I can create an alternative util class in core to prevent code duplication. will be based on openhab/openhab-addons#14430 (comment) where the implementation was confirmed working as expected.

@openhab/core-maintainers any thoughts before I start working on it?

[J-N-K]

I don't think that's necessary. We need org.apache.commons.net anyway, so we can also use it in add-ons.

[lsiepel]

Oké, in that case I think openhab/openhab-addons#7722 can be closed, as these are the last dependencies in addons repo.
Full list is here openhab/openhab-addons#7722 (comment)

@wborn wdyt?

[wborn]

Maybe you can use NetUtil / NetworkAddressService instead? It has a getAllInterfaceAddresses method.
Add-ons should also respect the openHAB "Network Configuration" settings like not using IPv6 if it is disabled.
Currently we cannot remove commons-net because it is a dependency required for rfc2217 connections using nrjavaserial.

[lsiepel]

This issue is not about removing commons-net at this moment, its scope is much smaller. It is about reducing some dependencies to commons-net. I know we still depend on commons-net due to nrjavaserial, but why not reduce it as much as possible?

I also see this as an opportunity to reduce and improve code that is used in multiple bindings that have about the same functionality. For instance, when i do a quick scan, it looks like none of the 5 involved bindings respect the openHAB "Network Configuration" settings.

[wborn]

I also see this as an opportunity to reduce and improve code that is used in multiple bindings that have about the same functionality. For instance, when i do a quick scan, it looks like none of the 5 involved bindings respect the openHAB "Network Configuration" settings.

Yes that might be a nice improvement to fix multiple issues at once. 👍

[lsiepel]

While working on this, i doubt if 'respecting' the openHAB "Network Configuration" settings is an improvement.

This configuration setting lets you choose a 'Primary Address'. How should one interpret the "Network Configuration" setting?

My initial thought was that bindings should only setup connections using this address. But when looking at multiple bindings i think this setting is much more limited. Main concerns when limiting bindings to this settings:

• none of the bindings respect this (breaking changes)
• what if you have vlan's or any other network segmentation with different devices on differnet networks.
• waht is the purpose of limiting bindings to use a network

So i guess this setting is only usefull for addons that expose a service and need to bind to a network address (like homekit etc).

TL:DR i think if the related PR's are merged, this issue can also be closed. WDYT?